USING THE SAME

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of priority of United States Provisional Patent

Application No. 61/980,414, filed April 16, 2014, which is incorporated herein, by reference in its entirety,

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

This invention was made with United States government support awarded by the National institutes of Health grant number R56A1093900. The United States has certain rights in this invention.

BACKGROUND

Nucleic acids are released from dead and dying ceils. These extracellular nucleic acids

(RNAs and DMAs) can be take up by immune cells that release inflammatory signals and can activate multiple Pattern Recognition Receptors (PRR) such as the Toll-Like Receptors (TLRs 3, 7, 8 and 9 in particular), which are localized in endosomes ( awai and Afcira, Nat. Immunol. 11(5):373»84 (2010)). The inappropriate activation of these TLRs can elicit a variety of inflammatory and autoimmune diseases, for example, systemic lupus erythematosus, rheumatoid arthritis, .multiple sclerosis, diabetes and chronic wounds.

it has been previously reported that certain nucleic acid-binding molecules (e.g.,

PAMAM-G3, CDP, HDMBr, protamine, polyethylenimine) can inhibit activation of nucleic acid-sensing PRRs, irrespective of whether they recognize ssR A, dsRNA or hypometbylated DNA (Lee et al, Proc, Natl. Acad. Set. USA 108(34); 14055-60 (201 1 )). Means of using these nucleic acid binding molecules to inhibit aberrant inflammation without compromising immune responsiveness systemica y are needed in the art.

In addition, bio.films often form in wound sites causing persistent inflammation and infection. These biofUms reduce the ability of the wound to heal. Means of reducing the ability of .microorganisms to form biofilms are also needed. Methods of inhibiting the ability of microorganisms to grow in wound sites or in or on medical devices are also needed. SUMMARY

Compositions comprising polycationic nanofibers, methods of making and methods of using the same are provided herein,

Polycationic nanofibers may be made by electrospinning a neutral poly mer with an acyl, anhydride or carbox l. group to form nanofibers with diameters of less than 2p.m. and grafting the a cationic polymer, such as an amine containing polymer, onto the nanofibers to allow covalent bonds to form via an amide covalent linkage to generate polycationic nanofibers.

Compositions comprising the polycationic nanofibers are also provided. These polycationic nanofibers may be incorporated into medical devices, used in filtration units, cut into pieces for direct addition to a solution or use in a medical device or used as a dressing for a wound or at a site of inflammation or infection.

The polycationic nanofibers may be used by adding the nanofibers to a solution or contacting the nanofibers with a solution to scavenge or adsorb anionic compounds or microbes in the solution. The interaction with the nanofibers can prevent microbes .from forming biofilms. The anionic compounds may be nucleic acid mediators of inflammation.

In another alternative, the polycationic nanofibers may be administered to a subject in need of treatment for inflammation or reversing the effects of an anti-coagulant such as heparin. The polyc tionic nanofibers adsorb anionic inflammatory mediators thus reducing inflammation. The nanofibers may also inhibit the growth of microbes and/or inhibit die formation of biofilms.

In yet another aspect, the poly cationic nanofibers are useful in medicaments for treating inflammatio or infections wound healing.

BRIEF DESCRIPTION ^* OF THE DRAWINGS

Figure 1 is a schematic showing the polymers used and the method of maki ng the polycationic nanofibers provided in the Examples.

Figure 2 is a set of photographs showing the scanning electron micrograph (SEM) i mages of the 100% polycationic nanofibers (100% poly-styrene maleic anhydride (PSMA) eiectrospim nanofibers with. 1.8 kDa branched polyethyienetmine (bPEI) covalentiy attached at two different levels of magn ification. The d iameters of the fibers are shown in the photograph.

Figure 3 is a set of photographs showing the scanning electron micrograph (SEM ) images of the 60% polycationic nanofibers (60% PSMA nanofibers with covalentiy attached 1.8 kDa bPEi) at two different levels of nrngnificatiotL The diameters of the fibers are shown in the photograph.

Figure 4 is a set of graphs showing the affect of the nanofibers on cells. Figure 4A is a graph showing the percentage cell viability after addition of the indicated nanofibers for 4 hours to adherent cells (fibroblasts; STO cells) and non-adherent (B lymphoma ceils; Ramos-blue). Figure 4B shows that the nanofibers do not inhibit proliferation by showing an increase in the percentage of live NBDF cells (normal human dermal fibroblasts) from 24 to 48 hours.

Figure 5 is a set of data showing the nanofibers and the ability of the nanofibers to bind CpG and DNA. Figure 5.A is an SEM image of neutral PSMA nanofibers. Figure S B is an SEM image of 1.SkDa modified PSMA nanofibers. Figure 5C (left) is a set of fluorescent microscope images of polycationic nanofibers after 4hrs interaction with varying concentrations of

AlexaFl«or48S-CpG. The .right side of Figure 5C shows a graph quantifying the average fluorescence after interaction with AlexaFluor488-CpG normalized to auto-fluorescence of polycationic nanoiiber alone, with the x axis indicating the initial amount of ASexaPiuor4S8-CpG added. Figure 5D is a graph showing salmon sperm DNA absorption onto the polycationic nanoiiber. Figure 5E is a set of SEM images of polycationic nanofibers following interaction with salmon sperm DNA.

Figure 6 is a graph showing that the polycationic nanofibers can block NF-KB expression caused by TLR activation by CpG whereas neutral nanofibers do not effectively block TLR activation by CpG therefore yielding high levels ofNF-κΒ.

Figure 7 is a set of SEM photographs showing the polycationic nanofibers made from 100% PSMA before (left) and after (right) interaction with CpG.

Figure 8 is a graph compar ing the F-κΒ expression following TLR ac ti vation of cells after incubation with the indicated stimulators and with or without the indicated nanofibers. 6% nanofibers are made with 60% (w/v) neutral polymer and 10% nanofibers are made with 100% (w/v) neutral polymer.

Figure 9 is a set. of drawings showing the structure of the stimulators used and a graph comparing the F- Β activation in cells after incubation with, the indicated stimulators and either no nanofibers or the indicated nanofibers. 6% nanofibers are made with 60% (w/v) neutral polymer and .1 % nanofibers are made with .100% (w/v) neutral polymer. Figure 10 is a graph showing the NF-t B expression in cells co-incubated with the indicated stimulators and polycationic nanofibers for 4 hours, followed by removal of the polycationic nanofibers; NF- Β expression was determined 16hrs after polycationic nanof!ber removal The data demonstrate the polycationic nanofibers were able to scavenge and remove the nucleic acid stimulators and prevent NF- Β induction in the presence of cells.

Figure 1 1 is a graph showing that similar results were obtained using PAMAM as the catioiMC polymer and in the presence of serum.

Figure 12 is a graph showing that similar results were obtained using PAMAM as the cationic polymer and in the presence of serum.

Figure 13 is a graph showing the ability of the polycationic nanofibers to block secreted alkaline phosphatase production from Ramos-blue cells which contain a NF- Β -alkaline phosphatase reporter construct Initial DOX dose to Raw cells describes the amount of DOX used to treat Raw cells 48 hrs prior to using the Raw cell debris for activation of the Ramos-blue cells. Polycationic nanofiber blocking demonstrates the polycationic nanofiber s ability to prevent NF-κΒ production by scavenging immune stimulating cell debris from the media.

Figure 14 is a set of scanning electron micrograph photographs showing the polycationic nanofibers and their interaction with Pseudomonas aeruginosa. Figure 14A is an SEM showing polycationic nanofibers which were not exposed to bacteria. Figure 148 is an SE showing Pseudomonas aeruginosa bacteria and biofilm infiltrating the polycationic nanofibers. Figure 14C and Figure 14D show SEM at two different magnifications of the Psemiomomis aeruginosa bacteria biofilm growth on the surface of the polycationic nanofibers.

Figure 15 is a graph showing polycationic nanofibers pre\>ent Pseudomonas aeruginosa biofilm formation after 481irs. 3mm and 4mm indicate the diameter of the circular polycationic nanofiber mesh used in the experiment.

Figure 16 is a set of SEM images showing polycationic nanofibers and their intereatton with Staphylococcus aureus. Figure 16A and Figure 1 B show wild-type Staphylococcus aureus after 48 hours incubation at 37°C with the polycationic nanofibers. Figure 16C and Figure 16D show coagulase negative Staphylococcus aureus on polycationic nanofibers after 48hrs incubation at 37*C. Figure 17 is a graph showing the effect of polycationic nan.ofibe.rs on S, aureus and coagulase negative S. aureus bacterial cell growth as represented by Colony Forming Units

(CFUs). The * represent statistical significance of p< 0.05 as compared to untreated. DETAILED DESCRIPTION

The present invention results, at least in part, from studies designed to develop non-toxic, nucleic acid-binding polymers that form stable polyplex.es with extracellular, pro-inflammatory nucleic acids and prevent cellular uptake, thereby inhibiting PRR activation, in. particular TLR3, 7, 8, and 9 or R1G-I activation and reducing cytokine production and NF-κΒ induction in response to nucleic acid agonists of these receptors or admini strati on of another anionic compound such as heparin. Nucleic acid agonists include any nucleic acid or nucleic acid complex capable of acti ating a PRR and inducing a cell to produce cytokines such as IL-6. Nucleic acid agonists include dsRNA, ssRNA, un- or hypo-methylated DMA or ssDNA, and any of the aforementioned complexed with proteins.

As described herein, an eiectrospun scaffold comprising polycationic nanofibers can be used to scavenge anionic compounds. These polycationic nanofibers are being developed as novel ex vivo or topical in vivo scavengers of a) pro-inflammatory, immunostimulatory anionic molecules (e.g DNA, RNA, LPS, heparan sulfate) b) anionic anticoagulant polymers (e.g heparin, enoxaparin, RNA aptamers) and c) microorganisms, in particular microorganisms capable of forming hiofllms. The immediate translation of these polycationic nanofibers has been in the development of a novel dressing for chronic wound healing. Additionally, we are pursuing the translation of these polycationic nanofibers into a novel membrane to be used in an ex vivo extracorporeal circuit for hemofil {ration or for use in other ex vivo or in vitro applications to remove or deplete anionic compounds from a solution. Use of the polycationic nanofibers described herein in medical devices, at sites of inflammation such as sites of chemotherapeotic treatment or other treatment likely to induce cell death or inflammation, or at wound sites in vivo is also contemplated,.

Our method of polycationic nanofiber forma ion is superior in its ease of .forma lion and replicability. The resulting polycationic nanofibers are stable over time at room temperature and easy to manipulate or form into shapes for use in a variety of applications. Our technology consists of a modular approach to generate caiiooic nanofibers from any amine-containing polycationic polymer; this allows for tunability in the size and charge of the attached polycatioa thus broadening the scavenging capabilities of the fibers. Briefly, a neutral polymer with an acyl, anhydride or carboxyl reactive group is electrospun using methods know to those of skill in the art into nanofibers less than 2pm in diameter. The polycationic nanofibers are between 0.1 and 2pm, 0.2 and LSum or 0.3 and Ι .Ομκι in diameter. In the Examples, polystyrene maleie anhydride (PSMA) was used as the neutral polymer and electrospun into nanofibers. In the Examples, the neutral polymer was dissolved in a solution such as acetone, dimethylformamide (DMF), tetrahydrofuran (THF) or combinations thereof at a concentration between 40% and 200% (w/v). I n the Exa mples a 1:1 : 1 solution of acetone, DMF and T BF was used, but the combination of solvents can be varied. Suitably 45, 50, 55, 60, 65% or higher concentrations of the neutral polymer are used. Suitably less than 200%, 1 0, 180, 175, 170, 160, 150, 1 0, 130, 120, 1 10% of the neutral polymer are used for electrospinning. Elecirospinning may be completed using between 10 and 22 volts and between 50 and 200 revolutions per minute.

Suitably the voltage used for electrospinning is between 13 and 17 volts, the voltage may be 10, Π, 12, 13, 14, .15, 16, 17, 18, 19 or 20 volts. The revolutions per minute used in the Examples was 130, but 100-150 is suitable. The concentration of the neutral polymer used, the voltage, the combination of solvents used and the rate of flow and the revolutions per minute will determine the characteristics such as the diameter of the resulting nanofibers.

The nanofibers were then grafted with a cationic polymer with a free amine group such as polyethyleneimine (PEI), branched ΡΕΪ (bPEI), polyamidoamine (PAMAM), in particular PAMAM generations 0-4 or other dendrimers or positively charged copolymers such as those identified in international Patent Publication No. 20! 4/ 169043 and United States Patent

Publication No. 2 10/0184822, both of which axe incorporated herei by re ference in thei r entireties. Other cationic polymers useful in the methods include, but are not limited to ^' Ν,Ν'- cystaminebisacrylamide and N _y N'-hexamethalyne bisacrylamide backbone components with histamine and 3-(diroethylamhio)- 1 -propylamine linkers. The grafting ma be completed by soaking or incubating the neutral nanofibers with the cationic polymer. The cationic polymer may be present in a solution at 0.00 M to 1 M. and the cationic polymers and neutral nanofibers may be co-incubated for 12 hours or more. In the Examples the nanofibers and cationic polymer were co-incubated for 24-48 hours in a 0.1M solution o bPEl or a 0.0.1 M PAMAM. The polycationic nanofibers may be made into any form such as a mesh, filter or other form and may be used in medical devices, filters, bandages or wound dressings as well as in other formulations available to those of skill in the art. The nanofibers can be cut or formed into any suitable shape.

Punched out discs were used in some of the Examples,

We hypothesized that the incorporation of cationic polymers onto insoluble nanofibers would enable the scavenging o pro-inflammatory species directly from blood, wounds or other solutions, reducmg cytotoxicity related to unwanted internalization of the polymers. Herein, we report preliminary, in vitro data to support that electrospun nanofibers grafted with cationic polymers can absorb agonists ofTLR 3. 7, 8, 9 directly from serum or medium and prevent the production of NF- Β, an immune system activating transcription factor while also demonstrating reduced cytotoxicity. We also demonstrate that the polycaiionic nanofibers can reduce the formation of biofilms and prevent or slow the proliferation of at least some microbes such as Staphylococcus.

Thus methods of using the composition containing the polycaiionic nanofibers provided herein are provided. The methods include adding the polycaiionic nanofibers to a solution containing or suspected of containing an anionic compound capable of binding and activating a P . The polycaiionic nanofibers may be contacted with a solution or applied to a site of inflammation suspected of containing an anion or anionic compound or a microorganism. The poiycationic nanofibers described herein may be contacted with a solution, cells or tissues directly or indirectly in vivo, hi vitro, or ex vivo. Contacting encompasses administration to a cell, tissue, mammal patient, or human. Further, contacting includes adding the poiycationic nanofibers to a cell culture to a wound site or site of inflammation or to a solution. Other suitable methods may include introducing or administering the polycaiionic nanofibers to a solution, cell, tissue, mammal, or patient using appropriate procedures and routes of administration as defined below.

In some embodiments the poiycationic nanofibers are administered to a subject.

Administration includes topical, subcutaneous, transcutaneous or any other means of bringing the poiycationic nanofibers in contact with the subject and the site of inflammation, infection or other she at which anionic compounds need to be adsorbed. The poiycationic nanofibers described herein may be administered in an amount and way such that the poiycationic nanofibers are in an effective amount to treat a condition, such as inflammation, infection or reversal of the effects of a anionic compound. An effective amount or a therapeutically effecti ve amount as used herein means the amount of the nanofibers that, when administered to a subject for treating a state, disorder or condition is sufficient to effect a treatment. The therapeutically effective amount will vary depending on the compound, formulation or composition, the disease and its severity and the age, weight, physical condition and

responsiveness of the subject to be treated. Treating a subject as used herein refers to any type of treatment that imparts a benefit to a subject afflicted with disease or a condition or at risk of developing the disease or condition, including improvement in the condition of the subject (e.g., in one or more symptoms), delay in the progression of the disease or condition, delay the onset of symptoms or slow the progression of symptoms, etc.

Without being limited by theory the inventors believe that the anionic compounds are adsorbed onto the polycationic nanofibers and not allowed to interact with the PRR on the cells and this prevents inflammation. The anionic compounds include nucleic acids, such as DMA or RN A, or heparin or heparin analogs, in particular low molecular weight heparins, enoxaparin or other anionic compounds. The solution include a wound site, blood, serum, synovial fluid, saliva, water, culture media, or other biological fluids. The methods also include administering the polycationic nanofibers to a subject in an amount effective to adsorb anionic compounds in the subject.

Elecirospun PSMA fibers modified with bPEl ca inhibit the activation of Toll-like receptors (TL s) by pro-inflammatory nucleic acids. These polycationic nanofibers show specificity for negatively charged, agonists and. demonstrate promise for developing novel dressings and treatments for inflammation in chronic wound healing in which a sustained immune response prevents completion of wound healing, thus leaving wounds open and exposed to further infection. A cationic fiber bandage has potential to eliminate immune agonists and promote wound healing, for example in chronic wounds. We are currently investigating the utility of these .nanofibers in animal models for chronic wound healing and control of

inflammation and microbial growth.

The polycationic nanofibers suitably have low or no cytotoxicity. As shown in the Examples, the polycationic nanofibers have demonstrated little or no cytotoxicity in three different cell lines: STO, RAMOS Blue, and human derived endothelial cells. The polycationic nanofibers provided herein can be exposed to cells or tissues as shown in the examples because the nanofibers are not cytotoxic or have low cytotoxicity when incubated with cells as compared to the viability of untreated ceils. Low cytotoxicity indicates that cellular viability in cells treated with the polycationic nanofibers is reduced by less than 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50% as compared to untreated control ceils.

Administration or co-incubation of the poiycat ionic nanofibers provided herein with a solution or at a site containing the riucieic acid agonists was required to inhibit PRR activation by a nucleic acid agonist. Co-incubation with the cells was not required and the polycationic nanofibers were used to scavenge the riucieic acids from a solution prior to addition to cells. The polycationic nanofibers provided herein either do not allow or inhibit cellular uptake of the nucleic acid agonists. Without being limited by theory, we hypothesize that the polycationic nanofibers provided herein work at least partially by adsorbing the anionic nucleic acids and thus inhibiting cellular uptake of the nucleic acid agonists of the PRRs. This inhibits interaction of the nucleic acid agonists with the receptors on the cells. The polycationic nanofibers may inhibit uptake of the nucleic acid or TLR agonists by 10%, 20%, 30%, 40%, 50% or even 60% or more as compared to control cells. The cellular response to the nucleic acids or TLR agonists is reduced by at least 10%, 20%, 30%, 40%, 50%, 60% or 70% when the polycationic nanofibers are present as compared to control cells treated with the nucleic acid agonists or with neutral nanofibers.

The present invention relates, in one embodiment, to methods of inhibiting nucleic acid- induced activation of PRRs, such as endosomal TLRs (e.g., TLR 9). The methods include adding polycationic nanofibers to cells (e.g., by adding the polycationic nanofibers to the extracellular space or media or pre-incub ting the polycationic nanofibers with the media) or administering the polycationic nanofibers to a subject (e.g., a human in vivo or ex vivo) in need thereof ^" The polycationic nanofibers are capable of inhibiting the cellular response to nucleic acid induction of PRR (TLR ) acti vation. The polycationic nanofibers are provided in an amount and under conditions such that inhibition of activation via the PRR is affected.

Advantageously, the polycationic nanofibers binds the nucleic acids in a manner that is independent of the nucleotide sequence, the chemistry (e.g., DMA or R A, with or without base or sugar modifications) and/or the structure (e.g.. double-stranded or single-stranded, eomplexed or uncompleted with, for example, a protein) of the nuc leic acids responsible for inducin nucleic acid receptor (TLR.) activation. The present methods can be used to treat inflammatory and/or autoimmune responses resulting from inappropriate activation of nucleic acid receptors on or in cells. Administration or addition of the polycationic nanofibers inhibits activation of die nucleic acid receptor by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or more. Suitably inhibition is in a dose-dependent manor such that addition of small amounts of the polycationic nanotibers are not or only slightly capable of inhibiting receptor activation and addition of higher amounts of the polycationic nanofibers results in additional inhibition up to fail inhibition of activation of the receptor by the nucleic acid or other TL agonist. The percentage inhibition of the receptor may refer to the percentage inhibition or reduction in cytokine productio (e.g. lL-6) or in activation of NF~KB in response to the agonist in combination with one or more of the polycationic nanofibers as compared to cells treated with the agonist alone or the agonist and an irrelevant polymer or nanofiber.

Advantageously, the binding affinity of a nucleic acid-binding polycationi c n anofibers of the invention for a nucleic acid, expressed in terms of d, is in the pM to mM. range, preferably, less than or equal to 50 nM; expressed in terms of binding constant (K), the binding affinity is advantageously equal to or greater than 10 M ^"! , preferably, 10 ⁵ M ^"f to 10 M ^{" l} . more preferably, equal to or greater than 1 CM ^"1 . Thus, the binding affinity of the sequence-independent nucleic acid-binding polycationic nanofibers can be, for example, about I x 10 ^" M ^" , 5 x 10' ^" \ 1 x 10 ^v 5 l0 ⁷ M- ⁵ ; or bout l O pM, 100 pM, 1 nM, 10 nM, 100 nM, 1 μΜ, 10 μΜ, 100 μΜ. "K." and ^w Kd" can be determined by methods known in the art, including Isothermal Caiorimetry (ITC), Forster Resonance Energy Transfer (FRET), surface plasmon resonance or a real time binding assay such as Biacore.

Preferred nucleic acid-binding polycationic nanofibers of the invention simultaneously limit the activation of multiple nucleic acid binding PRRs (endosomal TLRs, e.g., TLR3, TLR7, TLR8 and TLR9 and possibly cytosol c nucleic acid sensors such as R IG-l) by binding to a wide array of di fferent nucleic acids or other anionic compounds including but not limi ted to ssRN A, ssDNA, dsR A and dsDN and of which may be presented in a comple with protein such as viral proteins, histones, HMG BI or RIG-L Suitably the nucleic acid-binding polycationic nanofibers do not inhibit activation of non-nucleic acid binding TLRs such as TLR 2, TLR4, TLRS, or T1..R6. For example, the polycationic nanofibers do not inhibit activation by LPS, lipoproteins, or flagellin. The polycationic nanofibers are minimally cytotoxic. The polycationic nanofibers aiso bind to many microbes and may affect microorganism proliferation or biofilm formation. As indicated abo ve, the present invention provides a method of controlling (inhibiting or preventing) autoimmune and/or inflammatory responses associated with activation of PRRs by nucleic acids or other anionic compounds or TL agonists (e.g., endosomal TLRs, such as TLR9). Such responses play a role in the pathogenesis of diseases/disorders that are associated with presence in the circulation of the subject of free nucleic acids, either pathogen-derived (e.g., viral- or bacterial-derived) nucleic acids or nucleic acids released from dead or damaged host cells. Specific diseases/disorders that can be treated using nucleic acid-binding polycationic nanofibers of the invention include infectious diseases, cardiovascular disease, cancer, bacterial sepsis, multiple sclerosis, systemic lupus erythematosis, rheumatoid arthritis, inflammatory bowel disease, COPD, obesity, psoriasis, atherosclerosis, diabetes, wound healing, burns, infectious diseases, reperfusion injury, renal failure/dialysis, organ transplantation,

neurodegenerative disease and traumatic brain injury. (See also International Patent Applicatio No. PCT/US2010/002516, International Patent Publication No. WO20I 1/034583, filed

September 16, 2010.)

As shown in the Examples, the polycationic nanofibers are also able to inhibit the growth of microbes and formation of biofilms by microbes. The Examples demonstrate the ability of the polycationic nanofibers to reduce the formation of biofilms of Pseut monas aeruginosa and prevent the proliferation of certain bacteria such as Staphylococcus aureus or coagulase negati ve Staphylococcus aureus. Thus the polycationic nanofibers are able to inhibit die growth of and biofilm production by both gram positive and gram negative bacteria and we expect the polycationic nanofibers will also inhibit biofilm production and growth of fungi, such as yeast.

Gram-positive bacteria capable of forming biofilms include, but are not limited to.

Bacillus spp., Corynebacterium spp.. Listeria spp. (i.e. Listeria monocytogenes) , Staphylococcus spp. (i.e. Staphylococcus aureus and Staphylococcus epidermis). Micrococcus spp., and lactic acid bacteria (i.e. Lactobacillus plantarum, laciococcus laciis, Emercoccus spp.. Streptococcus spp. including Streptococcus mutans and Streptococcus pneumoniae). Gram-negative bacteria capable of forming biofilms include, but are not limited to, Escherichia spp, (i.e. Escherichia col ), Klebsiella spp. (i.e. Klebsiella pneumonia), Pseudo-manes spp. (i.e. Pseudom tas aeruginosa, Pseudamonas puiida, Pseudomonasfluorescem), Proteus spp., Legionella spp., Rhhobium spp. (i.e. Rhkobium leguminosarum), Sinorhizobium spp. (i.e Sinorhizobium metfioti), and Serraiia spp. Yeast capable of forming biofilms include, but are not limited to, Candida spp, (i.e. Candida albicans) and Aspergillus spp.

The polycationic nanofibers can also be used in combination with other treatments. The polycationic nanofibers may be used in conjunction wit another therapeutic, such as a cancer therapeutic, known to result in a robust inflammatory response by releasing nucleic acids possibly from dead or dying cells. Such treatments may be treatments known to induce cell death or nucleic acid based inflammation. Administration of the polycationic nanofibers may limit inflammation associated with these treatments and alleviate side effects, in one

embodiment, the polycationic nanofibers are administered to cells or a subject which previously received or were exposed to a nucleic acid-based pharmaceutical composition, such as an si NA, a DNA vaccine or an aptamer based therapy. The polycationic nanofibers described herein may be useful to limit inflammatory side effects associated with administration of such therapeutics.

Another application of nucleic acid-binding polycationic nanofibers described herein is to counteract the effects of DNA, RNA or pol phosphate molecules that are released from cells and subsequently induce thrombosis ( annemeier et al, Proc. Natl. Acad. Sci, 104:6388-6393 (2007); Fuchs et al, Proc. Naif Acad. Sci. Published Online before Print August 23, 2010). It has been observed that RNA and DN A molecules can activate the coagulation pathway as well as platelets and thereby engender blood clotting (Kannemeier et al, Proc. Natl. Acad. Sci. 104:6388-6393 (2007); Fuchs et al, Proc, Natl. Acad. Sci. Published Online before Print August 23, 2010), Since nucleic acid-binding polycationic nanofibers described herein can bind RNA and DNA molecules and shield them from other potential binding partners, such agents can be employed to inhibit the ability of DMA and RNA molecules to bind and activate coagulation factors and platelets, in so doing, these R A/DNA-bfnding polycationic nanofibers can be utilized to limit nucleic acid-induced pathological blood coagulation. Thus, nucleic acid-binding catkraic polymers described herein represent novel entities for preventing the induction and progression of a variety of thrombotic disorders, including myocardial infarction, stroke and deep vein thrombosis.

The precise nature of the compositions of the invention will depend, at least in part, on the nature of the nucleic acid-binding polycationic nanofibers and the route of administration . It will be appreciated that the treatment methods of the present invention are useful in the fields of both human medicine and veterinary medicine. Thus, the patient (subject) to be treated can be a mammal, preferably a human. For veterinary purposes ihe subject can be, for example, a farm animal such as a cow, pig, horse, goat or sheep, or a companion animal, such as a dog or a cat.

An effective amount or a therapeutically effective amount as used herein means the amount of a composition that, when administered to a subject for treating a state, disorder or condition is sufficient to effect a treatment. The therapeutically effective amount will vary depending on the composition, the disease and its severity and the age, weight, physical condition and responsi veness of the subject to be treated.

Suitably the polycationic nanofibers are also tested for the inability to block activation and cytokine production by cells in response to non-nucleic acid binding PRRs (TLRs) such as LPS activation of TL.R4; Pam3CS 4 activation of TLR2; endogenous DAM P or heparan sulfate activation of TL 4. The polycationic nanofibers should also be tested for cytotoxicity to cells after incubation and for lack of toxicity when administered to subjects such as mice.

The present disclosure is not limited to the specific details of construction, arrangement of components, or method steps set forth herein. The compositions and methods disclosed herein are capable of being made, practiced, used, carried out and or formed in various ways that will be apparent to one of skill in the art in l ight of the disclosure that follows. The phraseology and terminology used herein is for the purpose of description only and should not be regarded as limiting to the scope of the claims. Ordinal indicators, such as first, second, and third, as used in the description and the claims to refer to various structures or method steps, are not meant to be construed to indicate any specific structures or steps, or any particular order or configuration to such structures or steps. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to facilitate the disclosure and does not imply any limitation on the scope of the disclosure unless otherwise claimed. No languag in the specification, and no structures shown in the drawings, should be construed as indicating that any non-claimed element is essential to the practice of the disclosed subject matter. The use herein of the terms "including," "comprising " or "having," and variations thereof, is meant to encompass the elements listed thereafter and equivalents thereof as well as additional elements. Embodiments recited as "including," "comprising," or "having" certain elements are also contemplated as "consisting essentially of and "consisting of those certain elements.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. For example, if a concentration range is stated as .1 % to 50%, it is intended that values such as 2% to 40%, 10% to 30%, or 1% to 3%, etc., are expressly

enumerated in this specification. These are only examples of what is specifically intended, and all possible combinations of numerical values between and including the lo west value and the highest value enumerated are to be considered to be expressl stated in this disclosure. Use of the word "about" to describe a particular recited amount or range of amounts is meant to indicate that values very near to the recited amount are included in that amount, such as values that could or naturally would be accounted for due to manufacturing tolerances, instrument and human error in forming measurements, and the like. All percentages referring to amounts are by weight unless indicated otherwise.

No admission is made that any reference, including any non-patent or patent document cited in this specification, constitutes prior art. In particular, it will be understood that, unless otherwise stated, reference to any document herein does not constitute an admission that any of these documents forms part of the common general knowledge in the art in the United States or in any other country. Any discussion of the references states what their authors assert, and the applicant reserves the right to challenge the accuracy and pertinence of any of the documents cited herein. All references cited herein are fully incorporated by reference, unless explicitly indicated otherwise . The present disclosure shall control in the event there are any disparities between any definitions and/or description found in the cited references,

The following examples are meant only to be illustrative and are not meant as limitations on the scope of the invention or of the appended claims.

EXAMPLES

Methods

The method of making the po!ycaiionic nanoflbers is shown schematically in Figure 1. Briefly, unaligned nanofibers were fabricated by electtospimiing a solution of 60% or 100% fw v) Poly (styrene~co~maleic anhydride MW 350,000) in 1:1:1 (v/v) tetrahydrofuraa, N. dimethylformamide, and acetone at 15V. Nanofibers were collected on a fly-wheel 3.9 inches away from the solution source rotating at 130 revolutions per minute. Poiycationic fibers were made by soaking the eleetrospun PSMA fibers in O. IM l .Sl Da branched pory(ethylenimine) (hPEI) in water or 0.0 IM Polyamidoamine dendrimer G3 (PAMAM-G3) in water for 48hrs _s then washed with D3 water, and sterilized with ethanol for 20 mm. Nanofibers were imaged and characterized using Scanning Electron Microscopy (SEM). Figure 2 and 3 show SEM photographs of the 100% PMSA and 60% PMSA catk ic nanofibers, respectively. The 100% PMSA nanofibers had diameters of about 0.8-1 um and the 60% PMSA cationic nanofibers were abou 0,2-0 _; 4μπι in diameter.

Cell viability studies were performed in mouse fibroblast cells (STO) and a B lymphocyte cell line (Ramos Blue™, fnvivogen). Cell viability was determined by direct contact of the cells with the fibers. Cell proliferation studies were performed by plating strongly adherent ceils, normal hitman dermal fibroblasts (NHDFs) directl onto fibers. Growth on poiycationic nanofibers was encouraged by using a non-cell culture treated plate. Live/Dead staining aid imaging was performed at 24 and 48h.rs followed by analysis using ImageJ. Cell- activation and specificity studies were performed with Ramos Blue™ cells by submerging fibers in serum free media with nucleic acid and non-nucleic acid based TLR agonists and subsequently treating the cells with the fiber-exposed medium Resulting NF- β levels were measured using QUANTi-Bliie™ (In ivogen) a secreted embryonic alkaline phosphate (SEAP) detection medium.

Nucleic acid absorption studies using labeled CpG and salmo sperm DNA were performed as follows. Varying concentrations of Alexa Fluor 488 labeled CpG were incubated with 3mm fibers for 4hrs at RT under constant shaking, protected from light. The fibers were washed 3 times with DI water, placed on a cover slip, mounted with SbwF de Diamond reagent, and fluorescent images are captured with an Upright AxioImager.Al microscope powered by a Zeiss HBO 100 power supply and lamp housing. To create the DN absorption, curve, varying amounts of salmon sperm DMA were added to 3mm fibers for 4hrs at. RT under constant shaking. A total of 75pL of IxTE is used for the salmon sperm DNA, after 4hrs l-10pL is removed from the fibers and the total salmon sperm DNA concentration is determined using PicoGreen.

oxorubicin-induced ceil death debris experiments were performed by plating RAW cells in a.96 well plate at 40 cells pet well and incubated for 18-24hrs. Doxorubicin (BOX) was added at 3, 3.6, 6, or 9 .g h L and incubated for 48hrs. ΙΟΟμΤ of the su ern ta t from the DOX-treated cells was added to a 4mm piece of PSMA-bPFJ nanofiber. The fiber and supernatant were incubated for 30min and the entire volume was added to 200k RAMOS cells in Ι ΟΟμΙ.. 18-24hrs later, 40pL of the Ramos cells' supernatant was added to 160μΕ of Quanti- blue and the absorbance was read at 650nm at 3 and 5hrs.

SEM images of biofllois on the poiycationic nanofibers were taken after 48hrs incubation of Pse domonas aeruginosa or Staphylococcus a¾rra« Coagulase negative Staphylococcus aureus in LB broth at 3?°C with a starting concentration of 1x10 ^'" * cells/mL . lOOuL of bacteria dispersion was incubated with a 4mm diameter nanofiber folloxved by fixation and dehydration for SEM preparation. Biofi!m mass of Pseudomonas aeruginosa was determined by incubating the bacterial dispersion or co- incubating the bacterial dispersion with poiycationic nanofibers of 3 or 4mm diameter for 48hrs at 37°C, followed by 3 washes of PBS, a 15 minute room temperature incubation with 0.1 % crystal violet, 3 more PBS washes, a 15 minute room temperature incubation with 30% acetone, and a final absorbance reading at 550om, The Colony Forming Units (CPUs) of Staphylococcus aureus were determined by measuring the absorbance at 600nm of the bacterial dispersion following 48hrs incubation at 37°C.

Results:

SEM shows that the fibers are randomly aligned and in the nanometer range 270-3 ^■ 80nm and 800~ 00nm for 60% PSMA and 100% PSMA, respectively (See Figure 2 and 3). Ceil viability studies with STO and Ramos blue cells show minimal toxicity of the fibers upon, direct contact with the cells as shown in Figure 4. The nanofibers were placed in the wells with the cells and allowed to incubate for 4 hours at 37°C. The fibers were removed from the wells and Cell Titer Glo (Prornega, Madison, WI) was used to determine the cell viability. The minimal toxicity of the poiycationic nanofibers, either 60%+bPEI and 100%+bPEl in Fig. 4A is presumably due to the increased basicity of the cell media from bPEI. Figure 4B shows that the poiycationic nanofibers do not affect the proliferation of NHDFs. showing thai cells can still proliferate in the presence of the poiycationic nanofiber. Confirmation of successful preparation of polyeationie nanofibers was demonstrated through the electrostatic interaction with negatively charged nucleic acids including CpG and salmon sperm DNA as shown in figure 5, Alexa Fluor labeled CpG demonstrated the interaction of nucleic acids with the polyeationie nanofiber as shown in Figure 5C. As expected, increasing amounts of CpG resulted in increased fluorescence as compared to background nanofiber fluorescence. The increased fluorescence of the polyeationie nanofibers following soaking indicated that the were pulling the nucleic acids out of solution, therefore demonstrating functionality. Further absorption analysis using salmon sperm DNA as shown in Figure 5D resulted in an absorption curve showing the absorption capacity of the polyeationie nanofiber is -30 ^βηι ι fiber disc. SEM images show that the initial modification of neutral nanofibers with bPEI results in swelling of the fibers and some "melting" of the fibers where they overlap and appear to connect; however, interaction with salmon sperm DNA does not change the morphology as shown in Figure 5E,

The ability of polyeationie nanofibers to block expression of N F-kB was tested by incubating 2 x 10 ^' B cells with the polyeationie nanofibers or neutral nanofibers in the presence of CpG at 1 μΜ for 20 hours, Ramos B lymphocytes were obtained from I vivogen and express alkaline phosphatase from the NF-kB promoter such that alkaline phosphatase acti vity in the supernatant of these cells is indicati ve of NF-kB induction. The polyeation ie nanofibers effectively eliminated the immune stimulating response of NA based agonist CpG (TL 9) while neutral nanofibers had little effect on the ability of CpG to stimulate NF-kB as shown in Figure 6. Results show that unmodified PSMA fibers have no inhibitory effects, demonstrating that the fiber activity is not due to a physical or solvophobic interaction with the fibers. The cationic libers (60%/ 100%+fcPEI) , reduced the Ramos Blue™ NF-κβ response to the baseline of unstimulated cells. Figure 7 shows an SEM imaae of the 1 0% PS A polvcationic nanofibers after interaction with CpG. No change in structure is evident, in the SEM.

The ability of the polyeationie nanofibers to block activation of NF-kB was further tested by incubating B cells with the polyeationie nanofibers in the presence of CpG , poly i:C (TL .3) or non-nucleic acid, cationic TLR agonists (R848 ₅ . PAM3CS.K4; structures shown in Figure 9) at Ι Μ for 20 hours. Figure 8 shows that the polyeationie nanofibers selectively inhibit the activity of the nucleic acid (NA ) based agonists, CpG and Poly(I:C). Figure shows that similar results are obtained to those shown in Figure 8 when the polycationic nanofibers are p.re~incubated with the media containing the TLR agonists prior to the media being added to the Ramos Bine cells for 20 hours and subsequent measurement of alkaline phosphatase production as a read out of F- Β induction. Thus the TLR agonists are likely absorbed by the polycationic nanofibers and pulled out of the media or solution.

Figure 10 shows that the polycationic nanofibers can be incubated with the TLR agonist and the cells for as little as 4 hours, and result in a lack of NF- Β activation by nucleic acid agonists. In these experiments the cells were incubated with the nucleic acid agonists and the polycationic nanofibers for 4 hours and then the nanofibers were removed prior to addition of the B ceils. After 1 hours continued incubation, alkaline phosphatase levels indicated a lack of activation in the presence of the polycationic nanofibers for CpG and poly I:C, but no effect on PAMcsk.4. The nanofibers appear to have scavenged the nucleic acid agonists and removed the agonists from the media when the fibers were pre-incubated in the media+agonists before being exposed to cells as well as when the fibers were incubated with the cells in the presence of agonists.

Fi gure 1 1 demonstra tes that the polycationic n anofibers are still capable of scavenging the nucleic acid agonists in the presence of serum and activation of NF- Β was blocked. Figure 12 shows that similar results were obtained with a polycationic nanof!ber made with AMAM instead ofbPEI as the cationic polymer.

Figure 13 demonstrates a biological application of the polycationic nanofibers in the form of reducing chemotherapeutic toxicity; the polycationic nanoilber reduces the subsequent F- β expression in Ramos-Blue cells by as much as 40%. Given that the Ramos-Blue cells release ΝΡ- β due to activation by various agonists, not limited to nucleic acids, it is reasonable to assume that the polycationic nanofibers are able to scavenge out a significant amount of

extracellular nucleic acids released from DOX-killed RAW cells.

Figure 14 shows SEM images of Pseudomonas aeruginosa biofHm formation on the surface of the polycationic nanofibers after 24hrs (Figure 14B) and 48hrs (Figure 1.4C,D) as compared to the original electrospun nanofiber (Figure 14A). Figure 15 shows that treatment with polycationic nanofibers significantly reduces the total biofilm mass on an adjacent surface. Figure 15 shows SEM images of polycationic nanofibers after 48hrs incubation with (A-B) Staphylococcus aureus and (C-D) Coagulase-negative Staphylococcus aureus. The images suggest that the polycationic nanofibers do not promote bioiil.ro growth of these two types of Staphylococcus aureus. Figure 16 shows that the polycatiomc nanofibers reduce the total number of bacterial CFUs after 48hrs of incubation therefore demonstrating their utility i n reducing infection and potentially preventing biofilm formation.