CROSS-REFERENCE TO RELATED APPLICATION

The present Application claims the benefit of priority from United States Provisional Patent Application No. 61/436,536 filed January 26, 2011 and titled "Antimicrobial Insole"; the contents of which are incorporated in this disclosure by reference in its entirety.

TECHNICAL FIELD

This invention relates to devices incorporating antimicrobial compositions for simultaneously detecting diabetes while providing antimicrobial activity.

BACKGROUND ART

The human foot encased in a shoe provides an almost ideal environment for microbial colonization, which contributes to both foot odor and infections. Bacteria and fungi can grow on the skin surface of the foot, supported by the humid, warm microenvironment of a foot in a sock and shoe. Moreover, feet are prone to injuries affecting the skin surface, permitting aggressive colonization of opportunistic pathogens. Systemic conditions, including diabetes mellitus or related metabolic diseases can lead to exacerbation of foot colonization and infection, and in turn, the potential consequences of colonization by fungi or bacteria are generally far more serious in people with diabetes or immunosuppresion than without. Increased nutrient content in perspiration is one factor in diabetes contributing to increased susceptibility to colonization and infection, and impaired wound healing and sensation in the extremities increase the risk of serious consequences, such as chronic infected diabetic foot ulcers that can lead to amputations if infections are allowed to penetrate beneath the skin surface. Immunosuppression (whether caused by infections such as HIV or by immunosuppressive treatments for autoimmune or inflammatory diseases, or for organ transplants) can also exacerbate microbial colonization of the feet and its consequences. Even in people without diabetes or immunosuppression, foot colonization by bacteria or fungi can lead to conditions of chronic discomfort and itching, including tinea pedis (athlete's foot) as well as foot odor.

The principal cause of foot odor is production of bacterial degradation products of nutrients present in foot perspiration, especially plantar sweat. Isovaleric acid, for example, is produced by the action of bacterial leucine dehydrogenase on the amino acid leucine in perspiration. In addition, ammonia produced by deamination of leucine and other amino acids, increases the pH of skin to levels more favorable for colonization by various microbes and dermatophytes. In the setting of bacterial or fungal colonization, platar sweat can further increase the spread of infection and co-infection by compromising cutaneous integrity. Plantar sweat furthermore provides a medium for distributing and sustaining microorganisms across and within the shoe environment (insole, sole, and sock).

Tinea pedis, a chronic fungal foot infection, is the second most common skin disease in the United States behind acne, affecting about 15% of the population. The dominant causal flora are dermatophytes including trichophyton rubrum (75% of tinea pedis infections), tricophyton mentagropytes, and epidermophyton floccosum. Wet conditions in the setting of tinea pedis increases the incidence and severity of bacterial co-infection, and provides entry points for development of bacterial cellulites in the foot. There is a high failure rate for topical antifungal treatments for tinea pedis, in part due to poor compliance because of the requirement for relatively long courses of daily treatment.

Problems with ulceration and infection of the feet are common complications of diabetes, leading to tens of thousands of foot amputations every year. The incidence of type 2 diabetes is increasing worldwide in parallel with increases in bodyweight and overnutrition. A large fraction of people with diabetes or prediabetes (impaired glucose tolerance) are unaware of their condition, as it is often asymptomatic until tissue-damaging complications have already occurred. A noninvasive diagnostic indicator that can be used by large populations could have an immense impact on health care costs by enabling detection at a point where preventative measures can be applied before irreversible tissue damage (neuropathy, nephropathy, retinopathy or chronic skin ulceration) has occurred.

What is needed is an easy to use, cost-effective, disposable device and method for detecting diabetes and prediabetes. Such devices and methods are especially needed in developing countries. Also what is needed is a device that can not only act as an indicator of diabetes, but also decrease the bacterial and fungal skin infections associated with diabetes. With these goals in mind, the inventor created devices to detect diabetes in a cost-effective manner and simultaneously impart antimicrobial activity.

DISCLOSURE OF INVENTION

The present invention is directed to an antimicrobial device for detecting diabetes.

One embodiment of the device comprises a sulfonated rayon fabric and sulfonated cotton fabric. The fabric layer further comprises an antimicrobial composition comprising C.I. Reactive Blue 21, divalent copper, and divalent zinc, wherein the fabric layer undergoes a color change when the layer contacts a biological indicator of diabetes. The color change thereby provides an indicium of diabetes, while the layer simultaneously imparts antimicrobial activity and anti-odor activity.

Another embodiment of the device comprises at least one layer of material comprising an antimicrobial composition. The antimicrobial composition comprises one or more than one reactive dye and one or more divalent metallic salt or divalent metal ion. The layer of material undergoes a color change when the layer contacts a biological indicator of diabetes, such that the color change provides an indicium of diabetes, while the layer simultaneously imparts antimicrobial activity and anti-odor activity. The layer of material can be a cellulosic material such as rayon or cotton. The reactive dye can be C.I. Reactive Blue 21 dye. The one or more divalent metallic salt can comprise copper acetate or copper acetate and zinc acetate. The one or more divalent metal ion comprises divalent copper or divalent copper and divalent zinc. The device can be disposable or reusable and can be, for example, an insole or patch. The device can further comprise an adhesive layer.

According to another embodiment, the device comprises a layer of material having an antimicrobial composition. The antimicrobial composition comprising one or divalent copper salt or divalent copper ion and the layer of material undergoes a color change when the layer contacts a biological indicator of diabetes. The color change thereby provides an indicium of diabetes, while the layer simultaneously imparts antimicrobial activity and anti-odor activity.

Regarding insole embodiments of the device, the insole can have multiple layers. In one embodiment, the insole has a porous layer, an antimicrobial layer described herein and a cushioning layer. In another embodiment, the device has an antimicrobial layer described herein and a cushioning layer. In yet another embodiment, the insole comprises five layers, including a porous layer, one or more antimicrobial layers described herein, one or more cushioning layers, and one or more wear resistant layers.

The porous layer can be comprised of a punched woven fabric, a punched non woven fabric, a wrap knitted fabric, a mesh fabric, a terylene fabric, polyethylene terephthalate, polyethylene, polypropylene, polyamide and/or vinyon. The cushioning layer can be comprised of polyurethane foam, ethylene vinyl acetate foam, an air mesh terylene, and/or air mesh polyethylene terephthalate. The wear resistant layer can comprise a web of filaments of thermoplastic including but not limited to polyethylene terephthalate, polyethylene, polypropylene, polyamide, and vinyon. A method for detecting diabetes is provided comprising the steps of: providing a device according to the invention, placing the device in proximity to the skin of a person such that a bodily fluid secreted from the skin can contact the antimicrobial layer of the device; and observing an amount of color change of the antimicrobial layer to determine an amount of biological indicator of diabetes in said bodily fluid and thereby determine the severity of diabetes of said person.

In addition, a method of making an antimicrobial device for detecting diabetes is disclosed, comprising the steps of: preparing a sulfonated cellulosic fabric comprising a reactive dye; rinsing the sulfonated cellulosic fabric; drying the sulfonated cellulosic fabric; spraying an aerosol mixture or a solution of copper acetate and zinc acetate on the sulfonated cellulosic fabric; and drying the sulfonated cellulosic fabric.

Lastly, methods of making antimicrobial insole devices for detecting diabetes are described herein.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1-3 illustrate embodiments of an insole device in accordance with the present invention;

FIG. 4 illustrates an embodiment of a patch device in accordance with the present invention; and

FIG. 5 illustrates a cross-sectional view of an embodiment of a device in accordance with the present invention.

MODES FOR CARRYING OUT THE INVENTION

The present invention pertains to an antimicrobial and anti-odor devices such as insole or patch material for addressing the cycle of foot or body odor and microbial colonization aggravated by perspiration as a medium and source of nutrients, such as in the warm environment of shoes and socks. It may be also helpful to reduce the risk of foot infections in this vulnerable patient group. In addition to direct reduction of risk of infection through antimicrobial activity, the devices of the invention can be designed to also act as a sentinel for detection of diabetes and to provide information about progression or recovery over time.

The detailed description set forth below in connection with the appended drawings is intended to provide example embodiments of the present invention and is not intended to represent the only forms in which the invention may be constructed or utilized. The description sets forth the functions and the sequences of steps for constructing and operating the invention. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. Additional embodiments, features, and/or advantages of the invention will become apparent from the description or may be learned by practicing the invention.

All dimensions specified in this disclosure are by way of example only and are not intended to be limiting. As will be understood by those with skill in the art with reference to this disclosure, the actual dimensions of any device or part of a device disclosed in this disclosure will be determined by its intended use. Except where the context requires otherwise, the method steps disclosed are not intended to be limiting nor are they intended to indicate that each step is essential to the method or that each step must occur in the order disclosed.

As used in this disclosure, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising," "comprises" and "comprised" are not intended to exclude other additives, components, integers or steps.

As used in this disclosure, "pathogen" comprises bacteria, microorganisms, fungi and viruses that cause health problems in humans, including, but not limited to, skin infections, foot and/or body odor, and tinea pedis.

As used in this disclosure, "antimicrobial activity" comprises antimicrobial, biocidal, antibacterial, antifungal, and/or antiviral activity, as well as inactivation of bacteria, fungi, viruses, and/or microorganisms that cause foot or body odor, skin infections, and/or tinea pedis.

As used in this disclosure, "antimicrobial composition" can comprise a substance that can impart any antimicrobial activity described above. As a non-limiting example, an antimicrobial composition can, but need not, include a chemical group that chemically binds a pathogen, rather than presenting only a physical barrier to spatial passage of the pathogen. An antimicrobial composition can also comprise biocidal metal-containing particles.

As used in this disclosure, "cellulosic" means "comprising cellulose."

As used in this disclosure, a "biological indicator of diabetes" can comprise reducing sugars such as glucose, aldehydes, and ketone bodies such as alpha-hydroxyketones.

The device 10 of the present invention includes a layer of material 12 further comprising an antimicrobial composition 14 having both antimicrobial activity and a reactive color change when contacted with a biological indicator of diabetes. The noninvasive and cost-effective devices can be reusable and/or disposable.

A component of the device 10 is an antimicrobial textile 12 comprising cellulosic fabric treated with a sulfonated reactive phthalocyanine dye, further complexed with antimicrobial metal ions such as copper and zinc, disclosed in WO2009003057, and WO2009158527 herein incorporated by reference.

According to one embodiment of the present invention, the layer of material 12 is a cellulosic fabric (i.e., comprises cellulose). In particular, devices having a rayon fabric or a cotton fabric layer are disclosed herein. The antimicrobial composition 14 comprises one or more than one reactive dye and one or more than one divalent metal ion or divalent metallic salt.

Reactive dyes are a class of substances used to dye fibers and fabrics, both cellulosic fibers and cellulosic fabrics (such as acetate, cotton and rayon), and non-cellulosic fibers and non-cellulosic fabrics (such as wool and nylon, and fabrics made from polyester or poly olefin). Reactive dyes comprise a reactive linker group, usually either a haloheterocycle or an activated double bond that, when applied to a fiber in a dye bath, forms a covalent chemical bond with a hydroxyl group on the fiber or the fabric. Reactive dyes are classified according to the category of linker group that attaches the dye to the fiber or fabric. Reactive dyes further comprise a chromophore group, providing the specific color for the dye. The chromophore group commonly comprises a multi-ring aromatic group; however, multi-ring aromatic groups tend to decrease water solubility, so reactive dyes usually further comprise one or more sulfonate groups to increase water solubility. The sulfonate groups of reactive dyes can chemically bind pathogens, while the reactive linker groups of the reactive dyes bond to the layer of material of the present invention such as cellulosic fabrics.

A given dye frequently has several trade names, but the generic names (Color Index; CI) for dyes comprise the following format: [Category (acidic, basic, direct or reactive); Color; and Number]. Examples of metal phthalocyanine reactive dyes include CI Reactive Blue 4, CI Reactive Blue 21, CI Reactive Blue 140, CI Reactive Blue 163, CI Reactive Brown 23, CI Reactive Orange 4, CI Reactive Red 1, CI Reactive Red 2, CI Reactive Red 6, CI Reactive Red 11, CI Reactive Red 78, CI Reactive Yellow 39, and CI Reactive Yellow 86, each of which comprises sulfonate groups which function as an antimicrobial composition suitable for binding one or more than one pathogen according to the present invention, and each of which further comprises a linker group suitable for attaching the dye to the fabric. In one embodiment, the binding substance is CI Reactive Blue 21 [copper, (29H,31H - phthalocyaninato (2-)-N 29,N 30,N 31, N 32)-, sulfo((4-((2-(sulfooxy) ethyl) sulfonyl) phenyl) amino) sulfonyl derivatives] (CAS Reg. No. 73049-92-0), a sulfonated copper phthalocyanine dye with a vinyl sulfone linker group that attaches the dye to fibers and fabrics, including cellulosic fibers and fabrics. The appropriate reaction conditions for attaching reactive dyes, including for attaching CI Reactive Blue 21, to fibers and fabrics are well known to those with skill in the art, and can be found in instructions from the dye manufacturers, as well as in standard textile references, as will be understood by those with skill in the art with reference to this disclosure.

As will be understood by those with skill in the art with reference to this disclosure, using an antimicrobial composition 14 comprising a sulfate group or a sulfonate group on a layer of material comprising cellulose is both relatively inexpensive and suitable for industrial-scale production of devices according to the present invention.

The antimicrobial composition 14 of the present invention further comprises one or more than one additional substance that decreases the pathogenic capacity of one or more than one human pathogen. In a preferred embodiment, the one or more than one additional substance is one or more than one type of divalent metallic ion, such as for example divalent copper and divalent zinc, which are viricidal, bactericidal and fungicidal. In another embodiment, the antimicrobial composition comprises a divalent metallic salt, such as for example copper acetate and zinc acetate, which are bactericidal, viricidal and fungicidal. Acetate is advantageous as an anionic salt constituent as it is volatile and can be removed from the fabric by evaporation. The addition of the one or more than one substance to the antimicrobial layer 12 increases the effectiveness of the device of the present invention in decreasing the transmission of one or more than one pathogen by using mechanisms in addition to binding the pathogen to the fabric.

Further advantageously, an important principle of action is that moisture from body (such as foot) perspiration, along with the mechanical action of the body (such as a foot) flexing against the device (such as an insole or patch) of the invention, leads to sustained release and distribution of small but active amounts of the biocidal metal ions copper and zinc, thereby inhibiting or killing bacteria and fungi resident on the skin and within the sock fabric and shoe. Foot odors attributable to microorganisms in socks or on the feet are diminished by both direct biocidal activity of the metal ions against colonizing bacteria and fungi, and also through the direct inactivation of some odorant molecules by the metal phthalocyanine dye covalently linked to the cellulosic layer of the device. While perspiration reflects some aspects of blood chemistry, people with diabetes have increased concentrations of glucose and other reducing sugars, as well as aldehyde and alpha- hydroxyketone compounds in both blood and perspiration. Cupric ions under the right conditions can react with these biological indicators of diabetes, including but not limited to, reducing sugars, aldehydes and alpha-hydroxyketones. The cupric ions undergo a color change reaction as the blue-green cupric ions are converted to red-brown cuprous ions and copper oxide.

Thus, constituents of the devices that impart antimicrobial activity in essence can also behave like a Benedict's Reagent, providing a color change, the rate and extent of which is proportional to the severity of diabetic dysregulation of glucose and related metabolites, including ketone bodies. A device 10, such as the insole or patch of the present invention, can be fabricated to provide a color change reflecting control of blood sugars. The color change is cumulative over time, reflecting average control over a period of time approximating the useful lifetime of the insole device. Diabetes features large variations in blood sugars throughout the day, so averaging over time provides a more useful index of overall glucose control than indices reflecting a short time period. This is analogous to the clinical use of glycosylated hemoglobin (HbAlc) as index of glucose control for diagnosis or monitoring diabetes, reflecting average glucose levels over the 2 to 3 months preceding a measurement, versus blood glucose measurements at a few time points which can be misleading if they depict peak or trough levels rather than true averages.

A card or color comparison chart with colors depicting the determined color change effect of different levels of diabetic indicators in perspiration on the device color can be used to allow the user or a health care professional to assess the severity of diabetes or prediabetes, or by tracking color changes over time, the progression or remission of diabetes during treatment or lifestyle change. This provides not only a diagnostic tool, but a noninvasive feedback system for encouraging compliance to lifestyle changes or treatment regimens that may affect the progression of diabetes. Such feedback is particularly useful in type 2 diabetes, which can be asymptomatic even though irreversible complications may be developing over the course of a number of years.

A method for detecting diabetes can comprise the steps of providing any embodiment of the device according to the present invention, placing the device in proximity to the skin of a person such that a bodily fluid secreted from the skin can contact the antimicrobial layer of the device, and observing an amount of color change of the antimicrobial layer to determine an amount of biological indicators of diabetes in said bodily fluid and thereby determine the severity of diabetes of said person. The method can also comprise the step of comparing the color of the device with color shades obtained by exposure of the device to known amounts of biological indicators of diabetes. A color comparison card or chart may be used for this purpose.

A method of making the layer of material 12 used in the device 10 will now be disclosed by way of example only, primarily with respect to making a layer 12 comprising cellulose (for example, rayon and cotton) with antimicrobial compositions 14 comprising metal phthalocyanine dye and divalent metallic ions that react with biological indicators of diabetes, though other methods can be used to produce the same materials, and corresponding materials with other antimicrobial compositions according to the present invention, as will be understood by those with skill in the art with reference to this disclosure.

Example 1: Preparation of Antimicrobial Non Woven Layer

According to one embodiment of the present invention, antimicrobial layer 12 was prepared according to the present invention as follows. A solution was prepared by dissolving 30 grams of sodium sulfate in 600 grams distilled water, followed by mixing 4 grams of Reactive Blue 21 dye with it. 30 grams of nonwoven rayon fabric having a fabric weight of 70 g/m ² were immersed into the solution and gently swirled until uniformly submerged and wetted. Then, 12 grams of sodium carbonate were added with stirring, and the mixture was held at 30°C for 35 minutes. Next, the temperature was raised to 70°C for an additional 60 minutes yielding the sulfonated rayon fabric. The sulfonated rayon fabric was rinsed under running water until no more free dye was eluted, and the sulfonated rayon fabric was air-dried. Then, copper acetate and zinc acetate, both of which are divalent metal salts, were applied by aerosol to the fabric at 40 μΐ/cm ² using a concentration of 1 gram metal salt per 100 milliliters of water. The fabric comprising the additional substance was then air-dried yielding sulfonated rayon fabric comprising both divalent copper and divalent zinc ions.

Example 2: Preparation of Antimicrobial Textile Layer

According to another embodiment of the present invention, antimicrobial textile 12 was prepared according to the present invention as follows. A solution was prepared by dissolving 30 grams of sodium sulfate in 600 grams distilled water, followed by mixing 4 grams of Reactive Blue 21 dye with it. 30 grams of 230 g/m ² single sided velour cotton fabric were immersed into the solution and gently swirled until uniformly submerged and wetted. Then, 12 grams of sodium carbonate were added with stirring, and the mixture was held at 30°C for 35 minutes. Next, the temperature was raised to 70°C for an additional 60 minutes yielding the sulfonated cotton fabric. The sulfonated cotton fabric was rinsed under running water until no more free dye was eluted, and the sulfonated cotton fabric was air-dried. 50 grams each of copper acetate and zinc acetate per liter of water was sprayed on the sulfonated cotton at 0.08L/m ² producing the sulfonated cotton fabric comprising both divalent copper and divalent zinc ions. The sulfonated cotton fabric comprising both divalent copper and divalent zinc ions was again air-dried.

Physical substrates of the device comprising an insole can be but not limited to various structures such as multilayer punched version, multilayer laminated version and multilayer molded version. In one embodiment, an antimicrobial insole device 10 of the invention is a multilayer punched version which comprises three layers as shown in Figure 1. First, in contact with the sock (or foot sole if a user is not wearing socks) is a porous layer 18 such as a punched woven, punched non woven, wrap knitted or mesh fabric including but not limited to polyethylene terephthalate, polyethylene, polypropylene, polyamide or vinyon. This layer is 0.1 mm to 1.0 mm thick which permits diffusion of perspiration and its constituents (including odor compounds, nutrients, and even some bacterial or fungal cells) from the foot or sock into the antimicrobial insole of the invention, and also permits diffusion of low concentrations of copper and zinc ions from the insole device into perspiration in socks and onto the surface of the foot. Beneath the porous web is a layer of cellulosic fabric 12 such as cotton, rayon or their blended, which has been derivatized with a sulfonated metal phthalocyanine (including but not limited to C.I. Reactive Blue 21 dye) and further complexed with divalent copper and/or zinc ions ("antimicrobial textile"). Beneath antimicrobial textile 12 is a cushioning layer 20, e.g. molded or cast polyurethane foam, molded or cast ethylene vinyl acetate foam, or similar material which provides flexibility and cushioning, and which can be readily molded to fit inside shoes and to provide comfortable contact with the plantar surface of the foot.

In another embodiment, an antimicrobial insole device of the invention is a multilayer laminated version which comprises five layers as shown in Figure 2. First, in contact with the sock (or foot sole if a user is not wearing socks) is a porous layer 18 such as mesh fabric, wrap knitted fabric or filament web including but not limited to polyethylene terephthalate, polyethylene, polypropylene, polyamide, vinyon or a combination thereof. This layer is 0.1 mm to 1.0 mm thick which permits diffusion of perspiration and its constituents (including odor compounds, nutrients, and even some bacterial or fungal cells) from the foot or sock into the antimicrobial insole of the invention, and also permits diffusion of low concentrations of copper and zinc ions from the insole device into perspiration in socks and onto the surface of the foot. Beneath the porous layer is either a wear resistant layer 22 comprising a web of filaments of thermoplastic including but not limited to polyethylene terephthalate, polyethylene, polypropylene, polyamide, vinyon, or a layer of cellulosic fabric 12 such as cotton, rayon or their blended, which has been derivatized with a sulfonated metal phthalocyanine (including but not limited to C.I. Reactive Blue 21 dye) and further complexed with divalent copper and/or zinc ions ("antimicrobial textile"). The third layer is a cushioning layer 20, e.g. molded or cast polyurethane foam, molded or cast ethylene vinyl acetate foam, air mesh polyethylene terephthalate or similar material which provides flexibility and cushioning. Beneath the cushioning layer is either a layer of cellulosic fabric 12 such as cotton, rayon or their blended, which has been derivatized with a sulfonated metal phthalocyanine (including but not limited to C.I. Reactive Blue 21 dye) and further complexed with divalent copper and/or zinc ions ("antimicrobial textile") or a wear resistant layer 22 comprising a web of filaments of thermoplastic including but not limited to polyethylene terephthalate, polyethylene, polypropylene, polyamide or vinyon. The fifth layer is wear resistant layer 22 comprising a web of filaments of thermoplastic including but not limited to polyethylene terephthalate, polyethylene, polypropylene , polyamide, vinyon or blended for wear resistant.

In another embodiment, an antimicrobial insole device of the invention is a molded version which comprises two layers as shown in Figure 3. In contact with the sock (or foot sole if a user is not wearing socks) is a antimicrobial layer 12 such as 100 - 300 g/m ² non woven, woven, knitted, wrap knitted or mesh fabric including but not limited to celluosic or the blended of cellulosic such as cotton, rayon or their blended, which has been derivatized with a sulfonated metal phthalocyanine (including but not limited to C.I. Reactive Blue 21 dye) and further complexed with divalent copper and/or zinc ions ("antimicrobial textile"). Beneath antimicrobial textile 12 is a cushioning layer 20, e.g. molded or cast polyurethane foam, molded or cast ethylene vinyl acetate foam, or similar material which provides flexibility and cushioning, and which can be readily molded to fit inside shoes and to provide comfortable contact with the plantar surface of the foot.

Example 3: Fabrication of antimicrobial insole device (I)

According to one embodiment of the present invention, the sulfonated rayon fabric comprising divalent metal salts prepared in Example 1 was glued to a 3 mm thick polyurethane foam. The assembly was punched with holes of 0.9 mm in diameter and 94 holes per 22 cm ² in density. After that, a 0.2 mm wrap knitted terylene fabric was glued next to the layer of antimicrobial textile and obtained the antimicrobial insole device.

Example 4: Fabrication of antimicrobial insole device (II)

According to another embodiment of the present invention, the sulfonated rayon fabric comprising divalent metal salts prepared in Example 1 was glued to a 2.5 mm thick polyurethane foam. The assembly was punched with holes of 0.9 mm in diameter and 94 holes per 22 cm ² in density. After that, a 0.6 mm wrap knitted terylene fabric was glued next to the layer of antimicrobial textile and obtained the antimicrobial insole device.

Example 5: Fabrication of antimicrobial insole device (III)

According to another embodiment of the present invention, the sulfonated rayon fabric comprising divalent metal salts prepared in Example 1 was glued to a 3 mm thick polyurethane foam. Then, a 0.6 mm mesh terylene fabric was glued next to the layer of antimicrobial textile of the assembly. Finally, the triple layered assembly was punched with holes of 0.9 mm in diameter and 94 holes per 22 cm ² in density that the antimicrobial insole device was obtained.

Example 6: Fabrication of antimicrobial insole device (IV)

According to another embodiment of the present invention, an antimicrobial insole device of the invention is a multilayer laminated version which comprises five layers. Beneath the 90 g/m ² terylene mesh porous layer, it is a 500 g/m ² filament web made of 70% PVC sheath 30% terylene filament core, followed by the cushioning layer 150g/m ² air mesh terylene, the sulfonated rayon fabric comprising divalent metal salts prepared in Example 1 and a 470 g/m ² filament web made of 70% PVC sheath 30% terylene filament core respectively. The layers were welded together by ultrasonic along the edge of insole. Example 7: Fabrication of antimicrobial insole device (V)

According to another embodiment of the present invention, an antimicrobial insole device of the invention is a multilayer laminated version which comprises five layers. Beneath the 90 g/m ² terylene mesh porous layer, it is the sulfonated rayon fabric comprising divalent metal salts prepared in Example 1, followed by the cushioning layer 150g/m ² air mesh terylene and the wear resistant layers of 500 g/m ² filament web made of 70% PVC sheath 30% terylene filament core and 470 g/m ² filament web made of 70% PVC sheath 30% terylene filament core respectively. The layers were welded together by ultrasonic along the edge of insole.

Example 8: Fabrication of antimicrobial insole device (VI) According to another embodiment of the present invention, the sulfonated rayon fabric comprising divalent metal salts prepared in Example 2 was molded together with ethylene vinyl acetate foam to fit inside shoes and to provide comfortable contact with the plantar surface of the foot.

Example 9: Antibacterial activity of insole material

Antimicrobial activity of insole material was assessed based on the testing method AATCC 100 using staphylococcus epidermidis ATCC 1228 (challenge microorganism), which is a "gram-positive" bacterium responsible for human odor and specific skin infections. 1.25 inch by 2.25 inch insoles and control materials were exposed to UV for 30 minutes. A sterile barrier with a one inch by two inch opening was placed over the materials. Approximately 0.2 milliliters to 0.6 milliliters of challenge microorganism were misted on the materials in two pumps at rate one second per pump using a spray device from a distance of 3 inches to 6 inches under ambient condition. The misted materials were incubated at 37°C for 4, 8 and 24 hours respectively. After incubation, materials were placed into a sterile stomacher bag which contained 50 mL of DE neutralizing broth and processed for 5 minutes. 1 milliliter of extraction aliquot obtained from the stomacher bag was diluted ten-fold using Butterfield's phosphate buffered dilution water and the diluted aliquots were pour plated onto nutrient agar. The plates were inverted and incubated at 37±2°C for two nights. Following incubation, the plates were removed and the colonies on were counted to determine the CFU. Reduction percentage was calculated according to the following equation:

· Average Initial Counts ¹ - Recovered Counts _{i nn}

Percent Reduction = xl 00

Average Initial Counts Control

where Initital Counts ¹ = Initial Counts for Unmodified Control Material

Three replicates were performed in the test.

Percentage Reduction of Staphylococcus Epidermidis

Contact Time Replicate 1 Replicate 2 Replicate 3 Average

4 Hours 99.86 99.79 99.86 99.84

8 Hours 99.98 99.99 99.99 99.99

24 Hours 99.91 99.91 99.97 99.93

Example 10: Anti-fungal activity of insole material

Antimicrobial activity of insole material was assessed based on the testing method

AATCC 100 using trichophyton rubrum ATCC 18753 (challenge microorganism) which is the most common dermatophyte causing tinea pedis (Athletes Foot) and other fungal skin infections. 1.25"x 2.25" insoles and control materials were exposed to UV for 30 minutes. A sterile barrier with a l"x2"opening was placed over the materials. 0.2 - 0.6 mL of challenge microorganism were misted on the materials in two pumps at rate one second per pump using a spray device from a distance of 3" - 6" under ambient condition. The misted materials were incubated at 37°C for 4, 8 and 24 hours respectively. After incubation, materials were placed into a sterile stomacher bag which contained 50 mL of DE neutralizing broth and processed for 5 minutes. 1 mL of extraction aliquot obtained from the stomacher bag was diluted ten-fold using Butterfield's phosphate buffered dilution water and the diluted aliquots were pour plated onto Emmon's modification of sabouraud dextrose agar. The plates were inverted and incubated at 25-30°C for 3-5 days. Following incubation, the plated was removed and the colonies were counted to determine the CFU. Reduction percentage was calculated according to the following equation:

· Average Initial Counts ¹ - Recovered Counts _{i nn}

Percent Reduction = xl 00

Average Initial Counts Control

where Initital Counts ¹ = Initial Counts for Unmodified Control Material

Three replicates were performed in the test.

Percentage Reduction of Trichophyton Rubrum

Contact Time Replicate 1 Replicate 2 Replicate 3 Average

4 Hours 94.03 91.94 97.76 94.58

8 Hours 99.97 99.98 99.92 99.96

24 Hours >99.99 >99.99 >99.99 >99.99

Example 11: Efficacy of antimicrobial insole device against foot odor and athlete's foot symptoms

The activity of the antimicrobial insole device of the invention against food odor and symptoms of tinea pedis was tested in a group of 25 subjects with persistent foot odor problems. 12 subjects displayed symptoms consistent with chronic tinea pedis.

Subjects:

15 males (aged 23 to 37)

10 females (aged 21 to 25)

Persistent foot odor was quantified on a 3 point scale: 1= mild

2 = moderate

3= severe. Tinea pedis symptoms were quantified on a 3 point scale:

1 = mild (isolated dry skin and itchiness)

2 = moderate (isolated skin breaks)

3 = severe (distributed skin breaks) Participants wore a pair of their own running shoes (already laden with microbial colonization and foot odor) for consecutive 14 days, and severity of foot odor and tinea pedis symptoms (where present at baseline) were evaluated before and at the end of the 14 day trial period. The result is summarized in Table 1.

Table 1

Odor severity Athlete's Foot severity

Initial Odor Final Odor Initial Athlete's Final Athlete's

Subject severity severity Foot severity Foot severity

1 Medium Mild Mild -

2 Severe Mild - -

3 Severe Mild Medium Mild

4 Medium Mild Mild -

5 Medium Mild - -

6 Medium Mild - -

7 Mild - - -

8 Severe Medium Mild -

9 Severe Medium Medium Mild

10 Severe Medium - -

11 Mild - - -

12 Mild - - -

13 Medium Mild - -

14 Severe Medium Medium Mild

15 Severe Medium Mild -

16 Medium Mid - - 17 Medium Mid - -

18 Severe Medium - -

19 Severe Medium Mild -

20 Medium Mild Mild -

21 Medium Mild Mild -

22 Medium Mild Mild -

23 Medium Mild Severe Mild

24 Medium Mild - -

25 Mild - - -

All subjects displayed a reduction in foot odor severity during the 14 day trial, even when wearing shoes with pre-existing odor and microbial colonization. All subjects with tinea pedis symptoms at the beginning of the 14 day trial displayed reductions in symptoms at the end of the test period.

Example 12: Diffusion of Copper/Zinc from the Antimicrobial Insoles Device into Sock or Feet

In average, people will walk 5000-8000 steps per day and will generate 250-400 ml of moisture per foot. To evaluate how many copper and zinc ions will be released from the insoles device and distributed through the shoe environment which includes foot, sock and shoe during walking, a stepping test was set as follows. An electronic crockmeter TNH08 providing a repeated forward and backward moving action along a 16x100 mm rubbing track was adapted to simulate the stepping action. The rubbing head of the meter was wrapped with a cotton fabric and was designated as foot. A knitted cotton fabric which was designated as sock, the antimicrobial insoles device prepared in Example 3, 4, 5, 6, 7 or

8 and a woven cotton fabric which was designated shoe were clamped on the test platform.

When stepping was started, 9N vertical pressure would be applied from foot to the sock, insole and shoe. 3 ml moisture was applied to the test area every 600 steps. The copper and zinc content of the foot, sock and shoe was measured every 3600 steps and new set of foot and sock test fabrics were replaced before starting further stepping.

Table 2-7 are the stepping test result for the antimicrobial insoles device prepared in Example 3-8. It showed that less than 10% copper and zinc would diffuse from the antimicrobial insole device prepared in Examples 3-6 to foot, sock and shoe during stepping. Table 6 and 7 shows 2-18% copper and zinc would diffuse from the antimicrobial insole device prepared in Example 7, while 1-40% copper and zinc would diffuse from the antimicrobial insole device prepared in Example 8 to foot, sock and shoe respectively.

Table 2

Copper Zinc

(Relative % to Insole D evice) (Relative % to Insole D evice)

3,600 7,200 10,800 3,600 7,200 10,800

Steps Steps Steps Steps Steps Steps

Foot 4.5 4.0 3.0 5.2 4.2 4.0

Sock 8.3 4.5 3.4 6.3 3.8 3.1

Shoe 0.8 0.6 1.6 1.2 2.4 2.6

Table 3

Copper Zinc

(Relative % to Insole D evice) (Relative % to Insole D evice)

3,600 7,200 10,800 7,200 10,800

3,600 Steps

Steps Steps Steps Steps Steps

Foot 4.4 3.0 1.9 4.4 3.2 1.9

Sock 7.0 3.1 2.6 6.3 2.4 1.9

Shoe 0.7 0.7 0.8 2.1 1.5 0.9

Table 4

3,600 7,200 10,800 3,600 7,200 10,800

Copper

Steps Steps Steps Steps Steps Steps

Foot 6.2 4.4 3.2 6.0 4.5 3.6

Sock 9.0 5.2 3.7 7.7 5.3 3.4

Shoe 0.0 0.0 0.0 0.0 2.1 2.1

Table 5

3,600 7,200 10,800 3,600 7,200 10,800

Steps Steps Steps Steps Steps Steps Foot 5.3 6.9 5.6 5.7 4.6 4.2

Sock 5.5 4.3 4.4 8.6 5.1 4.4

Shoe 2.6 3.9 3.7 5.4 4.0 2.8

Table 6

3,600 7,200 10,800 3,600 7,200 10,800

Copper

Steps Steps Steps Steps Steps Steps

Foot 12.4 10.3 7.3 11.4 5.6 3.8

Sock 18.4 11.0 7.1 13.7 7.2 5.0

Shoe 4.0 4.1 4.6 4.8 3.8 2.7

Table 7

% Compared BioFriend™

3,600 7,200 10,800 3,600 7,200 10,800

Copper

Steps Steps Steps Steps Steps Steps

Foot 27.7 33.9 26.1 14.0 19.5 16.1

Sock 31.7 40.8 35.9 22.0 23.7 12.8

Shoe 1.2 1.0 2.4 0.0 5.9 9.7

While incorporation of colorimetric reagents for diabetes detection within an insole device 10 is a convenient embodiment of the invention for a cumulative signal over time, it is also possible to incorporate essentially the same chemistry into a patch 10 for prolonged attachment to skin at a site that may optionally not be on the feet. One embodiment of a patch 10 is shown in Figure 4. The patch 10 can be any suitable size or shape suitable for application to a targeted area of a body or surface. In one embodiment, such a device 10 would contain cupric ions loosely immobilized or chelated in a substrate with a nonreducing organic acid such as succinic or citric acid. Reducing sugars or aldehyde or ketone compounds in perspiration leach into the patch and cause a color-change reaction proportional to the concentration of, and time of exposure to, such indicators of diabetes or prediabetes in perspiration.

An adhesive layer 16 can be incorporated in all embodiments of the device 10, including insoles and patches described herein. As a non-limiting example, a layer of adhesive 16 can be placed about an edge of the antimicrobial layer 12 of the device 10 to secure the device 10 with a body part of a person. Alternatively, as shown in Figure 5, the adhesive layer 16 can be an adhesive backing layer 16 connected to one side of the antimicrobial layer 12 such that it can removably attach the device 10 to a surface while permitting the opposite side of the antimicrobial layer 12 to contact a body part of a person. For example, the device 10 can be a patch or insole that removably attaches within a shoe via the adhesive layer 16. Also shown in Figure 5, the adhesive layer 16 can further comprise a cover 24 removably connected to the adhesive layer 16 to protect the adhesive layer 16 until the device 10 is ready for use. The cover 24 can also cover the adhesive layer 16 of embodiments of the device wherein the adhesive layer 16 is located about the edge of the device 10.

The foregoing devices can provide cost-effective and disposable indicators of diabetes while imparting antimicrobial activity. While the present invention has been described with regards to particular embodiments, it is recognized that additional variations of the present invention may be devised without departing from the inventive concept. A person skilled in the art would appreciate that exemplary embodiments described hereinabove are merely illustrative of the general principles of the present invention. Therefore, the scope of the appended claims should not be limited to the description of preferred embodiments contained in this disclosure. Accordingly, the drawings and description are illustrative and not meant to be a limitation thereof.