NANOPARTICLES FOR TREATING PROSTATE CANCER CROSS-REFERENCE TO RELATED APPLICATION This application claims benefit of and priority to U.S. Provisional Application No. 63/208,401 filed June 8, 2021, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION This invention is generally in the field of compositions for treating prostate cancer. BACKGROUND OF THE INVENTION Prostate cancer represents a major health burden, being the most aggressive tumor and the second most frequent cause of tumor-related deaths among men in western countries. Treatment for prostate cancer involves systemic chemotherapy, which is associated with numerous severe side effects, such as damage to essential organs including the heart, lungs and brain, neurotoxicity, and infertility. The low specificity of the anticancer drugs to prostate cancer cells is responsible for causing these side effects in chemotherapy. There remains a need for improved materials and methods for treating prostate cancer. Therefore, it is the object of the present invention to provide compositions for treating prostate cancer in subject in need thereof. It is a further object of the present invention to provide pharmaceutical formulations for treating prostate cancer in a subject in need thereof. It is a further object of the present invention to provide methods for treating prostate cancer in a subject in need thereof. SUMMARY OF THE INVENTION Nanoparticles and formulations for treating or ameliorating one or more symptoms associated with a gonadotropin-releasing hormone (“GnRH”) related disease and/or disorder or gonadotropin-related disease and/or disorder (such as a GnRH- or gonadotropin-related cancer, a GnRH- or gonadotropin-related benign tumor, or endometriosis) are disclosed herein. Also disclosed are uses for the nanoparticles and formulations incorporating the nanoparticles. The nanoparticles for treating or ameliorating one or more symptoms associated with GnRH- related or gonadotropin-related disease and/or disorder contains a cage, such as a zeolitic imidazolate framework (“ZIF”), a surface modifying agent, a targeting ligand, and an active agent. The cage is a 3-dimentional structure that contains an opening for encapsulating a substance therein. Suitable materials for forming the cage of the nanoparticles include ZIF and other metal-organic frameworks, such as organic-inorganic hybrid crystalline porous materials and those described in Wang, et al., Chem. Rev.120(2):1438-1511 (2020); lipids, such as phospholipids, sterols, sphingolipids, PEGylated lipids, glycerolipids, anionic lipids, and cationic lipids, e.g. those described in Lu, et al., Frontiers in Nutrition, 8:783831 (2021) and Mitchell, et al., Nature Reviews, 20:101 (2021); polymers, such as polymersomes, dendrimers, polymeric micelles, and nanospheres, e.g. those described in Lu, et al., Frontiers in Nutrition, 8:783831 (2021) and Mitchell, et al., Nature Reviews, 20:101 (2021); and inorganic materials, such as silica, e.g. mesoporous silica and those described in Vallet-Regi, et al., Molecules, 23(47):23010047 (2018). Typically, the surface modifying ligand is attached to the outer surface of the cage and the targeting ligand is exposed to the surrounding environment. The active agent is encapsulated in the cage. For example, the surface modifying ligand is attached to the outer surface of the ZIF and the targeting ligand is exposed to the surrounding environment. The active agent is encapsulated in the ZIF. When the cage of the nanoparticles is a ZIF, the ZIF contains a metal ion and an imidazolate linker. The imidazolate linker may be un-modified or functionalized with amine, hydroxyl, thiol, aldehyde, or carboxyl, or a combination thereof. Optionally, the targeting ligand is conjugated to the surface modifying agent. At least 20 wt% (weight of the surface modifying agent conjugated to the targeting ligand/total weight of the surface modifying agent attached to the cage) of the surface modifying agent is conjugated to the targeting ligand. For example, at least 20 wt% (weight of the surface modifying agent conjugated to the targeting ligand/total weight of the surface modifying agent attached to the ZIF) of the surface modifying agent is conjugated to the targeting ligand. The surface modifying agent contains a polymer backbone, such as a polyalkylene glycol backbone (e.g. polyethylene glycol backbone) or a poly(lactic-co-glycolic acid) backbone. The surface modifying agent can ionically bind to the outer surface of the cage through a charged chemical moiety that is conjugated to one end of the surface modifying agent, such as folate, L- methylfolate, or glutamate, or a combination thereof. For example, the surface modifying agent is ionically bound to the outer surface of the ZIF through a charged chemical moiety that is conjugated to one end of the surface modifying agent, such as folate, L-methylfolate, or glutamate, or a combination thereof. The nanoparticles generally have an average diameter (including the surface modifying agent) of less than 100 nm and at least 10 nm, and a surface density of the surface modifying agent (“SMA”) of at least 1 SMA/nm ² . Typically, the targeting ligand binds to a reproductive hormone or a receptor of a reproductive hormone, such as a gonadotropin-releasing hormone (“GnRH”) agonist, a GnRH antagonist, a follicle stimulating hormone (“FSH”) receptor agonist, an FSH receptor antagonist, a luteinizing hormone (“LH”) receptor agonist, or an LH receptor antagonist, or a combination thereof. The description below describes nanoparticles that contain a ZIF cage. However, these descriptions apply to other suitable materials for forming the cage, as well, such as those described above. Thus references to a “ZIF” or “ZIF cage” herein also generally apply to other suitable materials for forming a cage of the nanoparticles. The active agent encapsulated in the ZIF can be a substance that kills gonadotroph cells and/or cells that contain receptors for GnRH or one or more gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, renal cancer cells, benign tumor cells, such as uterine fibroids, and cells in tissues associated with a reproductive tract disorder, such as endometriosis), reduces or prevents secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, and thereby ameliorates one or more symptoms associated with prostate cancer in the subject. Examples of active agents suitable for encapsulation in the ZIF are ribosome inactivating proteins, apoptosis inducers, hormones, receptor ligands, nucleic acids, or chemotherapy drugs, or a combination thereof. Pharmaceutical formulations containing a plurality of the nanoparticles described herein and a pharmaceutically acceptable carrier and/or excipient are disclosed. The pharmaceutical formulations can be in a suitable form for intramuscular administration, intravenous administration, intraperitoneal administration, or subcutaneous administration, or a combination thereof. Typically, the active agent is included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with a GnRH-related or gonadotropin-related disease and/or disorder in a subject in need thereof. Typically, the cells and/or tissues associated with the disease and/or disorder in the subject express receptors for GnRH and/or one or more gonadotropins. In some embodiments, the active agent is included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related cancer or a GnRH- or gonadotropin-related benign tumor in a subject, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, uterine fibroids, or renal cancer, or a combination thereof. The cancer and benign tumor cells of the GnRH-related or gonadotropin-related cancer or benign tumor express receptors for GnRH and/or one or more gonadotropins. For example, prostate cancer cells and ovarian cancer cells contain receptors for GnRH and/or one or more gonadotropins; thus prostate cancer and ovarian cancer are GnRH-related and/or gonadotropin-related cancers. For example, uterine fibroids tumor cells contain receptors for GnRH and/or one or more gonadotropins; thus uterine fibroids are GnRH-related and/or gonadotropin-related benign tumors. In some embodiments, the active agent is included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related disorder. Typically, the GnRH- or gonadotropin-related disorder is associated with the reproductive tract, such as endometriosis. For example, the cells and/or tissues associated with endometriosis contains receptors for GnRH or one or more gonadotropins; thus endometriosis is a GnRH- or gonadotropin-related disorder. In some embodiments, the active agent is included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with prostate cancer in a subject. For example, the amount of the active agent in the pharmaceutical formulation is effective to reduce the level of a biomarker associated with prostate cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment. Examples of biomarkers suitable for use in evaluating the treatment effect for prostate cancer are prostate specific antigen (“PSA”), a glycoform of PSA, microRNAs, circulating tumor cells, androgen receptor variants, and phosphatase and tensin homolog (PTEN) gene, and a combination thereof. The active agent can be present in the pharmaceutical formulation in an effective amount to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. In some embodiments, the active agent is included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with ovarian cancer in a subject. For example, the amount of the active agent in the pharmaceutical formulation is effective to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment. Examples of biomarkers suitable for use in evaluating the treatment effect for ovarian cancer are CA125, CEA (mucinous), LDH (dysgerminoma, mixed germ cell tumors), β-hCG (choriocarcinoma, mixed germ cell tumors), inhibin B (granulosa cell tumors), α-fetoprotein (yolk sac tumors, embryonal cell tumors), and HE4, or a combination thereof. The active agent can be present in the pharmaceutical formulation in an effective amount to reduce the mean diameter of a tumor associated with ovarian cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, such as by imaging, e.g. CT scan, ultrasound, MRI, or X-ray, or a combination thereof. The active agent may be included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with any other cancers or benign tumors that are related to GnRH or gonadotropins, such as pancreatic cancer, breast cancer, uterine cancer, renal cancer, or uterine fibroids, or a combination thereof in a subject, which may be indicated by a change in the level of a biomarker associated with the cancer and/or benign tumor being treated and/or a reduction of the mean diameter of a tumor associated with the cancer or the benign tumor being treated. Methods for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related disease or disorder in a subject in need thereof using the pharmaceutical formulations described herein are also disclosed. The subject can be a male or female mammal. The method includes administering to the subject the pharmaceutical formulation, where the administration step occurs one or more times. Methods are for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related cancer or benign tumor, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, renal cancer, or a tumor of uterine fibroids, or a combination thereof, in a subject in need thereof using the pharmaceutical formulations described herein. Following a single administration or more than one administration of the pharmaceutical formulation, an effective amount of the nanoparticles to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related cancer or benign tumor in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of the subject compared to the level of the biomarker in the biological sample of the subject before treatment and/or reduce the mean diameter of a tumor associated with the GnRH- or gonadotropin-related cancer or the benign tumor in the subject compared to the mean diameter of the tumor in the subject before treatment, is administered to the subject. For example, following a single administration or more than one administration of the pharmaceutical formulation, an effective amount of the nanoparticles to reduce the level of a biomarker associated with prostate cancer, such as PSA, in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment, is administered to the subject. In some embodiments, the methods are for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related disorder, such as endometriosis, in a subject in need thereof. Following a single administration or more than one administration of the pharmaceutical formulations described herein, an effective amount of the nanoparticles to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related disorder (such as endometriosis) in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of the subject compared to the level of the biomarker in the biological sample of the subject before treatment, is administered to the subject. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A is a schematic showing the components forming an exemplary nanoparticle. Figure 1B is a schematic of the structure of an exemplary nanoparticle that contains a zeolitic imidazolate framework (“ZIF”) cage, folic acid (“FA”) conjugated PEG, FA and Buserelin (“BUS”) conjugated PEG, saporin (“SAP”), and CF647. Figure 1C is a schematic of the structure of an exemplary nanoparticle that contains a ZIF cage, FA and Buserelin (“BUS”) conjugated PEG, and saporin (“SAP”). Figure 2 shows a scanning electron microscope (“SEM”) image of exemplary GnRH NPs. Figures 3A-3B are graphs showing the fluorescent property of three types of nanoparticles: ZIF, ZIF with CF647 and SAP encapsulated therein, and GnRH NPs, analyzed using a Horiba FluoroLog-3 spectrofluorometer (Horiba Scientific, Edison, NJ, USA) equipped with a 450-W xenon arc lamp, a photomultiplier tube (measurement range, 240–850 nm). Figure 3A shows the fluorescent emission of the nanoparticles excited at 600 nm. Figure 3B shows the fluorescent emission of the nanoparticles excited at 645 nm. Figure 4 is a graph showing X-ray diffraction analysis of GnRH nanoparticles (NPs). The peak file generated from the peak search was compared to the International Center for Diffraction Data (ICDD) powder diffraction file. The patterns match with PDF#00-066-0916 as ZIF-90 (91% match). Figure 5 is a bar graph showing the inhibition effect (%) of RC4B/C pituitary cells by unconjugated ZIF NPs or GnRH NPs at varied concentrations. Figure 6 is a graph showing the extent of cell death of DU145 prostate cancer cells in comparison to pituitary cancer cells caused by exposure to GnRH NPs at varied concentrations. DETAILED DESCRIPTION OF THE INVENTION I. Nanoparticles Nanoparticles for treating or ameliorating one or more symptoms associated with prostate cancer are described herein. Generally, the nanoparticles contain a cage, a surface modifying agent, a targeting ligand, and an active agent. For example, the cage forming the nanoparticles is a zeolitic imidazolate framework (also referred herein as “ZIF”). The cage is a 3-dimensional structure that contains an opening for encapsulating a substance therein. Suitable materials for forming the cage of the nanoparticles include ZIF and other metal-organic frameworks, such as organic-inorganic hybrid crystalline porous materials and those described in Wang, et al., Chem. Rev.120(2):1438-1511 (2020); lipids, such as phospholipids, sterols, sphingolipids, PEGylated lipids, glycerolipids, anionic lipids, and cationic lipids, e.g. those described in Lu, et al., Frontiers in Nutrition, 8:783831 (2021) and Mitchell, et al., Nature Reviews, 20:101 (2021); polymers, such as polymersome, dendrimers, polymeric micelles, and nanospheres, e.g. those described in Lu, et al., Frontiers in Nutrition, 8:783831 (2021) and Mitchell, et al., Nature Reviews, 20:101 (2021); and inorganic materials, such as silica, e.g. mesoporous silica and those described in Vallet-Regi, et al., Molecules, 23(47):23010047 (2018). The surface modifying ligand can be attached to the outer surface of the cage. Typically, the targeting ligand is arranged on the outer surface of the cage such that it is exposed to the surrounding environment. Optionally, the targeting ligand is conjugated to the surface modifying ligand and is exposed to the surrounding environment. The active agent can be encapsulated in the cage. For example, the surface modifying ligand is attached to the outer surface of the ZIF. The targeting ligand is arranged on the outer surface of the ZIF such that it is exposed to the surrounding environment. Optionally, the targeting ligand is conjugated to the surface modifying ligand and is exposed to the surrounding environment. The active agent can be encapsulated in the ZIF. The nanoparticles can degrade in an acidic environment (i.e. pH ≤6.5, such as in a range from 4.5 to about 5.0) and thereby release the active agent. For example, following intravenous administration of the nanoparticles in a subject, such as a mammal, for example a male mammal or a female mammal, the nanoparticles remain intact in an environment having physiological pH (i.e. pH > 6.5, such as in a range from about 6.5 to about 8.0). After the nanoparticles are engulfed by the cell membrane and enter the cell, they are delivered to the lysosomes which generally maintain an acidic pH, such as from about 4.5 to about 5.0, in which the nanoparticles degrade. The overall charge of the nanoparticles is generally neutral or near neutral. A. Components 1. ZIF The cage of the nanoparticles may be a ZIF. ZIFs are metal-organic frameworks formed by metal ions and imidazolate linkers. Any suitable ZIF may be used in the nanoparticles. Preferably, the ZIFs suitable for use in the nanoparticles are synthesized using water-based preparation conditions to maintain the biological activities of the targeting ligands and the active agents of the nanoparticles. For example, suitable ZIFs and water-based synthesis methods for making ZIFs are described in Jian, et al., RSC Adv., 5:48433 (2015) and Shieh, et al., Chem. Eur. J., 19:11139 (2013). For example, a ZIF can be formed through three-dimensional assembly of tetrahedrally- coordinated metal-imidazolate building units corresponding to a general Formula (I) below: Formula (I) in which: M represents a metal ion; Each of L1, L2, L3, and L4 represents an imidazolate linker; they may be the same or different; The metal ion binds to each of the imidazolate linkers L1, L2, L3, and L4 via a nitrogen atom of the imidazolate linker. Each solid line in Formula (I) indicates a coordinate covalent bond. The ZIF can have any suitable crystal structure, such as ZIF-2, ZIF-3, ZIF-4, ZIF-8, ZIF- 10, ZIF-11, ZIF-12, ZIF-14, ZIF-20, ZIF-21, ZIF-60, ZIF-61, ZIF-62, ZIF-64, ZIF-65, ZIF-66, ZIF-67, ZIF-68, ZIF-69, ZIF-70, ZIF-71, ZIF-72, ZIF-73, ZIF-74, ZIF-75, ZIF-76, ZIF-77, ZIF- 78, ZIF-81, ZIF-82, ZIF-90, ZIF-91, ZIF-92, ZIF-95, or ZIF-100. For example, the ZIF has a crystal structure of ZIF-90. a. Metal Ions The ZIF can include building units as shown in Formula (I), containing a metal ion. Examples of metal ions contained in a building unit of ZIF include, but are not limited to, Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Cs ⁺ , Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Sc ³⁺ , Sc ²⁺ , Sc ⁺ , Y ³⁺ , Y ²⁺ , Y ⁺ , Ti ⁴⁺ , Ti ³⁺ , Ti ²⁺ , Zr ⁴⁺ , Zr ³⁺ , Zr ²⁺ , Hf ⁴⁺ , Hf ³⁺ , V ⁵⁺ , V ⁴⁺ , V ³⁺ , V ²⁺ , Nb ⁵⁺ , Nb ⁴⁺ , Nb ³⁺ , Nb ²⁺ , Ta ⁵⁺ , Ta ⁴⁺ , Ta ³⁺ , Ta ²⁺ , Cr ⁶⁺ , Cr ⁵⁺ , Cr ⁴⁺ , Cr ³⁺ , Cr ²⁺ , Cr ⁺ , Mo ⁶⁺ , Mo ⁵⁺ , Mo ⁴⁺ , Mo ³⁺ , Mo ²⁺ , Mo ⁺ , W ⁶⁺ , W ⁵⁺ , W ⁴⁺ , W ³⁺ , W ²⁺ , W ⁺ , Mn ⁷⁺ , Mn ⁶⁺ , Mn ⁵⁺ , Mn ⁴⁺ , Mn ³⁺ , Mn ²⁺ , Mn ⁺ , Re ⁷⁺ , Re ⁶⁺ , Re ⁵⁺ , Re ⁴⁺ , Re ³⁺ , Re ²⁺ , Re ⁺ , Fe ⁶⁺ , Fe ⁴⁺ , Fe ³⁺ , Fe ²⁺ , Fe ⁺ , Ru ⁸⁺ , Ru ⁷⁺ , Ru ⁶⁺ , Ru ⁴⁺ , Ru ³⁺ , Ru ²⁺ , Os ⁸⁺ , Os ⁷⁺ , Os ⁶⁺ , Os ⁵⁺ , Os ⁴⁺ , Os ³⁺ , Os ²⁺ , Os ⁺ , Co ⁵⁺ , Co ⁴⁺ , Co ³⁺ , Co ²⁺ , Co ⁺ , Rh ⁶⁺ , Rh ⁵⁺ , Rh ⁴⁺ , Rh ³⁺ , Rh ²⁺ , Rh ⁺ , Ir ⁶⁺ , Ir ⁵⁺ , Ir ⁴⁺ , Ir ³⁺ , Ir ²⁺ , Ir ⁺ , Ni ³⁺ , Ni ²⁺ , Ni ⁺ , Pd ⁶⁺ , Pd ⁴⁺ , Pd ²⁺ , Pd ⁺ , Pt ⁶⁺ , Pt ⁵⁺ , Pt ⁴⁺ , Pt ³⁺ , Pt ²⁺ , Pt ⁺ , Cu ⁴⁺ , Cu ³⁺ , Cu ²⁺ , Cu ⁺ , Ag ³⁺ , Ag ²⁺ , Ag ⁺ , Au ⁵⁺ , Au ⁴⁺ , Au ³⁺ , Au ²⁺ , Au ⁺ , Zn ²⁺ , Zn ⁺ , Cd ²⁺ , Cd ⁺ , Hg ⁴⁺ , Hg ²⁺ , Hg ⁺ , B ³⁺ , B ²⁺ , B ⁺ , Al ³⁺ , Al ²⁺ , Al ⁺ , Ga ³⁺ , Ga ²⁺ , Ga ⁺ , In ³⁺ , In ²⁺ , In ⁺ , Tl ³⁺ , Tl ⁺ , Si ⁴⁺ , Si ³⁺ , Si ²⁺ , Si ⁺ , Ge ⁴⁺ , Ge ³⁺ , Ge ²⁺ , Ge ⁺ , Sn ⁴⁺ , Sn ²⁺ , Pb ⁴⁺ , Pb ²⁺ , As ⁵⁺ , As ³⁺ , As ²⁺ , As ⁺ , Sb ⁵⁺ , Sb ³⁺ , Bi ⁵⁺ , Bi ³⁺ , Te ⁶⁺ , Te ⁵⁺ , Te ⁴⁺ , Te ²⁺ , La ³⁺ , La ²⁺ , Ce ⁴⁺ , Ce ³⁺ , Ce ²⁺ , Pr ⁴⁺ , Pr ³⁺ , Pr ²⁺ , Nd ³⁺ , Nd ²⁺ , Sm ³⁺ , Sm ²⁺ , Eu ³⁺ , Eu ²⁺ , Gd ³⁺ , Gd ²⁺ , Gd ⁺ , Tb ⁴⁺ , Tb ³⁺ , Tb ²⁺ , Tb ⁺ , Db ³⁺ , Db ²⁺ , Ho ³⁺ , Er ³⁺ , Tm ⁴⁺ , Tm ³⁺ , Tm ²⁺ , Yb ³⁺ , Yb ²⁺ , Lu ³⁺ , La ³⁺ , La ²⁺ , La ⁺ . Optionally, the metal ion contained in a building unit of ZIF is Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Sc ²⁺ , Y ³⁺ , Ti ²⁺ , Zr ²⁺ , V ²⁺ , Nb ²⁺ , Ta ²⁺ , Cr ²⁺ , Mo ²⁺ , W ²⁺ , Mn ²⁺ , Re ²⁺ , Fe ²⁺ , Ru ²⁺ , Os ²⁺ , Co ²⁺ , Rh ²⁺ , Ir ²⁺ , Ni ²⁺ , Pd ²⁺ , Pt ²⁺ , Cu ²⁺ , Ag ²⁺ , Au ²⁺ , Zn ²⁺ , Cd ²⁺ , Hg ²⁺ , B ²⁺ , Al ²⁺ , Ga ²⁺ , In ²⁺ , Si ²⁺ , Ge ²⁺ , Sn ²⁺ , Pb ²⁺ , As ²⁺ , Te ²⁺ , La ²⁺ , Ce ²⁺ , Pr ²⁺ , Nd ²⁺ , Sm ²⁺ , Eu ²⁺ , Gd ²⁺ , Tb ²⁺ , Db ²⁺ , Tm ²⁺ , or Yb ²⁺ . Optionally, the metal ion contained in a building unit of ZIF is Zn ⁺ , Zn ²⁺ , Pd ²⁺ , Pd ⁴⁺ , Pt ²⁺ , Pt ⁴⁺ , Ni ⁺ , Ni ²⁺ , Ni ³⁺ , Mn ²⁺ , Mn ³⁺ , Mn ⁴⁺ , Mn ⁶⁺ , Mn ⁷⁺ , Co ²⁺ , Co ³⁺ , Cu ²⁺ , Cd ²⁺ , Fe ²⁺ , Fe ³⁺ , and Ti ⁴⁺ . The ZIF structure can include building units containing a single type of metal ion as described above, such as Zn ⁺ , Zn ²⁺ , Pd ²⁺ , Pd ⁴⁺ , Pt ²⁺ , Pt ⁴⁺ , Ni ⁺ , Ni ²⁺ , Ni ³⁺ , Mn ²⁺ , Mn ³⁺ , Mn ⁴⁺ , Mn ⁶⁺ , Mn ⁷⁺ , Co ²⁺ , Co ³⁺ , Cu ²⁺ , Cd ²⁺ , Fe ²⁺ , Fe ³⁺ , and Ti ⁴⁺ , for example, Zn ²⁺ . Optionally, the ZIF structure includes building units containing different metal ions, and is commonly referred to as mixed-metal ZIFs. For example, the ZIF structure includes a first building unit containing a first metal ion, such as Zn ²⁺ , and a second building unit containing a second metal ion that is different from the first metal ion, such as Cd ²⁺ , Co ²⁺ , or Ni ²⁺ ; the assembly of the first and second building units forms the ZIF. b. Imidazolate Linkers The ZIF can include building units as shown in Formula (I), containing four imidazolate linkers L1, L2, L3, and L4. In ZIFs formed by the building units of Formula (I), the imidazolate linker coordinates to at least two metal ions. The imidazolate linker is neutral or has an overall negative charge. The imidazolate linkers participate in providing distance between these metal ions, resulting in a three-dimensional network of organic and inorganic components. The ZIF structure can include building units containing a single type of imidazolate linker. For example, the ZIF structure includes building units of Formula (I), where L ₁ -L ₄ are the same. Optionally, the ZIF structure includes a group of building unit, where the building units contain one or more different imidazolate linkers. For example, the ZIF structure includes a first building unit containing a first imidazolate linker, and a second building unit containing a second imidazolate linker that is different from the first imidazolate linker; the assembly of the first and second building units forms the ZIF. For example, the ZIF structure includes a first building unit of Formula (I) containing a first imidazolate linker, and a second building unit of Formula (I) containing a second imidazolate linker that is different from the first imidazolate linker; the assembly of the first and second building units forms the ZIF. In each of the first and second building units of Formula (I), L1-L4 are the same. Optionally, at least one building unit forming the ZIF contains different imidazolate linkers. For example, the ZIF structure includes at least one building unit that contains a first imidazolate linker and a second imidazolate linker that is different from the first imidazolate linker. For example, the ZIF structure includes at least one building unit of Formula (I), where at least one of L ₁ -L ₄ is different from the others. Optionally, the ZIF structure includes building units containing a single type of metal ion and a single type of imidazolate linker. Optionally, the ZIF structure includes a group of building units containing different metal ions and/or imidazolate linkers. For example, the ZIF structure can include a first building unit containing a first metal ion and an imidazolate linker, and a second building unit containing a second metal ion and the same imidazolate linker, where the second metal ion is different from the first metal ion. For example, the ZIF structure can include a first building unit containing a metal ion and a first imidazolate linker, and a second building unit containing the same metal ion and a second imidazolate linker, where the second imidazolate linker is different from the first imidazolate linker. For example, the ZIF structure can include a first building unit containing a first metal ion and a first imidazolate linker, and a second building unit containing a second metal ion and a second imidazolate linker, where the second metal ion is different from the first metal ion, and the second imidazolate linker is different from the first imidazolate linker. i. Linker Structures The imidazolate linker can be an unmodified imidazole compound or a modified imidazole compound. Optionally, each of the imidazolate linker L ₁ , L ₂ , L ₃ , and L ₄ can be represented by a general Formula (II) shown below: Formula (II) wherein R1, R2, and R3 are independently hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a halogen, a hydroxyl, a substituted or unsubstituted alkoxy, an aroxy, a cyano, an isocyano, a nitro, a substituted or unsubstituted carbonyl, an amino, an amido, an azido, or a thiol, or R2 and R3 together form a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; wherein the substituents can be an unsubstituted alkyl, an unsubstituted alkenyl, an unsubstituted alkynyl, an unsubstituted heterocyclyl, an unsubstituted aryl, an unsubstituted heteroaryl, an unsubstituted polyaryl, an unsubstituted polyheteroaryl, an unsubstituted aralkyl, an unsubstituted carbonyl, an unsubstituted alkoxy, a halogen, a hydroxyl, a phenoxy, an aroxy, a cyano, an isocyano, a nitro, a carboxyl, an amino, an amido, an azido, an oxo, or a thiol, or a combination thereof. Optionally, R1, R2, and R3 are hydrogen (which is an “unmodified imidazole”). Optionally, R1, R2, and R3 are independently hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted aralkyl, a halogen, a hydroxyl, a cyano, a nitro, an aldehyde, a carboxyl, an amino, or a thiol, or R ₂ and R ₃ together form a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl; where the substituents can be a halogen, a hydroxyl, a cyano, a nitro, an aldehyde, a carboxyl, an amino, or a thiol, or a combination thereof. The term "substituted” refers to moieties having one or more substituents replacing a hydrogen on one or more carbons of the hydrocarbon backbone. The term “alkyl,” as used herein, refers to the radical of saturated aliphatic groups. The alkyl for R ₁ , R ₂ , and R ₃ of Formula (II) can be a linear alkyl, a branched alkyl, or a cyclic alkyl (either monocyclic or polycyclic; also referred herein as “cycloalkyl”). Exemplary alkyl include a linear C ₁ -C ₃₀ alkyl, a branched C ₄ -C ₃₀ alkyl, a cyclic C ₃ -C ₃₀ alkyl, a linear C ₁ -C ₂₀ alkyl, a branched C4-C20 alkyl, a cyclic C3-C20 alkyl, a linear C1-C10 alkyl, a branched C4-C10 alkyl, a cyclic C ₃ -C ₁₀ alkyl, a linear C ₁ -C ₆ alkyl, a branched C ₄ -C ₆ alkyl, a cyclic C ₃ -C ₆ alkyl, a linear C1-C4 alkyl, cyclic C3-C4 alkyl, such as a linear C1-C10, C1-C9, C1-C8, C1-C7, C1-C6, C1-C5, C1-C4, C1-C3, C1-C2 alkyl group, a branched C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 alkyl group, or a cyclic C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 alkyl group. The term “alkenyl” as used herein is a hydrocarbon group of from 2 to 24 carbon atoms and structural formula containing at least one carbon-carbon double bond. The alkenyl for R ₁ , R2, and R3 of Formula (II) can be a linear alkenyl, a branched alkenyl, or a cyclic alkenyl (either monocyclic or polycyclic; also referred herein as “cycloalkenyl”). Exemplary alkenyl include a linear C1-C30 alkenyl, a branched C4-C30 alkenyl, a cyclic C3-C30 alkenyl, a linear C1-C20 alkenyl, a branched C ₄ -C ₂₀ alkenyl, a cyclic C ₃ -C ₂₀ alkenyl, a linear C ₁ -C ₁₀ alkenyl, a branched C ₄ -C ₁₀ alkenyl, a cyclic C3-C10 alkenyl, a linear C1-C6 alkenyl, a branched C4-C6 alkenyl, a cyclic C3-C6 alkenyl, a linear C1-C4 alkenyl, cyclic C3-C4 alkenyl, such as a linear C1-C10, C1-C9, C1-C8, C1-C7, C1-C6, C1-C5, C1-C4, C1-C3, C1-C2 alkenyl group, a branched C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 alkenyl group, or a cyclic C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 alkenyl group. The term “alkynyl group” as used herein is a hydrocarbon group of 2 to 24 carbon atoms and a structural formula containing at least one carbon-carbon triple bond. The alkynyl for R ₁ , R2, and R3 of Formula (II) can be a linear alkynyl, a branched alkynyl, or a cyclic alkynyl (either monocyclic or polycyclic; also referred herein as “cycloalkynyl”). Exemplary alkynyl include a linear C1-C30 alkynyl, a branched C4-C30 alkynyl, a cyclic C3-C30 alkynyl, a linear C1-C20 alkynyl, a branched C4-C20 alkynyl, a cyclic C3-C20 alkynyl, a linear C1-C10 alkynyl, a branched C4-C10 alkynyl, a cyclic C ₃ -C ₁₀ alkynyl, a linear C ₁ -C ₆ alkynyl, a branched C ₄ -C ₆ alkynyl, a cyclic C ₃ -C ₆ alkynyl, a linear C1-C4 alkynyl, cyclic C3-C4 alkynyl, such as a linear C1-C10, C1-C9, C1-C8, C ₁ -C ₇ , C ₁ -C ₆ , C ₁ -C ₅ , C ₁ -C ₄ , C ₁ -C ₃ , C ₁ -C ₂ alkynyl group, a branched C ₃ -C ₉ , C ₃ -C ₉ , C ₃ -C ₈ , C ₃ -C ₇ , C3-C6, C3-C5, C3-C4 alkynyl group, or a cyclic C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 alkynyl group. It is understood that any of the exemplary alkyl, alkenyl, and alkynyl groups for R1, R2, and R ₃ of Formula (II) can be heteroalkyl, heteroalkenyl, and heteroalkynyl, respectively. “Heteroalkyl,” “Heteroalkenyl,” and “Heteroalkynyl,” as used herein, refers to straight or branched chain, or cyclic carbon containing alkyl, alkenyl, or alkynyl radicals, or combinations thereof, containing at least one heteroatom. Suitable heteroatoms include, but are not limited to, O, N, Si, P and S, wherein the nitrogen, phosphorous and sulfur atoms are optionally oxidized, and the nitrogen heteroatom is optionally quaternized. For example, the alkyl can be a linear C2-C30 heteroalkyl, a branched C4-C30 heteroalkyl, a cyclic C ₃ -C ₃₀ heteroalkyl (i.e. a heterocycloalkyl), a linear C ₁ -C ₂₀ heteroalkyl, a branched C4-C20 heteroalkyl, a cyclic C3-C20 heteroalkyl, a linear C1-C10 heteroalkyl, a branched C4-C10 heteroalkyl, a cyclic C3-C10 heteroalkyl, a linear C1-C6 heteroalkyl, a branched C4-C6 heteroalkyl, a cyclic C3-C6 heteroalkyl, a linear C1-C4 heteroalkyl, cyclic C3-C4 heteroalkyl, such as a linear C1-C10, C1-C9, C1-C8, C1-C7, C1-C6, C1-C5, C1-C4, C1-C3, C1-C2 heteroalkyl group, a branched C ₃ -C ₉ , C ₃ -C ₉ , C ₃ -C ₈ , C ₃ -C ₇ , C ₃ -C ₆ , C ₃ -C ₅ , C ₃ -C ₄ heteroalkyl group, or a cyclic C ₃ -C ₉ , C ₃ -C ₉ , C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 heteroalkyl group. The alkenyl for R ₁ , R ₂ , and R ₃ of Formula (II) can be a linear C ₂ -C ₃₀ heteroalkenyl, a branched C4-C30 heteroalkenyl, a cyclic C3-C30 heteroalkenyl (i.e. a heterocycloalkenyl), a linear C ₁ -C ₂₀ heteroalkenyl, a branched C ₄ -C ₂₀ heteroalkenyl, a cyclic C ₃ -C ₂₀ heteroalkenyl, a linear C1-C10 heteroalkenyl, a branched C4-C10 heteroalkenyl, a cyclic C3-C10 heteroalkenyl, a linear C1-C6 heteroalkenyl, a branched C4-C6 heteroalkenyl, a cyclic C3-C6 heteroalkenyl, a linear C1-C4 heteroalkenyl, cyclic C3-C4 heteroalkenyl, such as a linear C1-C10, C1-C9, C1-C8, C1-C7, C1-C6, C1-C5, C1-C4, C1-C3, C1-C2 heteroalkenyl group, a branched C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C3-C4 heteroalkenyl group, or a cyclic C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C ₃ -C ₄ heteroalkenyl group. The alkynyl for R1, R2, and R3 of Formula (II) can be a linear C2-C30 heteroalkynyl, a branched C ₄ -C ₃₀ heteroalkynyl, a cyclic C ₃ -C ₃₀ heteroalkynyl (i.e. a heterocycloalkynyl), a linear C1-C20 heteroalkynyl, a branched C4-C20 heteroalkynyl, a cyclic C3-C20 heteroalkynyl, a linear C ₁ -C ₁₀ heteroalkynyl, a branched C ₄ -C ₁₀ heteroalkynyl, a cyclic C ₃ -C ₁₀ heteroalkynyl, a linear C1-C6 heteroalkynyl, a branched C4-C6 heteroalkynyl, a cyclic C3-C6 heteroalkynyl, a linear C1-C4 heteroalkynyl, cyclic C3-C4 heteroalkynyl, such as a linear C1-C10, C1-C9, C1-C8, C1-C7, C ₁ -C ₆ , C ₁ -C ₅ , C ₁ -C ₄ , C ₁ -C ₃ , C ₁ -C ₂ heteroalkynyl group, a branched C ₃ -C ₉ , C ₃ -C ₉ , C ₃ -C ₈ , C ₃ -C ₇ , C3-C6, C3-C5, C3-C4 heteroalkynyl group, or a cyclic C3-C9, C3-C9, C3-C8, C3-C7, C3-C6, C3-C5, C ₃ -C ₄ heteroalkynyl group. The aryl group for R1, R2, and R3 of Formula (II) can be a C5-C30 aryl, a C5-C20 aryl, a C ₅ -C ₁₂ aryl, a C ₅ -C ₁₁ aryl, a C ₅ -C ₉ aryl, a C ₆ -C ₂₀ aryl, a C ₆ -C ₁₂ aryl, a C ₆ -C ₁₁ aryl, or a C ₆ -C ₉ aryl. It is understood that the aryl can be a heteroaryl, such as a C5-C30 heteroaryl, a C5-C20 heteroaryl, a C ₅ -C ₁₂ heteroaryl, a C ₅ -C ₁₁ heteroaryl, a C ₅ -C ₉ heteroaryl, a C ₆ -C ₃₀ heteroaryl, a C ₆ -C ₂₀ heteroaryl, a C ₆ -C ₁₂ heteroaryl, a C ₆ -C ₁₁ heteroaryl, or a C ₆ -C ₉ heteroaryl. The polyaryl group can be a C10-C30 polyaryl, a C10-C20 polyaryl, a C10-C12 polyaryl, a C10-C11 polyaryl, or a C ₁₂ -C ₂₀ polyaryl. It is understood that the aryl can be a polyheteroaryl, such as a C ₁₀ -C ₃₀ polyheteroaryl, a C10-C20 polyheteroaryl, a C10-C12 polyheteroaryl, a C10-C11 polyheteroaryl, or a C ₁₂ -C ₂₀ polyheteroaryl. The term “aryl” as used herein refers to any C5-C26 carbon-based aromatic group, heteroaromatic, fused aromatic, or fused heteroaromatic. For example, “aryl,” as used herein can include 5-, 6-, 7-, 8-, 9-, 10-, 14-, 18-, and 24-membered single-ring aromatic groups, including, but not limited to, benzene, naphthalene, anthracene, phenanthrene, chrysene, pyrene, corannulene, coronene, etc. “Aryl” further encompasses polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (i.e., “fused aromatic rings”), wherein at least one of the rings is aromatic, e.g., the other cyclic ring or rings can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/or heterocycles. The aryl group can be substituted with one or more groups including, but not limited to, alkyl, alkynyl, alkenyl, aryl, halide, nitro, amino, ester, ketone, aldehyde, hydroxy, carboxylic acid, or alkoxy. “Heterocyclyl” refers to a cyclic radical attached via a ring carbon or nitrogen atom of a non-aromatic monocyclic or polycyclic ring containing 3-30 ring atoms, 3-20 ring atoms, 3-10 ring atoms, or 5-6 ring atoms, where each ring contains carbon and one to four heteroatoms each selected from the group consisting of non-peroxide oxygen, sulfur, and N(Y) wherein Y is absent or is H, O, C1-C10 alkyl, phenyl or benzyl, and optionally containing 1-3 double bonds and optionally substituted with one or more substituents. Heterocyclyl are distinguished from heteroaryl by definition. Heterocycles can be a heterocycloalkyl, a heterocycloalkenyl, a heterocycloalkynyl, etc, such as piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, dihydrofuro[2,3 b]tetrahydrofuran, morpholinyl, piperazinyl, piperidinyl, piperidonyl, 4 piperidonyl, piperonyl, pyranyl, 2H-pyrrolyl, 4H-quinolizinyl, quinuclidinyl, tetrahydrofuranyl, 6H-1,2,5-thiadiazinyl. Heterocyclic groups can optionally be substituted with one or more substituents as described above for alkyl and aryl. The term “heteroaryl” refers to C ₅ -C ₃₀ membered aromatic, fused aromatic, biaromatic ring systems, or combinations thereof, in which one or more carbon atoms on one or more aromatic ring structures have been substituted with a heteroatom. Suitable heteroatoms include, but are not limited to, oxygen, sulfur, and nitrogen. “Heteroaryl,” as used herein, includes 5-, 6-, 7-, 8-, 9-, 10-, 14-, 18-, and 24-membered single ring aromatic groups that may include from one to four heteroatoms, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, tetrazole, pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, and the like. The heteroaryl group may also be referred to as “aryl heterocycles” or “heteroaromatics”. “Heteroaryl” further encompasses polycyclic ring systems having two or more rings in which two or more carbons are common to two adjoining rings (i.e., “fused rings”) wherein at least one of the rings is heteroaromatic, e.g., the other cyclic ring or rings can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls, heterocycles, or combinations thereof. Examples of heteroaryl rings include, but are not limited to, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzoxazolinyl, benzthiazolyl, benztriazolyl, benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H indazolyl, indolenyl, indolinyl, indolizinyl, indolyl, 3H indolyl, isatinoyl, isobenzofuranyl, isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl, isothiazolyl, isoxazolyl, methylenedioxyphenyl, naphthyridinyl, octahydroisoquinolinyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4- oxadiazolyl, oxazolidinyl, oxazolyl, oxindolyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxathinyl, phenoxazinyl, phthalazinyl, pteridinyl, purinyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridooxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, tetrazolyl, 1,2,3- thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl and xanthenyl. The term “polyaryl” refers to a chemical moiety that includes two or more aryls, heteroaryls, and combinations thereof. The aryls, heteroaryls, and combinations thereof, are fused, or linked via a single bond, ether, ester, carbonyl, amide, sulfonyl, sulfonamide, alkyl, azo, and combinations thereof. For example, a “polyaryl” can be polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (i.e., “fused aromatic rings”), wherein two or more of the rings are aromatic. When two or more heteroaryls are involved, the chemical moiety can be referred to as a “polyheteroaryl.” The term “aralkyl” as used herein is an aryl group or a heteroaryl group having an alkyl, alkynyl, or alkenyl group as described above attached to the aromatic group, such as an aryl, a heteroaryl, a polyaryl, or a polyheteroaryl. An example of an aralkyl group is a benzyl group. The terms “alkoxyl” or “alkoxy,” “aroxy” or “aryloxy,” generally describe compounds represented by the formula -OR ^v , wherein R ^v includes, but is not limited to, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocycloalkenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted arylalkyl, a substituted or unsubstituted heteroalkyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted alkylheteroaryl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted carbonyl, a thiol, an amido, and an amino. Exemplary alkoxyl groups include methoxy, ethoxy, propyloxy, tert-butoxy and the like. A “lower alkoxy” group is an alkoxy group containing from one to six carbon atoms. An “ether” is two functional groups covalently linked by an oxygen as described below. Accordingly, the substituent of an alkyl that renders that alkyl an ether is or resembles an alkoxyl, such as can be represented by one of -O-alkyl, -O-alkenyl, -O-alkynyl, -O-aryl, -O-heteroaryl, -O-polyaryl, -O-polyheteroaryl, -O-h eterocyclyl, etc. The terms “aroxy” and “aryloxy,” as used interchangeably herein, are represented by -O-aryl or -O-heteroaryl, wherein aryl and heteroaryl are as described herein. The term "amino" as used herein includes the group (primary amino), (secondary amino), (tertiary amino), and (quaternary amino), wherein, E is absent, or E is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl, wherein independently of E, R ^x , R ^xi , and R ^xii each independently represent a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a thiol, an amido, an amino, or -(CH2)m-R’’’; R’’’ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, an amido, or an amino; and m is zero or an integer ranging from 1 to 8. The term “quaternary amino” also includes the groups where the nitrogen, R ^x , R ^xi , and R ^xii with the N ⁺ to which they are attached complete a heterocyclyl or heteroaryl having from 3 to 14 atoms in the ring structure. The terms “amide” or “amido” are used interchangeably, refer to both “unsubstituted amido” and “substituted amido” and are represented by the general formula: wherein, E is absent, or E is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, or a substituted or unsubstituted heterocyclyl, wherein independently of E, R and R’ each independently represent a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, a thiol, an amido, an amino, or -(CH ₂ ) _m -R’’’, or R and R’ taken together with the N atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R’’’ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an azido, an alkoxy, an amido, or an amino; and m is zero or an integer ranging from 1 to 8. In some forms, when E is oxygen, a carbamate is formed. “Carbonyl,” as used herein, is art-recognized and includes such moieties as can be represented by the general formula: wherein X is a bond, or represents an oxygen or a sulfur, and R represents a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, an azido, an amido, an amino, or -(CH2)m-R’’, or a pharmaceutical acceptable salt; E’’ is absent, or E’’ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, substituted or unsubstituted heterocyclyl; R’ represents a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted carbonyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl), a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted heterocyclyl, a hydroxyl, an alkoxy, an amido, an amino, or -(CH ₂ ) _m -R’’; R’’ represents a hydroxyl group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted aryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted cycloalkenyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, an alkoxy, an amido, or an amino; and m is zero or an integer ranging from 1 to 8. Where X is oxygen and R is described as above, the moiety is also referred to as a carboxyl group. Where X is oxygen and R is hydrogen, the formula represents a “carboxylic acid”. Where X is oxygen and R’ is hydrogen, the formula represents a “formate”. Where X is oxygen and R or R’ is not hydrogen, the formula represents an "ester". In general, where the oxygen atom of the above formula is replaced by a sulfur atom, the formula represents a “thiocarbonyl” group. Where X is sulfur and R or R’ is not hydrogen, the formula represents a “thioester”. Where X is sulfur and R is hydrogen, the formula represents a “thiocarboxylic acid”. Where X is sulfur and R’ is hydrogen, the formula represents a “thioformate”. Where X is a bond and R is not hydrogen, the above formula represents a “ketone”. Where X is a bond and R is hydrogen, the above formula represents an “aldehyde”. The term “carboxyl” is as described above for carbonyl and is described more specifically by the formula -R ^iv COOH, wherein R ^iv is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, or a substituted or unsubstituted heteroaryl. The term “phenoxy” refers to a compound of the formula -OR ^v wherein R ^v is (i.e., -O-C ₆ H ₅ ). A phenoxy is a species of the aroxy genus. The terms “thiol” are used interchangeably and are represented by –SR, where R can be a hydrogen, a sugar group, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted heterocyclyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted aralkyl (e.g. a substituted or unsubstituted alkylaryl, a substituted or unsubstituted arylalkyl, etc.), a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted carbonyl, an amido, an amino, an azido, an alkoxy, or an oxo, described above. ii. Post-Framework Modification When the imidazolate linker is a modified imidazole compound, the modification may be performed prior to ZIF assembly or following ZIF assembly (also referred herein as “post- framework functionalization”). For example, the imidazolate linker used to form the ZIF is a modified imidazole compound. Alternatively, the imidazolate linker used to form the ZIF is an unmodified imidazole compound, and the ZIF may be further modified with reacting with one or more post- framework reactants to introduce one or more functional group(s) as described above on the imidazolate linker. For example, the ZIF is formed by unmodified imidazole compounds and then further modified with one or more post-framework reactants to introduce amino, hydroxyl, thiol, aldehyde, or carboxyl, or a combination thereof on the imidazolate linker. Methods and reactions for introducing functional groups on an unmodified imidazole compound, prior to ZIF assembly or post-framework functionalization, are known, such as those described in Bellina and Rossi, Adv. Synth. Catal., 352:1223 (2010). 2. Targeting Ligands The nanoparticles include a targeting ligand, optionally more than one targeting ligand, that targets a reproductive hormone or the receptor of a reproductive hormone. Typically, the targeting ligand is arranged on the outer surface of the cage such that it is exposed to the surrounding environment. The targeting ligand is directly attached to the outer surface of the cage and/or is conjugated to a surface modifying agent through which it attaches to the outer surface of the cage. For example, the targeting ligand is arranged on the outer surface of the ZIF such that it is exposed to the surrounding environment. The targeting ligand is directly attached to the outer surface of the ZIF and/or is conjugated to a surface modifying agent through which it attaches to the outer surface of the ZIF, as described below. The description below describes nanoparticles that contain a ZIF cage. However, these descriptions apply to other suitable materials for forming the cage, as well, such as those described above. Thus the references to a “ZIF” or “ZIF cage” herein also generally apply to other suitable materials for forming a cage. Optionally, the targeting ligand is directly attached to the outer surface of the ZIF through an ionic bond, a covalent bond, a polar covalent bond, or Van der Waals interactions, or a combination thereof. For example, the targeting ligand contains a chemical moiety containing one or more charges (negative charges or positive charges), such that it can ionically bind to the metal ions or the imidazolate linkers of the ZIFs and thereby attach to the outer surface of the ZIF. Generally, the targeting ligand can bind to a reproductive hormone or the receptor of a reproductive hormone, such as gonadotropin-releasing hormone (“GnRH”). The growth of prostate cancer depends on androgen, a steroid hormone. The production of androgen is stimulated by follicle stimulating hormone (“FSH”) and luteinizing hormone (“LH”) from gonadotrophs, which contain GnRH receptors. Further, receptors in the pituitary, such as GnRH receptors, are also expressed in prostate cancer cells. By targeting reproductive hormones or their receptors, the compositions and methods described herein are able to regulate androgen production and/or specifically deliver drugs to prostate cancer cells, to reduce or prevent growth and proliferation of prostate cancer cells. a. Exemplary Targeting Ligands The nanoparticles include at least one of the following targeting ligands: a gonadotropin- releasing hormone (“GnRH”) agonist, a GnRH antagonist, a follicle stimulating hormone (“FSH”) receptor agonist, a FSH receptor antagonist, a luteinizing hormone (“LH”) receptor agonist, or a LH receptor antagonist, or a combination thereof. Optionally, the nanoparticles include one or more additional targeting ligands. For example, the targeting ligand included in the nanoparticles is buserelin, azagly- naflorein, deslorelin, fertirelin, gonadorelin, goserelin, histrelin, lecirelin, leuprorelin, nafarelin, peforelin, peforelin acetate, triptorelin, leuprolide, leuprolide acetate, abarelix, cetorelix, degarelix, elagolix, ganirelix, linzagolix, relugolix, thiazolidinone compound 5, hexahydroquinoline derivative Org 214444-0, thienopyrimidine derivatives, such as thienopyrimidine derivative Org 43553, 5-amino-N-(tert-butyl)-4-(3-(isonicotinamido)phenyl)-2- (methylthio)thieno-[2,3-d]pyrimidine-6-carboxamide, 5-amino-N-(tert-butyl)-2-(methylthio)-4- (3-(thiophene-3-carboxamido)phenyl thieno[2,3-d]pyrimidine-6-carboxamide, 5-amino-N-(tert- butyl-2-(methylsulfonyl)-4-(3-(nicotinamido)phenyl)thieno[2, 3-d]pyrimidine-6-carboxamide, 5- amino-N-(tert-butyl-4-(3-(1-methyl-1H-pyrazole-4-carboxamido )phenyl)-2- (methylsulfanyl)thieno[2,3-d]pyrimidine-6-carboxamide, 5-amino-N-(tert-butyl)-4-(3-(2- metoxynicotinamido)phenyl)-2-(methylthio)thieno[2,3-d]pyrimi dine-6-carboxamide, 4-((3-(5- amino-6-(tert-butylcarbamoyl)-2-(methylthio)thieno[2,3-d]pyr imidine-4- il)phenyl)carbamoyl)pyridine 1-oxide, and 5-amino-N-(tert-butyl)-4-(3-(2- chloronicotinamido)phenyl)-2-(methylthio)thieno[2,3-d]pyrimi dine-6-carboxamide, a diketopiperazine, m-dihydropyridine, or deglycosylated human chorionic gonadotropins (hCGs), or a combination thereof. In some embodiments, the targeting ligand included in the nanoparticles is buserelin. 3. Surface Modifying Agents a. Chemical Moiety for ZIF Attachment The nanoparticles include a surface modifying agent, optionally more than one surface modifying agent, that attaches to the outer surface of the cage. The surface modifying agent can attach to the outer surface of the cage through an ionic bond, a covalent bond, a polar covalent bond, or Van der Waal interactions, or a combination thereof. For example, the nanoparticles include a surface modifying agent, optionally more than one surface modifying agent, that attaches to the outer surface of the ZIF, where the surface modifying agent attaches to the outer surface of the ZIF through an ionic bond, a covalent bond, a polar covalent bond, or Van der Waal interactions, or a combination thereof. The description below describes nanoparticles that contain a ZIF cage. However, these descriptions apply to other suitable materials for forming the cage, as well, such as those described above. Thus the references to a “ZIF” or “ZIF cage” herein also generally apply to other suitable materials for forming a cage. Optionally, the surface modifying agent attaches to the outer surface of the ZIF though an ionic bond. In these embodiments, the surface modifying agent may contain a chemical moiety containing one or more charges (positive charges or negative charges), such that it forms ionic bonding with the metal ions or the imidazolate linkers of the ZIF and thereby attaches to the outer surface of the ZIF. The charged chemical moiety can be on any suitable location of the surface modifying agent. For example, when the surface modifying agent is a polymer, the charged chemical moiety can be incorporated in any location in the backbone of the polymer, conjugated to one end or both ends of the polymer backbone, conjugated to the polymer backbone as a side group, or conjugated to a side chain of the polymer. For example, the end of the surface modifying agent can contain a chemical moiety containing one or more charges (positive charges or negative charges), such that it forms ionic bonding with the metal ions or the imidazolate linkers of the ZIF and thereby attaches to the outer surface of the ZIF though the chemical moiety. For example, the end of the surface modifying agent contains a chemical moiety containing one or more negative charges, such that it forms ionic bonding with the metal ions of the ZIF and thereby attaches to the outer surface of the ZIF through the chemical moiety. For example, the end of the surface modifying agent contains a chemical moiety containing one or more positive charges, such that it ionically binds with one or more negative charges on the imidazolate linkers of the ZIF. Optionally, the surface modifying agent itself contains one or more charges (positive charges or negative charges), such that it forms ionic bonds with the metal ions or the imidazolate linkers of the ZIF and thereby attaches to the outer surface of the ZIF though the chemical moiety. For example, the surface modifying agent contains a positively charged polyethylenimine backbone, such that if forms ionic bonding with the imidazolate linkers of the ZIF. Examples of chemical moieties suitable to be incorporated in or conjugated to the surface modifying agent include, but are not limited to folate, L-methylfolate (5-MTHF), and glutamate, and a combination thereof. b. Polymers The surface modifying agent included in the nanoparticles can contain a polymer backbone. Any suitable polymer backbone can be used in forming the surface modifying agent of the nanoparticles. The polymer backbone can be hydrophobic or hydrophilic, or contain blocks that are hydrophobic and blocks that are hydrophilic. For example, the polymer backbone can be formed from hydrophobic monomers, hydrophilic monomers, or a combination of hydrophobic monomers and hydrophilic monomers. Examples of suitable polymer backbones for forming the surface modifying agent include, but are not limited to, polyalkylene glycol, polylactic acid, polyglycolic acid, poly(lactic-co-glycolic acid), polyanhydrides, poly(ortho)esters, polyurethanes, poly(butyric acid), poly(valeric acid), poly(lactide-coaprolactone), and polyethylenimine, and a copolymer thereof. For example, the polymer backbone of the surface modifying agent is polyethylene glycol. The polymer backbone of the surface modifying agent may be unmodified or modified with one or more functional groups. The functional groups can be conjugated to the backbone of the polymer, conjugated to one end or both ends of the polymer backbone, or conjugated to a side chain of the polymer. For example, the polymer backbone of the surface modifying agent is modified to introduce one or more functional groups, such as amino, hydroxyl, thiol, aldehyde, or carboxyl, or a combination thereof. Surface modifying agents with functionalized polymer backbone are commercially available, for example, functionalized polyethylene glycols by Sigma Aldrich. i. Molecular Weight Generally, the polymer backbone of the surface modifying agent can have a molecular weight in a range from about 1 kDa to about 10 kDa. Optionally, the polymer backbone of the surface modifying agent can have a molecular weight in a range from about 2 kDa to about 10 kDa, from about 3 kDa to about 10 kDa, from about 4 kDa to about 10 kDa, from about 1 kDa to about 9 kDa, from about 2 kDa to about 9 kDa, from about 3 kDa to about 9 kDa, from about 4 kDa to about 9 kDa, from about 1 kDa to about 8 kDa, from about 2 kDa to about 8 kDa, from about 3 kDa to about 8 kDa, from about 4 kDa to about 8 kDa, from about 1 kDa to about 7 kDa, from about 2 kDa to about 7 kDa, from about 3 kDa to about 7 kDa, from about 4 kDa to about 7 kDa, from about 1 kDa to about 6 kDa, from about 2 kDa to about 6 kDa, from about 3 kDa to about 6 kDa, or from about 4 kDa to about 6 kDa. For example, the polymer backbone of the surface modifying agent can have a molecular weight of about 5 kDa. ii. Targeting Ligand Conjugation Optionally, the surface modifying agent has a targeting ligand or more than one targeting ligand conjugated thereto. The targeting ligand may be conjugated to conjugated to the backbone of the polymer, conjugated to one end of the polymer backbone, or conjugated to a side chain of the polymer, as long as the targeting ligand is exposed to the surrounding environment following nanoparticle assembly. For example, the surface modifying agent has a first end that contains a charged chemical moiety, and a second end that is opposite to the first end and contains a targeting ligand conjugated thereto. In such embodiments, when the surface modifying agent is attached to the outer surface of the ZIF through the first end by ionic bonding, the second end containing the targeting ligand conjugated thereto is exposed to the surrounding environment. Optionally, at least 20 wt% (weight of the surface modifying agent conjugated to the targeting ligand/total weight of the surface modifying agent attached to the cage) of the surface modifying agent is conjugated to the targeting ligand. For example, at least 20 wt% (weight of the surface modifying agent conjugated to the targeting ligand/total weight of the surface modifying agent attached to the ZIF) of the surface modifying agent is conjugated to the targeting ligand. For example, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, in a range from 20 wt% to 100 wt%, from 30 wt% to 100 wt%, or from 40 wt% to 100 wt% of the surface modifying agent is conjugated to the targeting ligand. 4. Active Agents The nanoparticles include an active agent, optionally more than one active agent, encapsulated in the cage. For example, the nanoparticles include an active agent, optionally more than one active agent, encapsulated in the ZIF. The active agents are generally able to ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related disease and/or disorder in the subject, such as a GnRH- or gonadotropin-related cancer (e.g. prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, renal cancer, etc.), a GnRH- or gonadotropin-related benign tumor, and endometriosis. Typically, the active agent can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells that contain receptors for GnRH or gonadotropins (for example, cancer cells of a GnRH- or gonadotropin-related cancer, such as any of the cancers described above, tumor cells of a GnRH- or gonadotropin-related benign tumor, such as a tumor of uterine fibroids, and/or cells in tissues associated with a GnRH- or gonadotropin-related disorder, such as endometriosis), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in a subject. In some embodiments, the active agent can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen. In some embodiments, the active agent can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or benign tumor cells that contain receptors for GnRH or gonadotropins (e.g., uterine fibroids tumor cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen. In some embodiments, the active agent can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells/tissue associated with a GnRH- or gonadotropin-related disorder that contain receptors for GnRH or gonadotropins (e.g., endometriosis), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen. The description below describes nanoparticles that contain a ZIF cage. However, these descriptions apply to other suitable materials for forming the cage, as well. Thus the references to a “ZIF” or “ZIF cage” herein also generally apply to other suitable materials for forming a cage. Optionally, the active agent encapsulated in the ZIF of the nanoparticles is a ribosome inactivating protein, an apoptosis inducer, a hormone, a receptor ligand, a nucleic acid, or a chemotherapy drug, or a combination thereof, that can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in a subject. Optionally, the active agent encapsulated in the ZIF of the nanoparticles is a ribosome inactivating protein, an apoptosis inducer, a hormone, a receptor ligand, a nucleic acid, or a chemotherapy drug, or a combination thereof, that can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells or ovarian cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in a subject. Optionally, the active agent encapsulated in the ZIF of the nanoparticles is a ribosome inactivating protein, an apoptosis inducer, a hormone, a receptor ligand, or a nucleic acid, or a combination thereof, that can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or benign tumor cells that contain receptors for GnRH or gonadotropins (e.g., uterine fibroids tumor cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in a subject. Optionally, the active agent encapsulated in the ZIF of the nanoparticles is a ribosome inactivating protein, an apoptosis inducer, a hormone, a receptor ligand, or a nucleic acid, or a combination thereof, that can kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells in the tissues associated with a GnRH- or gonadotropin-related disorder that contain receptors for GnRH or gonadotropins (e.g., endometriosis), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in a subject. For example, the active agent encapsulated in the ZIF of the nanoparticles is a ribosome inactivating protein, such as saporin, gelonin, or a pokeweed antiviral protein (“PAP”), or a combination thereof. Other examples of ribosome inactivating proteins suitable for encapsulation in the ZIF include, but are not limited to, trichosanthin (“TCS”), bryodin, luffaculin, beta-luffin, a-momorcharin, cucurmosin, MAP30, b-momorcharin, GAP31, ricin, ebulin, abrus, mistletoe, bouganin, PD-L4, dianthin, lychnin, MOD, charybdin, shiga, and cinnamomin, and a combination thereof. For example, the active agent encapsulated in the ZIF of the nanoparticles is an apoptosis inducer, such as ±-anatoxin fumarate, actinomycin D, anisomycin, apoptosis activator 2, AT101, betulinic Acid, bioymifi, BZ423, C75, camptothecin, chaetoglobosin A, clindamycin hydrochloride, cycloheximide, 2,3,-DCPE hydrochloride, captomycin, doxorubicin hydrochloride, ellipticine, epirubicin hydrochloride, G 418 disulfate, gambogic acid, gedunin, hygromycin B, kaempferol, linezolid, mithramycin A, MPC 6827 hydrochloride, narciclasine, oncrasin 1, oxaliplatin, piperlongumine, puromycin dihydrochloride, rifampicin, rifaximin, SMBA 1, streptozotocin, temozolomide, tobramycin, triptolide, or trovafloxacin mesylate, or a combination thereof. For example, more than one active agent is encapsulated in the ZIF structure of the nanoparticles, where a first active agent is a ribosome inactivating protein, such as any of the ribosome inactivating proteins described above, and a second active agent is an apoptosis inducer, such as any of the apoptosis inducers described above. For example, the active agent encapsulated in the ZIF of the nanoparticles is a chemotherapy drug, such as doxorubicin. Other examples of chemotherapy drugs suitable for encapsulation in the nanoparticles include, but are not limited to, olaparib, abemaciclib, abiraterone acetate, methotrexate, paclitaxel, adriamycin, acalabrutinib, brentuximab vedotin, ado-trastuzumab emtansine, aflibercept, afatinib, netupitant, palonosetron, imiquimod, aldesleukin, alectinib, alemtuzumab, pemetrexed disodium, copanlisib, melphalan, brigatinib, chlorambucil, amifostine, aminolevulinic acid, anastrozole, apalutamide, aprepitant, pamidronate disodium, exemestane, nelarabine, arsenic trioxide, ofatumumab, atezolizumab, bevacizumab, avelumab, axicabtagene ciloleucel, axitinib, azacitidine, carmustine, belinostat, bendamustine, inotuzumab ozogamicin, bevacizumab, bexarotene, bicalutamide, bleomycin, blinatumomab, bortezomib, bosutinib, brentuximab vedotin, brigatinib, busulfan, irinotecan, capecitabine, fluorouracil, carboplatin, carfilzomib, ceritinib, daunorubicin, cetuximab, cisplatin, cladribine, cyclophosphamide, clofarabine, cobimetinib, cabozantinib-S-malate, dactinomycin, crizotinib, ifosfamide, ramucirumab, cytarabine, dabrafenib, dacarbazine, decitabine, daratumumab, dasatinib, defibrotide, degarelix, denileukin diftitox, denosumab, dexamethasone, dexrazoxane, dinutuximab, docetaxel, doxorubicin, durvalumab, rasburicase, epirubicin, elotuzumab, oxaliplatin, eltrombopag olamine, enasidenib, enzalutamide, eribulin, vismodegib, erlotinib, etoposide, everolimus, raloxifene, toremifene, panobinostat, fulvestrant, letrozole, filgrastim, fludarabine, flutamide, pralatrexate, obinutuzumab, gefitinib, gemcitabine, gemtuzumab ozogamicin, glucarpidase, goserelin, propranolol, trastuzumab, topotecan, palbociclib, ibritumomab tiuxetan, ibrutinib, ponatinib, idarubicin, idelalisib, imatinib, talimogene laherparepvec, ipilimumab, romidepsin, ixabepilone, ixazomib, ruxolitinib, cabazitaxel, palifermin, pembrolizumab, ribociclib, tisagenlecleucel, lanreotide, lapatinib, olaratumab, lenalidomide, lenvatinib, leucovorin, leuprolide, lomustine, trifluridine, olaparib, vincristine, procarbazine, mechlorethamine, megestrol, trametinib, temozolomide, methylnaltrexone bromide, midostaurin, mitomycin C, mitoxantrone, plerixafor, vinorelbine, necitumumab, neratinib, sorafenib, nilutamide, nilotinib, niraparib, nivolumab, tamoxifen, romiplostim, sonidegib, omacetaxine, pegaspargase, ondansetron, osimertinib, panitumumab, pazopanib, interferon alfa-2b, pertuzumab, pomalidomide, mercaptopurine, regorafenib, rituximab, rolapitant, rucaparib, siltuximab, sunitinib, thioguanine, temsirolimus, thalidomide, thiotepa, trabectedin, valrubicin, vandetanib, vinblastine, vemurafenib, vorinostat, zoledronic acid, or combinations thereof such as cyclophosphamide, methotrexate, 5-fluorouracil (CMF); doxorubicin, cyclophosphamide (AC); mustine, vincristine, procarbazine, prednisolone (MOPP); sdriamycin, bleomycin, vinblastine, dacarbazine (ABVD); cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP); rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone (RCHOP); bleomycin, etoposide, cisplatin (BEP); epirubicin, cisplatin, 5-fluorouracil (ECF); epirubicin, cisplatin, capecitabine (ECX); methotrexate, vincristine, and cisplatin (MVAC), and a combination thereof. For example, more than one active agent is encapsulated in the ZIF structure of the nanoparticles, where a first active agent is a ribosome inactivating protein or an apoptosis inducer, such as any of those described above, and a second active agent is a chemotherapy agent, such as doxorubicin. For example, more than one active agent is encapsulated in the ZIF structure of the nanoparticles, where a first active agent is a ribosome inactivating protein, such as any of the ribosome inactivating proteins described above, a second active agent is an apoptosis inducer, such as any of the apoptosis inducers described above, and a third active agent is a chemotherapy agent, such as doxorubicin. The nanoparticle can contain one or more active agents in a total concentration in the nanoparticle of at least about 0.00005 wt%, at least about 0.0001 wt%, at least about 0.0005 wt%, at least about 0.001 wt%, at least about 0.005 wt%, at least about 0.01 wt%, up to 10 wt%, up to 5 wt%, up to 1 wt%, up to 0.5 wt%, up to 0.1 wt%, in a range from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.00005 wt% to about 1 wt%, from about 0.0001 wt% to about 1 wt%, from about 0.0005 wt% to about 1 wt%, from about 0.001 wt% to 1 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.00005 wt% to about 0.1 wt%, from about 0.0001 wt% to about 0.1 wt%, from about 0.0005 wt% to about 0.1 wt%, from about 0.001 wt% to 0.1 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.00005 wt% to about 0.01 wt%, from about 0.0001 wt% to about 0.01 wt%, from about 0.0005 wt% to about 0.01 wt%, from about 0.001 wt% to 0.01 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.00005 wt% to about 0.001 wt%, from about 0.0001 wt% to about 0.001 wt%, or from about 0.0005 wt% to about 0.001 wt%, such as about 0.0006 wt%. The term “total concentration” with respect to the total concentration of the one or more active agents in the nanoparticle refers to the sum of the weight of all of the active agent(s) encapsulated in a nanoparticle relative to the weight of the nanoparticle. 5. Optional Components Optionally, the nanoparticles also include a diagnostic agent encapsulated in the cage. For example, the nanoparticles also include a diagnostic agent encapsulated in the ZIF. Any suitable diagnostic agent can be encapsulated in the cage of the nanoparticles. The encapsulation of the diagnostic agent allows visualization of the nanoparticles in vivo. Nanoparticles including a diagnostic agent are useful for imaging or assessing tissues of interest, such as prostate cancer tissue. Exemplary diagnostic agents suitable to be encapsulated in the cage, such as the ZIF of the nanoparticles, include, but are not limited to, paramagnetic molecules, fluorescent/dye molecules, magnetic molecules, radionuclides, x-ray imaging agents, MRI imaging agents, ultrasound imaging agents, and contrast media. For example, the nanoparticles includes a dye molecule encapsulated in the ZIF, such as Alexa Fluor 350, Alexa Fluor 405, Alexa Fluor 488, Alexa Fluor 532, Alexa Fluor 546, Alexa Fluor 555, Alexa Fluor 561, Alexa Fluor 568, Alexa Fluor 594, Alexa Fluor 647, Alexa Fluor 660, Alexa Fluor 680, Alexa Fluor 700, Alexa Fluor 750, pacific blue, coumarin, BODIPY FL, pacific green, oregon green, FITC, Cy3, pacific orange, PE-Cyanine7, PerCP-Cyanine5.5, TRITC, texas red, Cy5, eFLuor 450, eFluor 506, eFluor 660, PE-eFluor 610, PerCP-eFluor 710, APC-eFluor 780, super bright 436, super bright 600, super bright 645, super bright 702, super bright 780, DAPI, SYTOX green, SYTO 9, TO-PRO-3, propidium iodide, Qdot 525, Qdot 565, Qdot 605, Qdot 655, Qdot 705, Qdot 800, R-PE, APC, CFP, GFP, RFP, CF®350, CF®405S, CF®405M, CF®405L, CF®430, CF®440, CF®450, CF®488A, CF®503R, CF®514, CF®532, CF®535ST, CF®543, CF®550R, CF®555, CF®568, CF®570, CF®583, CF®583R, CF®594, CF®594ST, CF®620R, CF®633, CF®640R, CF®647, CF®660C, CF®660R, CF®680, CF®680R, CF®700, CF®750, CF®770, CF®790, CF®800, CF®820, or DyLight®649, or a combination thereof. B. Properties 1. Surface Density of Surface Modifying Agents Typically, the surface density of the surface modifying agent (also referred herein as “SMA”) on the outer surface of the cage of the nanoparticles is sufficient to reduce non-specific protein adsorption in vivo. For example, the surface density of the SMA on the outer surface of the ZIF of the nanoparticles is sufficient to reduce non-specific protein adsorption in vivo. For example, the SMA has a surface density sufficient to achieve a brush configuration on the outer surface of the ZIF of the nanoparticles. Optionally, the surface density of the SMA on the outer surface of the cage of the nanoparticles is at least 1 SMA/nm ² . For example, the surface density of the SMA on the outer surface of the cage of the nanoparticles is at least 2 SMA/nm ² , at least 3 SMA/nm ² , at least 4 SMA/nm ² , at least 5 SMA/nm ² , at least 7 SMA/nm ² , at least 10 SMA/nm ² , at least 15 SMA/nm ² , at least 20 SMA/nm ² , at least 25 SMA/nm ² , at least 30 SMA/nm ² , at least 35 SMA/nm ² , at least 40 SMA/nm ² , at least 45 SMA/nm ² , or at least 50 SMA/nm ² . For example, the surface density of the SMA on the outer surface of the ZIF of the nanoparticles is at least 1 SMA/nm ² . For example, the surface density of the SMA on the outer surface of the ZIF of the nanoparticles is at least 2 SMA/nm ² , at least 3 SMA/nm ² , at least 4 SMA/nm ² , at least 5 SMA/nm ² , at least 7 SMA/nm ² , at least 10 SMA/nm ² , at least 15 SMA/nm ² , at least 20 SMA/nm ² , at least 25 SMA/nm ² , at least 30 SMA/nm ² , at least 35 SMA/nm ² , at least 40 SMA/nm ² , at least 45 SMA/nm ² , or at least 50 SMA/nm ² . 2. Nanoparticles Average Diameter Typically, the nanoparticles have an average diameter (including the SMA) that is effective to increase nanoparticle circulation time and improve nanoparticle uptake by target cells. Generally, the nanoparticles can have an average diameter (including the SMA) that is less than 100 nm and at least 10 nm. For example, the nanoparticles have an average diameter (including the SMA) in a range from about 10 nm to about 100 nm, from about 10 nm to about 90 nm, from about 10 nm to about 80 nm, from about 10 nm to about 70 nm, from about 10 nm to about 60 nm, from about 10 nm to about 50 nm, from about 20 nm to about 100 nm, from about 20 nm to about 90 nm, from about 20 nm to about 80 nm, from about 30 nm to about 100 nm, from about 30 nm to about 90 nm, or from about 30 nm to about 80 nm, such as in a range from about 10 nm to about 50 nm. The average diameter of the nanoparticles can be determined using a standard technique, such as using scanning electron microscopy (“SEM”) or using dynamic light scattering (“DLS”). For example, the nanoparticles have an average diameter (including the SMA) of less than 100 nm, or in a range from about 10 nm to about 100 nm, from about 10 nm to about 90 nm, from about 10 nm to about 80 nm, from about 20 nm to about 100 nm, from about 20 nm to about 90 nm, from about 20 nm to about 80 nm, from about 30 nm to about 100 nm, from about 30 nm to about 90 nm, or from about 30 nm to about 80 nm, measured by DLS. II. Pharmaceutical Formulations Pharmaceutical formulations that contain nanoparticles in a form suitable for administration to a mammal are disclosed. The pharmaceutical formulations may contain a plurality of the nanoparticles described herein. The nanoparticles in the plurality of nanoparticles may be formed from the same components or different components. For example, the nanoparticles in the plurality of nanoparticles contained in the pharmaceutical formulation are all the same, i.e. formed from the same cage, such as the same ZIF, same surface modifying agent, same targeting ligand, and same active agent. For example, one or more of the nanoparticles in the plurality of nanoparticles are formed from a cage, a surface modifying agent, a targeting ligand, and/or an active agent that is(are) different from the cage, surface modifying agent, targeting ligand, and/or active agent forming one or more of the other nanoparticles in the plurality of nanoparticles. For example, a first set of nanoparticles in the plurality of nanoparticles contained in the pharmaceutical formulation is formed from a first ZIF, a first surface modifying agent, a first targeting ligand, and a first active agent; and a second set of nanoparticles in the plurality of nanoparticles contained in the pharmaceutical formulation is formed from a second ZIF, a second surface modifying agent, a second targeting ligand, and a second active agent, where the first ZIF is the same or different from the second ZIF, the first surfacing modifying agent is the same or different from the second surface modifying agent, the first targeting ligand is the same or different from the second targeting ligand, and the first active agent is the same or different from the second active agent. In some embodiments, the pharmaceutical formulations are for delivery of nanoparticles to the pituitary, testes, and/or cancer cells, such as prostate cancer cells, pancreatic cancer cells, and/or renal cancer cells, of a male mammal. In some embodiments, the pharmaceutical formulations are for delivery of nanoparticles to the pituitary, ovaries, uterus, benign tumor cells, such as uterine fibroids tumor cells, and/or cancer cells, such as ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells, of a female mammal. In some embodiments, the pharmaceutical formulations are for delivery of nanoparticles to the testes and/or prostate cancer cells of the male mammal. In some embodiments, the pharmaceutical formulations are for delivery of nanoparticles to the ovarian and/or ovarian cancer cells of the female mammal. In some embodiments, the pharmaceutical formulations are for delivery of nanoparticles to the uterus, uterine cancer cells, and/or uterine benign tumor cells (such as uterine fibroids tumor cells) of the female mammal. Typically, the active agent(s) in the pharmaceutical formulation is present in an amount effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells that contain receptors for GnRH or gonadotropins (for example, cancer cells of a GnRH- or gonadotropin-related cancer, such as any of the cancers described above, cells of a GnRH- or gonadotropin-related benign tumor, and/or cells in tissues associated with a GnRH- or gonadotropin-related disorder, such as endometriosis), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in a subject. In some embodiments, the active agent(s) in the pharmaceutical formulation is present in an amount effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells, benign tumor cells (e.g., uterine fibroids tumor cells), and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, in the subject. Typically, the active agent(s) in the pharmaceutical formulation is present in an amount effective to ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related disease and/or disorder, such as a GnRH- or gonadotropin-related cancer, a GnRH- or gonadotropin-related benign tumor, and/or endometriosis. In some embodiments, the active agent(s) in the pharmaceutical formulation is present in an amount effective to ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, for example, prostate cancer or ovarian cancer. In some embodiments, the active agent(s) in the pharmaceutical formulation is present in an amount effective to ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related benign tumor, such as a tumor of uterine fibroids. Optionally, the active agent(s) in the pharmaceutical formulation is present in an amount effective to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related cancer, in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a subject compared to the level of the biomarker in the biological sample of the subject before treatment and/or reduce the mean diameter of a tumor associated with the GnRH- or gonadotropin-related cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the active agent(s) in the pharmaceutical formulation is present in an amount effective to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related benign tumor, in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a subject compared to the level of the biomarker in the biological sample of the subject before treatment and/or reduce the mean diameter of the tumor in the subject compared to the mean diameter of the tumor in the subject before treatment. For example, the active agent(s) in the pharmaceutical formulation is present in an amount effective to reduce the level of a biomarker associated with prostate cancer, such as PSA, in the blood of a subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. For example, the active agent(s) in the pharmaceutical formulation is present in an amount effective to reduce the level of a biomarker associated with ovarian cancer, such as CA125, in the blood of a subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. For example, the active agent(s) in the pharmaceutical formulation is present in an amount effective to reduce the level of a biomarker associated with uterine fibroids, such as CA125, in the blood of a subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor of uterine fibroid in the subject compared to the mean diameter of the tumor in the subject before treatment. The pharmaceutical formulation may include pharmaceutically acceptable carriers and/or one or more pharmaceutically acceptable excipients. For example, the pharmaceutical formulation may be in the form of a liquid, such as a solution or a suspension, and contain a plurality of the disclosed nanoparticles in an aqueous medium and, optionally, one or more suitable excipients for the liquid formulation. Optionally, the pharmaceutical formulation is in a solid form, and contains a plurality of the disclosed nanoparticles and one or more suitable excipients for a solid formulation. The solid formulation can be dissolved or suspended in a suitable carrier to form a liquid pharmaceutical formulation prior to use. A. Carriers and Excipients The pharmaceutical formulation contains one or more pharmaceutically acceptable carriers and/or excipients. Suitable pharmaceutically acceptable carriers and excipients are generally recognized as safe (GRAS), and may be administered to an individual without causing undesirable biological side effects or unwanted interactions. Representative carriers and excipients include solvents (including buffers), diluents, pH modifying agents, preservatives, antioxidants, suspending agents, wetting agents, viscosity modifiers, tonicity agents, and stabilizing agents, and a combination thereof. Nanoparticles for delivering active agents to the pituitary, testes, and/or prostate cancer cells of the mammal can be dissolved or suspended in a suitable carrier to form a liquid pharmaceutical formulation, such as sterile saline, phosphate buffered saline (PBS), balanced salt solution (BSS), viscous gel, or other pharmaceutically acceptable carriers for administration. The pharmaceutical formulation may also be a sterile solution, suspension, or emulsion in a nontoxic, parenterally acceptable diluent or solvent. Excipients can be added to a liquid or solid pharmaceutical formulation to assist in sterility, stability (e.g. shelf-life), integration, and to adjust and/or maintain pH or isotonicity of the nanoparticles in the pharmaceutical formulation, such as diluents, pH modifying agents, preservatives, antioxidants, suspending agents, wetting agents, viscosity modifiers, tonicity agents, and stabilizing agents, and a combination thereof. B. Form The pharmaceutical formulation containing a plurality of the disclosed nanoparticles can be in a liquid form as a liquid formulation for parenteral administration (e.g. intramuscular administration, intravenous administration, intraperitoneal administration, and subcutaneous administration) to a subject. Optionally, the pharmaceutical formulation containing a plurality of the disclosed nanoparticles can be in a solid form, which can be dissolved or suspended in a suitable carrier to form a liquid formulation for parenteral administration. 1. Parenteral Formulations Optionally, the pharmaceutical formulation containing a plurality of the disclosed nanoparticles is in a form suitable for administration directly into the blood stream, into muscle, or into an internal organ. Suitable routes for such parenteral administration include intravenous, intraarterial, intraperitoneal, intrathecal, epidural, intracerebroventricular, intraurethral, intrasternal, intracranial, intramuscular, and subcutaneous delivery. Suitable means for parenteral administration include needle (including microneedle) injectors, needle-free injectors, and infusion techniques. For example, the pharmaceutical formulation containing a plurality of the nanoparticles is in a form suitable for intramuscular administration, intravenous administration, intraperitoneal administration, or subcutaneous administration, or a combination thereof. Parenteral formulations containing the nanoparticles described herein are typically aqueous solutions which can contain excipients such as salts, carbohydrates and buffering agents (e.g., from about pH 6.5 to about pH 8.0, from about pH 6.5 to about pH 7.4, from about pH 6.5 to about pH 7.0, from about pH 7.0 to pH 8.0, or from about pH 7.0 to about pH 7.4), but, for some applications, they may be more suitably formulated as a sterile aqueous solution or as a dried form to be used in conjunction with a suitable vehicle such as sterile, pyrogen-free water. The liquid formulations containing the nanoparticles for parenteral administration may be a solution, a suspension, or an emulsion. The liquid pharmaceutically acceptable carrier forming the parenteral formulation containing the nanoparticles can include one or more physiologically compatible buffers, such as a phosphate buffers. One skilled in the art can readily determine a suitable saline content and pH for an aqueous carrier for administration (e.g., from pH 6.5 to about pH 8.0, from about pH 6.5 to about pH 7.4, from about pH 6.5 to about pH 7.0, from about pH 7.0 to pH 8.0, or from about pH 7.0 to about pH 7.4). Liquid formulations containing the nanoparticles for parenteral administration may include one or more suspending agents, such as cellulose derivatives, sodium alginate, polyvinylpyrrolidone, gum tragacanth, or lecithin. The liquid formulations may also include one or more preservatives, such as ethyl or n-propyl p-hydroxybenzoate. Optionally, the liquid formulation containing the nanoparticles contains one or more solvents that are low toxicity organic (i.e., nonaqueous) class 3 residual solvents, such as ethanol, acetone, ethyl acetate, tetrahydofuran, ethyl ether, and propanol, and a combination thereof. Any such solvents included in the liquid formulation should not detrimentally react with the one or more active agents present in the nanoparticles in the liquid formulation. Solvents such as freon, alcohol, glycol, polyglycol, or fatty acid, can also be included in the liquid formulation containing the nanoparticles as desired to increase the volatility of the solution or suspension. Liquid formulations containing the nanoparticles for parenteral administration may also contain minor amounts of polymers, surfactants, or other pharmaceutically acceptable excipients known to those in the art. In this context, "minor amounts" means an amount that is sufficiently small to avoid adversely affecting uptake of the nanoparticles by the targeted cells, such as pituitary gonadotrophs and/or prostate cancer cells. The preparation of parenteral formulations containing the nanoparticles is typically under sterile conditions, for example, by lyophilisation, which can be accomplished using standard pharmaceutical techniques known to those skilled in the art. Formulations for parenteral administration containing the nanoparticles may be formulated to provide immediate and/or modified release of the active agent. Modified release formulations include delayed, sustained, pulsed, controlled, targeted and programmed release formulations. C. Dosage/wt % concentration The pharmaceutical formulation contains an effective amount of the active agent(s) encapsulated in the nanoparticles for treating or ameliorating one more symptoms associated with a GnRH- or gonadotropin-related disease or disorder, such as a GnRH- or gonadotropin- related cancer, a benign tumor (such as a tumor of uterine fibroids), or a disorder that is associated with the reproductive tract (such as endometriosis). Typically, the active agent(s) is present in the pharmaceutical formulation in an effective amount to ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related disease and/or disorder in a subject in need thereof. The cells and/or tissues associated with the GnRH- or gonadotropin- related disease and/or disorder in the subject express receptors for GnRH or one or more gonadotropins. In some embodiments, the active agent(s) is present in the pharmaceutical formulation in an effective amount to ameliorate one or more symptoms associated with a GnRH- or gonadotropins-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in the subject. Optionally, the amount of the active agent(s) in the pharmaceutical formulation is effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen. In some embodiments, the active agent(s) is present in the pharmaceutical formulation in an effective amount to ameliorate one or more symptoms associated with a GnRH- or gonadotropins-related benign tumor, such as a tumor of uterine fibroids, in the subject. Optionally, the amount of the active agent(s) in the pharmaceutical formulation is effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or benign tumor cells that contain receptors for GnRH or gonadotropins (e.g., uterine fibroids tumor cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen. In some embodiments, the active agent is included in the pharmaceutical formulation in an effective amount to treat or ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related disorder, such as endometriosis, in the subject. Optionally, the amount of the active agent(s) in the pharmaceutical formulation is effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells in tissues associated with the GnRH- or gonadotropin-related disorder that contain receptors for GnRH or gonadotropins (e.g., endometriosis), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen. Optionally, the pharmaceutical formulation contains active agent(s) in an amount that is effective to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related cancer in a biological sample (e.g. blood, urine, feces, or tissues, or a combination thereof) of a subject, compared to the level of the biomarker in the biological sample of the subject before treatment and/or reduce the mean diameter of a tumor associated with the GnRH- or gonadotropin-related cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains active agent(s) in an amount that is effective to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related cancer in the blood of a subject, compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with the GnRH- or gonadotropin-related cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. For example, the pharmaceutical formulation contains active agent(s) in an amount that is effective to reduce the level of a biomarker associated with prostate cancer, pancreatic cancer, or renal cancer in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a male subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the male subject before treatment and/or reduce the mean diameter of a tumor associated with the prostate cancer, pancreatic cancer, or renal cancer in the male subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the mean diameter of the tumor in the male subject before treatment. For example, the pharmaceutical formulation contains nanoparticles in an amount that is effective to reduce the level of a biomarker associated with prostate cancer, pancreatic cancer, or renal cancer in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a male subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the male subject before treatment and/or reduce the mean diameter of a tumor associated with the prostate cancer, pancreatic cancer, or renal cancer in the male subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the mean diameter of the tumor in the male subject before treatment. Examples of biomarkers suitable for evaluating the treatment effect for prostate cancer are described below. Examples of biomarkers suitable for evaluating the treatment effect for pancreatic cancer include, but are not limited to, carbohydrate antigen 19-9, microRNAs (e.g., miR-143, miR-223, miR-30e, miR-223, miR-204, and combinations thereof), and PAM4, and a combination thereof. Additional examples of biomarkers suitable for evaluating the treatment effect for pancreatic cancer are described in Hasan, et al., Oncol Rev., 13(1):410 (2019). Examples of biomarkers suitable for evaluating the treatment effect for renal cancer include, but are not limited to, carbonic anhydrase IX, vascular endothelial-derived growth factor, and MMR- D/MSI-H, or a combination thereof. For example, the pharmaceutical formulation contains active agent(s) in an effective amount to reduce the level of a biomarker associated with ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a female subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the female subject before treatment and/or reduce the mean diameter of a tumor associated with the ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer in the female subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the mean diameter of the tumor in the female subject before treatment. For example, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a female subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the female subject before treatment and/or reduce the mean diameter of a tumor associated with the ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer in the female subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the mean diameter of the tumor in the female subject before treatment. Examples of biomarkers suitable for evaluating the treatment effect for ovarian cancer are described below. Examples of biomarkers suitable for evaluating the treatment effect for breast cancer include, but are not limited to, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), or a combination thereof. Examples of biomarkers suitable for use in evaluating the treatment effect for uterine cancer include, but are not limited to, CA-125, K-ras, HER2/neu, epithelial growth factor receptor (EGFR), phosphatidylinositol 3-kinase catalytic subunit (PI3KCA) and fibroblast growth factor receptor 2 (FGFR2) oncogenes; the phosphatase and tensin homolog (PTEN), p53, p21 and cyclin-dependent kinase inhibitor 2A (CDKN2A) cancer suppressor genes; the hMLH1, hMSH2, hMSH6, PMS1 and PMS2 mismatch repair genes; Ki-67, an index of cell proliferation; BCL2-associated X protein (Bax), an apoptosis promotor gene; Bcl-2, an apoptosis suppressor; expression levels of estrogen and progesterone receptors; microvascular density (MVD); and vascular endothelial growth factor A (VEGF-A); E/P-cadherin and β-catenin; or a combination thereof. For example, the pharmaceutical formulation contains active agent(s) in an amount that is effective to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of a subject before treatment and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains active agent(s) in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment. Examples of biomarkers suitable for use in evaluating the treatment effect for prostate cancer include, but are not limited to, prostate specific antigen (“PSA”), a glycoform of PSA, microRNAs, circulating tumor cells, androgen receptor variants, and PTEN gene, and a combination thereof. Optionally, the pharmaceutical formulation contains active agent(s) in an effective amount to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of a subject before treatment and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with prostate cancer, such as those described above, in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with prostate cancer, such as those described above, in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, and to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains an active agent(s) in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of a subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains an active agent(s) in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment. Examples of biomarkers suitable for use in evaluating the treatment effect for ovarian cancer are CA125, CEA (mucinous), LDH (dysgerminoma, mixed germ cell tumors), β-hCG (choriocarcinoma, mixed germ cell tumors), inhibin B (granulosa cell tumors), α-fetoprotein (yolk sac tumors, embryonal cell tumors), and HE4, or a combination thereof. Optionally, the pharmaceutical formulation contains an active agent(s) in an effective amount to reduce the mean diameter of a tumor associated with ovarian cancer in a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject compared to the level of the biomarker in the blood of a subject before treatment and/or reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with ovarian cancer, such as those described above, in the blood of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the mean diameter of a tumor associated with ovarian cancer in a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with ovarian cancer, such as those described above, in the blood of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, and to reduce the mean diameter of a tumor associated with ovarian cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains an active agent(s) in an effective amount to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related benign tumor (such as a tumor of uterine fibroids) in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the subject before treatment, and/or to reduce the mean diameter of the tumor in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Examples of biomarkers suitable for use in evaluating the treatment effect for uterine fibroids include, but are not limited to, CA-125, LDH, and IGF-1, or a combination thereof. For example, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related benign tumor (such as a tumor of uterine fibroids) in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the subject before treatment, and/or to reduce the mean diameter of the tumor in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation contains an active agent(s) in an effective amount to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related disorder (such as endometriosis) in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the subject before treatment. Examples of biomarkers suitable for use in evaluating the treatment effect for endometriosis include, but are not limited to, VEGF, CA-125, Annexin V, and glycodelin, or a combination thereof. Additional examples of biomarkers suitable for evaluating the treatment effect for endometriosis can be any of those described in Anastasiu, et al., Int J Mol Sci, 21(5):1750 (2020). For example, the pharmaceutical formulation contains nanoparticles in an effective amount to reduce the level of a biomarker associated with GnRH- or gonadotropin-related disorder (such as endometriosis) in a biological sample (such as blood, urine, feces, or tissues, or a combination thereof) of a subject, optionally by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%, compared to the level of the biomarker in the biological sample of the subject before treatment. The total concentration of the active agent(s) in the pharmaceutical formulation that is effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, renal cancer cells, benign tumor cells, and cells in tissues associated with a reproductive tract disorder), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen is typically in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. The term “total concentration of the active agent(s) in the pharmaceutical formulation” refers to the sum of the weight of all active agent(s) encapsulated in the nanoparticles relative to the weight of the formulation. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen is typically in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. Optionally, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with a GnRH- or gonadotropins-related disorder (e.g., endometriosis) in a biological sample (such as blood) of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample (such as blood) of the subject before treatment is in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. Optionally, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with a GnRH- or gonadotropins-related benign tumor (e.g., a tumor of uterine fibroids) in a biological sample (such as blood) of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample (such as blood) of the subject before treatment, and/or to reduce the mean diameter of the tumor in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment is in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. Optionally, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with a GnRH- or gonadotropins-related cancer (e.g., prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof) in a biological sample (such as blood) of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample (such as blood) of the subject before treatment, and/or to reduce the mean diameter of a tumor associated with the GnRH- or gonadotropins-related cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment is in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%.For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to ameliorate one or more symptoms associated with prostate cancer in a subject is typically in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with prostate cancer in the blood of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment is in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the mean diameter of a tumor associated with prostate cancer in a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment is in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with prostate cancer in the blood of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, and to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment is in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. The total concentration of the active agent(s) in the pharmaceutical formulation that is effective to ameliorate one or more symptoms associated with ovarian cancer in a subject is typically in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with ovarian cancer in the blood of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment is in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the mean diameter of a tumor associated with ovarian cancer in a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment is in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. For example, the total concentration of the active agent(s) in the pharmaceutical formulation that is effective to reduce the level of a biomarker associated with ovarian cancer in the blood of a subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, and to reduce the mean diameter of a tumor associated with ovarian cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment is in a range from 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. The pharmaceutical formulation containing a plurality of the nanoparticles is optionally provided in a unit dosage form. The dosage of the nanoparticles in the unit dosage form can be in a range from about 0.01 mg to about 100 mg, from about 0.01 mg to about 90 mg, from about 0.01 mg to about 80 mg, from about 0.01 mg to about 60 mg, from about 0.01 mg to about 50 mg, from about 0.01 mg to about 30 mg, from about 0.01 mg to about 20 mg, from about 0.01 mg to about 10 mg, from about 0.1 mg to about 100 mg, from about 0.2 mg to about 100 mg, from about 0.3 mg to about 100 mg, from about 0.5 mg to about 100 mg, from about 1 mg to about 100 mg, from about 0.3 mg to about 90 mg, from about 0.3 mg to about 80 mg, from about 0.3 mg to about 60 mg, from about 0.3 mg to about 50 mg, from about 0.3 mg to about 30 mg, from about 0.2 mg to about 20 mg, or from about 0.1 mg to about 10 mg. The pharmaceutical formulation containing a plurality of the nanoparticles is optionally provided in a unit dosage form. The dosage of the active agents in the pharmaceutical formulation in the unit dosage form can be in a range from about 5×10 ^-5 µg to about 0.5 µg, from about 5×10 ^-5 µg to about 0.1 µg, from about 5×10 ^-5 µg to about 0.01 µg, from about 5×10 ^-5 µg to about 0.005 µg, from about 5×10 ^-5 µg to about 0.001 µg, from about 5×10 ^-5 µg to about 5×10 ^-4 µg, from about 1×10 ^-4 µg to about 0.5 µg, from about 5×10 ^-4 µg to about 0.5 µg, from about 0.001 µg to about 0.5 µg, or from about 0.01 µg to about 0.5 µg. III. Methods of Using the Nanoparticles A. Treating GnRH- or Gonadotropin-related Disease or Disorder Methods for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related disease or disorder in a subject in need thereof using the pharmaceutical formulations described herein are disclosed. The subject can be a male or female mammal. Generally, the method for treating or ameliorating one or more symptoms associated with the GnRH- or gonadotropin-related disease or disorder, such as a GnRH- or gonadotropin-related cancer, a GnRH- or gonadotropin-related benign tumor (such as a tumor of uterine fibroids), or endometriosis, in a subject in need thereof includes administering to the subject a pharmaceutical formulation containing a plurality of the nanoparticles described above. Optionally, a second active agent that is different from the active agent encapsulated in the nanoparticles is administered to the subject prior to, during, and/or subsequent to step (i) administering the pharmaceutical formulation. The second active agent can be a drug suitable for treating the GnRH- or gonadotropin-related disease or disorder. The amount of the second active agent required will vary from subject to subject according to their need. The pharmaceutical formulation containing a plurality of the nanoparticles can be administered by intramuscular administration, intravenous administration, intraperitoneal administration, or subcutaneous administration, or a combination thereof. 1. Administering an effective amount of the pharmaceutical formulation The step of administering an effective amount of the pharmaceutical formulation can be achieved in a single administration step or using multiple steps of administering the pharmaceutical formulation. For example, if the unit dosage form contains an effective amount of the active agent(s) to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related disease or disorder in the subject, then method only requires a single administration step. Alternatively, if the unit dosage form contains less than the required effective amount of the active agent(s) to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related disease or disorder, in the subject, then the method involves at least two steps of administering the pharmaceutical formulation, and optionally more than two steps of administering the pharmaceutical formulation to the subject until an effective amount of the pharmaceutical formulation is administered to the subject to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related disease or disorder in the subject. When multiple administration steps are needed to administer an effective amount of the pharmaceutical formulation to the patient, each administration step may involve administering the same dosage or different dosages of the pharmaceutical formulation to the patient. When multiple administration steps are needed to administer an effective amount of the pharmaceutical formulation to the patient, the administration steps may be performed regularly or irregularly. For example, the administration steps are performed at a suitable frequency, such as every hour, every 2 hours, every 5 hours, every 8 hours, every day, every 2 days, every 3 days, every 5 days, every 7 days, every 10 days, every two weeks, or every month. For example, the administration step is performed every hour, every 2 hours, every 5 hours, every 8 hours, every day, every 2 days, every 3 days, every 5 days, every 7 days, every 10 days, every two weeks, or every month for a period between one day and 6 months, between one day and 3 months, between one and thirty days, between one and ten days, between one and three days, between one and two days, or for one day. Alternatively, the administration may be performed irregularly, for example, the administration step is performed 1 day after the first administration, then 2 days after the second administration, then 5 days after the third administration, then 7 days after the fourth administration, and then 30 days after the fifth administration. The time interval between administrations is determined based on the patient’s needs. Following one or more steps of administering the pharmaceutical formulation, the pharmaceutical formulation administered to the subject is in an amount effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, renal cancer cells, benign tumor cells such as uterine fibroids tumor cells), and cells in tissues associated with a reproductive tract disorder such as endometriosis), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, and thereby ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related disease or disorder in the subject. Optionally, following one or more steps of administering the pharmaceutical formulation, the pharmaceutical formulation administered to the subject is in an amount effective to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related disease or disorder in a biological sample (blood, urine, feces, or tissues, or a combination thereof) of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample of the subject before treatment. For example, following one or more steps of administering the pharmaceutical formulation, the pharmaceutical formulation administered to the subject is in an amount effective to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related benign tumor (such as a tumor of uterine fibroids) in a biological sample (blood, urine, feces, or tissues, or a combination thereof) of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample of the subject before treatment, and/or to reduce the mean diameter of the tumor in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, optionally where the reduction of the level of the biomarker in the biological sample of the subject and/or the reduction of mean diameter of the tumor in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. Biomarkers suitable for use in the methods for treating or ameliorating one or more symptoms associated with uterine fibroids to evaluate the treatment effect can be any of those described above. For example, following one or more steps of administering the pharmaceutical formulation, the pharmaceutical formulation administered to the subject is in an amount effective to reduce the level of a biomarker associated with a GnRH- or gonadotropin-related disorder (such as endometriosis) in a biological sample (blood, urine, feces, or tissues, or a combination thereof) of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample of the subject before treatment, optionally where the reduction of the level of the biomarker in the biological sample of the subject and the reduction of mean diameter of the tumor in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. Biomarkers suitable for use in the methods for treating or ameliorating one or more symptoms associated with endometriosis to evaluate the treatment effect can be any of those described above. Optionally, the concentration of nanoparticles in the pharmaceutical formulation that is administered to the subject in an effective amount to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related disease or disorder, in the subject is in a range from about 0.1 µg to about 100 µg, from about 0.5 µg to about 50 µg, from about 1 µg to about 100 µg, from about 1 µg to about 50 µg, from about 1 µg to about 25 µg, from about 1 µg to about 10 µg, from about 1 µg to about 5 µg, from about 4 µg to about 10 µg, from about 1 µg to about 4 µg, from about 2 µg to about 100 µg, from about 2 µg to about 50 µg, from about 2 µg to about 25 µg, from about 2 µg to about 10 µg, from about 2 µg to about 5 µg, from about 2 µg to about 4 µg, from about 3 µg to about 100 µg, from about 3 µg to about 50 µg, from about 3 µg to about 25 µg, from about 3 µg to about 10 µg, or from about 3 µg to about 5 µg per g of the subject. 2. Treating Cancer The methods described herein may be methods for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in a subject in need thereof. Typically, the method for treating or ameliorating one or more symptoms associated with the GnRH- or gonadotropin-related cancer in a subject in need thereof follows the method step described above. For example, a pharmaceutical formulation containing a plurality of the nanoparticles described above is administered to the subject. In some embodiments, the method for treating or ameliorating one or more symptoms associated with prostate cancer in a subject in need thereof includes administering to the subject a pharmaceutical formulation containing a plurality of the nanoparticles described above. In some embodiments, the method for treating or ameliorating one or more symptoms associated with ovarian cancer in a subject in need thereof includes administering to the subject a pharmaceutical formulation containing a plurality of the nanoparticles described above. In these embodiments, the pharmaceutical formulation is typically administered in an effective amount to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in the subject. Optionally, the method includes the step of administering a second active agent that is different from the active agent encapsulated in the nanoparticles to the subject prior to, during, and/or subsequent to step (i) administering the pharmaceutical formulation. The second active agent can be an apoptosis inducer, a chemotherapy drug (e.g. doxorubicin) or a combination of two or more chemotherapy drugs described above. The amount of the second active agent required will vary from subject to subject according to their need. The subject can be a male or female mammal. For example, when the method is for treating or ameliorating one or more symptoms associated with prostate cancer, the subject is a male mammal, such as a man, a male dog, a male cat, a male rat, a male monkey, a male rabbit, a male guinea pig, etc., that is in need of being treated for prostate cancer or one or more symptoms associated with prostate cancer. When the method is for treating or ameliorating one or more symptoms associated with ovarian cancer, breast cancer, and/or uterine cancer, the subject is a female mammal, such as a woman, a female dog, a female cat, a female rat, a female monkey, a female rabbit, a female guinea pig, etc., that is in need of being treated for ovarian cancer, breast cancer, and/or uterine cancer or one or more symptoms associated with ovarian cancer, breast cancer, and/or uterine cancer. When the method is for treating or ameliorating one or more symptoms associated with pancreatic cancer and/or renal cancer, the subject can be a male or female mammal, such as those described above, that is in need of being treated for pancreatic cancer and/or renal cancer or one or more symptoms associated with pancreatic cancer and/or renal cancer. a. Administering an Effective Amount of Pharmaceutical Formulation for Treating Cancer The step of administering an effective amount of the pharmaceutical formulation can be achieved in a single administration step or using multiple steps of administering the pharmaceutical formulation as described above. Optionally, the step of administering the pharmaceutical formulation is repeated more than one time, and following all of the steps of administering the formulation, an effective amount of the formulation is administered. For example, if the unit dosage form contains an effective amount of the active agent(s) to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in the subject, then method only requires a single administration step. Alternatively, if the unit dosage form contains less than the required effective amount of the active agent(s) to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in the subject, then the method involves at least two steps of administering the pharmaceutical formulation, and optionally more than two steps of administering the pharmaceutical formulation to the subject until an effective amount of the pharmaceutical formulation is administered to the subject to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in the subject. When multiple administration steps are needed to administer an effective amount of the pharmaceutical formulation to the cancer patient, the dosage involved in each administration step may be the same or different and the frequency of administration can be any of those described above. Optionally, the pharmaceutical formulation administered is in an amount effective to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related cancer being treated (such as any of those described above) in a biological sample (such as blood, urine, feces, tissues, or a combination thereof) of the subject compared to the level of the biomarker in the biological sample of the subject before treatment, and/or reduce the mean diameter of a tumor associated with GnRH- or gonadotropin-related cancer being treated in the subject compared to the mean diameter of the tumor in the subject before treatment. Suitable biomarkers for use in the methods for treating or ameliorating one or more symptoms of a GnRH- or gonadotropin- related cancer to evaluate treatment effect can be any of those described above, such as those for prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, and renal cancer. Optionally, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related cancer (such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof) in a biological sample (blood, urine, feces, or tissues, or a combination thereof) of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample of the subject before treatment, and to reduce the mean diameter of a tumor associated with the GnRH- or gonadotropin-related cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, optionally where the reduction of the level of the biomarker in the biological sample of the subject and the reduction of mean diameter of the tumor in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered in an effective amount to treat or ameliorate one or more symptoms associated with prostate cancer of the subject. For example, the pharmaceutical formulation administered is in an amount effective to reduce the level of a biomarker associated with prostate cancer (such as PSA, a glycoform of PSA, microRNAs, circulating tumor cells, androgen receptor variants, or phosphatase and tensin homolog (PTEN) gene, or a combination thereof) in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment, and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. For example, the pharmaceutical formulation is administered in an effective amount to treat or ameliorate one or more symptoms associated with ovarian cancer of the subject. For example, the pharmaceutical formulation administered is in an amount effective to reduce the level of a biomarker associated with ovarian cancer (such as CA125, CEA, LDH, β-hCG, inhibin B, α-fetoprotein, or HE4, or a combination thereof) in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment, and/or reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. The mean diameter of the tumor associated with the cancer being treated in the subject (prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, and/or renal cancer) can be measured using a non-invasive imaging test, such as transrectal ultrasound, MRI, computerized tomography (“CT”) scan, positron emission tomography (“PET”) imaging, multiparametric ultrasound (“US”), or a combination thereof, for example, PET-CT, PET-MRI, MRI-US, etc. Optionally, the pharmaceutical formulation administered to the subject is in an amount effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or cancer cells that contain receptors for GnRH or gonadotropins (e.g., prostate cancer cells, ovarian cancer cells, pancreatic cancer cells, breast cancer cells, uterine cancer cells, and/or renal cancer cells), reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, and thereby ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related cancer in the subject, optionally without significant side effects, such as damage to skin and hair, infections, paralysis, coma, damages to essential organs such as heart, brain, lung, and kidney, and other side effects associated with surgery and chemotherapy. For example, the pharmaceutical formulation administered to the subject is in an amount effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or prostate cancer cells, reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, and thereby ameliorate one or more symptoms associated with the prostate cancer in the subject, optionally without significant side effects, such as those described above. For example, the pharmaceutical formulation administered to the subject is in an amount effective to kill and/or reduce or prevent growth or proliferation of gonadotroph cells and/or ovarian cancer cells, reduce or prevent secretion of FSH and/or LH, and/or reduce or prevent production of gonadal steroids, such as androgen, and thereby ameliorate one or more symptoms associated with the ovarian cancer in the subject, optionally without significant side effects, such as those described above. Optionally, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment. Optionally, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment, without one or more significant side effects, such as damage to skin and hair, infections, paralysis, coma, damages to essential organs such as heart, brain, lung, and kidney, and other side effects associated with surgery and chemotherapy. For example, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment, where the reduction of the level of the biomarker in the blood of the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following the step of administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, where the reduction of the level of the biomarker in the blood of the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment is administered to the subject, where the reduction of the mean diameter of the tumor associated with prostate cancer in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, where the reduction of the mean diameter of the tumor associated with prostate cancer in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment, within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, and to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, where the reduction of the level of the biomarker in the blood of the subject and the reduction of mean diameter of the tumor in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. Optionally, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment. Optionally, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation is administered to the subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. Optionally, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment, without causing one or more significant side effects, such as infections, paralysis, coma, damages to essential organs such as heart, brain, lung, and kidney, and/or other side effects associated with surgery and chemotherapy. For example, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood ofthe subject compared to the level of the biomarker in the blood of the subject before treatment, where the reduction of the level of the biomarker in the blood of the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following the step of administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, where the reduction of the level of the biomarker in the blood of the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the mean diameter of a tumor associated with ovarian cancer in thesubject compared to the mean diameter of the tumor in the subject before treatment is administered to the subject, where the reduction of the mean diameter of the tumor associated with ovarian cancer in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the mean diameter of a tumor associated with ovarian cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, where the reduction of the mean diameter of the tumor associated with ovarian cancer in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment, within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. For example, the pharmaceutical formulation is administered to a subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the blood of the subject before treatment, and to reduce the mean diameter of a tumor associated with ovarian cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment, where the reduction of the level of the biomarker in the blood of the subject and the reduction of mean diameter of the tumor in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within about 3 months following administration of the pharmaceutical formulation. Optionally, the concentration of nanoparticles in the pharmaceutical formulation that is administered to the subject in an effective amount to treat or ameliorate one or more symptoms associated with the GnRH- or gonadotropin-related cancer, such as prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, in the subject is in a range from about 0.1 µg to about 100 µg, from about 0.5 µg to about 50 µg, from about 1 µg to about 100 µg, from about 1 µg to about 50 µg, from about 1 µg to about 25 µg, from about 1 µg to about 10 µg, from about 1 µg to about 5 µg, from about 4 µg to about 10 µg, from about 1 µg to about 4 µg, from about 2 µg to about 100 µg, from about 2 µg to about 50 µg, from about 2 µg to about 25 µg, from about 2 µg to about 10 µg, from about 2 µg to about 5 µg, from about 2 µg to about 4 µg, from about 3 µg to about 100 µg, from about 3 µg to about 50 µg, from about 3 µg to about 25 µg, from about 3 µg to about 10 µg, or from about 3 µg to about 5 µg per g of the subject. For example, the concentration of nanoparticles in the pharmaceutical formulation administered to the subject in an effective amount to reduce the level of a biomarker associated with prostate cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with prostate cancer in the subject compared to the mean diameter of the tumor in the subject before treatment is in a range from about 1 µg to about 20 µg, from about 2 µg to about 20 µg, from about 1 µg to about 10 µg, from about 2 µg to about 10 µg, from about 1 µg to about 5 µg, from about 2 µg to about 4 µg, from about 3 µg to about 10 µg, about 3 µg to about 5 µg, or from about 4 µg to about 10 µg per g of the subject. For example, the concentration of nanoparticles in the pharmaceutical formulation administered to the subject in an effective amount to reduce the level of a biomarker associated with ovarian cancer in the blood of the subject compared to the level of the biomarker in the blood of the subject before treatment and/or reduce the mean diameter of a tumor associated with ovarian cancer in the subject compared to the mean diameter of the tumor in the subject before treatment is in a range from about 1 µg to about 20 µg, from about 2 µg to about 20 µg, from about 1 µg to about 10 µg, from about 2 µg to about 10 µg, from about 1 µg to about 5 µg, from about 2 µg to about 4 µg, from about 3 µg to about 10 µg, about 3 µg to about 5 µg, or from about 4 µg to about 10 µg per g of the subject. The disclosed nanoparticles, pharmaceutical formulations, and methods of using can be further understood through the following enumerated paragraphs. 1. A plurality of nanoparticles for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related disease and/or disorder, wherein the nanoparticles comprise a cage, a surface modifying agent, a targeting ligand, and an active agent, wherein the surface modifying ligand is attached to the outer surface of the cage and wherein the targeting ligand exposed to the surrounding environment, and wherein the active agent is encapsulated in the cage. 2. The plurality of nanoparticles of paragraph 1, wherein the cage is a zeolitic imidazolate framework (“ZIF”), and wherein the ZIF comprises a metal ion selected from the group consisting of Zn ⁺ , Zn ²⁺ , Pd ²⁺ , Pd ⁴⁺ , Pt ²⁺ , Pt ⁴⁺ , Ni ⁺ , Ni ²⁺ , Ni ³⁺ , Mn ²⁺ , Mn ³⁺ , Mn ⁴⁺ , Mn ⁶⁺ , Mn ⁷⁺ , Co ²⁺ , Co ³⁺ , Cu ²⁺ , Cd ²⁺ , Fe ²⁺ , Fe ³⁺ , and Ti ⁴⁺ . 3. The plurality of nanoparticles of paragraph 2, wherein the ZIF comprises imidazolate functionalized with amine, hydroxyl, thiol, aldehyde, or carboxyl, or a combination thereof. 4. The plurality of nanoparticles of paragraph 2 or 3, wherein the ZIF is ZIF-2, ZIF-3, ZIF- 4, ZIF-8, ZIF-10, ZIF-11, ZIF-12, ZIF-14, ZIF-20, ZIF-21, ZIF-60, ZIF-61, ZIF-62, ZIF-64, ZIF-65, ZIF-66, ZIF-67, ZIF-68, ZIF-69, ZIF-70, ZIF-71, ZIF-72, ZIF-73, ZIF-74, ZIF-75, ZIF- 76, ZIF-77, ZIF-78, ZIF-81, ZIF-82, ZIF-90, ZIF-91, ZIF-92, ZIF-95, or ZIF-100. 5. The plurality of nanoparticles of any one of paragraphs 1-4, wherein at least 20 wt% (weight of the surface modifying agent conjugated to the targeting ligand/total weight of the surface modifying agent attached to the cage), at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, in a range from 20 wt% to 100 wt%, from 30 wt% to 100 wt%, or from 40 wt% to 100 wt% of the surface modifying agent is conjugated to the targeting ligand. 6. The plurality of nanoparticles of any one of paragraphs 1-5, wherein the end of the surface modifying agent that is attached to the cage comprises a chemical moiety containing one or more negative charges. 7. The plurality of nanoparticles of paragraph 6, wherein the chemical moiety is folate, L- methylfolate, or glutamate, or a combination thereof. 8. The plurality of nanoparticles of any one of paragraphs 1-7, wherein the surface modifying agent comprises a polymer backbone selected from the group consisting of polyalkylene glycol, polylactic acid, polyglycolic acid, poly(lactic-co-glycolic acid), polyanhydrides, poly(ortho)esters, polyurethanes, poly(butyric acid), poly(valeric acid), poly(lactide-coaprolactone), and polyethylenimine, and a copolymer thereof. 9. The plurality of nanoparticles of paragraph 8, wherein the polymer backbone of the surface modifying agent is polyethylene glycol. 10. The plurality of nanoparticles of paragraph 8 or 9, wherein the polymer backbone has a molecular weight in a range from about 1 kDa to about 10 kDa, from about 2 kDa to about 10 kDa, from about 3 kDa to about 10 kDa, from about 4 kDa to about 10 kDa, from about 1 kDa to about 9 kDa, from about 2 kDa to about 9 kDa, from about 3 kDa to about 9 kDa, from about 4 kDa to about 9 kDa, from about 1 kDa to about 8 kDa, from about 2 kDa to about 8 kDa, from about 3 kDa to about 8 kDa, from about 4 kDa to about 8 kDa, from about 1 kDa to about 7 kDa, from about 2 kDa to about 7 kDa, from about 3 kDa to about 7 kDa, from about 4 kDa to about 7 kDa, from about 1 kDa to about 6 kDa, from about 2 kDa to about 6 kDa, from about 3 kDa to about 6 kDa, or from about 4 kDa to about 6 kDa. 11. The plurality of nanoparticles of any one of paragraphs 1-10 having an average diameter in a range from about 10 nm to about 100 nm, from about 10 nm to about 90 nm, from about 10 nm to about 80 nm, from about 20 nm to about 100 nm, from about 20 nm to about 90 nm, from about 20 nm to about 80 nm, from about 30 nm to about 100 nm, from about 30 nm to about 90 nm, or from about 30 nm to about 80 nm. 12. The plurality of nanoparticles of any one of paragraphs 1-11, wherein the surface density of the surface modifying agent (“SMA”) on the surface of the nanoparticle is at least 1 SMA/nm ² , at least 5 SMA/nm ² , at least 7 SMA/nm ² , at least 10 SMA/nm ² , at least 15 SMA/nm ² , at least 20 SMA/nm ² , at least 25 SMA/nm ² , at least 30 SMA/nm ² , at least 35 SMA/nm ² , at least 40 SMA/nm ² , at least 45 SMA/nm ² , or at least 50 SMA/nm ² . 13. The plurality of nanoparticles of any one of paragraphs 1-12, wherein the targeting ligand is a gonadotropin-releasing hormone (“GnRH”) agonist, a GnRH antagonist, a follicle stimulating hormone (“FSH”) receptor agonist, a FSH receptor antagonists, a luteinizing hormone (“LH”) receptor agonist, or a LH receptor antagonist, or a combination thereof. 14. The plurality of nanoparticles of any one of paragraphs 1-13, wherein the targeting ligand is selected from the group consisting of buserelin, azagly-naflorein, deslorelin, fertirelin, gonadorelin, goserelin, histrelin, lecirelin, leuprorelin, nafarelin, peforelin, triptorelin, leuprolide acetate, abarelix, cetorelix, degarelix, elagolix, ganirelix, linzagolix, relugolix, thiazolidinone compound 5, hexahydroquinoline derivative Org 214444-0, thienopyrimidine derivatives, such as thienopyrimidine derivative Org 43553, 5-amino-N-(tert-butyl)-4-(3- (isonicotinamido)phenyl)-2-(methylthio)thieno-[2,3-d]pyrimid ine-6-carboxamide, 5-amino-N- (tert-butyl)-2-(methylthio)-4-(3-(thiophene-3-carboxamido)ph enyl thieno[2,3-d]pyrimidine-6- carboxamide, 5-amino-N-(tert-butyl-2-(methylsulfonyl)-4-(3-(nicotinamido) phenyl)thieno[2,3- d]pyrimidine-6-carboxamide, 5-amino-N-(tert-butyl-4-(3-(1-methyl-1H-pyrazole-4- carboxamido)phenyl)-2-(methylsulfanyl)thieno[2,3-d]pyrimidin e-6-carboxamide, 5-amino-N- (tert-butyl)-4-(3-(2-metoxynicotinamido)phenyl)-2-(methylthi o)thieno[2,3-d]pyrimidine-6- carboxamide, 4-((3-(5-amino-6-(tert-butylcarbamoyl)-2-(methylthio)thieno[ 2,3-d]pyrimidine-4- il)phenyl)carbamoyl)pyridine 1-oxide, and 5-amino-N-(tert-butyl)-4-(3-(2- chloronicotinamido)phenyl)-2-(methylthio)thieno[2,3-d]pyrimi dine-6-carboxamide; diketopiperazines, and m-dihydropyridine, and deglycosylated human chorionic gonadotropins, or a combination thereof. 15. The plurality of nanoparticles of any one of paragraphs 1-14, wherein the targeting ligand is buserelin. 16. The plurality of nanoparticles of any one of paragraphs 1-15, wherein the active agent is a ribosome inactivating protein, an apoptosis-inducer, a hormone, a receptor ligand, a nucleic acid, or a chemotheraphy drug, or a combination thereof. 17. The plurality of nanoparticles of ay one of paragraphs 1-16, wherein the active agent is saporin, gelonin, or a pokeweed antiviral protein, or a combination thereof. 18. The plurality of nanoparticles of any one of paragraphs 1-16, wherein the active agent is doxorubicin. 19. A pharmaceutical formulation comprising the plurality of nanoparticles of any one of paragraphs 1-18 and a pharmaceutically acceptable carrier and/or excipient. 20. The pharmaceutical formulation of paragraph 19, wherein the pharmaceutical formulation comprises an effective amount of the nanoparticles to treat or ameliorate one or more symptoms associated with a GnRH- or gonadotropin-related disease or disorder in a subject in need thereof. 21. The pharmaceutical formulation of paragraph 20, wherein the GnRH- or gonadotropin- related disease or disorder is a GnRH- or gonadotropin-related cancer, a GnRH- or gonadotropin-related benign tumor, or endometriosis, optionally wherein the GnRH- or gonadotropin-related cancer is prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, and optionally wherein the GnRH- or gonadotropin-related benign tumor is a tumor of uterine fibroids. 22. The pharmaceutical formulation of paragraph 20 or 21, wherein the effective amount of the nanoparticles is effective to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related disease or disorder in a biological sample of the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the level of the biomarker in the biological sample of the subject before treatment. 23. The pharmaceutical formulation of paragraph 22, wherein the biological sample is blood, urine, feces, or tissues, or a combination thereof.24. The pharmaceutical formulation of any one of paragraphs 20-23, wherein the GnRH- or gonadotropin-related disease or disorder is prostate cancer, and wherein the biomarker associated with prostate cancer is prostate specific antigen (“PSA”), a glycoform of PSA, microRNAs, circulating tumor cells, androgen receptor variants, or PTEN gene, or a combination thereof. 25. The pharmaceutical formulation of any one of paragraphs 20-24, wherein the GnRH- or gonadotropin-related disease or disorder is prostate cancer, and wherein the effective amount of the nanoparticles is effective to reduce the mean diameter of a tumor associated with prostate cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. 26. The pharmaceutical formulation of any one of paragraphs 20-23, wherein the GnRH- or gonadotropin-related disease or disorder is ovarian cancer, and wherein the biomarker associated with ovarian cancer is CA125, CEA, LDH, β-hCG, inhibin B, α-fetoprotein, or HE4, or a combination thereof. 27. The pharmaceutical formulation of any one of paragraphs 20-23 and 26, wherein the GnRH- or gonadotropin-related disease or disorder is ovarian cancer, and wherein the effective amount of the nanoparticles is effective to reduce the mean diameter of a tumor associated with ovarian cancer in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. 28. The pharmaceutical formulation of any one of paragraphs 20-27, wherein the GnRH- or gonadotropin-related disease or disorder is a tumor of uterine fibroids, and wherein the biomarker associated with uterine fibroids is CA125, LDH, or IGF-1, or a combination thereof. 29. The pharmaceutical formulation of any one of paragraphs 20-23 and 28, wherein the GnRH- or gonadotropin-related disease or disorder is a tumor of uterine fibroids, and wherein the effective amount of the nanoparticles is effective to reduce the mean diameter of the tumor associated with uterine fibroids in the subject by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30% compared to the mean diameter of the tumor in the subject before treatment. 30. The pharmaceutical formulation of any one of paragraphs 19-29, wherein the concentration of the active agent in the pharmaceutical formulation is in a range from about 0.000001 wt% to 20 wt%, from about 0.000005 wt% to 20 wt%, from about 0.00001 wt% to 20 wt%, from about 0.00005 wt% to 20 wt%, from about 0.0001 wt% to 20 wt%, from about 0.0005 wt% to 20 wt%, from about 0.001 wt% to 20 wt%, from about 0.000001 wt% to 10 wt%, from about 0.000005 wt% to 10 wt%, from about 0.00001 wt% to 10 wt%, from about 0.00005 wt% to 10 wt%, from about 0.0001 wt% to 10 wt%, from about 0.0005 wt% to 10 wt%, from about 0.001 wt% to 10 wt%, from about 0.000001 wt% to 5 wt%, from about 0.000005 wt% to 5 wt%, from about 0.00001 wt% to 5 wt%, from about 0.00005 wt% to 5 wt%, from about 0.0001 wt% to 5 wt%, from about 0.0005 wt% to 5 wt%, from about 0.001 wt% to 5 wt%, from about 0.000001 wt% to 2 wt%, from about 0.000005 wt% to 2 wt%, from about 0.00001 wt% to 2 wt%, from about 0.00005 wt% to 2 wt%, from about 0.0001 wt% to 2 wt%, from about 0.0005 wt% to 2 wt%, from about 0.001 wt% to 2 wt%, from about 0.000001 wt% to 0.5 wt%, from about 0.000005 wt% to 0.5 wt%, from about 0.00001 wt% to 0.5 wt%, from about 0.00005 wt% to 0.5 wt%, from about 0.0001 wt% to 0.5 wt%, from about 0.0005 wt% to 0.5 wt%, from about 0.001 wt% to 0.5 wt%, from about 0.000001 wt% to 0.2 wt%, from about 0.000005 wt% to 0.2 wt%, from about 0.00001 wt% to 0.2 wt%, from about 0.00005 wt% to 0.2 wt%, from about 0.0001 wt% to 0.2 wt%, from about 0.0005 wt% to 0.2 wt%, from about 0.001 wt% to 0.2 wt%, from about 0.000001 wt% to 0.05 wt%, from about 0.000005 wt% to 0.05 wt%, from about 0.00001 wt% to 0.05 wt%, from about 0.00005 wt% to 0.05 wt%, from about 0.0001 wt% to 0.05 wt%, from about 0.0005 wt% to 0.05 wt%, from about 0.001 wt% to 0.05 wt%, from about 0.000001 wt% to 0.02 wt%, from about 0.000005 wt% to 0.02 wt%, from about 0.00001 wt% to 0.02 wt%, from about 0.00005 wt% to 0.02 wt%, from about 0.0001 wt% to 0.02 wt%, from about 0.0005 wt% to 0.02 wt%, from about 0.001 wt% to 0.02 wt%, from about 0.000001 wt% to 0.005 wt%, from about 0.000005 wt% to 0.005 wt%, from about 0.00001 wt% to 0.005 wt%, from about 0.00005 wt% to 0.005 wt%, from about 0.0001 wt% to 0.005 wt%, from about 0.0005 wt% to 0.005 wt%, from about 0.000001 wt% to 0.002 wt%, from about 0.000005 wt% to 0.002 wt%, from about 0.00001 wt% to 0.002 wt%, from about 0.00005 wt% to 0.002 wt%, from about 0.0001 wt% to 0.002 wt%, or from about 0.0005 wt% to 0.002 wt%. 31. The pharmaceutical formulation of any one of paragraphs 19-28, wherein the pharmaceutical formulation is in a unit dosage form, and wherein the dosage of the active agent is in a range from about 5×10 ^-5 µg to about 0.5 µg, from about 5×10 ^-5 µg to about 0.1 µg, from about 5×10 ^-5 µg to about 0.01 µg, from about 5×10 ^-5 µg to about 0.005 µg, from about 5×10 ^-5 µg to about 0.001 µg, from about 5×10 ^-5 µg to about 5×10 ^-4 µg, from about 1×10 ^-4 µg to about 0.5 µg, from about 5×10 ^-4 µg to about 0.5 µg, from about 0.001 µg to about 0.5 µg, or from about 0.01 µg to about 0.5 µg. 32. The pharmaceutical formulation of any one of paragraphs 19-29, wherein the pharmaceutical formulation is in a form suitable for intramuscular administration, intravenous administration, intraperitoneal administration, or subcutaneous administration, or a combination thereof. 33. A method for treating or ameliorating one or more symptoms associated with a GnRH- or gonadotropin-related disease or disorder in a subject in need thereof comprising (i) administering to the subject the pharmaceutical formulation of paragraph 19, wherein step (i) occurs one or more times. 34. The method of paragraph 33, wherein the GnRH- or gonadotropin-related disease or disorder is a GnRH- or gonadotropin-related cancer, a GnRH- or gonadotropin-related benign tumor, or endometriosis. 35. The method of paragraph 33 or 34, wherein the method comprises only a single administration of the pharmaceutical formulation. 36. The method of paragraph 35, wherein the pharmaceutical formulation comprises an effective amount of the nanoparticles to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related disease or disorder in a biological sample of the subject compared to the level of the biomarker in the biological sample of the subject before treatment. 37. The method of any one of paragraphs 35 or 36, wherein the GnRH- or gonadotropin- related disease or disorder is a GnRH- or gonadotropin-related cancer, and wherein the pharmaceutical formulation comprises an effective amount of the nanoparticles to reduce the mean diameter of a tumor associated with the cancer in the subject compared to the mean diameter of the tumor in the subject before treatment. 38. The method of any one of paragraphs 35 or 36, wherein the GnRH- or gonadotropin- related disease or disorder is a GnRH- or gonadotropin-related benign tumor, and wherein the pharmaceutical formulation comprises an effective amount of the nanoparticles to reduce the mean diameter of the tumor in the subject compared to the mean diameter of the tumor in the subject before treatment. 39. The method of paragraph 33 or 34, wherein the method comprises more than one step of administering to the subject the pharmaceutical formulation. 40. The method of paragraph 39, wherein following all of the administration steps an effective amount of the nanoparticles to reduce the level of a biomarker associated with the GnRH- or gonadotropin-related disease or disorder in a biological sample of the subject compared to the level of the biomarker in the biological sample of the subject before treatment. 41. The method of paragraph 39 or 40, wherein the GnRH- or gonadotropin-related disease or disorder is a GnRH- or gonadotropin-related cancer, and wherein the pharmaceutical formulation comprises an effective amount of the nanoparticles to reduce the mean diameter of a tumor associated with the cancer in the subject compared to the mean diameter of the tumor in the subject before treatment is administered to the subject. 42. The method of paragraph 39 or 40, wherein the GnRH- or gonadotropin-related disease or disorder is a GnRH- or gonadotropin-related benign tumor, and wherein the pharmaceutical formulation comprises an effective amount of the nanoparticles to reduce the mean diameter of the tumor in the subject compared to the mean diameter of the tumor in the subject before treatment is administered to the subject. 43. The method of any one of paragraphs 33 to 42, wherein the subject is a mammal. 44. The method of any one of paragraphs 36-38 and 40-43, wherein the biological sample is blood, urine, feces, or tissues, or a combination thereof. 45. The method of any one of paragraphs 33 to 44, wherein in step (i) the pharmaceutical formulation is administered by intramuscular administration, intravenous administration, intraperitoneal administration, or subcutaneous administration, or a combination thereof. 46. The method of any one of paragraphs 33 to 45, wherein during step (i), the dosage of the nanoparticles in the pharmaceutical formulation is from about 0.1 µg to about 100 µg, from about 0.5 µg to about 50 µg, from about 1 µg to about 100 µg, from about 2 µg to about 100 µg, from about 3 µg to about 100 µg, from about 2 µg to about 50 µg, from about 2 µg to about 25 µg, from about 2 µg to about 10 µg, from about 2 µg to about 5 µg, from about 3 µg to about 50 µg, from about 3 µg to about 25 µg, from about 3 µg to about 10 µg, or from about 3 µg to about 5 µg per g of the subject. 47. The method of any one of paragraphs 36-38 and 40-46, wherein the reduction of the level of the biomarker in the biological sample of the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within 3 months, following step (i). 48. The method of any one of paragraphs 37, 38, and 41-47, wherein the reduction of the mean diameter of the tumor in the subject occurs within about 8 days, within about 10 days, within about 12 days, within about 14 days, within about 1 month, or within 3 months, following step (i). 49. The method of any one of paragraphs 33-48, wherein the method further comprises administering a second active agent to the subject prior to, during, or subsequent to step (i). 50. The method of any one of paragraphs 34-49, wherein the cancer is prostate cancer, ovarian cancer, pancreatic cancer, breast cancer, uterine cancer, or renal cancer, or a combination thereof, optionally wherein the cancer is prostate cancer or ovarian cancer. 51. The method of any one of paragraphs 34-50, wherein the benign tumor is a tumor of uterine fibroids. The present invention will be further understood by reference to the following non-limiting examples. Examples Example 1. Structure and properties of exemplary organic nanoparticles Material and Methods Preparation of GnRH nanoparticles There are four major steps in the preparation of GnRH nanoparticles [BUS-PEG-(CF647- SAP@ZIF)]. They are as follows: (1) conjugation of CF647-SAP; (2) conjugation of BUS-PEG- FA; (3) synthesis of CF647-SAP@ZIF; (4) prepare BUS-PEG-(CF647-SAP@ZIF). (1) Conjugation of the dye CF647 with Saporin (SAP) The conjugation of CF647-SAP was accomplished by dissolving 1 mg SAP in 1 mL of 0.1 M sodium bicarbonate buffer (pH 8.3) and 52.4 µl 10 mM CF647 succinimidyl ester dyes in DMSO to react for 1 hour at room temperature. The purified conjugation of CF647-SAP was obtained by using ultrafiltration devices (Amicon Ultra-2 Centrifugal Filter Unit) and the concentration was characterized by UV-Vis absorbance spectrometer (Shimadzu UV-2450). (2) Conjugation of buserelin (BUS) to PEG-FA The conjugation of BUS-PEG-FA was obtained by reacting 10 mg BUS and 50 mg FA- PEG-NHS in PBS buffer (pH = 7.4) for 1h. The conjugation of BUS-PEG-FA was purified by ultrafiltration devices (Amico Ultra-15 Centrifugal Filter Unit), and then freeze-dried under vacuum. (3) Synthesis of CF647-SAP@ZIF CF647-SAP@ZIF nanoparticles were synthesized via rapid pouring 0.5875 g Zinc nitrate hexahydrates (in 4 g water) into an aqueous solution containing 11.35 g 2-methylimidazole, 722 µg CF647-SAP and 40 g water to form CF647-SAP@ZIF nanoparticles 30 min after the reaction at room temperature. The product was washed and collected by centrifugation. (4) Preparation of BUS-PEG-(CF647-SAP@ZIF) 100 mg of the as-synthesized CF646-SAP@ZIF nanoparticles was dispersed in 10 mg/mL BUS-PEG−FA water solution, and then stirred for 48 h under room temperature. Then the BUS-PEG-(CF647-SAP@ZIF) product was collected by centrifugation, and then freeze- dried under vacuum for long-term storage. The resulting BUS-PEG-modified ZIF nanoparticles containing the dye CF647 and active agent, saporin, encapsulated therein are referred to in the Examples as “GnRH nanoparticles” or “GnRH NPs”. Morphology and Fluorescence of GnRH Nanoparticles The size of the nanoparticles was determined using scanning electron microscopy. The morphology of the ZIF NPs was assessed using a field emission gun scanning electron microscope (FEG-SEM, FEI Inspect F). Fluorescent properties of ZIF, ZIF with CF647 and saporin encapsulated therein, and BUS-PEG-modified ZIF with CF647 and SAP encapsulated therein (“GnRH NP”) were analyzed using a Horiba FluoroLog-3 spectrofluorometer (Horiba Scientific, Edison, NJ, USA) equipped with a 450-W xenon arc lamp, a photomultiplier tube (measurement range, 240–850 nm). Purity of GnRH NPs Core bulk samples prepared for X-ray diffraction (XRD) were air-dried and powdered for random particle orientation and mounting as a pressed powder. Sample was ground briefly with mortar and pestle. XRD patterns were collected using a Bruker D8 Advance diffractometer. Instrument conditions included using CoKα radiation (generated at 35 kV and 40 mA), 217.5 mm goniometer radius, 0.6 mm primary slit, Fe-filter, and a Lynx-Eye position sensitive solid- state detector. XRD scan parameters were run at 0.3 s/step in 0.01 °2θ step increments. Data was processed using Bruker Eva software, which includes background correction, Kα2 stripping and peak d-spacing and intensity assignments. The peak file generated from the peak search was compared to the International Center for Diffraction Data (ICDD) Powder Diffraction File (PDF- 4+ 2018). Results Figure 1A shows the components of the exemplary organic nanoparticle before assembling. As shown in Figures 1A, each organic nanoparticle contains a ZIF cage made from Zn ²⁺ and imidazole, folic acid (“FA”) conjugated PEG, FA and buserelin (“BUS”) conjugated PEG, an active agent (i.e. saporin), and optionally dye molecules (i.e. CF647). Figure 1B shows the structure of an assembled GnRH nanoparticle. Figure 1C shows the structure of an assembled GnRH nanoparticles that does not include a dye molecule. As shown in Figure 1B, the surface of the ZIF cage is tagged with Buserelin, a drug that acts as a GnRH agonist. Buserelin binds to receptors that are present on gonadotrophs in the pituitary. Saporin, which is a ribosome inactivating protein, and CF647 are encapsulated in the core of the organic nanoparticle. Figures 1A and 1B are schematics of the different components in each organic nanoparticle (the components are not shown to scale). As shown in Figure 2, the sizes of GnRH nanoparticles are between 60 nm and 130 nm (including PEG). As shown in Figures 3A and 3B, the GnRH nanoparticles emit light (shown in dashed lines) with a maximum intensity at about 665 nm, when excited at two different wavelengths, i.e.600 nm (Figure 3A) and 645 nm (Figure 3B), demonstrating the formation of the nanoparticles. Additionally, as shown in Figure 4, XRD analysis of the GnRH nanoparticles shows that the patterns are 91% matches to PDF#00-066-0916 as ZIF-90 crystal structure. Example 2. The GnRH nanoparticles inhibit pituitary cell viability. Materials and Methods Solutions of GnRH nanoparticles in PBS were tested in RC4B/C pituitary cells. Pituitary cells were plated into a 96-well plate at the density of 3×10 ⁵ cells/cm ² and cultured in vitro in complete medium under standard conditions (i.e.37°C, 5% CO ₂ , 95% humidity) for 3 days. They were exposed to varying concentrations of the GnRH nanoparticles or an unconjugated ZIF nanoparticle for 1 hour, and then medium was refreshed (to remove the nanoparticles) and the cells were in culture for the following 3 days before being used in the MTT assay. The unconjugated ZIF nanoparticle contains all the elements of the GnRH nanoparticles expect for BUS. The concentrations of each nanoparticle-containing solution were 2, 5, 10, 25, 50, 75, and 100 µg/mL. At the end of this period, the cells were subjected to an MTT assay (Cat No.30- 1010K, ATCC) to measure cell viability. Results Solutions containing 25µg/ml or more of the GnRH nanoparticles, resulted in 23-28% inhibition of growth of RC4B/C pituitary cells, demonstrating that the GnRH nanoparticles affect about 25% of the cell population that accounts for FSH and LH producing cells (Figure 5). Example 3. The GnRH nanoparticles decrease prostate cancer cell viability compared to RC4B/C cells Materials and Methods Solutions of GnRH nanoparticles in PBS were tested in DU145 prostate cancer cells (ATCC-HTB-81) and RC4B/C pituitary adenoma cells (ATCC-CRL-1903). DU145 cells were plated into a 96-well plate at the density of 5000 cells/well and cultured in vitro in complete growth medium under standard conditions (i.e.37°C, 5% CO2, 95% humidity) overnight. RC4B/C cells were cultured at 3×10 ⁵ cells/cm ² for 3 days. The extent of GnRH receptor expression was different between the two cell lines. While 95% of DU145 cells expressed the GnRH receptor, only 20-25% of RC4B/C cells expressed the GnRH receptor. They were exposed to varying concentrations of the GnRH nanoparticles for 4 hours and 1 hour for DU145 and RC4B/C cells respectively. The concentrations of nanoparticle-containing solutions were 2, 5, 10, 25, 50, 75, and 100 µg/mL respectively. At the end of the incubation period, the medium was refreshed (to remove the nanoparticles) and the cells were in culture for the following 3 days before being used in the MTT assay (Cat No.30-1010K, ATCC) for measuring cell viability. . Results There was a difference in the extent of cell death in the two cell lines which was directly proportional to the level of expression of GnRH receptors. While RC4B/C cells, which express GnRH receptor at ~25%, resulted in 23-28% inhibition, DU145 cells, which express GnRH receptors in 95% of the cells, had about 95% inhibition. The doses at which inhibition was achieved were also different. A much lower dose (25µg/mL) was required to inhibit ~25% of the RC4B/C cells, while it took 100µg/mL of the GnRH nanoparticles to inhibit ~95% of the DU145 cells (Figure 6).