A hydrogel dressing for oral wound repair and its preparation method

Abstract

This invention belongs to the field of hydrogel dressing technology, specifically relating to a hydrogel dressing for oral wound repair and its preparation method. The hydrogel dressing for oral wound repair comprises the following raw materials in parts by weight: 3-10 parts of sodium methacrylamide alginate, 1-6.5 parts of HERS complex, 0.02-0.2 parts of photoinitiator, and 0.2-4 parts of TAP complex. The HERS complex prepared by this invention forms a stable supramolecular structure, effectively improving the stability of EGCG and mitigating the defects of resveratrol's poor water solubility and easy aggregation and precipitation. Simultaneously, hyaluronic acid oligosaccharides provide steric hindrance protection, preventing resveratrol molecule aggregation and achieving long-term stability of the active ingredient. In the TAP complex, ε-polylysine and tannic acid synergistically endow the complex with excellent antibacterial properties and enhance the stability of both, while also improving biocompatibility and adding long-lasting antibacterial ability.

Description

Technical Field

[0001] This invention belongs to the field of hydrogel dressing technology, specifically relating to a hydrogel dressing for oral wound repair and its preparation method. Background Technology

[0002] Oral wounds are common clinical tissue injuries, and their repair process is easily affected by the unique oral environment—constant moisture, saliva rinsing, chewing friction, and the proliferation of microorganisms. Furthermore, the mucosa is delicate and has a short healing cycle, placing extremely high demands on the performance of repair dressings. An ideal oral wound repair dressing must simultaneously possess good biocompatibility, strong wetting and adhesion, resistance to saliva rinsing, gentle and long-lasting antibacterial properties, and the ability to promote mucosal regeneration. It must also address issues such as poor stability and insufficient water solubility of active ingredients.

[0003] Currently, there are many types of dressings used for oral wound repair in clinical practice and existing technologies. Among them, hydrogel dressings have become a research hotspot in oral wound repair due to their excellent moisturizing properties, tissue compatibility, and adherence. However, existing oral hydrogel dressings generally have many technical shortcomings, making it difficult to meet the needs of oral wound repair: on the one hand, traditional hydrogel dressings have weak mechanical strength and poor adhesion in moist environments, making them easily washed away by saliva and unable to maintain stable adhesion to the wound for a long time; on the other hand, many existing hydrogel dressings have limited functionality, either only providing moisturizing and adhesion or only exerting antibacterial effects, failing to simultaneously meet the multiple needs required for oral wound repair; some composite dressings achieve functional superposition through simple stacking of multiple components without forming synergistic effects at the molecular level, which not only easily leads to system instability but may also increase the irritation of the dressing. Therefore, developing a composite hydrogel dressing with strong moisturizing adhesion, resistance to saliva erosion, and simultaneously possessing antibacterial, anti-inflammatory, and oral mucosal regeneration functions has become an urgent technical problem to be solved in the field of oral wound repair. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a hydrogel dressing for oral wound repair and its preparation method. This invention achieves stable solubility and synergistic efficacy of active ingredients by constructing an interaction between a HERS complex and a TAP complex. Using sodium methacrylamide as a base material, a photoinitiator is added, followed by photocrosslinking molding to physically confine the HERS complex within a covalently crosslinked three-dimensional network, forming a stable composite hydrogel dressing. This solves the technical problems of existing oral hydrogel dressings, such as poor water solubility of active ingredients, poor synergy among components, insufficient mechanical properties of the hydrogel, susceptibility to saliva rinsing and detachment, and inability to meet the multiple repair needs of oral wounds. The hydrogel dressing of this invention possesses good biocompatibility and mildness, enabling long-term sustained release of active ingredients, exerting multiple effects such as antibacterial, anti-inflammatory, and promoting oral mucosal regeneration. It can precisely adapt to the special environment of oral wounds and meet the needs of oral wound repair.

[0005] To address the shortcomings of existing technologies, the present invention adopts the following technical solution: This invention provides a hydrogel dressing for oral wound repair, the hydrogel dressing for oral wound repair comprising the following raw materials in parts by weight: 3-10 parts of sodium methacrylamide, 1-6.5 parts of HERS complex, 0.02-0.2 parts of photoinitiator, and 0.2-4 parts of TAP complex. Preferably, the photoinitiator is selected from lithium phenyl-2,4,6-trimethylbenzoyl phosphite (photoinitiator LAP), 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone (Irgacure 2959), and riboflavin; The HERS complex comprises raw materials in the following mass ratio: hyaluronic acid oligosaccharide: epigallocatechin gallate (EGCG): resveratrol = 1-2:2:0.2; The preparation method of the HERS complex includes the following steps: (1) Weigh out hyaluronic acid oligosaccharide and dissolve it in deionized water. The ratio of hyaluronic acid oligosaccharide to deionized water is 1g:100-150 mL. Stir magnetically at room temperature until completely dissolved to obtain hyaluronic acid oligosaccharide aqueous solution. (2) Weigh EGCG and add it to the hyaluronic acid oligosaccharide aqueous solution. Stir magnetically for 2 hours at room temperature in the dark to obtain a complex solution; (3) Weigh resveratrol and add it to the complexation solution. Place the reaction system in a constant temperature water bath at 40°C and stir continuously for 4-6 hours in the dark. After the reaction is completed, a uniform, transparent light yellow HERS complex is obtained.

[0006] The TAP complex comprises raw materials in the following mass ratio: ε-polylysine: tannic acid (TA) = 1-1.5:1; The preparation method of the TAP complex includes the following steps: (a) Weigh the Tris base, dissolve it in deionized water, adjust the pH to 8.5 with 1M HCl, and make up to volume to obtain Tris buffer solution. Filter the solution through a filter membrane for sterilization. Weigh the TA and dissolve it in part of the Tris buffer solution. The ratio of TA to Tris buffer solution is 0.1-0.5g:50mL. Stir magnetically until completely dissolved to obtain TA solution. (b) Weigh ε-polylysine and dissolve it in the remaining Tris buffer. The ratio of ε-polylysine to Tris buffer is 0.1-0.5 g: 50 mL. Stir magnetically until completely dissolved to obtain an ε-polylysine solution. Under magnetic stirring, slowly add the ε-polylysine solution to the TA solution, controlling the adding rate to about 1 mL / min. Continue stirring at room temperature for 2-4 hours. After the reaction is complete, centrifuge the mixture at 8000-10000 rpm for 10-15 minutes and collect the precipitate. The precipitate is pale yellow to brown in color. Wash the precipitate 2-3 times with deionized water to remove unreacted TA and ε-polylysine. Pre-freeze the washed precipitate at -80℃ for 4-6 hours and freeze-dry for 24-48 hours to obtain the TAP complex.

[0007] This invention also provides a method for preparing a hydrogel dressing for oral wound repair, specifically including the following steps: S1. Weigh out sodium methacrylamide and dissolve it in a phosphate buffer solution (PBS buffer) with a pH of 7.4. The ratio of sodium methacrylamide to PBS buffer is 3-10 g: 100 mL. Stir at room temperature in the dark until completely dissolved to obtain a sodium methacrylamide solution. S2, add photoinitiator to sodium methacrylamide solution, stir in the dark until completely dissolved to obtain a mixture, weigh TAP complex powder, add to the mixture, place it in an ice-water bath, use a probe sonicator to sonicate for 10 minutes to obtain a uniform suspension, add all HERS complex to the suspension, adjust the volume to 20 mL with PBS buffer, stir magnetically at room temperature in the dark for 1 hour to mix evenly to obtain hydrogel prepolymer solution; S3. Inject the hydrogel prepolymer into the mold and irradiate it under a 405 nm blue light source for 3-5 minutes at a light intensity of 80 mW / cm². 2 A uniform and stable shaped hydrogel is formed. The shaped composite hydrogel is washed three times with PBS buffer for 5 minutes each time to remove unreacted substances. After washing, a hydrogel dressing for oral wound repair is obtained.

[0008] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This invention, through the rational design of the compounding ratio and preparation process of each component, ultimately produces a hydrogel dressing for oral wound repair with excellent comprehensive performance: The HERS complex forms a stable supramolecular structure, and hyaluronic acid oligosaccharides are tightly anchored to EGCG through hydrogen bonds, effectively improving the stability of EGCG. EGCG and resveratrol interact strongly through π-π stacking interactions, effectively improving the poor water solubility and easy aggregation and precipitation defects of resveratrol, ensuring its uniform dispersion in the system without destroying its biological activity, fully preserving its antibacterial, anti-inflammatory, and wound-healing effects; simultaneously, hyaluronic acid oligosaccharides provide steric hindrance protection, preventing resveratrol molecule aggregation, reducing the impact of the external environment on the two active ingredients, lowering their oxidative degradation probability, and achieving long-term stability of the active ingredients. In the TAP complex, ε-polylysine and tannic acid synergistically endow the complex with excellent antibacterial properties, and the combination enhances the stability of both components while reducing the irritation of individual components, improving biocompatibility, adding long-term antibacterial ability to the hydrogel, adapting to the special environment of oral microbial growth, and reducing the risk of wound infection. During the preparation of the hydrogel prepolymer solution, the molecular structure of sodium methacrylamide exhibits good compatibility with the HERS and TAP complexes. After ultrasonic dispersion, the TAP complex is uniformly dispersed in the sodium methacrylamide solution, ensuring both system homogeneity and the uniform exertion of its antibacterial efficacy. The addition of the HERS complex aqueous solution ensures thorough mixing with the system, preserving its supramolecular structure and active ingredients, while also creating a synergistic effect with the TAP complex, further enhancing the hydrogel's antibacterial, anti-inflammatory, and healing capabilities. The hydrogel dressing for oral wound repair prepared by this invention possesses excellent biocompatibility, mildness, long-lasting antibacterial and anti-inflammatory effects, and promotes oral mucosal regeneration. It precisely adapts to the unique environment of the oral cavity—moist, easily flushable, delicate, and prone to microbial growth—comprehensively meeting the multiple needs of oral wound repair and effectively promoting wound healing. Attached Figure Description

[0009] Figure 1 The swelling rate curve of the hydrogel dressing for oral wound repair according to the present invention is shown. Figure 2 HE staining images of the healed oral mucosa of rabbits in Example 2 and the control group of the present invention; Figure 3 This is an adhesion diagram of the hydrogel dressing for oral wound repair according to the present invention. Detailed Implementation

[0010] To enable those skilled in the art to better understand the technical solutions of the present invention and to make the above-mentioned features, objectives, and advantages of the present invention clearer and easier to understand, the present invention will be further described below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0011] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0012] Unless otherwise specified, all methods described in the following embodiments are conventional. Unless otherwise specified, all materials used in the following embodiments are new materials purchased from the market.

[0013] Example 1: This example provides a hydrogel dressing for oral wound repair, which comprises the following raw materials in parts by weight: 3 parts of sodium methacrylamide, 1 part of HERS complex, 0.02 parts of photoinitiator LAP, and 0.2 parts of TAP complex. The HERS complex comprises raw materials in the following mass ratio: hyaluronic acid oligosaccharide: EGCG: resveratrol = 1:2:0.2; The preparation method of the HERS complex includes the following steps: (1) Weigh out hyaluronic acid oligosaccharide, dissolve it in deionized water, the ratio of hyaluronic acid oligosaccharide to deionized water is 1g:100 mL, stir magnetically at room temperature until completely dissolved, and obtain hyaluronic acid oligosaccharide aqueous solution. (2) Weigh EGCG and add it to the hyaluronic acid oligosaccharide aqueous solution. Stir magnetically at room temperature in the dark for 2 hours to allow EGCG molecules to be fully anchored to the hyaluronic acid oligosaccharide molecular chain through hydrogen bonding, and obtain a complex solution. (3) Weigh resveratrol and add it to the complexation solution. Place the reaction system in a constant temperature water bath at 40°C and stir continuously for 4 hours in the dark. After the reaction is completed, a uniform, transparent light yellow HERS complex is obtained.

[0014] The TAP complex comprises raw materials in the following mass ratio: ε-polylysine:TA = 1:1; The preparation method of the TAP complex includes the following steps: (a) Weigh the Tris base, dissolve it in deionized water, adjust the pH to 8.5 with 1M HCl, and make up to volume to obtain a Tris buffer solution with pH 8.5. Filter the solution through a filter membrane to remove bacteria, weigh the TA, dissolve it in the Tris buffer solution, and use TA to Tris buffer solution at a ratio of 0.1g:50mL. Stir magnetically until completely dissolved to obtain a TA solution. (b) Weigh ε-polylysine and dissolve it in Tris buffer at a ratio of 0.1 g to 50 mL. Stir magnetically until completely dissolved to obtain an ε-polylysine solution. Under magnetic stirring, slowly add the ε-polylysine solution to the TA solution at a rate of about 1 mL / min. Continue stirring at room temperature for 2 hours. After the reaction is complete, centrifuge the mixture at 8000 rpm for 10 minutes and collect the precipitate. The precipitate is pale yellow to brown in color. Wash the precipitate twice with deionized water to remove unreacted TA and ε-polylysine. Pre-freeze the washed precipitate at -80℃ for 4 hours and freeze-dry for 24 hours to obtain the TAP complex.

[0015] This embodiment also provides a method for preparing a hydrogel dressing for oral wound repair, specifically including the following steps: S1. Weigh out sodium methacrylamide and dissolve it in PBS buffer at pH 7.4. The ratio of sodium methacrylamide to PBS buffer is 3g:100mL. Stir at room temperature in the dark until completely dissolved to obtain sodium methacrylamide solution. S2, add photoinitiator to sodium methacrylamide solution, stir in the dark until completely dissolved to obtain a mixture, weigh TAP complex powder, add to the mixture, place in an ice-water bath, use a probe sonicator, power 200W, work for 2 seconds, pause for 3 seconds, sonicate for 10 minutes to obtain a uniform suspension, add all HERS complex to the suspension, adjust the volume to 20 mL with PBS buffer, stir magnetically at room temperature in the dark for 1 hour to mix evenly to obtain hydrogel prepolymer solution; S3. Inject the hydrogel prepolymer into the mold and irradiate it under a 405 nm blue light source for 3 minutes at a light intensity of 80 mW / cm². 2 A uniform and stable shaped composite hydrogel was formed. The shaped composite hydrogel was washed three times with PBS buffer for 5 minutes each time to remove unreacted substances. After washing, a hydrogel dressing for oral wound repair was obtained.

[0016] Example 2: This example provides a hydrogel dressing for oral wound repair, which comprises the following raw materials in parts by weight: 6 parts of sodium methacrylamide, 2.5 parts of HERS complex, 0.1 parts of riboflavin, and 2.2 parts of TAP complex. The HERS complex comprises raw materials in the following mass ratio: hyaluronic acid oligosaccharide: EGCG: resveratrol = 1.5:2:0.2; The preparation method of the HERS complex includes the following steps: (1) Weigh out hyaluronic acid oligosaccharide, dissolve it in deionized water, and use hyaluronic acid oligosaccharide to deionized water in a ratio of 1g:120mL. Stir magnetically at room temperature until completely dissolved to obtain hyaluronic acid oligosaccharide aqueous solution. (2) Weigh EGCG and add it to the hyaluronic acid oligosaccharide aqueous solution. Stir magnetically at room temperature in the dark for 2 hours to allow EGCG molecules to be fully anchored to the hyaluronic acid oligosaccharide molecular chain through hydrogen bonding, and obtain a complex solution. (3) Weigh resveratrol and add it to the complexation solution. Place the reaction system in a constant temperature water bath at 40°C and stir continuously for 5 hours in the dark. After the reaction is completed, a uniform, transparent light yellow HERS complex is obtained.

[0017] The TAP complex comprises raw materials in the following mass ratio: ε-polylysine:TA = 1.2:1; The preparation method of the TAP complex includes the following steps: (a) Weigh the Tris base, dissolve it in deionized water, adjust the pH to 8.5 with 1M HCl, and bring the volume to 100 mL to obtain a Tris buffer solution with a pH of 8.5. Filter the solution through a filter membrane to remove bacteria. Weigh the TA and dissolve it in the Tris buffer solution at a ratio of 0.3 g to 50 mL. Stir the solution magnetically until completely dissolved to obtain the TA solution. (b) Weigh ε-polylysine and dissolve it in Tris buffer at a ratio of 0.3 g to 50 mL. Stir magnetically until completely dissolved to obtain an ε-polylysine solution. Under magnetic stirring, slowly add the ε-polylysine solution to the TA solution at a rate of about 1 mL / min. Continue stirring at room temperature for 3 hours. After the reaction is complete, centrifuge the mixture at 9000 rpm for 12 minutes and collect the precipitate. The precipitate is pale yellow to brown in color. Wash the precipitate three times with deionized water to remove unreacted TA and ε-polylysine. Pre-freeze the washed precipitate at -80℃ for 5 hours and freeze-dry for 36 hours to obtain the TAP complex.

[0018] This embodiment also provides a method for preparing a hydrogel dressing for oral wound repair, specifically including the following steps: S1. Weigh out sodium methacrylamide and dissolve it in PBS buffer at pH 7.4. The ratio of sodium methacrylamide to PBS buffer is 6g:100mL. Stir at room temperature in the dark until completely dissolved to obtain sodium methacrylamide solution. S2, add photoinitiator to sodium methacrylamide solution, stir in the dark until completely dissolved to obtain a mixture, weigh TAP complex powder, add to the mixture, place in an ice-water bath, use a probe sonicator, power 200W, work for 2 seconds, pause for 3 seconds, sonicate for 10 minutes to obtain a uniform suspension, add all HERS complex to the suspension, adjust the volume to 20 mL with PBS buffer, stir magnetically at room temperature in the dark for 1 hour to mix evenly to obtain hydrogel prepolymer solution; S3. Inject the hydrogel prepolymer into the mold and irradiate it under a 405 nm blue light source for 4 minutes at a light intensity of 80 mW / cm². 2 A uniform and stable shaped composite hydrogel was formed. The shaped composite hydrogel was washed three times with PBS buffer for 5 minutes each time to remove unreacted substances. After washing, a hydrogel dressing for oral wound repair was obtained.

[0019] Example 3: This example provides a hydrogel dressing for oral wound repair, which comprises the following raw materials in parts by weight: 10 parts of sodium methacrylamide, 6.5 parts of HERS complex, 0.2 parts of Irgacure 2959, and 4 parts of TAP complex. The HERS complex comprises raw materials in the following mass ratio: hyaluronic acid oligosaccharide: EGCG: resveratrol = 2:2:0.2; The preparation method of the HERS complex includes the following steps: (1) Weigh out hyaluronic acid oligosaccharide and dissolve it in deionized water. The ratio of hyaluronic acid oligosaccharide to deionized water is 1g:150mL. Stir magnetically at room temperature until completely dissolved to obtain hyaluronic acid oligosaccharide aqueous solution. (2) Weigh EGCG and add it to the hyaluronic acid oligosaccharide aqueous solution. Stir magnetically at room temperature in the dark for 2 hours to allow EGCG molecules to be fully anchored to the hyaluronic acid oligosaccharide molecular chain through hydrogen bonding, and obtain a complex solution. (3) Weigh resveratrol and add it to the complexation solution. Place the reaction system in a constant temperature water bath at 40°C and stir continuously for 6 hours in the dark. After the reaction is completed, a uniform, transparent light yellow HERS complex is obtained.

[0020] The TAP complex comprises raw materials in the following mass ratio: ε-polylysine:TA = 1.5:1; The preparation method of the TAP complex includes the following steps: (a) Weigh the Tris base, dissolve it in deionized water, adjust the pH to 8.5 with 1M HCl, and make up to volume to obtain a Tris buffer solution with a pH of 8.5. Filter the solution through a filter membrane to remove bacteria, weigh the TA, dissolve it in the Tris buffer solution, and use TA to Tris buffer solution at a ratio of 0.5g:50mL. Stir magnetically until completely dissolved to obtain a TA solution. (b) Weigh ε-polylysine and dissolve it in Tris buffer at a ratio of 0.5 g to 50 mL. Stir magnetically until completely dissolved to obtain an ε-polylysine solution. Under magnetic stirring, slowly add the ε-polylysine solution to the TA solution at a rate of about 1 mL / min. Continue stirring at room temperature for 4 hours. After the reaction is complete, centrifuge the mixture at 10,000 rpm for 15 minutes and collect the precipitate. The precipitate is pale yellow to brown in color. Wash the precipitate three times with deionized water to remove unreacted TA and ε-polylysine. Pre-freeze the washed precipitate at -80°C for 6 hours and freeze-dry for 48 hours to obtain the TAP complex.

[0021] This embodiment also provides a method for preparing a hydrogel dressing for oral wound repair, specifically including the following steps: S1. Weigh out sodium methacrylamide and dissolve it in PBS buffer at pH 7.4. The ratio of sodium methacrylamide to PBS buffer is 10g:100mL. Stir at room temperature in the dark until completely dissolved to obtain sodium methacrylamide solution. S2, add photoinitiator to sodium methacrylamide solution, stir in the dark until completely dissolved to obtain a mixture, weigh TAP complex powder, add to the mixture, place in an ice-water bath, use a probe sonicator, power 200W, work for 2 seconds, pause for 3 seconds, sonicate for 10 minutes to obtain a uniform suspension, add all HERS complex to the suspension, adjust the volume to 20 mL with PBS buffer, stir magnetically at room temperature in the dark for 1 hour to mix evenly to obtain hydrogel prepolymer solution; S3. Inject the hydrogel prepolymer into the mold and irradiate it under a 405 nm blue light source for 5 minutes at a light intensity of 80 mW / cm². 2 A uniform and stable composite hydrogel is formed. The formed hydrogel dressing is washed three times with PBS buffer for 5 minutes each time to remove unreacted substances. After washing, a hydrogel dressing for oral wound repair is obtained.

[0022] The difference between Comparative Example 1 and Example 2 is that the addition of the HPER complex was omitted, while the rest is exactly the same as Example 2.

[0023] The difference between Comparative Example 2 and Example 2 is that the addition of the TAP complex was omitted, while the rest is exactly the same as Example 2.

[0024] The difference between Comparative Example 3 and Example 2 is that EGCG was omitted; otherwise, they are exactly the same as Example 2.

[0025] Experimental example: 1. Cell Compatibility: The effect of APPF hydrogel on cell growth was assessed using a CCK-8 assay kit, and the cytotoxicity of APPF hydrogel was assessed using a PI / FDA staining kit. Hydrogels from each group were placed in 96-well plates and irradiated with sterile UV light for 24 hours. All other experimental equipment was sterilized. Mouse fibroblast L929 cells were resuscitated and passaged three times. The culture medium was discarded, and 1 mL of trypsin was added. The cells were treated at 37°C for 30 seconds to digest approximately 80% of the cells. Digestion was stopped by adding DMEM medium containing 10% FBS. The digested cell suspension was centrifuged for 5 minutes to obtain a cell pellet. The cell pellet was resuspended in DMEM medium containing 10% FBS, and the cell suspension was seeded in 12-well plates and cultured in a CO2 incubator. Subsequently, 10 μL of the cell suspension was transferred to each well of a new 96-well plate and incubated at 37°C for 24 and 48 hours. The cells were divided into Examples 1-3 and Comparative Examples 1-3. Then, a CCK-8 mixture was prepared by mixing CCK-8 staining solution and basal culture medium at a ratio of 1:10 in the dark. Approximately 200 μL of this mixture was added to each well and incubated in the dark for 3 hours. A new 96-well plate was then prepared, and 100 μL of the supernatant from the original wells was transferred to each new well according to the original grouping. The absorbance of the solution was measured at 450 nm. Cell viability was calculated using the following formula: ; where AT, A0, and AC represent the absorbance of the sample group, control group, and blank group, respectively. The calculated cell viability results are recorded in Table 1.

[0026] 2. Cell Adhesion: The hydrogel dressings from Example 2 of this invention were placed in 12-well plates and irradiated with sterile ultraviolet light for 24 hours. 100 μL of revived L929 cell suspension was seeded onto the gel surface per well. After 72 hours of culture, the culture medium liquid in each well was aspirated with a pipette, and the cells were washed three times with PBS. At room temperature, the bottom of the wells was immersed in a 3.7% paraformaldehyde solution prepared with PBS to fix the cells for approximately 30 minutes. The cell membranes were perforated four times with PBS containing 0.3% Triton X-100, for 5 minutes each time. For staining preparation, Actin-Tracker Red stain was diluted 1:40 and PBS containing 5% BSA and 0.1% Triton X-100 was added. 200 μL of the diluted staining working solution was applied to each well to stain the cell skeleton, and the cells were incubated at room temperature in the dark for 45 minutes. The Actin-Tracker was removed, and the cells were washed with PBS. Then, DAPI staining solution (1:1000) was added to stain the cell nuclei, and the cells were incubated at room temperature in the dark for 5 minutes. The DAPI staining solution was then removed. Finally, the cells were observed using a fluorescence microscope. Results are as follows: Figure 3 As shown.

[0027] 3. Antibacterial Properties: Antibacterial experiments were conducted using the plating method and OD value calculation method. Hydrogel dressings for oral wound repair prepared in Examples 1-3 and Comparative Examples 1-3 of this invention were used as samples. Before the experiment, the equipment was sterilized. Staphylococcus aureus and Escherichia coli were selected as model bacteria and cultured separately on sterile agar plates at 37°C. Colonies were dispersed using the streak plating method. A single colony from the agar plate was picked and placed in 4 mL of broth. The shaker temperature was set to 37°C, and the culture medium was shaken at 180 rpm for 12 h. 3 mL of the shaken culture medium was taken, 50 mL of broth was added, and shaking continued for 3.5 h. The bacterial solution was then diluted to 10... 6 The bacterial suspension was diluted to a concentration of CFU / mL, and then 5 mL of the bacterial suspension was mixed with 1 mL of sample hydrogel and incubated for 12 h. Subsequently, the bacterial suspension was cascaded diluted, with 100 μL of each dilution spread evenly on 20 mL of agar solid medium using an L-shaped glass rod, and then incubated in a constant temperature incubator for 24 h. Colony formation on the surface of the medium was recorded. To measure the inhibition rate, the bacterial solution was diluted to 10... 6 The concentration of CFU / mL was determined, and then 5 mL of bacterial suspension was mixed with 1 mL of sample and incubated for 12 h. The absorbance of the bacterial suspension at 600 nm was measured using a spectrophotometer. The antibacterial rates against Escherichia coli and Staphylococcus aureus were calculated based on the absorbance results and recorded in Table 1.

[0028] 4. Swelling Test of Hydrogels: The swelling characteristics of hydrogels were evaluated using a standard gravimetric method. The swelling characteristics of the group in Example 2 of this invention were tested, and the specific steps are as follows: First, hydrogel samples of the same size were prepared using a cylindrical mold (10 mm in diameter and 4 mm in height). After weighing at room temperature, they were immersed in deionized water. Every 1 hour, they were removed, excess moisture was wiped off with filter paper, and then weighed. The swelling rate (%) was calculated using the following formula: Where Mt represents the mass of the swollen gel at a specific time point t, and M0 represents the initial wet weight. For example... Figure 1 As shown.

[0029] 5. Wound Repair: Twelve healthy New Zealand white rabbits, weighing approximately 2 kg, were randomly divided into two groups: Example 2 group and a blank control group. Chloral hydrate solution was prepared by dissolving 10 g of chloral hydrate crystals in 100 ml of physiological saline to a concentration of 0.1 g / ml. The rabbits underwent hair removal and disinfection along the ear margin, and the ear vein was located. Chloral hydrate was injected at a rate of 4 ml / kg, followed by anesthesia. After anesthesia, the rabbits were fixed, their mouths were opened, and a circular wound was created on one buccal mucosa with hemostasis. In the experimental group, sterilized hydrogel, after pre-gelation treatment, was dripped onto the wound and fixed by UV light irradiation. The blank control group's wounds were left untreated and the rabbits were placed until recovery.

[0030] On day 14 of healing of the buccal mucosal wound in rabbits, three rabbits from each group were euthanized by injecting 5 ml of air into the marginal ear vein. The full-thickness mucosal layer of the healed wound, along with some surrounding normal mucosal tissue, was completely removed using surgical instruments. Blood was flushed off the tissue surface, and the obtained tissue was fixed in paraformaldehyde solution for 24 hours. The tissue was then embedded in paraffin. First, the paraformaldehyde on the tissue surface was flushed off, followed by gradient dehydration. The dehydrated tissue was then immersed in xylene solution until it became transparent, and then quickly placed in liquid paraffin. Both were placed in an oven and baked at 37°C for 3 hours. The baked tissue block was placed in an embedding cassette, and the remaining space was filled with liquid paraffin. After the paraffin cooled, the cooled paraffin block was cut into 5 μm thick slices, attached to glass slides, and baked in an oven at 50°C. The glass slides were then placed in pure xylene solution for 15 minutes, and this step was repeated twice. Rinse the xylene surface of the slide with deionized water, then soak it in hematoxylin staining solution for 5 minutes. Rinse the slide again with deionized water and dehydrate it in a gradient of different concentrations of alcohol. Next, soak it in eosin staining solution for 5 minutes. Repeat the above steps with alcohol for dehydration, and finally, mount the slide with resin. Observe the specimen under a microscope. Figure 2 As shown.

[0031] Table 1: Performance test results of the hydrogel dressing for oral wound repair of the present invention in each group

[0032] As shown in Table 1, Example 2 exhibited the highest cell viability, significantly superior to the comparative examples. Comparative Example 2 showed a cell viability of 88.7%, lower than Example 2 but still at a high level, indicating that the HERS complex itself has good cell compatibility, and the addition of the TAP complex did not have a significant negative impact on cell viability. Comparative Example 1 showed a cell viability of 86.3%, lower than Example 2, indicating that the active ingredients in the HERS complex have a positive effect on promoting cell proliferation. Comparative Example 3 showed a cell viability of 83.5%, indicating that EGCG plays a key role in promoting cell viability. These results demonstrate that all components of the present invention have good cell compatibility, and there is a synergistic effect among the components in the HERS complex, jointly promoting cell adhesion and proliferation. Examples 1-3 all achieved antibacterial rates of over 90% against Escherichia coli and Staphylococcus aureus, exhibiting excellent broad-spectrum antibacterial activity. The antibacterial rate of Comparative Example 2 decreased significantly, with the antibacterial rates against *Escherichia coli* and *Staphylococcus aureus* decreasing to 72.4% and 76.8%, respectively, showing the most significant decrease. This indicates that the TAP complex provides potent antibacterial activity to the hydrogel dressing of the present invention. The antibacterial rates of Comparative Example 1 were 88.5% (*Escherichia coli*) and 90.1% (*Staphylococcus aureus*), lower than Example 2 but still at a high level, indicating that the TAP complex has strong antibacterial ability, while the HERS complex further enhances the antibacterial effect. The antibacterial rates of Comparative Example 3 were 91.2% (*Escherichia coli*) and 93.5% (*Staphylococcus aureus*), slightly lower than Example 2 but higher than Comparative Example 1, indicating that EGCG has certain antibacterial activity and forms an antibacterial synergy with the TAP complex.

[0033] Figure 1 As shown, by continuously monitoring the changes in gel quality, the hydrogels of all groups reached expansion equilibrium at around 4 hours, and the curve changes became gentler. The swelling rate of Comparative Example 1 increased because the addition of the HERS complex was removed, and the network structure became loose, resulting in an increased swelling rate. The swelling rate of Example 2 was better than that of the comparative examples, indicating that the HERS complex added in this invention forms a good synergistic effect with the TAP complex, effectively inhibiting the excessive water absorption and swelling of the hydrogel, which is beneficial to maintaining dimensional stability in the moist environment of the oral cavity.

[0034] Figure 2HE staining results of rabbit buccal mucosa healing tissue at 14 days for the hydrogel dressing for oral wound repair prepared in Example 2 of the present invention and the control group. At 14 days, it can be observed that the mucosa of both groups has completed healing. However, the mucosal epithelium of the control group is irregular in morphology, the keratinized layer is thin, and a relatively large number of inflammatory cells can still be seen in the lamina propria. The mucosa of the Example 2 group is more normal and the epithelial thickness is thicker.

[0035] like Figure 3 As shown, the cells grow well on the surface of the hydrogel dressing for oral wound repair prepared in Example 2 of this invention, and the expression of cytoskeletal proteins is obvious, indicating that the hydrogel dressing of this invention has excellent adhesion to cells, which helps cells adhere and grow.

[0036] In summary, this invention, through scientifically designed component compounding and preparation processes, constructs stable HERS and TAP complexes. Utilizing the specific intermolecular interactions within and between each complex, and using sodium methacrylamide as a substrate, photoinitiators are added followed by photocrosslinking molding. This rationally disperses and confines the HERS and TAP complexes within a covalently crosslinked three-dimensional network, achieving functional complementarity and synergistic effects among the components. This ensures both the structural stability and erosion resistance of the hydrogel, while also achieving long-term sustained release of active ingredients. The hydrogel possesses multiple effects, including mild antibacterial, anti-inflammatory, and oral mucosal regeneration promotion, precisely adapting to the special environment of oral wounds and meeting the comprehensive needs of oral wound repair. It exhibits outstanding technical advantages and good practical value.

[0037] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A hydrogel dressing for oral wound repair, characterized in that, The raw materials include the following parts by weight: 3-10 parts of sodium methacrylamide, 1-6.5 parts of HERS complex, 0.02-0.2 parts of photoinitiator, and 0.2-4 parts of TAP complex; The HERS complex comprises raw materials in the following mass ratio: hyaluronic acid oligosaccharide: EGCG: resveratrol = 1-2:2:0.2; The preparation method of the HERS complex includes the following steps: (1) Weigh out the hyaluronic acid oligosaccharide, dissolve it in deionized water, and stir magnetically until dissolved to obtain an aqueous solution of hyaluronic acid oligosaccharide; (2) Weigh EGCG, add it to the hyaluronic acid oligosaccharide aqueous solution, stir, and obtain a complex solution; (3) Weigh resveratrol and add it to the complexing solution. Stir in a constant temperature water bath in the dark to obtain the HERS complex. The TAP complex comprises raw materials in the following mass ratio: ε-polylysine:TA = 1-1.5:1; The preparation method of the TAP complex includes the following steps: (a) Weigh the Tris base, dissolve it in deionized water, adjust the pH to obtain Tris buffer, filter it through a filter membrane to remove bacteria, weigh the TA, dissolve it in part of the Tris buffer, stir magnetically until dissolved, and obtain the TA solution; (b) Weigh ε-polylysine and dissolve it in the remaining Tris buffer. Stir magnetically until dissolved to obtain an ε-polylysine solution. Slowly add the ε-polylysine solution to the TA solution, controlling the adding speed. Continue stirring, then centrifuge, collect the precipitate, wash, pre-freeze, and freeze-dry to obtain the TAP complex.

2. The hydrogel dressing for oral wound repair according to claim 1, characterized in that, In step (1), the ratio of the amount of hyaluronic acid oligosaccharide to deionized water is 1g:100-150 mL.

3. The hydrogel dressing for oral wound repair according to claim 1, characterized in that, The photoinitiator is selected from one of the photoinitiators LAP, Irgacure 2959, and riboflavin.

4. The hydrogel dressing for oral wound repair according to claim 1, characterized in that, In step (a), the ratio of TA to Tris buffer is 0.1-0.5 g: 50 mL; In step (b), the ratio of ε-polylysine to Tris buffer is 0.1-0.5 g: 50 mL.

5. A method for preparing a hydrogel dressing for oral wound repair according to any one of claims 1-4, characterized in that, Specifically, the following steps are included: S1, Weigh out sodium methacrylamide, dissolve it in PBS buffer, stir in the dark to obtain sodium methacrylamide solution; S2, add photoinitiator to sodium methacrylamide solution, stir in the dark to obtain a mixture, weigh out TAP complex and add to the mixture, disperse by sonication in an ice water bath to obtain a suspension, add HERS complex to suspension, make up to volume with PBS buffer, stir in the dark to obtain hydrogel prepolymer solution; S3. The hydrogel prepolymer is injected into the mold and placed under a light source to obtain a hydrogel dressing for oral wound repair.

6. The method for preparing a hydrogel dressing for oral wound repair according to claim 5, characterized in that, In step S1, the ratio of sodium methacrylamide to PBS buffer is 3-10 g: 100 mL.

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