Gel dressing and preparation method thereof

Abstract

The invention provides a gel dressing and a preparation method thereof, and belongs to the technical field of medical materials.The gel dressing comprises a basement membrane which is a PVA membrane; the gel layer is arranged on the surface of the basement membrane, and the gel layer is prepared from recombinant collagen, exosome, sodium hyaluronate, sodium carboxymethyl cellulose, chitosan and water; the microneedles are evenly arranged on the side, away from the basement membrane, of the gel layer, the microneedles are made of polylactic acid-hydroxy acid copolymer, and the needle tips of the microneedles are loaded with recombinant collagen and exosomes. A skin channel is opened through the microneedle array, the permeation efficiency of recombinant collagen and exosome is improved by multiple times, a large number of active ingredients can quickly reach the deep layer of the skin, and the skin repairing effect is remarkably enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical materials, and in particular to a gel dressing and a preparation method thereof. Background Art

[0002] Currently, gel dressings with recombinant collagen and exosomes as core ingredients have been widely used in the field of skin repair and care. Conventional gel dressings typically evenly disperse active ingredients such as recombinant collagen and exosomes in a gel matrix, and by directly applying them to the skin, attempt to allow the active ingredients to penetrate deep into the skin. For example, some patents disclose recombinant collagen hydrogel dressings that can replenish collagen to a certain extent. However, due to the lack of effective penetration-enhancing methods, the active ingredients have difficulty penetrating the skin's stratum corneum barrier, resulting in low penetration efficiency. Only a small amount of recombinant collagen and exosomes can actually reach skin cells to exert their effects.

[0003] The reason for this is that the stratum corneum, serving as the natural barrier of human skin, is composed of tightly packed keratinocytes and lipids, providing a strong barrier to macromolecules and foreign substances. However, recombinant collagen and exosome molecules are relatively large, and conventional gel dressings, relying solely on the skin's natural permeability, cannot meet the demand for efficient delivery of active ingredients. Furthermore, existing gel dressings lack control over the sustained release of ingredients, with active ingredients easily released in a short period of time, making it difficult to achieve a sustained and stable repair effect. Furthermore, their poor adhesion to the skin makes them prone to shifting and falling off during use, further impacting the effectiveness of the treatment. These deficiencies limit the effectiveness of recombinant collagen and exosomes in the application of skin repair and care, and require urgent solutions through innovative technologies. Summary of the Invention

[0004] In view of the technical problems existing in the background technology, the present application provides a gel dressing and a preparation method thereof, aiming to solve the technical problems of low active ingredient delivery efficiency, too fast active ingredient release rate, and poor skin adhesion of conventional gel dressings.

[0005] In a first aspect, an embodiment of the present application provides a gel dressing, comprising: Basement membrane, the basement membrane is PVA membrane; The gel layer is arranged on the surface of the basement membrane, and the gel layer includes recombinant collagen, exosomes, sodium hyaluronate, sodium carboxymethyl cellulose, chitosan and water; Microneedles, several microneedles are evenly arranged on the side of the gel layer away from the basement membrane. The microneedles are made of polylactic acid-hydroxy acid copolymer, and the needle tips of the microneedles are loaded with recombinant collagen and exosomes.

[0006] In some embodiments, the basement membrane has a thickness of 0.1-0.3 mm.

[0007] In some embodiments, a release paper is provided on the side of the base film away from the gel layer.

[0008] In some embodiments, the gel layer comprises, by weight, 5-10 parts of recombinant collagen, 2-5 parts of exosomes, 1-3 parts of sodium hyaluronate, 0.5-2 parts of sodium carboxymethyl cellulose, 0.2-1 parts of chitosan, and 91.2-79 parts of water.

[0009] In some embodiments, the gel layer has a thickness of 0.5 to 1.5 mm.

[0010] In some embodiments, the microneedles are 0.1-0.5 mm in length and 0.05-0.1 mm in diameter. A plurality of microneedles are arranged on the surface of the gel layer in a square or hexagonal array, and the spacing between two adjacent microneedles is 0.5-1.5 mm.

[0011] In some embodiments, the total mass of the recombinant collagen and exosomes loaded on the needle tip is 0.1-0.5 μg, and the mass ratio of the recombinant collagen to the exosomes is (5-10):(2-5).

[0012] In a second aspect, an embodiment of the present application provides a method for preparing a gel dressing, comprising the following steps: Dispersing recombinant collagen, exosomes, sodium hyaluronate, sodium carboxymethyl cellulose, and chitosan in water to obtain a gel stock solution; dispersing the polylactic acid-hydroxy acid copolymer in water to obtain a polylactic acid-hydroxy acid copolymer solution; The polylactic acid-hydroxy acid copolymer solution is injected into the microneedle mold, and the mold is removed after drying to obtain a microneedle array, and the recombinant collagen and exosomes are loaded on the needle tips of the microneedle array; The gel stock solution is coated on the basement membrane to obtain a gel layer, the microneedle array is attached to the gel layer, and release paper is attached to the side of the basement membrane away from the gel layer to obtain a gel dressing.

[0013] In some embodiments, loading recombinant collagen and exosomes onto the needle tips of the microneedle array comprises the following steps: dispersing the recombinant collagen and exosomes in a buffer solution to obtain a mixed solution; Immerse the tips of the microneedle array in the mixed solution and allow it to adsorb for 1 to 12 hours at a temperature of 4 to 25°C. After the adsorption is completed, the microneedle array is taken out from the mixed solution and dried and solidified to obtain a microneedle array loaded with recombinant collagen and exosomes.

[0014] In some embodiments, the buffer solution is phosphate buffer.

[0015] Different from the existing technical solutions, the beneficial effects of this application include: 1. Efficient penetration: In existing technologies, active ingredients such as recombinant collagen and exosomes have difficulty penetrating the skin's stratum corneum. However, the present invention uses a microneedle array to open skin channels, increasing the penetration efficiency of recombinant collagen and exosomes several times. A large amount of active ingredients can quickly reach the deep layers of the skin, significantly enhancing the skin repair effect.

[0016] 2. Sustained Action: Existing gel dressings suffer from rapid ingredient release. The gel layer of this invention is composed of hydrophilic polymers (hyaluronic acid and chitosan) forming a three-dimensional network structure. Recombinant collagen (a macromolecular protein with a molecular weight of approximately 300 kDa) and exosomes (nanovesicles with a diameter of 30-150 nm) are dispersed within the gel network through physical adsorption or entrapment. When the gel comes into contact with skin tissue fluid or moisture, the matrix swells, the network pores expand, and the ingredients are released through diffusion along a concentration gradient. This allows for a slow release of the active ingredients, prolonging the action of the recombinant collagen and exosomes on skin cells and ensuring a sustained and stable repair process.

[0017] 3. Good fit: Conventional gel dressings are easy to shift and fall off. The basement membrane of the present invention is highly flexible and can serve as a support for the gel layer. Combined with the viscosity of the gel layer, the dressing can fit closely to the skin and is not easy to fall off even during exercise or daily activities, thereby improving the user experience.

[0018] 4. Safety and environmental protection: The existing technology may use non-degradable materials. The microneedles of the present invention use biodegradable PLGA material. They do not need to be removed after use and can be naturally degraded and absorbed in the body without residual risk, making them safer and more environmentally friendly.

[0019] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0021] Figure 1 Graph showing the test results of fibroblasts treated with the dressings prepared in various examples and comparative examples of the present application.

[0022] Figure 2 Graph showing the test results of epidermal cells treated with the dressings prepared in each embodiment and comparative example of the present application.

[0023] Figure 3 This is a graph showing the sustained-release effect test results of the dressings prepared in various examples and comparative examples of this application. DETAILED DESCRIPTION

[0024] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0025] In order to solve the technical problems of low active ingredient delivery efficiency, too fast active ingredient release speed and poor skin adhesion of conventional gel dressings, the present application provides a gel dressing, including a basement membrane, a gel layer arranged on the surface of the basement membrane, a plurality of microneedles are provided on the side of the gel layer away from the basement membrane, the plurality of microneedles are evenly arranged to form a microneedle array, the needle tips of the microneedles are loaded with sufficient collagen and exosomes, and a release paper is provided on the side of the basement membrane away from the gel layer.

[0026] In some embodiments, the basement membrane is a flexible, transparent medical-grade polyvinyl alcohol (PVA) film with a thickness of 0.1 to 0.3 mm. The PVA film has a stable structure and strong flexibility, adapting to different skin surface morphologies.

[0027] In some embodiments, the gel layer comprises, by weight, 5-10 parts recombinant collagen, 2-5 parts exosomes, 1-3 parts sodium hyaluronate, 0.5-2 parts sodium carboxymethylcellulose, 0.2-1 parts chitosan, and 91.2-79 parts water, with a gel layer thickness of 0.5-1.5 mm. Sodium carboxymethylcellulose acts as a thickener, imparting the gel layer with suitable viscosity to enable it to adhere firmly to the basement membrane surface; sodium hyaluronate acts as a humectant to maintain skin hydration; and chitosan acts as an antibacterial agent to prevent infection. Its positive charge allows for electrostatic bonding with the recombinant collagen, delaying its release.

[0028] Recombinant collagen and exosomes are the core active ingredients. As a major component of the extracellular matrix (ECM), recombinant collagen provides an adhesion scaffold for skin cells (such as fibroblasts), inducing cell migration and proliferation, and accelerating wound healing. Exosomes can target the site of injury, inducing keratinocyte proliferation and migration, accelerating epidermal regeneration. They also activate dermal fibroblasts, promoting ECM synthesis, and improving scar tissue texture and elasticity. Furthermore, the immunomodulatory effects of exosomes can reduce the risk of wound infection and optimize the repair microenvironment. Recombinant collagen, acting as an ECM scaffold, provides a stable microenvironment for exosome signaling. Exosomes regulate cellular function and enhance the synthesis and deposition of recombinant collagen, forming a dual repair mechanism of "exogenous supplementation + endogenous induction."

[0029] In some embodiments, a plurality of microneedles are arranged in a square or hexagonal array on the surface of the gel layer to form a microneedle array. The spacing between adjacent microneedles is 0.5-1.5 mm, the microneedles are 0.1-0.5 mm long, and the diameters are 0.05-0.1 mm. Each microneedle tip is loaded with 0.1-0.5 μg of recombinant collagen and exosomes. Parameters such as microneedle length, diameter, loading capacity, array arrangement, and needle spacing are optimized to ensure that the microneedles effectively open skin channels without causing excessive damage to the skin, while achieving uniform penetration of active ingredients. The microneedles are made of biodegradable poly(lactic-co-glycolic acid) (PLGA) and do not need to be removed after use. They are naturally degraded and absorbed in the body, eliminating the risk of residual residues and making them safer and more environmentally friendly.

[0030] When the gel dressing of this invention is applied to the skin, the microneedle array penetrates the stratum corneum through tiny physical incisions, opening up absorption pathways. Active ingredients in the gel layer, such as recombinant collagen and exosomes, can now more efficiently penetrate deep into the skin's cells, leveraging the channels created by the microneedles. Simultaneously, the adhesiveness of the gel layer ensures a tight fit with the skin, ensuring the microneedles remain stable. Furthermore, the ingredients in the gel layer are slowly released over time, ensuring a continuous supply of active ingredients, promoting skin repair and care.

[0031] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0032] 1. Preparation method Example 1 A method for preparing a gel dressing comprises the following steps: 10 parts of recombinant collagen, 2 parts of exosomes, 3 parts of sodium hyaluronate, 0.5 parts of sodium carboxymethyl cellulose, and 1 part of chitosan were dispersed in 83.5 parts of water to obtain a gel stock solution.

[0033] The polylactic acid-hydroxy acid copolymer is dispersed in water to obtain a polylactic acid-hydroxy acid copolymer solution.

[0034] A polylactic acid-hydroxy acid copolymer solution was injected into a microneedle mold and then released from the mold after drying to produce a microneedle array. The microneedles were 0.1 mm long and 0.1 mm in diameter, arranged in a square or hexagonal array on the surface of the gel layer, with a spacing of 0.5 mm between adjacent microneedles.

[0035] Recombinant collagen and exosomes were loaded on the tip of the microneedle, and 10 parts of recombinant collagen and 2 parts of exosomes were dispersed in phosphate buffer to obtain a mixed solution.

[0036] The needle tips of the microneedle array were immersed in the mixed solution and adsorbed at 25°C for 1 h; After the adsorption is completed, the microneedle array is taken out from the mixed solution and dried and solidified to obtain a microneedle array loaded with recombinant collagen and exosomes.

[0037] A PVA film with a thickness of 0.3 mm was selected as the basement membrane, and the gel stock solution was coated on the basement membrane to obtain a gel layer with a thickness of 0.5 mm. The microneedle array was attached to the gel layer, and release paper was attached to the side of the basement membrane away from the gel layer to obtain a gel dressing.

[0038] Example 2 A method for preparing a gel dressing comprises the following steps: 5 parts of recombinant collagen, 5 parts of exosomes, 1 part of sodium hyaluronate, 2 parts of sodium carboxymethyl cellulose, and 0.2 parts of chitosan were dispersed in 86.8 parts of water to obtain a gel stock solution.

[0039] The polylactic acid-hydroxy acid copolymer is dispersed in water to obtain a polylactic acid-hydroxy acid copolymer solution.

[0040] The polylactic acid-hydroxy acid copolymer solution was injected into the microneedle mold and demolded after drying to obtain a microneedle array; the microneedles were 0.5 mm in length and 0.05 mm in diameter. Several microneedles were arranged on the surface of the gel layer in a square or hexagonal array, and the spacing between two adjacent microneedles was 1.5 mm.

[0041] Recombinant collagen and exosomes were loaded on the tip of the microneedle, and 5 parts of recombinant collagen and 5 parts of exosomes were dispersed in phosphate buffer to obtain a mixed solution.

[0042] The needle tips of the microneedle array were immersed in the mixed solution and adsorbed at 4°C for 12 h; After the adsorption is completed, the microneedle array is taken out from the mixed solution and dried and solidified to obtain a microneedle array loaded with recombinant collagen and exosomes.

[0043] A PVA film with a thickness of 0.1 mm was selected as the basement membrane, and the gel stock solution was coated on the basement membrane to obtain a gel layer with a thickness of 1.5 mm. The microneedle array was attached to the gel layer, and release paper was attached to the side of the basement membrane away from the gel layer to obtain a gel dressing.

[0044] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the gel layer does not contain recombinant collagen and exosomes.

[0045] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the gel layer does not contain chitosan.

[0046] II. Analysis of test results of various embodiments and comparative examples The proliferation capacity of fibroblasts and epidermal cells after being treated with the dressings prepared in each embodiment and comparative example was detected by MTT / CCK-8 method to evaluate the promoting effect of the dressing on cell activity. The test results are shown in FIG. Figures 1 and 2 .from Figures 1 and 2 It can be seen that the gel layer in Comparative Example 1 does not contain recombinant collagen and exosomes, and the activity of fibroblasts and epidermal cells is reduced compared with that in Examples 1 and 2, indicating that adding recombinant collagen and exosomes to the gel layer can improve the repair effect of the dressing.

[0047] After using the dressings prepared in each embodiment and comparative example for 1 hour, 4 hours, 8 hours and 12 hours, the epidermal cells were treated with them to detect the proliferation ability of fibroblasts and evaluate the sustained release effect of the dressings. The test results are shown in FIG. Figure 3 .

[0048] from Figure 3 It can be seen that the dressings in Examples 1 and 2 still have a good activity-promoting effect on epidermal cells after 12 hours of use, while the cell viability effect of the dressing in Comparative Example 1 is greatly reduced after 4 hours, indicating that only by adding recombinant collagen and exosomes to the microneedle array, the active ingredients are released quickly and the sustainability is poor; the cell viability of the dressing in Comparative Example 2 is reduced after 8 hours, indicating that chitosan can improve the sustained-release effect of the dressing.

[0049] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A gel dressing, characterized in that: include: Basement membrane, wherein the basement membrane is a PVA membrane; A gel layer, the gel layer being disposed on the surface of the basement membrane, the gel layer comprising recombinant collagen, exosomes, sodium hyaluronate, sodium carboxymethyl cellulose, chitosan and water; Microneedles, wherein a plurality of the microneedles are evenly arranged on the side of the gel layer away from the basement membrane, the microneedles are made of polylactic acid-hydroxy acid copolymer, and the needle tips of the microneedles are loaded with recombinant collagen and exosomes.

2. The gel dressing according to claim 1, characterized in that The thickness of the base film is 0.1-0.3 mm by mass.

3. The gel dressing according to claim 1, characterized in that A release paper is provided on the side of the basement membrane away from the gel layer.

4. The gel dressing according to claim 1, characterized in that The gel layer comprises, by mass, 5 to 10 parts of recombinant collagen, 2 to 5 parts of exosomes, 1 to 3 parts of sodium hyaluronate, 0.5 to 2 parts of sodium carboxymethyl cellulose, 0.2 to 1 part of chitosan, and 91.2 to 79 parts of water.

5. The gel dressing according to claim 1, characterized in that The thickness of the gel layer is 0.5-1.5 mm.

6. The gel dressing according to claim 1, characterized in that The microneedles have a length of 0.1-0.5 mm and a diameter of 0.05-0.1 mm. A plurality of the microneedles are arranged on the surface of the gel layer in a square or hexagonal array, and the spacing between two adjacent microneedles is 0.5-1.5 mm.

7. The gel dressing according to claim 1, characterized in that The total mass of the recombinant collagen and exosomes loaded on the needle tip is 0.1-0.5 μg, and the mass ratio of the recombinant collagen to the exosomes is (5-10):(2-5).

8. A method for preparing the gel dressing according to any one of claims 1 to 7, characterized in that: The steps include: Dispersing recombinant collagen, exosomes, sodium hyaluronate, sodium carboxymethyl cellulose, and chitosan in water to obtain a gel stock solution; dispersing the polylactic acid-hydroxy acid copolymer in water to obtain a polylactic acid-hydroxy acid copolymer solution; injecting the polylactic acid-hydroxy acid copolymer solution into a microneedle mold, and demoulding after drying to obtain a microneedle array, wherein the recombinant collagen and exosomes are loaded on the needle tips of the microneedle array; The gel stock solution is coated on a basement membrane to obtain a gel layer, the microneedle array is attached to the gel layer, and release paper is attached to the side of the basement membrane away from the gel layer to obtain a gel dressing.

9. The method for preparing the gel dressing according to claim 8, characterized in that: Loading recombinant collagen and exosomes on the needle tips of the microneedle array comprises the following steps: dispersing the recombinant collagen and exosomes in a buffer solution to obtain a mixed solution; Immersing the needle tips of the microneedle array in the mixed solution and adsorbing for 1 to 12 hours at a temperature of 4 to 25°C; After the adsorption is completed, the microneedle array is taken out from the mixed solution and dried and solidified to obtain a microneedle array loaded with recombinant collagen and exosomes.

10. The method for preparing the gel dressing according to claim 9, characterized in that: The buffer solution is phosphate buffer.

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