Cleanable and intelligent aerogel wound dressing

Abstract

Aerogel wound dressings comprising one or more aerogel layers, including sensing means for monitoring the environment of a wound, and methods of treating a wound using the aerogel wound dressings. The wound dressing includes a base layer that may include a sensing component, and optionally a removable layer that may be removed after saturation of wound exudate when used to treat a wound. A method of treating a wound includes applying an aerogel wound dressing to a wound, monitoring an infection, replacing the wound dressing after the infection, and replacing the removable layer after wound exudate saturation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. US63 / 350,963, filed on June 10, 2022, the entire contents of which are incorporated herein by reference.

[0003] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0004] This invention was made with government support from the National Science Foundation under Grant CMMI-1826030. The government has certain rights in this invention. Technical Field

[0005] The present invention relates to the field of medical devices, and in particular to wound dressings for treating wounds, including chronic wounds. In a specific embodiment, the present invention relates to an aerogel-based wound dressing that promotes the healing process of wounds, including chronic wounds. In a further embodiment, the present invention relates to a method of treating a wound using an aerogel-based wound dressing. Background Art

[0006] Wound healing is a complex process. Some wounds, such as chronic wounds, fail to heal for weeks or even years, which further complicates the healing process. The goal of wound care is to speed healing and prevent wounds from becoming chronic. The four phases of wound healing include hemostasis, inflammation, proliferation, and remodeling. In chronic wounds, the healing process is still in the inflammatory phase, where patients experience local swelling, redness, heat, and pain. During this phase, the wound typically exudes a fluid composed of water, salts, proteins, fluid from injured blood vessels, debris from damaged tissue, growth factors, etc. This fluid is called wound exudate. Proper exudate management and removal is essential for the healing of such wounds and for entering the later stages of wound healing. In addition, it is important to prevent the wound from becoming infected with pathogens from the environment. Any such infection can slow healing or cause further damage to the wound. When a wound becomes infected with a pathogen, it forms a layer of "biofilm," a membrane tissue formed by microorganisms that attach to the wound surface and produce destructive enzymes and toxins that promote the inflammatory phase in the wound.

[0007] In the current scenario, poor absorption of exudate by dressings and the need to monitor wounds for infection are some of the reasons why wound dressings are changed frequently every day. When dressings are changed, the wound bed is disturbed and the wound is exposed to the environment, increasing the risk of biofilm formation and delayed healing. For this reason, new wound dressings that can absorb large amounts of exudate and stay on the wound for a longer period of time are profitable. Two key properties that wound dressings, especially chronic wound dressings, should possess are: high absorption of exudate from the wound and restriction of bacteria / viruses from the environment. Therefore, there is a need for a cleanable and smart dressing that has all of the above properties. Summary of the invention

[0008] Embodiments of the present invention provide an aerogel wound dressing comprising an aerogel layer, wherein the aerogel layer comprises a sensing component.

[0009] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component indicates changes in pH of wound exudate absorbed by the aerogel layer.

[0010] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component changes color due to a pH change of wound exudate absorbed by the aerogel layer.

[0011] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component comprises curcumin.

[0012] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component is added to the first aerogel layer during its formation.

[0013] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component comprises a probe connected to an external sensing device.

[0014] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer absorbs 10 times or more of the exudate per weight of the first aerogel layer.

[0015] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, further comprising a second aerogel layer in contact with the first aerogel layer, wherein the second aerogel layer is removable from the aerogel wound dressing.

[0016] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the second aerogel layer absorbs the fluid absorbed by the first aerogel layer.

[0017] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a first plurality of interconnected pores, and wherein the second aerogel layer comprises a second plurality of interconnected pores.

[0018] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the average pore size of the first plurality of interconnected pores is greater than the average pore size of the second plurality of interconnected pores.

[0019] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a sensing component.

[0020] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel wound dressing is configured so that the second aerogel layer is user replaceable when the second aerogel layer is saturated and removed.

[0021] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel wound dressing is configured such that the first aerogel layer is configured to remain in place after the second aerogel layer is removed.

[0022] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a sensing component.

[0023] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein pathogens cannot pass through the first aerogel layer.

[0024] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer is formed of at least one of cellulose, cellulose nanocrystals, chitosan, Kevlar, lignin, or any combination thereof, and wherein the second aerogel layer is formed of at least one of cellulose, cellulose nanocrystals, chitosan, Kevlar, lignin, or any combination thereof.

[0025] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component is sensitive to the pH of wound exudate absorbed by the aerogel wound dressing.

[0026] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component indicates a change in pH of the wound exudate in response to the presence of pathogens or pathogenic byproducts in the wound exudate.

[0027] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component changes color due to the change in pH of the wound exudate.

[0028] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component exhibits keto-enol tautomerism.

[0029] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component comprises curcumin.

[0030] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component is added to the aerogel layer during formation of the aerogel layer.

[0031] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the sensing component comprises a probe connected to an external sensing device.

[0032] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel layer comprises a biopolymer.

[0033] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the biopolymer comprises at least one of cellulose, cellulose nanocrystals, chitosan, Kevlar, lignin or any combination thereof.

[0034] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel layer comprises two or more biopolymers.

[0035] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel layer comprises a biopolymer gel grown within another biopolymer gel.

[0036] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel layer comprises a biopolymer.

[0037] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the aerogel layer has a filtration efficiency of 98.9% or higher.

[0038] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein pathogens cannot pass through the aerogel layer.

[0039] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the aerogel layer absorbs 10 times or more of the exudate per weight of the aerogel layer by weight.

[0040] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the aerogel layer has a microstructure feature.

[0041] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the microstructure comprises a plurality of interconnected pores.

[0042] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the pores in the plurality of interconnected pores have a pore size of about 2 nm to about 50 nm.

[0043] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the microstructure has a polymer domain thickness of about 10 nm to about 50 nm.

[0044] An embodiment of the present invention provides an aerogel wound dressing, comprising a first aerogel layer and a second aerogel layer in contact with the first aerogel layer, wherein the second aerogel layer is removable from the aerogel wound dressing.

[0045] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the first aerogel layer has a first microstructure feature.

[0046] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the first microstructure comprises a plurality of interconnected macropores.

[0047] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the macropores in the plurality of interconnected macropores have a pore size of about 50 nm to about 200 nm.

[0048] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the second aerogel layer has a second microstructure feature.

[0049] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the second microstructure comprises a plurality of interconnected micropores.

[0050] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the micropores in the plurality of interconnected micropores have a pore size of about 2 nm to about 50 nm.

[0051] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a first biopolymer.

[0052] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the second aerogel layer comprises a second biopolymer.

[0053] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer and the second aerogel layer comprise a biopolymer.

[0054] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a first plurality of pores and the second aerogel layer comprises a second plurality of pores, wherein the average size of the first plurality of pores is the same as the average size of the second plurality of pores.

[0055] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a first plurality of pores and the second aerogel layer comprises a second plurality of pores, wherein the average size of the first plurality of pores is larger than the average size of the second plurality of pores.

[0056] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein the first aerogel layer comprises a sensing component.

[0057] Another embodiment of the present invention provides an aerogel wound dressing as described in any of the above embodiments, wherein the first aerogel layer has a filtration efficiency of 98.9% or higher.

[0058] Another embodiment of the present invention provides an aerogel wound dressing as in any of the above embodiments, wherein pathogens cannot pass through the first aerogel layer.

[0059]

[0013] Embodiments of the present invention provide a method of treating a wound comprising applying an aerogel wound dressing to the wound.

[0060] Another embodiment of the present invention provides a method for treating a wound as in any of the above embodiments, further comprising the steps of monitoring a sensing component for the presence of a pathogen, removing the aerogel wound dressing from the wound when the sensing component indicates the presence of a pathogen, and applying a treatment to the aerogel wound dressing when the sensing component indicates the presence of a pathogen.

[0061] Another embodiment of the present invention provides a method for treating a wound as in any of the above embodiments, wherein the aerogel wound dressing is a multi-layer aerogel wound dressing, comprising a first aerogel layer comprising a sensing component, and a second aerogel layer in contact with the first aerogel layer, wherein the second aerogel layer is removable from the aerogel wound dressing; and the method further comprises removing the second aerogel layer after being saturated with exudate from the wound, and applying a replacement second aerogel layer to the first aerogel layer, so that the replacement second aerogel layer removes exudate from the first aerogel layer.

[0062] Another embodiment of the present invention provides a method for treating a wound as described in any of the above embodiments, wherein the aerogel wound dressing comprises a sensing component.

[0063] Another embodiment of the present invention provides a method for treating a wound as described in any of the above embodiments, further comprising the aerogel wound dressing comprising the sensing component.

[0064] Another embodiment of the present invention provides a method for treating a wound as in any of the above embodiments, further comprising removing the aerogel wound dressing from the wound when the sensing component indicates the presence of a pathogen.

[0065] Another embodiment of the present invention provides a method of treating a wound as in any of the above embodiments, further comprising applying a treatment to the aerogel wound dressing when the sensing component indicates the presence of a pathogen.

[0066] Another embodiment of the present invention provides a method for treating a wound as in any of the above embodiments, wherein the aerogel wound dressing is a multi-layer wound dressing, comprising a first aerogel layer and a second aerogel layer in contact with the first aerogel layer, wherein the second aerogel layer is removable from the aerogel wound dressing.

[0067] Another embodiment of the present invention provides a method for treating a wound as described in any of the above embodiments, further comprising removing the second aerogel layer after the wound is saturated with exudate.

[0068] Another embodiment of the present invention provides a method for treating a wound as in any of the above embodiments, further comprising applying a replacement second aerogel layer to the first aerogel layer so that the replacement second aerogel layer contacts the first aerogel layer and removes exudate from the first aerogel layer.

[0069] Another embodiment of the present invention provides a method for treating a wound as in any of the above embodiments, wherein the aerogel wound dressing is applied to the wound for 20 days or longer. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 is a representative side view of a cross-section of an embodiment of an aerogel wound dressing applied to a wound;

[0071] Figure 2A An aerogel wound dressing according to an embodiment of the present invention is shown, comprising a sensing component;

[0072] Figure 2B An aerogel wound dressing according to an embodiment of the present invention is shown, comprising a sensing component subjected to artificial wound fluid;

[0073] Figure 2C An aerogel wound dressing according to an embodiment of the present invention is shown, comprising a sensing component that has undergone a color change after being subjected to an increase in pH by an artificial wound fluid. DETAILED DESCRIPTION

[0074] The present invention relates to the use of aerogels in wound dressings as a means of improving the functionality of wound dressings to promote wound healing and improve wound care. Aerogel wound dressings provide highly absorbent dressings that require less frequent changes and eliminate the need for bulky negative pressure wound therapy (NPWT) devices to improve the wound healing environment. In some embodiments, the present invention relates to methods of treating wounds using wound dressings comprising aerogels and aerogel composites.

[0075] Aerogels are a class of materials with low density and high porosity, typically consisting of 90-99% air by volume. Aerogels are known for their unique physical properties, such as low thermal conductivity, high surface area, and high specific surface area. These properties are attributed to the porous microstructure created during the aerogel formation process. The porous microstructure of the aerogel is the defining feature. The pore structure of the aerogel can be controlled by adjusting synthesis parameters such as precursor concentration, solvent selection, and drying conditions. This allows the generation of aerogels with a wide range of pore sizes, from microporous to mesoporous to macroporous.

[0076] As used herein, pore size may refer to an average pore size. As will be appreciated by one of ordinary skill in the art, the porous structure of an aerogel will include a distribution of pore sizes. As used herein, pore size may refer to the situation where the majority of pores of a particular aerogel composition fall within a specified range.

[0077] Microporous aerogels have pore sizes less than 2 nm and are often used in applications such as gas separation and catalysis. Mesoporous aerogels have pore sizes between 2 and 50 nm and are often used in applications such as energy storage and drug delivery. Macroporous aerogels have pore sizes greater than 50 nm and are often used in applications such as thermal insulation and sound absorption.

[0078] In one or more embodiments, aerogels suitable for use in wound dressings according to the present invention include mesopores. In one or more embodiments, the mesopores have a pore size of about 2 nm to about 50 nm.

[0079] In one or more embodiments, aerogels suitable for use in wound dressings according to the present invention include macropores. In one or more embodiments, the macropores have a pore size of about 50 nm to about 500 nm. In other embodiments, about 50 nm to about 450 nm. In other embodiments, about 50 nm to about 400 nm. In other embodiments, about 50 nm to about 350 nm. In other embodiments, about 50 nm to about 300 nm. In other embodiments, about 50 nm to about 250 nm. In other embodiments, about 50 nm to about 200 nm.

[0080] Pore ​​size is a key parameter that determines the capillary action of an aerogel. Capillary action is the ability of a liquid to flow through narrow spaces, such as the interconnected pores of an aerogel. The driving force for capillary action is the surface tension of the liquid, which pulls the liquid into narrow spaces. In general, smaller pores result in greater capillary action. This is because smaller pores have a higher surface area to volume ratio, which increases the surface tension at the liquid-gel interface. Therefore, liquids can flow more easily through smaller pores, even against the force of gravity.

[0081] In the context of wound healing, the capillary action of aerogels is important for promoting a moist wound healing environment while removing wound exudate from the wound surface. The interconnected pores of the aerogel can absorb wound exudate and hold it within the aerogel. The capillary action of the aerogel can help keep the wound moist, which is beneficial for wound healing.

[0082] It is also important to control pore size to prevent excessive fluid retention, which can lead to maceration of surrounding healthy tissue. Therefore, the pore size of aerogels used in wound dressings should be optimized to achieve the desired capillary action while also preventing fluid overload.

[0083] Advantageously, aerogels suitable for use in embodiments of the present invention act as a breathable barrier against bacteria and viruses. The interconnected pores of the aerogels used according to some embodiments of the present invention allow oxygen to diffuse through the aerogel and reach the wound. The same interconnected pores filter or repel the infiltration of bacteria or viruses into the aerogel. This filtration protects the wound from contact with bacteria or viruses present in the environment, thereby protecting the wound from infection caused by bacteria or viruses.

[0084] In one or more embodiments, the aerogel has a filtration efficiency of about 98.9% or more for nanoparticles with a size of 25 nm to 250 nm. In other embodiments, about 99.0% or more. In other embodiments, about 99.1% or more. In other embodiments, about 99.2% or more. In other embodiments, about 99.3% or more. In other embodiments, about 99.4% or more. In other embodiments, about 99.5% or more. In other embodiments, about 99.6% or more. In other embodiments, about 99.7% or more. In other embodiments, about 99.8% or more. In other embodiments, about 99.9% or more.

[0085] In one or more embodiments, the aerogel has a filtration efficiency of about 95% or more for E. Coli bacteria. In other embodiments, about 96% or more. In other embodiments, about 97% or more. In other embodiments, about 98% or more. In other embodiments, about 99% or more.

[0086] Aerogels are formed by converting a gel into an aerogel. The material composition of an aerogel suitable for use in the present invention is determined by the gel and the method used to convert the gel into an aerogel. As mentioned above, the gel and method used will also affect the resulting porous microstructure of the obtained aerogel.

[0087] The choice of material also depends on the use of the aerogel in wound dressings as a biomedical application. According to the purposes of the present invention, suitable aerogel compositions can be safely used in wounds, including chronic wounds. In addition, the choice of materials for aerogel formation depends on the mechanical properties required for use in wound dressings. In some embodiments, the aerogel composition may include a biopolymer. In other embodiments, the aerogel composition may include a mixture of biopolymers. In other embodiments, the aerogel composition may include a biopolymer gel grown in another biopolymer.

[0088] As used herein, biopolymers may refer to polymers that are compatible with animal use. Biopolymers may also refer to polymers derived from biomass or other natural sources, including natural polymers produced by cells of living organisms. The biocompatibility of aerogel materials allows dressings to be used on a wide range of wounds, including chronic wounds that require long-term treatment. The aerogel layer provides a highly absorbent and breathable layer that conforms to the contours of the wound surface, promotes a moist wound healing environment, and aids in tissue regeneration. The use of biocompatible aerogel materials further enhances the effectiveness of the dressing by minimizing the risk of infection or other complications that may arise from the use of non-biocompatible materials.

[0089] In some embodiments, materials suitable for aerogel compositions include biopolymers. In some embodiments, biopolymers include polynucleotides, polypeptides, and polysaccharides. In some embodiments, polypeptides include proteins and amino acids, including collagen, actin, and fibrin. In some embodiments, polysaccharides include starch, cellulose, and alginate. Other biopolymers include natural rubber, suberin, lignin, cutin, gelatin, and melanin. In some embodiments, materials suitable for aerogel compositions include chitosan, cellulose, cellulose nanocrystals, lignin, and combinations of two or more.

[0090] In some embodiments, materials suitable for aerogel compositions include biocompatible polymers, including those produced synthetically.

[0091] In some embodiments, the mechanical properties of the aerogel can be improved by forming a composite aerogel. In these and other embodiments, a sol network or framework can be first formed. The sol of the second gel can then be diffused within the framework and then gelled. Advantageously, this composite structure reduces the shrinkage of the aerogel during solvent exchange, thereby improving nucleation and growth. In such an embodiment, the framework can include synthetic fibers. Synthetic fibers suitable for use in the present invention include, but are not limited to, Kevlar.

[0092] According to some embodiments, the invention is an aerogel comprising a layer of aerogel material including a sensing component therein. The sensing component is designed to provide real-time feedback about the wound environment, allowing monitoring of the healing process and enabling informed decisions regarding treatment.

[0093] In one embodiment, the sensing component may be a pH sensor that detects changes in the acidity or alkalinity of the wound environment. In another embodiment, the sensing component may be a temperature sensor that measures the temperature of the wound surface. Other possible sensing components may include pressure sensors, oxygen sensors, or sensors that detect the presence of specific bacteria, viruses, or other pathogens.

[0094] In some embodiments, the sensing component in these embodiments can be an additive that changes color in response to pH changes. According to the purpose of the present invention, the additive of the aerogel composition should be biocompatible. This type of additive is generally referred to as a pH indicator. The pH indicator can be added to the aerogel during the aerogel synthesis process or as a post-processing step. The sensing additive can be included during gel formation or during solvent exchange and gel drying. The sensing additive can also be included in the aerogel by emulsion template, precipitation, or using non-solvent precipitation during the solvent exchange step. The pH indicator can be selected according to its sensitivity to a specific pH range, which can be customized according to the needs of the wound healing application.

[0095] When the aerogel wound dressing is in contact with the wound bed, the pH indicator can detect changes in the pH level of the wound exudate. The pH indicator will change color in response to the pH change, which is visually detectable. This can provide a simple and non-invasive way to monitor the pH level of the wound over time.

[0096] In some embodiments, the color change of the pH indicator can be associated with a specific pH value, which can be determined by calibration experiments. This can provide a quantitative measurement of pH levels that can be recorded and tracked over time to monitor the progress of wound healing.

[0097] In summary, in some embodiments of the aerogel wound dressing of claim 1, the sensing component is designed to measure the pH level in the wound bed using a pH indicator additive. The pH indicator changes color in response to pH changes, thereby providing a simple and non-invasive way to monitor the pH level of the wound over time.

[0098] In some embodiments, the sensing agent is a compound that exhibits keto-enol tautomerism. Tautomers are isomers of molecules in which the positions of protons and double bonds are different. Keto-enol tautomerism is a type of tautomerism involving a proton transfer between a carbonyl group (ketone) and a hydroxyl group (enol) in an organic molecule.

[0099] As described above, the sensing agent can be added as an additive to the aerogel layer of the wound dressing. When the wound dressing is in contact with wound exudate, the pH indicator will undergo a proton transfer between the keto and enol forms in response to changes in pH levels. This proton transfer causes a change in the absorption spectrum of the pH indicator, resulting in a color change that can be visually detected.

[0100] The pH indicator is not particularly limited, and one of ordinary skill in the art will be able to select a suitable pH indicator without undue experimentation. In various embodiments, suitable pH indicators may include, but are not limited to, curcumin. Advantageously, curcumin is known to have beneficial effects on oxidative and inflammatory conditions.

[0101] like Figures 2A to 2C As shown, an aerogel wound dressing according to an embodiment of the present invention shows a change in the color of the wound dressing when subjected to an artificial wound fluid that increases the pH of the wound dressing. Figure 2A In the figure, the unused aerogel wound dressing is shown with a yellow color. Figure 2B In the experiment, the aerogel wound dressing was subjected to artificially infected wound fluid, which increased the pH of the aerogel wound dressing and initiated a yellow to red color change. Figure 2C In the figure, the entire aerogel wound dressing is reddish brown, indicating changes caused by the absorption of artificial wound exudate.

[0102] Other additives may be included in aerogel compositions suitable for use with the present invention. For example, aerogel compositions may be used as a means of delivering drug therapy to a wound. The drug therapy is not particularly limited, and one of ordinary skill in the art will be able to select a suitable drug therapy without undue experimentation. In various embodiments, suitable drug therapy may include, but is not limited to, biocides and antibiotics.

[0103] In some embodiments, two aerogels may be used in a wound dressing according to the present invention. In these and other embodiments, the two aerogels may be provided as a base layer and a top layer, also referred to as a first layer and a second layer, respectively. In these and other embodiments, the base layer functions to remove exudate from the wound surface, while the top layer removes exudate from the base layer. Without wishing to be bound by theory, it is believed that capillary action caused by the pore size of the aerogel provides the necessary driving force to remove exudate from the base layer, through the interface between the base layer and the top layer, and into the top layer. In these and other embodiments, the capillary action may be provided by a base layer having a porous structure with a pore size larger than the pore size of the porous structure of the top layer.

[0104] Reference now Figure 1 , a multilayer aerogel wound dressing, generally indicated by the numeral 100, is shown. The multilayer aerogel wound dressing 100 includes a first layer 101, also referred to as a base layer, and a second layer 102, also referred to as a top layer. The multilayer aerogel wound dressing 100 is applied to a wound surface 11 of a subject 10 so that the first layer 102 is in contact with the wound surface 11. The first layer 101 includes a macroporous structure. The second layer 102 includes a mesoporous structure. Arrow 121 represents exudate flowing from the wound surface 11 through the first layer 101 and into the second layer 102. Arrow 122 represents a breathable multilayer aerogel wound dressing 100, in which oxygen can permeate the first layer 101 and the second layer 102 to reach the wound surface 11. Arrow 123 represents the repellency of pathogens including bacteria and viruses by the multilayer aerogel wound dressing 100 due to the mesoporous structure of the second layer 102.

[0105] In an embodiment according to the present invention, the base layer comprises an aerogel having macropores. In these and other embodiments, the top layer comprises an aerogel having mesopores. In such an embodiment, the difference in pore size between the two layers allows exudate to be collected in the top layer while remaining moist in the bottom layer. Advantageously, removal of the exudate prevents the formation of biofilms, while the two layers of aerogel protect the wound from bacteria, viruses and other pathogens. In addition, the two-layer structure provides for removal and replacement of the top layer when the top layer is saturated with exudate. In these and other embodiments, the base layer can remain in contact with the wound while the top layer is removed and replaced with a clean top layer to provide continuous removal of exudate without irritating the wound due to changing wound dressings.

[0106] In embodiments according to the invention, one or more of the base layer and the top layer may include a sensing agent according to the above description.

[0107] The role of a wound dressing is to provide optimal conditions for wound healing while protecting the wound from further trauma and invasion of pathogenic microorganisms. It is also important that the dressing can be removed without damage to prevent further damage to the wound surface during dressing changes. In an embodiment according to the present invention, an aerogel wound dressing comprising at least an aerogel layer is provided. In some embodiments, the aerogel layer comprises an aerogel composition according to any of the descriptions included above.

[0108] In some embodiments, the aerogel layer of the aerogel wound dressing is the bottom layer that contacts the wound.

[0109] In some embodiments, the aerogel wound dressing may further include a fiber dressing as a bottom layer in contact with the wound. In other embodiments, the aerogel wound dressing may include a foam dressing as a bottom layer in contact with the wound.

[0110] In some embodiments, the aerogel wound dressing comprises two layers formed from an aerogel composition according to any of the descriptions included above. In these and other embodiments, the aerogel wound dressing may include a first aerogel layer as a base layer and a second aerogel layer as a top layer. In these and other embodiments, the top layer may be removable from the base layer. In these and other embodiments, the top layer may have a pore size that is smaller than the pore size of the base layer. In these and other embodiments, the base layer may include a sensing component for providing insight into the wound environment. In these and other embodiments, the sensing component may include any sensing component described above.

[0111] In some embodiments, the aerogel wound dressing can be secured to the wound using a medical adhesive.

[0112] In some embodiments, an aerogel wound dressing according to the present invention may be considered a primary wound dressing. In these and other embodiments, a secondary wound dressing known in the art may be used to secure the aerogel wound dressing in place. In these and other embodiments, a secondary dressing may be removed to access the primary wound dressing, which may include monitoring sensing components or remove and replace a second layer of a multi-layer aerogel wound dressing.

[0113] In some embodiments, the aerogel wound dressing according to the present invention is sized according to the type of wound to be treated. In some embodiments, the aerogel wound dressing according to the present invention is sized according to known standards in the field of wound dressings. An appropriately sized wound dressing can ensure that the entire surface area of ​​the wound to be treated is covered by the wound dressing.

[0114] In some embodiments, an aerogel wound dressing according to the present invention absorbs 10 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 15 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 20 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 25 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 30 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 35 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 40 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 45 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 50 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, 55 times or more of the weight of fluid per unit weight of the aerogel wound dressing. In other embodiments, there is 60 times or more weight of fluid per unit weight of aerogel wound dressing.

[0115] In some embodiments comprising a removable second layer in contact with the first layer, the removable second layer can have the same thickness as the first layer. In other embodiments, the removable second layer can have a thickness that is thicker than the first layer. One of ordinary skill in the art will readily appreciate that the thickness of a layer directly affects the amount of wound exudate absorbed by the layer.

[0116] In use, the aerogel wound dressing according to the present invention provides a highly absorbent and breathable dressing that conforms to the contours of the wound surface. The sensing component, when present, provides real-time feedback of the wound environment, allowing monitoring of the healing process. The unique combination of aerogel material and sensing component provides a versatile and effective wound dressing that can be used to treat a wide range of wounds, including chronic wounds that are difficult to heal using traditional treatments.

[0117] According to embodiments of the present invention, methods for treating wounds using aerogel wound dressings are provided. In some embodiments, the method for treating a wound may include applying an aerogel wound dressing to a wound. In these and other embodiments, the application may include applying an optional secondary wound dressing to secure the aerogel wound dressing in place. In these and other embodiments, the aerogel wound dressing may remove exudate from the wound as described above. In some embodiments, the aerogel wound dressing may include a sensing component. In these and other embodiments, the method may include monitoring the sensing component for the presence of pathogens. As described above, determining whether a pathogen is present in the wound environment may be indicated by a sensing component. In these and other embodiments, the method may further include removing the aerogel wound dressing from the wound when the sensing component indicates the presence of a pathogen. Removal allows the wound to be treated as needed.

[0118] In embodiments, when the method includes applying an aerogel wound dressing including at least a base aerogel layer and a top aerogel layer, the method may further include removing the top aerogel layer after the top aerogel layer is saturated with exudate from the wound. In these and other embodiments, the method may further include replacing the top aerogel layer with a replacement top aerogel layer so that exudate can continue to be removed from the wound. In these and other embodiments, the method may include contacting the base layer of the aerogel wound dressing with the wound for 7 days or more. In other embodiments, 14 days or more. In other embodiments, 15 days or more. In other embodiments, 16 days or more. In other embodiments, 17 days or more. In other embodiments, 18 days or more. In other embodiments, 19 days or more. In other embodiments, 20 days or more. In other embodiments, 21 days or more.

[0119] As described above, embodiments of the present invention can be manufactured according to the following methods. In some embodiments, a gel composition is formed according to the desired final properties of the resulting aerogel. In these and other embodiments, this can include providing any desired additives during gel formation. In these and other embodiments, gel formation includes providing a sol that undergoes a sol-gel transition. In some embodiments, a second sol of a second gel can be diffused within a sol network or framework produced by the first gel. In these embodiments, the second sol gels after diffusion. The shape of the resulting aerogel can be determined by the mold in which the gel composition is solidified. Depending on the type of wound that the resulting aerogel wound dressing is intended to treat, various molds can be used to produce different aerogels.

[0120] After the gel solidifies in the mold, the gel may be subjected to a solvent exchange. In some embodiments, additives may be included in the gel during the solvent exchange step. In some embodiments, after the solvent exchange step, the gel may undergo a supercritical drying step.

[0121] Other techniques known in the art may be suitable for producing aerogel compositions according to the above-described embodiments.

[0122] In view of the above, it should be understood that the present invention significantly advances the field by providing wound dressings and methods for treating wounds that are improved in structure and function in a variety of ways. Although specific embodiments of the present invention have been disclosed in detail herein, it should be understood that the present invention is not limited thereto, or that a person of ordinary skill in the art will readily understand variations of the present invention. The scope of the present invention should be understood from the following claims.

[0123] Example

[0124] To illustrate and put the present invention into practice, aerogel wound dressings of the present invention were synthesized as described above and evaluated to more fully determine the following properties.

[0125] Samples of various wound dressings were tested to determine their absorbency. The wound dressings included Duoderm, Algisite, Drawtex, Aquacel, and an aerogel wound dressing according to an embodiment of the present invention. Each sample was soaked in 100 ml of water and the mass increase over time was recorded. The results are reported in Table 1.

[0126] Table I. Absorption capacity results

[0127]

[0128]

[0129] The aerogel wound dressing according to the present invention shows a superior absorption rate per unit weight relative to other types of wound dressings.

[0130] Samples of wound dressings were tested to determine their filtration efficiency for nanoscale impurities. This test simulates the performance of the dressing in the presence of microorganisms. Samples of Algisite, Drawtex, Aquacel, and aerogel wound dressings according to embodiments of the present invention were subjected to a solution including NaCl nanoparticles having a size of 25 nm to 250 nm at a flow rate of 20 liters / min. The results of this test are reported in Table II.

[0131] Table II. Filtration efficiency results

[0132] Sample Filtration efficiency (%) Algisite 9.43±0.8 Drawtex 23.03±0.4 Aqualcel 22.73±0.7 Aerogel wound dressing 99.46±0.5

[0133] The above experimental parameters and settings are used to generate the data and information provided herein to support the claimed invention. Although the present invention has been described in detail with particular reference to certain embodiments described in detail herein, other embodiments can achieve the same results. Variations and modifications of the present invention will be apparent to those skilled in the art, and the present invention is intended to cover all such modifications and equivalents in the appended claims.

Claims

1. An aerogel wound dressing, comprising: A first aerogel layer, wherein the first aerogel layer comprises a sensing component.

2. The aerogel wound dressing according to claim 1, wherein The sensing component indicates changes in pH of wound exudate absorbed by the aerogel layer.

3. The aerogel wound dressing according to claim 2, wherein: Due to the change in pH of wound exudate absorbed by the aerogel layer, the sensing component changes color.

4. The aerogel wound dressing according to claim 1, wherein The sensing component includes curcumin.

5. The aerogel wound dressing according to claim 1, wherein: The sensing component is added to the first aerogel layer during formation of the first aerogel layer.

6. The aerogel wound dressing according to claim 1, wherein The sensing component includes a probe connected to an external sensing device.

7. The aerogel wound dressing according to claim 1, wherein: The first aerogel layer absorbs 10 times or more by weight of the exudate per weight of the first aerogel layer.

8. The aerogel wound dressing according to claim 1, further comprising: A second aerogel layer in contact with the first aerogel layer, wherein the second aerogel layer is removable from the aerogel wound dressing.

9. The aerogel wound dressing according to claim 8, wherein: The second aerogel layer absorbs the fluid absorbed by the first aerogel layer.

10. The aerogel wound dressing according to claim 8, wherein: The first aerogel layer comprises a first plurality of interconnected pores, and wherein the second aerogel layer comprises a second plurality of interconnected pores.

11. The aerogel wound dressing according to claim 10, wherein: The average pore size of the first plurality of interconnected pores is greater than the average pore size of the second plurality of interconnected pores.

12. The aerogel wound dressing according to claim 8, wherein: The first aerogel layer includes a sensing component.

13. The aerogel wound dressing according to claim 8, wherein: The aerogel wound dressing is configured such that the second aerogel layer is user replaceable when the second aerogel layer is saturated and removed.

14. The aerogel wound dressing according to claim 13, wherein: The aerogel wound dressing is arranged such that the first aerogel layer is arranged to remain in place after the second aerogel layer is removed.

15. The aerogel wound dressing according to claim 8, wherein: The first aerogel layer includes a sensing component.

16. The aerogel wound dressing according to claim 8, wherein Pathogens cannot pass through the first aerogel layer.

17. The aerogel wound dressing according to claim 8, wherein: The first aerogel layer is formed of at least one of cellulose, cellulose nanocrystals, chitosan, Kevlar, lignin, or any combination thereof, and wherein the second aerogel layer is formed of at least one of cellulose, cellulose nanocrystals, chitosan, Kevlar, lignin, or any combination thereof.

18. A method for treating a wound, the method comprising: The aerogel wound dressing is applied to the wound.

19. The method according to claim 18, wherein: The aerogel wound dressing includes a sensing component, and the method further includes: monitoring the sensing component for the presence of pathogens; When the sensing component indicates the presence of a pathogen, removing the aerogel wound dressing from the wound; and When the sensing component indicates the presence of a pathogen, a treatment is applied to the aerogel wound dressing.

20. The method according to claim 19, wherein: The aerogel wound dressing is a multi-layer aerogel wound dressing comprising: A first aerogel layer including the sensing component; and a second aerogel layer in contact with the first aerogel layer, wherein the second aerogel layer is removable from the aerogel wound dressing; and The method further comprises: removing the second aerogel layer after saturation with exudate from the wound; as well as A replacement second aerogel layer is applied to the first aerogel layer such that the replacement second aerogel layer removes exudates from the first aerogel layer.

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