A wet-state adhesive microneedle patch, a preparation method and application thereof

Abstract

The application discloses a wet-state adhesive microneedle patch, a preparation method and application thereof, and belongs to the technical field of medical devices. The wet-state adhesive microneedle patch comprises a silk microneedle patch layer and a wet-state adhesive film layer. The silk microneedle patch layer comprises a patch substrate and a microneedle array integrally connected to the patch substrate. The wet-state adhesive film layer comprises a silk outer film and a silk-tannic acid glue layer on the silk outer film. The patch substrate and the silk outer film are connected through the silk-tannic acid glue layer. The wet-state adhesive microneedle patch is applied to the preparation of a drug-loaded patch for oral mucosa diseases. The wet-state adhesive microneedle patch has the advantages of low price, simple preparation process, stable interface combination, convenient disinfection, long-term storage and transportation, and application to oral mucosa local drug delivery for oral mucosa diseases.

Description

Technical Field

[0001] This invention relates to the field of transmucosal drug delivery systems, specifically to a wet adhesive microneedle patch for the treatment of oral mucosal diseases, its preparation method, and its application. Background Technology

[0002] Oral mucosal diseases are a common group of illnesses affecting human health, such as oral ulcers, inflammatory diseases of the oral mucosa, and potential oral malignancies. These diseases can cause varying degrees of pain, discomfort, and anxiety, thus severely impacting patients' quality of life. For the treatment of oral mucosal diseases, glucocorticoids (such as triamcinolone acetonide) are the most common medications, possessing multiple effects including anti-inflammatory, immunomodulatory, and analgesic properties, which are beneficial for the healing of oral mucosal diseases and the maintenance of oral mucosal integrity.

[0003] Topical medication is currently an important treatment method for oral mucosal diseases. For example, topical corticosteroids are highly recommended in the latest version of the "Guidelines for the Diagnosis and Clinical Management of Oral Submucosal Fibrosis". Topical medication can be administered via topical application or submucosal injection. On the one hand, because the oral cavity is a moist, moving microenvironment, there are saliva rinsing and oral movement (mechanical barriers), enzymatic degradation in saliva (enzymatic barrier), and the epithelial layer's resistance to drug absorption (permeability barrier). Therefore, topical application methods such as pastes have short drug retention times and low bioavailability. On the other hand, the significant pain caused by submucosal injection greatly reduces patient compliance. Therefore, developing a highly efficient, stable, minimally invasive, and painless drug delivery system that can achieve efficient delivery in the moist, moving oral environment is an urgent clinical problem to be solved in the treatment of oral mucosal diseases.

[0004] Microneedle patches can effectively penetrate the mechanical and permeability barriers of the oral mucosa, forming a micron-scale drug delivery channel array with minimal contact with submucosal blood vessels and nerves. This represents a highly promising minimally invasive, painless, and efficient local drug delivery method. However, due to the moist and dynamic nature of the oral environment, conventional microneedle patches rely solely on mechanical interlocking with the mucosa, making sustained adhesion and drug delivery difficult. Current research focuses on utilizing oral microneedles for vaccine injection. [1] and local anesthesia [2] A small number of studies have utilized microneedles for drug delivery to oral ulcers. [3]These microneedles, when applied to the oral mucosa, are transient and their adhesive properties are not improved, making them unsuitable for stable and continuous drug delivery. While there are studies in other fields that enhance the wet adhesiveness of membranes (for membranes used in cardiac and intestinal tissue regeneration), these studies suffer from complex preparation processes, expensive materials, and interfacial delamination issues between different materials. Furthermore, sterilization of medical patches is a crucial step, and wet adhesive membranes are prone to losing their adhesive properties upon drying (sterilization), posing challenges for storage and transportation. Therefore, developing a low-cost, simple-to-prepare, interfacially stable, easily sterilizable, and long-term storage and transportation double-layered wet adhesive microneedle patch for local drug delivery in oral mucosal diseases is the scientific problem addressed by this patent.

[0005] References:

[0006] [1]Creighton RL, Woodrow K A.Microneedle-mediated vaccine delivery to the oral mucosa[J].Advanced healthcare materials, 2019,8(4):1801180.

[0007] [2]Zhu T,Yu X,Yi

[0008] [3]Guo X, Zhu T, Yu X, et al. Betamethasone-loaded dissolvable microneedle patch for oral ulcer treatment [J]. Colloids and Surfaces B: Biointerfaces, 2023, 222: 113100. Summary of the Invention

[0009] In view of the above-mentioned shortcomings, the present invention provides a wet adhesive microneedle patch, a preparation method thereof and its application. The wet adhesive microneedle patch of this application has the advantages of low price, simple preparation process, stable interface bonding, easy sterilization, long-term storage and transportation, and can be applied to local mucosal drug delivery for oral mucosal diseases.

[0010] To achieve the above objectives, the present invention provides a wet-adhesive microneedle patch, comprising a silk microneedle patch layer and a wet-adhesive film layer; the silk microneedle patch layer includes a patch substrate and a microneedle array integrally connected to the patch substrate; the wet-adhesive film layer includes a silk outer film and a silk-tannic acid adhesive layer located on the silk outer film; the patch substrate and the silk outer film are connected through the silk-tannic acid adhesive layer.

[0011] According to one aspect of the invention, the microneedle tip diameter in the microneedle array is less than 10 μm.

[0012] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned wet-state adhesive microneedle patch, comprising the following steps:

[0013] Step 1: Pour the silk solution into the microneedle patch template, dry and crosslink it, and then demold to obtain the silk microneedle patch layer;

[0014] Step 2: Mix the silk solution with the tannic acid solution, let it stand to precipitate, discard the supernatant, and wash the precipitate with ultrapure water to obtain a viscous, gel-like silk-tannic acid complex.

[0015] Step 3: Pour the silk solution onto the template of the silk outer membrane, and after drying, cross-linking, and demolding, obtain the silk outer membrane;

[0016] Step 4: Spread the viscous, gel-like silk-tannic acid composite obtained in Step 2 onto the outer silk membrane obtained in Step 3 to obtain a wet adhesive film layer; then place the patch substrate of the silk microneedle patch layer obtained in Step 1 onto the silk-tannic acid composite.

[0017] According to one aspect of the present invention, the preparation process of the silk solution includes the following steps:

[0018] Silkworm cocoons are degummed by adding them to a boiling sodium carbonate solution, then washed with ultrapure water and dried to obtain degummed silk.

[0019] Degummed silk was dissolved in lithium bromide solution at 60°C, followed by dialyzing the silk solution with ultrapure water for 48 hours, and then diluted to the required concentration.

[0020] According to one aspect of the present invention, in step 1, the crosslinking specifically comprises:

[0021] Place overnight in a vacuum dryer filled with water vapor at 4°C; or overnight in a vacuum dryer filled with water vapor at 25°C; or soak in methanol solution for 30 minutes.

[0022] In step 3, the crosslinking specifically involves:

[0023] Place overnight in a vacuum dryer filled with water vapor at 25°C.

[0024] According to one aspect of the present invention, in step 2, the silk-tannic acid complex can be used directly or freeze-dried and ground to obtain freeze-dried powder, stored at -20°C, and disinfected by ultraviolet irradiation and sprayed with water to restore the viscous gel-like silk-tannic acid complex.

[0025] According to one aspect of the present invention, the mass concentration of the silk solution in step 1 is 7%; the mass concentration of the silk solution in steps 2 and 3 is 2%; and the mass concentration of the tannic acid solution in step 2 is 10%.

[0026] According to one aspect of the invention, the concentration of the sodium carbonate solution is 0.02 mol·L⁻¹. -1 The concentration of the lithium bromide solution is 9.3 mol·L⁻¹. -1 .

[0027] Based on the same inventive concept, the present invention also provides the application of the above-mentioned wet adhesive microneedle patch or the wet adhesive microneedle patch prepared by the above preparation method in the preparation of drug-loaded patches for oral mucosal diseases.

[0028] According to one aspect of the invention, the drug on the drug-loaded patch includes triamcinolone acetonide.

[0029] The principle behind the adhesive properties of the wet-state adhesive microneedle patch of this invention in a humid environment:

[0030] Tannic acid (TA) is an FDA-approved polyphenol derived from nature; the silk-tannic acid complex (SF-TA) contains abundant pyrogallol and catechol groups, see [link to relevant documentation]. Figure 10 It can achieve strong adhesion between various materials through hydrogen bonding, π–π interactions, and metal chelation. The silk-tannic acid complex (SF-TA) adheres to oral mucosal tissue mainly by forming hydrogen bonds with carboxyl and amino groups in proteins, thus forming a wet adhesion.

[0031] The beneficial effects of this invention are:

[0032] (1) The raw materials used in this invention are silk protein and tannic acid, which are widely available and inexpensive;

[0033] (2) The raw materials of this invention, silk protein and tannic acid, are natural animal protein and natural plant-derived polyphenols, both of which are FDA-approved medical biomaterials with good biosafety and biodegradability.

[0034] (3) The preparation process of the present invention is simple, does not require complex equipment and chemical synthesis process, and has high reproducibility;

[0035] (4) The silk-tannic acid complex of the present invention can be stored and transported in the form of freeze-dried powder, and can be sterilized before use. It can be restored to silk-tannic acid gum when exposed to water, and the operation process is simple.

[0036] (5) The wet adhesive microneedle patch of the present invention has mucosal penetration and wet adhesive membrane adhesion in a humid environment, which can realize minimally invasive, painless and continuous stable drug delivery under the wet mucosa.

[0037] (6) Each layer of the wet adhesive microneedle patch of the present invention uses silk protein as the base material, and the layers are tightly bonded to each other, avoiding the separation between different material interfaces.

[0038] (7) The silk protein in the wet adhesive microneedle patch of the present invention can regulate the drug release rate by controlling the secondary structure.

[0039] (8) The wet adhesive microneedle patch of this application can be used as a drug-loaded patch (loaded with triamcinolone) for a variety of oral mucosal diseases (such as oral lichen planus, oral submucosal fibrosis, etc.). Attached Figure Description

[0040] Figure 1 This is a front view schematic diagram of the wet-adhesive microneedle patch described in this invention;

[0041] Figure 2 This is a side view of the wet-adhesive microneedle patch described in this invention;

[0042] Figure 3 This is an electron microscope schematic diagram of the wet-state adhesive microneedle patch described in this invention;

[0043] Figure 4 This is a macroscopic photograph of the wet-adhesive microneedle patch described in this invention;

[0044] Figure 5 This describes the yield of precipitate after mixing silk solutions and tannic acid solutions in different mass ratios as described in Example 4 of the present invention.

[0045] Figure 6 This is a comparison diagram of the interfacial adhesion test between the silk-tannic acid adhesive layer and the silk film described in Embodiment 4 of the present invention.

[0046] Figure 7 This is a comparison chart of the adhesion test results between the wet-state adhesive microneedle patch described in Embodiment 5 of the present invention and a silk film and an existing commercial film.

[0047] Figure 8 This is a comparison chart of the biocompatibility test results of the extracts of each layer of the wet-state adhesive microneedle patch described in Example 5 of the present invention with ordinary culture medium and culture medium containing 5% DMSO.

[0048] Figure 9 The drug loading performance test curve of the wet-state adhesive microneedle patch described in Example 6 of the present invention;

[0049] Figure 10 This is a schematic diagram illustrating the wet adhesion principle of the microneedle patch of the present invention.

[0050] Explanation of reference numerals in the attached diagram: 1. Outer layer of silk; 2. Silk-tannic acid adhesive layer; 3. Patch substrate; 4. Microneedle array. Detailed Implementation

[0051] To make the present invention easier to understand, specific embodiments are described below to further illustrate the invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art; unless otherwise specified, the raw materials and reagents involved herein can be purchased commercially or prepared by known methods.

[0052] To address the technical problems mentioned in the background section, this invention provides a wet-adhesive microneedle patch, such as... Figure 1-4 As shown, it includes a silk microneedle patch layer and a wet adhesive film layer; the silk microneedle patch layer includes a patch substrate 3 and a microneedle array 4 integrally connected to the patch substrate 3; the wet adhesive film layer includes a silk outer film 1 and a silk-tannic acid adhesive layer 2 located on the silk outer film 1; the patch substrate 3 and the silk outer film 1 are connected through the silk-tannic acid adhesive layer 2.

[0053] Preferably, the diameter of the microneedle tips in the microneedle array is less than 10 μm.

[0054] To address the technical problems mentioned in the background section, this invention provides a method for preparing wet-adhesive microneedle patches, comprising the following steps:

[0055] Step 1: Pour the silk solution into the microneedle patch template, dry and crosslink it, and then demold to obtain the silk microneedle patch layer;

[0056] Step 2: Mix the silk solution with the tannic acid solution, let it stand to precipitate, discard the supernatant, and wash the precipitate with ultrapure water to obtain a viscous, gel-like silk-tannic acid complex.

[0057] Step 3: Pour the silk solution into the PDMS mold of the silk outer layer film, and after drying, cross-linking and demolding, obtain the silk outer layer film;

[0058] It should be noted that the outer membrane of silk can prevent the wet adhesive membrane from adhering to oral tissues such as the tongue.

[0059] Step 4: Spread the viscous, gel-like silk-tannic acid composite obtained in Step 2 onto the outer silk membrane obtained in Step 3 to obtain a wet adhesive film layer; then place the patch substrate of the silk microneedle patch layer obtained in Step 1 onto the silk-tannic acid composite.

[0060] Preferably, the preparation process of the silk solution includes the following steps:

[0061] Silkworm cocoons are degummed by adding them to a boiling sodium carbonate solution, then washed with ultrapure water and dried to obtain degummed silk.

[0062] Degummed silk was dissolved in lithium bromide solution at 60°C, followed by dialysis of the silk solution with ultrapure water for 48 hours, and then diluted to the required concentration.

[0063] Preferably, in step 1, the crosslinking specifically involves:

[0064] Place overnight in a vacuum dryer filled with water vapor at 4°C; or overnight in a vacuum dryer filled with water vapor at 25°C; or soak in methanol solution for 30 minutes.

[0065] In step 3, the crosslinking specifically involves:

[0066] Place overnight in a vacuum dryer filled with water vapor at 25°C.

[0067] Preferably, in step 2, the silk-tannic acid complex can be used directly or freeze-dried and ground to obtain freeze-dried powder, stored at -20°C, and disinfected by ultraviolet irradiation and sprayed with water to restore the viscous gel-like state of the silk-tannic acid complex.

[0068] Preferably, the mass concentration of the silk solution in step 1 is 7%; the mass concentration of the silk solution in steps 2 and 3 is 2%; and the mass concentration of the tannic acid solution in step 2 is 10%.

[0069] Preferably, the concentration of the sodium carbonate solution is 0.02 mol·L⁻¹. -1 The concentration of the lithium bromide solution is 9.3 mol·L⁻¹. -1 .

[0070] To address the technical problems mentioned in the background section, this invention also provides the application of wet-adhesive microneedle patches in the preparation of drug-loaded patches for oral mucosal diseases.

[0071] Example 1

[0072] A method for preparing a silk microneedle patch layer:

[0073] (1) Add the silkworm cocoons to boiling 0.02 mol·L⁻¹ water. -1 Degummed silk was obtained by degumming in sodium carbonate solution for 30 minutes, washing with ultrapure water, and drying. The degummed silk was then treated with 9.3 mol·L⁻¹ sodium carbonate solution. -1 Degummed silk was dissolved in lithium bromide solution at 60°C, followed by dialysis of the silk solution with ultrapure water for 48 hours, further centrifugation to remove insoluble residues, and dilution to 7 w / v.

[0074] (2) The 7 w / v% silk solution prepared above was poured into a PDMS microneedle template (microneedle patch mold specifications: 10 mm * 10 mm, 10 * 10 microneedle array, single microneedle base diameter 300 μm, tip diameter < 10 μm, microneedle length 670 μm), degassed in a vacuum dryer (> 0.09 MPa) and centrifuged to remove air bubbles. After drying for 48 hours (25℃, 60% humidity), the microneedle patch was demolded. Since the microneedle patch is used in a humid environment, it should be cross-linked to make it insoluble in water. Low β phase silk microneedle patches were prepared by placing them overnight in a vacuum dryer filled with water vapor at 4℃.

[0075] Example 2

[0076] A silk microneedle patch layer and its preparation method

[0077] A method for preparing a silk microneedle patch layer:

[0078] (1) Add the silkworm cocoons to boiling 0.02 mol·L⁻¹ water. -1 Degummed silk was obtained by degumming in sodium carbonate solution for 30 minutes, washing with ultrapure water, and drying. The degummed silk was then treated with 9.3 mol·L⁻¹ sodium carbonate solution. -1 Degummed silk was dissolved in lithium bromide solution at 60°C, followed by dialysis of the silk solution with ultrapure water for 48 hours, further centrifugation to remove insoluble residues, and dilution to 7 w / v.

[0079] (2) The 7 w / v% silk solution prepared above was poured into a PDMS microneedle template (microneedle patch mold specifications: 10mm*10mm, 10*10 microneedle array, single microneedle base diameter 300μm, tip diameter <10μm, microneedle length 670μm), degassed in a vacuum dryer (>0.09MPa) and centrifuged to remove air bubbles. After drying for 48 hours (25℃, 60% humidity), the microneedle patch was demolded. Since the microneedle patch is used in a humid environment, it should be cross-linked to make it insoluble in water. The mid-β phase silk microneedle patch was prepared by placing it in a vacuum dryer filled with water vapor at 25℃ overnight.

[0080] Example 3

[0081] A silk microneedle patch layer and its preparation method

[0082] Preparation method of silk microneedle patch layer:

[0083] (1) Add the silkworm cocoons to boiling 0.02 mol·L⁻¹ water. -1 Degummed silk was obtained by degumming in sodium carbonate solution for 30 minutes, washing with ultrapure water, and drying. The degummed silk was then treated with 9.3 mol·L⁻¹ sodium carbonate solution. -1 Degummed silk was dissolved in lithium bromide solution at 60°C, followed by dialysis of the silk solution with ultrapure water for 48 hours, further centrifugation to remove insoluble residues, and dilution to 7 w / v.

[0084] (2) The 7 w / v% silk solution prepared above was poured into a PDMS microneedle mold (microneedle patch mold specifications: 10mm*10mm, 10*10 microneedle array, single microneedle base diameter 300μm, tip diameter <10μm, microneedle length 670μm), degassed in a vacuum dryer (>0.09MPa) and centrifuged to remove air bubbles. After drying for 48 hours (25℃, 60% humidity), the microneedle patch was demolded. Since the microneedle patch is used in a humid environment, it should be cross-linked to make it insoluble in water. High β-phase silk microneedle patches were prepared by soaking in methanol solution for 30 minutes.

[0085] Performance checks and results analysis:

[0086] Morphological statistics and mechanical strength testing of silk microneedle patches:

[0087] The morphology of the three types (low, medium, and high) β-phase microneedle patches in Examples 1-3 was statistically analyzed under an optical microscope. The selected indicators were tip bending rate (number of bent tips / total number of microneedles counted * 100%) and microneedle tilt rate (number of microneedles deviating more than 20° from the vertical line of the substrate / total number of microneedles counted * 100%). The parallel number was 3. The test results are shown in Table 1 below.

[0088] The mechanical properties of the three types (low, medium, and high) β-phase microneedle patches from Examples 1-3 were tested using a universal mechanical testing instrument. The microneedles were attached to a horizontally positioned rigid platform with their tips facing upwards. A test sensor approached and compressed the microneedles vertically at a speed of 10 mm / min, recording displacement and force, with a parallel count of 4. The test results are shown in Table 1 below.

[0089] Table 1:

[0090] Test content low β phase Middle β phase High β phase Needle tip curvature (%) 9.33±4.50 7.00±2.16 4.00±0.82 Microneedle tilt rate (%) 1.00±0.82 1.67±1.25 20.33±2.49 Mechanical strength (mN / needle) 40.5±0.12 71.0±1.63 34.4±0.39

[0091] As shown in Table 1, all three β-phase silk microneedles have good tip morphology, but the high β-phase silk microneedles have a high needle tilt rate, which may be due to the rapid cross-linking process causing material curling. Mechanical property tests show that the medium β phase has stronger mechanical properties than the other two groups (P < 0.01), indicating that the medium β phase group has both good microneedle morphology and strong mechanical properties. Moreover, the mechanical properties (71 mN / needle) are higher than the minimum force required to penetrate the mucosa (58 mN), which can effectively penetrate the mucosa and can be used as the preparation conditions for subsequent silk microneedle patches.

[0092] Example 4

[0093] Preparation method of silk-tannic acid adhesive layer

[0094] (1) Add the silkworm cocoons to boiling 0.02 mol·L⁻¹ water. -1 Degummed silk was obtained by degumming in sodium carbonate solution for 60 minutes, washing with ultrapure water, and drying. The degummed silk was then treated with 9.3 mol·L⁻¹ sodium carbonate solution. -1 Degummed silk was dissolved in lithium bromide solution at 60°C, followed by dialysis of the silk solution with ultrapure water for 48 hours, further centrifugation to remove insoluble residues, and dilution to 2 w / v.

[0095] (2) The silk solution prepared above was mixed with 10% tannic acid solution at different mass ratios. After standing and settling for half an hour, the supernatant was discarded. The precipitate was washed with ultrapure water for 1 hour (37℃ shaker, 60 rpm, 15 minutes / time, 4 times in total) to remove residues, and the silk-tannic acid complex was obtained. The complex was freeze-dried and ground to obtain freeze-dried powder, which was stored at -20℃. When used, it can be disinfected by ultraviolet irradiation and can be restored to a viscous gel-like substance when sprayed with a small amount of water.

[0096] The yield of precipitates after mixing silk solutions and tannic acid solutions in different mass ratios was statistically analyzed, with a parallel count of 3. The results are as follows: Figure 5 As shown, by Figure 5 It can be seen that when the mass ratio of tannic acid / silk solution is 5, the precipitation yield reaches a plateau, indicating that a mass ratio of tannic acid / silk solution of 5 is the optimal preparation condition for the silk-tannic acid complex to achieve its production capacity.

[0097] Performance checks and results analysis:

[0098] Interfacial adhesion test of silk-tannic acid adhesive layer:

[0099] The aforementioned viscous, gel-like silk-tannic acid composite (tannic acid / silk solution mass ratio of 5) was placed between two silk films, with an adhesion area of ​​1×1 cm. 2A universal mechanical testing instrument was used to clamp the silk film and apply a tangential tensile test at a speed of 10 mm / min. Displacement and force were recorded. A control group was set up, in which the silk-tannic acid composite was replaced with the silk film (single comparison, i.e., all parameters were the same except for the material). The above experimental steps were repeated, with four replicates for each group. The results are as follows: Figure 6 As shown, by Figure 6 It can be seen that, compared with the ordinary intermediate layer (silk membrane), the silk-tannic acid adhesive layer, the outer membrane, and the silk microneedle patch layer have a larger interfacial bonding force, indicating that the patch will not detach from the interface during use.

[0100] Example 5

[0101] A method for preparing wet-adhesive microneedle patches

[0102] (1) Preparation of silk microneedle patch layer: See Example 2;

[0103] (2) Preparation of silk-tannic acid adhesive layer: Refer to Example 4 to prepare a viscous gel-like silk-tannic acid composite (precipitate product obtained in any mass ratio); freeze-dry and grind it to obtain freeze-dried powder, and store it at -20℃;

[0104] (3) Preparation of the outer silk membrane: The prefabricated size is 20×20×0.2mm. 3 A grooved PDMS mold was used to cover the remaining 2% w / v silk solution from Example 4 with a thin layer inside the mold, followed by drying and crosslinking.

[0105] (4) Preparation of wet-state adhesive microneedle patch: The freeze-dried powder prepared in (2) was rehydrated to a gel state and spread on top of the outer silk membrane in (3). Then, the microneedle patch layer prepared in (1) was placed with the microneedle tips facing upwards in the center of the wet-state adhesive membrane layer (silk-tannic acid adhesive layer). See [link to relevant documentation]. Figure 1-2 As shown, the wet-state adhesive microneedle patch was obtained after demolding.

[0106] Performance checks and results analysis:

[0107] Adhesion test of wet-adhesive microneedle patches:

[0108] The isolated porcine buccal mucosa was cut into 3×1×0.5cm pieces. 3 Size: The wet adhesive microneedle patch was placed between two mucosal tissues for adhesion, with an adhesion area of ​​1×1cm. 2The mucosa was tangentially stretched using a universal mechanical testing instrument clamp at a speed of 10 mm / min, and the displacement and force were recorded. Two control groups were set up, in which the wet-state adhesive microneedle patches were replaced with silk film and an existing commercial film (Medi oral adhesive patch, National Drug Approval Number H20058401, whose main components are carbomer, hydroxymethylpropyl cellulose and betacyclodextrin) respectively (single comparison, i.e., all parameters are the same except for the material), with 4 replicates for each group; the results are as follows. Figure 7 As shown, by Figure 7 It can be seen that, compared with silk films and existing commercial films, wet-adhesive microneedle patches have strong wet adhesion to mucosa, indicating that the patch can achieve continuous and stable adhesion on moist oral mucosa.

[0109] Biocompatibility testing of wet-adhesive microneedle patches:

[0110] Fibroblasts were co-cultured with extracts of silk-tannic acid membranes and silk microneedle patches (which were soaked in DMEM medium at 37°C for 24 hours, then filtered through a sterile filter to remove bacteria, followed by the addition of 5% bovine serum albumin and 1% penicillin-streptomycin solution) in a cell incubator (37°C, 5% CO2). Cell proliferation was detected using a CCK8 microplate reader at 1, 2, and 3 days. Two control groups were set up: one in ordinary medium (negative control) and one in medium containing 5% DMSO (positive control), with four replicates for each group. The results are as follows: Figure 8 As shown, by Figure 8 It can be seen that neither the silk-tannic acid membrane layer nor the silk microneedle layer inhibited cell proliferation, indicating that the wet adhesive patch has good cell biocompatibility.

[0111] Example 6

[0112] A drug-loaded wet-adhesive microneedle patch:

[0113] (1) Preparation of drug-loaded silk microneedle patch layer: 10 mg / ml triamcinolone solution was added to the silk solution at a volume ratio of 1:10. Other operations and steps are described in Example 5.

[0114] (2) Preparation of silk-tannic acid adhesive layer: See Example 5;

[0115] (3) Preparation of the outer silk membrane: See Example 5;

[0116] (4) Drug-loadable wet adhesive microneedle patch: The lyophilized powder prepared in (2) was rehydrated to a gel state and spread on top of the outer silk membrane in (3). Then, the microneedles of the drug-loaded silk microneedle patch prepared in (1) were placed with the tips facing upwards in the center of the wet adhesive membrane layer (silk-tannic acid adhesive layer). See [link to relevant documentation]. Figure 1-2As shown, the drug-loaded wet adhesive microneedle patch was obtained after demolding.

[0117] One drug-loaded wet-state adhesive microneedle patch was immersed in 1 ml of PBS solution and placed in a shaker at 37°C. 0.5 ml of supernatant was extracted at different time points, and 0.5 ml of PBS solution was added. The drug concentration in the extract was measured using a UV spectrophotometer. The relationship between cumulative drug release and release time was calculated. The number of parallel trials was 3. The results are as follows: Figure 9 As shown, by Figure 9 It can be seen that the wet-adhesive microneedle patch successfully achieved triamcinolone acetonide loading and release, and the release time was as long as 7 days, indicating that the drug-loaded wet-adhesive microneedle patch can achieve controlled release of drugs for oral mucosal diseases.

[0118] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A wet-adhered microneedle patch, characterized by, The wet adhesion micro-needle patch comprises a silk micro-needle patch layer and a wet adhesion film layer; the silk micro-needle patch layer comprises a patch substrate and a micro-needle array integrally connected to the patch substrate; the wet adhesion film layer comprises a silk outer film and a silk-tannic acid glue layer on the silk outer film; the patch substrate is connected to the silk outer film through the silk-tannic acid glue layer.

2. The wet adhesive microneedle patch of claim 1, wherein, The micro-needle tip diameter in the micro-needle array is less than 10 μm.

3. A method of preparing a wet-adhered microneedle patch according to any one of claims 1-2, characterized by, The preparation method comprises the following steps: Step 1: pour the silk solution into a micro-needle patch template, dry and cross-link, and then demold to obtain a silk micro-needle patch layer; Step 2: mix the silk solution with a tannic acid solution, discard the supernatant after standing and precipitating, and then wash the precipitate with ultrapure water to obtain a viscous glue-like silk-tannic acid compound; Step 3: pour the silk solution into a template of a silk outer film, dry and cross-link, and then demold to obtain a silk outer film; Step 4: spread the viscous glue-like silk-tannic acid compound obtained in Step 2 on the silk outer film obtained in Step 3 to obtain a wet adhesion film layer; and then place the patch substrate of the silk micro-needle patch layer obtained in Step 1 on the silk-tannic acid compound.

4. The method of making a wet adhesive microneedle patch according to claim 3, wherein, The preparation process of the silk solution comprises the following steps: add cocoon to a boiling sodium carbonate solution for degumming, then wash and dry with ultrapure water to obtain degummed silk; dissolve the degummed silk in a lithium bromide solution at 60℃, then dialyze the silk solution with ultrapure water for 48 hours, and then dilute to the required concentration.

5. The method of making a wet adhesive microneedle patch according to claim 3, wherein, In Step 1, the cross-linking is specifically: place in a vacuum dryer filled with water vapor at 4℃ overnight; or place in a vacuum dryer filled with water vapor at 25℃ overnight; or soak in a methanol solution for 30 minutes; In Step 3, the cross-linking is specifically: place in a vacuum dryer filled with water vapor at 25℃ overnight.

6. The method of making a wet adhesive microneedle patch according to claim 3, wherein, In Step 2, the silk-tannic acid compound is used directly or freeze-dried and ground to obtain a freeze-dried powder, which is stored at -20℃; when used, the freeze-dried powder is sterilized by ultraviolet irradiation and sprayed with water to restore the viscous glue-like silk-tannic acid compound.

7. The method of making a wet adhesive microneedle patch according to claim 3, wherein, The mass concentration of the silk solution in Step 1 is 7%; the mass concentration of the silk solution in Steps 2 and 3 is 2%; and the mass concentration of the tannic acid solution in Step 2 is 10%.

8. The method of making a wet adhesive microneedle patch according to claim 4, wherein, The concentration of the sodium carbonate solution is 0.02 mol·L −1 The concentration of the lithium bromide solution is 9.3 mol·L -1 .

9. Use of the wet adhesion micro-needle patch of any one of claims 1-2 or prepared by the preparation method of any one of claims 3-8 in the preparation of a drug-loaded patch for treating oral mucosal diseases.

10. The use according to claim 9, wherein the drug on the drug-loaded patch comprises triamcinolone acetonide.

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