Modified hydrogel for skin wound healing and preparation method thereof

Abstract

The invention belongs to the technical field of medical gel, and particularly relates to modified hydrogel for skin wound healing and a preparation method thereof.The modified hydrogel is prepared from, by weight, 2-5 parts of drug-loaded GDVLNs, 1-2 parts of chitosan, 0.6-1.5 parts of antioxidant, 0.2 part of LAP, 1.5 parts of MA, 18 parts of gel matrix and 100 parts of buffer solution, the drug-loaded GDVLNs prepared from the traditional Chinese medicine active ingredients and the ginseng vesicles have the functions of resisting oxidative stress, promoting angiogenesis, promoting cell proliferation and the like, and the MA modified hydrogel system can realize slow release and controlled release of the drug-loaded GDVLNs and play a long-acting healing promoting role.

Description

Technical Field

[0001] This invention belongs to the field of medical gel technology, specifically relating to a modified hydrogel for skin wound healing and its preparation method. Background Technology

[0002] Against the backdrop of the rapid development of intelligent regenerative medicine, skin wound healing materials have shifted from traditional reliance on the body's self-repair to a stage of actively regulated intelligent dressings. Current research on novel dressings mainly focuses on biocompatible natural and synthetic polymer gels, electrospun nanofiber membranes, growth factor preparations, and stem cell and derivative preparations, accelerating healing by providing a moist environment, controlling wound exudation, and promoting granulation tissue formation. With the development of intelligent responsive dressings, novel materials such as pH-responsive, enzyme-responsive, or photoresponsive materials can dynamically release drugs according to the wound condition, demonstrating enormous potential for application research. However, due to the high complexity of the wound microenvironment, the abundance of regulatory factors and pharmacological signaling pathways, and the high risk of inflammation and infection, research on skin repair materials still faces significant challenges.

[0003] Ginseng, a traditional herbal medicine, possesses a wide range of pharmacological effects, including antioxidant, anticancer, immune-enhancing, and angiogenesis-promoting properties. Increasing research focuses on the active ingredients and medicinal pathways of ginseng. Among these, ginseng-based vesicle-like nanoparticles not only exhibit good activity but also serve as natural nanocarriers, enabling simultaneous therapeutic and drug delivery. Therefore, developing a smart dressing based on ginseng-derived vesicles is of great significance for promoting cell proliferation and healing in skin wounds. Summary of the Invention

[0004] To address the above issues, this invention provides a modified hydrogel for skin wound healing and its preparation method. Active nanoparticles are prepared by loading active ingredients of traditional Chinese medicine into ginseng vesicles that promote skin healing. The activity of the nanoparticles is dispersed and maintained by a three-dimensional cross-linked network structure formed by methacrylylation-modified gel, thus constructing a drug-loaded hydrogel with thermosensitive and photocurable properties. This achieves the goals of anti-infection, oxidative stress relief, and cell regeneration promotion during wound healing.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a modified hydrogel for skin wound healing, the modified hydrogel comprising the following raw materials in parts by weight: 2-5 parts of drug-loaded GDVLNs (ginseng-derived vesicle-like nanoparticles), 1-2 parts of chitosan, 0.6-1.5 parts of antioxidant, 0.2 parts of LAP (phenyl-2,4,6-trimethylbenzoyl lithium phosphinate), 1.5 parts of MA (methacrylic anhydride), 18 parts of gel matrix, and 100 parts of buffer solution.

[0006] Furthermore, the antioxidant is selected from any one of gallic acid, ferulic acid, and tannic acid.

[0007] Furthermore, the gel matrix is ​​selected from any one of poloxamer, gelatin, and sodium alginate.

[0008] Furthermore, the buffer solution is 0.1 M pH 7.4 PBS (phosphate) buffer.

[0009] Furthermore, the drug-loaded GDVLNs comprise the following raw materials: ginseng, resveratrol, baicalin, DSPE-PEG2000 (phospholipid polyethylene glycol copolymer), and sucrose, wherein the mass ratio of ginseng, resveratrol, baicalin, DSPE-PEG2000, and sucrose is 1000:0.7:0.3:1:2.

[0010] Furthermore, the preparation method of the drug-loaded GDVLNs is as follows: S1: After cutting ginseng into pieces, homogenize it at high speed to obtain a homogenate. Centrifuge the homogenate at differential speed to remove cell debris, large organelles and large vesicles. Collect the supernatant, which mainly contains small ginseng vesicles and soluble proteins. Centrifuge the supernatant at high speed to collect the milky white precipitate, namely GDVLNs. S2: Resveratrol, baicalin and DSPE-PEG2000 were dissolved in a mixed solvent prepared by anhydrous ethanol and chloroform in a volume ratio of 1:1 and transferred to a round-bottom flask. The mixed solvent was removed by rotary evaporation to obtain a composite film. S3: After resuspending GDVLNs, they were added to the composite film and hydrated and co-loaded by water bath heating. The phospholipid membrane of GDVLNs fused with the composite film and exchanged substances. Hydrophobic resveratrol and baicalin were loaded into the vesicles of GDVLNs. At the same time, DSPE-PEG2000 fused with the phospholipid membrane of GDVLNs. The hydrophobic end of DSPE was embedded in the phospholipid membrane, and the hydrophilic end of PEG2000 was exposed on the surface of the phospholipid membrane, thus obtaining the initial product. S4: The initial product is homogenized by ultrasound to further promote the uniformity of resveratrol and baicalein drug loading and particle size. After ultrafiltration and centrifugation, the ultrafiltrate is obtained. Sucrose is dissolved in the ultrafiltrate and lyophilized to obtain drug-loaded GDVLNs.

[0011] This invention also provides a method for preparing a modified hydrogel for skin wound healing, the specific preparation method of which is as follows: Step 1: Dissolve chitosan and antioxidant together in 50 parts of buffer solution, stir in a 60°C water bath for 4 hours. The amino groups in chitosan and the hydroxyl groups in antioxidant undergo covalent cross-linking to form a prepolymer network, which provides certain gel mechanical strength and long-lasting and stable antioxidant capacity, thus obtaining a cross-linked solution. Step 2: Dissolve the gel matrix to prepare a solution, add MA to modify it to obtain a modified gel matrix, and redissolve the modified gel matrix in 40 parts of buffer solution to obtain a modified solution; Step 3: Dissolve drug-loaded GDVLNs in 10 parts of buffer solution to obtain a nanoparticle solution. Mix the nanoparticle solution with the cross-linking solution evenly, add LAP and stir to dissolve in the dark to obtain a precursor solution. Mix the precursor solution with the modification solution and gel to form a gel. Adjust the mechanical strength of the gel by temperature or light to obtain a modified hydrogel for skin wound healing.

[0012] The beneficial effects achieved by this invention are as follows: The modified hydrogel for skin wound healing prepared in this invention utilizes naturally derived ginseng vesicles (GDVLNs) containing bioactive substances such as ginsenosides, small RNAs, and proteins. These vesicles also serve as multifunctional carriers for loading resveratrol and baicalin, traditional Chinese medicine components with antioxidant, angiogenesis-promoting, cell proliferation-promoting, and anti-infective properties. The phospholipid bilayer on the surface, similar in structure to cells, significantly enhances drug bioavailability and cell fusion regulation, further combining the inherent immunomodulatory function of the vesicles with the therapeutic function of the drugs. The drug-loaded GDVLNs can be taken up by macrophages at the wound site. Through strong oxidative phosphorylation and glycolysis, macrophages are driven to polarize from a pro-inflammatory M1 phenotype to an anti-inflammatory and coarse-repairing M2 phenotype. Simultaneously, a large number of cytokines promoting tissue regeneration are released, creating favorable conditions for skin repair. Based on this, drug-loaded GDVLNs can also promote the proliferation and migration of fibroblasts, accelerate their synthesis of collagen and elastin, activate vascular endothelial cells, promote angiogenesis, solve the problem of insufficient blood supply to the wound, and their phospholipid bilayer can also directly neutralize some reactive oxygen species, protecting new cells from oxidative damage.

[0013] In the construction of the gel system, a primary network with both mechanical strength and long-lasting antioxidant capacity was built through in-situ crosslinking of chitosan with antioxidants such as gallic acid, providing a stable microenvironment for the wound. Furthermore, a thermosensitive gel matrix modified with methacrylamide was introduced, and a smart hydrogel dressing with adjustable mechanical strength was formed through photocuring technology. This multi-level gel system effectively improves the dispersibility and activity retention of drug-loaded GDVLNs, and the gel network, which collapses over time, also has a sustained-release effect, providing a long-lasting active microenvironment for skin repair and healing. Attached Figure Description

[0014] Figure 1 The gel-forming properties of the modified hydrogel for skin wound healing prepared in Example 2 are characterized. Figure 2 The results of the cell compatibility study of the modified hydrogels for skin wound healing prepared in Examples 2, 4 and Comparative Examples 1-2 are as follows; Figure 3 The results of the investigation on the effect of the modified hydrogel for skin wound healing prepared in Example 2 on macrophage polarization; Figure 4 The results of the skin healing promotion ability of the modified hydrogels for skin wound healing prepared in Example 2 and Comparative Example 2 are presented. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0016] 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.

[0017] Unless otherwise specified, all methods used in the following examples are conventional. Unless otherwise specified, all materials used in the following examples are new materials purchased from the market. All quantities are parts by weight. Specifically, the PBS buffer used is 0.1M pH 7.4 PBS buffer; the poloxamer used is PF-127; the gelatin used is medical-grade type A gelatin; the sodium alginate used is high-G type, with a molecular weight of 80-150 kDa; and the chitosan used is low molecular weight, 50-150 kDa, with a degree of deacetylation ≥90%.

[0018] In the following examples and comparative examples, the drug-loaded GDVLNs comprise the following raw materials in parts by weight: 2000 parts ginseng, 1.4 parts resveratrol, 0.6 parts baicalein, 2 parts DSPE-PEG2000, and 4 parts sucrose; The preparation method of the drug-loaded GDVLNs is as follows: S1: Take 2000 portions of ginseng, cut them into pieces, and mix them with 2000 portions of PBS buffer containing protease inhibitors and pre-cooled at 4℃. Homogenize at 10000 rpm for 5 min at 4℃ to obtain a homogenate. Centrifuge the homogenate at 300×g for 10 min at 4℃ to remove cells and collect supernatant 1. Centrifuge supernatant 1 at 2000×g for 10 min at 4℃ to remove cell debris and collect supernatant 2. Centrifuge supernatant 2 at 10000×g for 10 min at 4℃ to remove apoptotic bodies and collect the supernatant. The supernatant mainly contains small ginseng vesicles and soluble proteins. Centrifuge the supernatant at 100000×g at 4℃ to collect the milky white precipitate, namely GDVLNs. S2: Dissolve 1.4 parts of resveratrol, 0.6 parts of baicalein and 2 parts of DSPE-PEG2000 in 20 parts of mixed solvent (anhydrous ethanol and chloroform in a volume ratio of 1:1) and transfer to a round-bottom flask. Remove the mixed solvent by rotary evaporation at 40°C and 100 rpm for 45 min to obtain the composite film. S3: GDVLNs were resuspended in 100 portions of PBS buffer and added to the composite membrane. The membrane was heated in a water bath at 50°C and 200 rpm for 60 min for hydration. The phospholipid membrane of GDVLNs fused with the composite membrane and exchanged substances. Hydrophobic resveratrol and baicalin were loaded into the vesicles of GDVLNs. At the same time, DSPE-PEG2000 fused with the phospholipid membrane of GDVLNs. The hydrophobic end of DSPE was embedded in the phospholipid membrane and the hydrophilic end of PEG2000 was exposed on the surface of the phospholipid membrane, thus obtaining the initial product. S4: The initial product was homogenized by ultrasonication for 3 min using a probe ultrasonic instrument with a power of 200 W, operating for 2 s and then pausing for 5 s to further promote the uniformity of resveratrol and baicalein drug loading and particle size. After centrifugation at 3500×g for 15 min in a 100 kDa ultrafiltration tube, the ultrafiltrate was obtained. Four portions of sucrose were dissolved in the ultrafiltrate and lyophilized to obtain drug-loaded GDVLNs. Liquid chromatography analysis showed that the resveratrol loading in the drug-loaded GDVLNs was 2.15% with an encapsulation rate of 87.3%, and the baicalein loading was 0.76% with an encapsulation rate of 92.2%.

[0019] Example 1: This example provides a modified hydrogel for skin wound healing, the modified hydrogel comprising the following raw materials in parts by weight: 2 parts drug-loaded GDVLNs, 1 part chitosan, 1 part ferulic acid, 0.2 parts LAP, 1.5 parts MA, 18 parts poloxamer and 100 parts buffer solution.

[0020] This embodiment also provides a method for preparing a modified hydrogel for skin wound healing, the specific preparation method is as follows: Step 1: Dissolve 1 part of ferulic acid in 5 parts of anhydrous ethanol to obtain a ferulic acid solution. Dissolve 1 part of chitosan in 50 parts of buffer solution to obtain a chitosan solution. Slowly add the ferulic acid solution to the chitosan solution at 4℃ and 800 rpm. After the addition is complete, stir in a water bath at 60℃ for 4 h to evaporate the anhydrous ethanol. At the same time, it promotes the covalent cross-linking of the amino groups in chitosan and the hydroxyl groups in ferulic acid to form a prepolymer network, which provides a certain gel mechanical strength and long-lasting and stable antioxidant capacity, thus obtaining a cross-linked solution. Step 2: Dissolve 18 parts of poloxamer in 100 parts of dichloromethane to prepare a poloxamer solution. Add 0.5 parts of DMAP (4-dimethylaminopyridine) and 1 part of TEA (triethylamine) and stir until homogeneous. Under ice bath, nitrogen protection, and light protection, add 1.5 parts of MA dropwise for modification. After the addition is complete, stir at room temperature and 500 rpm for 24 h to obtain a reaction solution. Slowly pour the reaction solution into 10 times the volume of ice-cold anhydrous diethyl ether. A white precipitate will precipitate. After centrifugation, wash with ice-cold diethyl ether and dry to obtain a modified gel matrix. Redissolve the modified gel matrix in 40 parts of buffer solution to obtain a modified solution. Step 3: Dissolve 2 parts of drug-loaded GDVLNs in 10 parts of buffer solution to obtain a nanoparticle solution. Mix the nanoparticle solution with the cross-linking solution evenly, add 0.2 parts of LAP and stir to dissolve in the dark to obtain a precursor solution. Mix the precursor solution with the modification solution under ice bath conditions, inject into a mold, incubate at 37°C to trigger gel formation, and then irradiate with 405 nm light to cure, to obtain a modified hydrogel for skin wound healing.

[0021] Example 2: This example provides a modified hydrogel for skin wound healing. The modified hydrogel comprises the following raw materials in parts by weight: 4 parts of drug-loaded GDVLNs, 2 parts of chitosan, 0.6 parts of gallic acid, 0.2 parts of LAP, 1.5 parts of MA, 18 parts of poloxamer, and 100 parts of buffer solution.

[0022] This embodiment also provides a method for preparing a modified hydrogel for skin wound healing, the specific preparation method is as follows: Step 1: Dissolve 0.6 parts of gallic acid in 5 parts of anhydrous ethanol to obtain a gallic acid solution. Dissolve 2 parts of chitosan in 50 parts of buffer solution to obtain a chitosan solution. Slowly add the gallic acid solution to the chitosan solution at 4℃ and 800 rpm. After the addition is complete, stir in a water bath at 60℃ for 4 h. The amino groups in chitosan and the hydroxyl groups in gallic acid undergo covalent cross-linking to form a prepolymer network, which provides certain gel mechanical strength and long-lasting and stable antioxidant capacity, thus obtaining a cross-linked solution. Step 2: Dissolve 18 parts of poloxamer in 100 parts of dichloromethane to prepare a poloxamer solution. Add 0.5 parts of DMAP and 1 part of TEA and stir well. Under ice bath, nitrogen protection and in the dark, add 1.5 parts of MA dropwise for modification. After the addition is complete, stir at room temperature and 500 rpm for 24 h to obtain a reaction solution. Slowly pour the reaction solution into 10 times the volume of ice-cold anhydrous ether. A white precipitate will precipitate. After centrifugation, wash with ice-cold ether and dry to obtain a modified gel matrix. Redissolve the modified gel matrix in 40 parts of buffer solution to obtain a modified solution. Step 3: Dissolve 4 parts of drug-loaded GDVLNs in 10 parts of buffer solution to obtain a nanoparticle solution. Mix the nanoparticle solution with the cross-linking solution evenly, add 0.2 parts of LAP and stir to dissolve in the dark to obtain a precursor solution. Mix the precursor solution with the modification solution under ice bath conditions, inject into a mold, incubate at 37°C to trigger gel formation, and then irradiate with 405 nm light to cure, to obtain a modified hydrogel for skin wound healing.

[0023] Example 3: This example provides a modified hydrogel for skin wound healing. The modified hydrogel comprises the following raw materials in parts by weight: 5 parts of drug-loaded GDVLNs, 1.5 parts of chitosan, 1.5 parts of tannic acid, 0.2 parts of LAP, 1.5 parts of MA, 18 parts of gelatin, and 100 parts of buffer solution.

[0024] This embodiment also provides a method for preparing a modified hydrogel for skin wound healing, the specific preparation method is as follows: Step 1: Dissolve 1.5 parts of tannic acid in 5 parts of deionized water to obtain a tannic acid solution. Dissolve 1.5 parts of chitosan in 50 parts of buffer solution to obtain a chitosan solution. Slowly add the tannic acid solution to the chitosan solution at 4℃ and 800 rpm. After the addition is complete, stir in a water bath at 60℃ for 4 h to obtain a cross-linking solution. Step 2: Dissolve 18 parts of gelatin in 162 parts of preheated deionized water at 50℃ to obtain a gelatin solution. Take 1.5 parts of MA and slowly add it dropwise to the gelatin solution at 50℃ and 100 rpm. After the addition is complete, continue the reaction at 300 rpm for 3 h to obtain a modified solution. Dialyze the modified solution through a 12 kDa dialysis bag for 2 days, changing the water every 12 h to obtain a modified gel matrix. Freeze-dry the modified gel matrix and reconstitute it in 40 parts of buffer solution to obtain a modified solution. Step 3: Dissolve 5 parts of drug-loaded GDVLNs in 10 parts of buffer solution to obtain a nanoparticle solution. Mix the nanoparticle solution with the crosslinking solution evenly, add 0.2 parts of LAP and stir to dissolve in the dark to obtain a precursor solution. Mix the precursor solution with the modification solution under ice bath conditions, inject into a mold, incubate at 37°C to trigger gel formation, and then irradiate with 405 nm light to cure, to obtain a modified hydrogel for skin wound healing.

[0025] Example 4: This example provides a modified hydrogel for skin wound healing. The modified hydrogel comprises the following raw materials in parts by weight: 4 parts of drug-loaded GDVLNs, 2 parts of chitosan, 0.6 parts of gallic acid, 0.2 parts of LAP, 1.5 parts of MA, 18 parts of gelatin, and 100 parts of buffer solution.

[0026] This embodiment also provides a method for preparing a modified hydrogel for skin wound healing, the specific preparation method is as follows: Step 1: Dissolve 0.6 parts of gallic acid in 5 parts of anhydrous ethanol to obtain a gallic acid solution. Dissolve 2 parts of chitosan in 50 parts of buffer solution to obtain a chitosan solution. Slowly add the gallic acid solution to the chitosan solution at 4℃ and 800 rpm. After the addition is complete, stir in a water bath at 60℃ for 4 h to obtain a cross-linking solution. Step 2: Dissolve 18 parts of gelatin in 162 parts of preheated deionized water at 50℃ to obtain a gelatin solution. Take 1.5 parts of MA and slowly add it dropwise to the gelatin solution at 50℃ and 100 rpm. After the addition is complete, continue the reaction at 300 rpm for 3 h to obtain a modified solution. Dialyze the modified solution through a 12 kDa dialysis bag for 2 days, changing the water every 12 h to obtain a modified gel matrix. Freeze-dry the modified gel matrix and reconstitute it in 40 parts of buffer solution to obtain a modified solution. Step 3: Dissolve 4 parts of drug-loaded GDVLNs in 10 parts of buffer solution to obtain a nanoparticle solution. Mix the nanoparticle solution with the cross-linking solution evenly, add 0.2 parts of LAP and stir to dissolve in the dark to obtain a precursor solution. Mix the precursor solution with the modification solution under ice bath conditions, inject into a mold, incubate at 37°C to trigger gel formation, and then irradiate with 405 nm light to cure, to obtain a modified hydrogel for skin wound healing.

[0027] Example 5: This example provides a modified hydrogel for skin wound healing. The modified hydrogel comprises the following raw materials in parts by weight: 4 parts of drug-loaded GDVLNs, 2 parts of chitosan, 0.6 parts of gallic acid, 0.2 parts of LAP, 1.5 parts of MA, 18 parts of sodium alginate, and 100 parts of buffer solution.

[0028] This embodiment also provides a method for preparing a modified hydrogel for skin wound healing, the specific preparation method is as follows: Step 1: Dissolve 0.6 parts of gallic acid in 5 parts of anhydrous ethanol to obtain a gallic acid solution. Dissolve 2 parts of chitosan in 50 parts of buffer solution to obtain a chitosan solution. Slowly add the gallic acid solution to the chitosan solution at 4℃ and 800 rpm. After the addition is complete, stir in a water bath at 60℃ for 4 h to obtain a cross-linking solution. Step 2: Slowly add 18 parts of sodium alginate to 162 parts of deionized water. Stir at room temperature and 500 rpm for 2 h. Then add 2 parts of DMAP and continue stirring until the lipids are completely dissolved. Adjust the pH to 8.0 with 1 M NaOH solution to obtain a sodium alginate solution. Add 1.5 parts of MA dropwise to the sodium alginate solution. After completion, react at room temperature and in the dark at 500 rpm for 24 h to obtain a reaction solution. Add 10 times the volume of anhydrous ethanol to the reaction solution and filter to obtain the precipitate, which is the modified gel matrix. After drying, redissolve it in 40 parts of buffer solution to obtain the modified solution. Step 3: Dissolve 4 parts of drug-loaded GDVLNs in 10 parts of buffer solution to obtain a nanoparticle solution. Mix the nanoparticle solution with the cross-linking solution evenly, add 0.2 parts of LAP and stir to dissolve in the dark to obtain a precursor solution. Mix the precursor solution with the modification solution under ice bath conditions, inject into a mold, incubate at 37°C to trigger gel formation, and then irradiate with 405 nm light to cure, to obtain a modified hydrogel for skin wound healing.

[0029] The difference between Comparative Example 1 and Example 2 is that GDVLNs of equal weight were used instead of drug-loaded GDVLNs, while the other raw material composition and preparation steps were the same as in Example 2.

[0030] The difference between Comparative Example 2 and Example 2 is that resveratrol and baicalein of medium mass were used instead of drug-loaded GDVLNs to prepare the modified hydrogel. The amount of resveratrol and baicalein added was calculated based on a drug loading of 2.15% and 0.76%, respectively, which were 0.09 parts and 0.03 parts. The raw materials were as follows: 0.09 parts resveratrol, 0.03 parts baicalein, 2 parts chitosan, 0.6 parts gallic acid, 0.2 parts LAP, 1.5 parts MA, 18 parts poloxamer and 100 parts buffer solution. The preparation method was the same as in Example 2.

[0031] Gelation performance evaluation: The modified hydrogel for skin wound healing prepared in Example 2 was used, and its fluid state before and after molding was recorded. The results are shown in the table below. Figure 1 .

[0032] Cell compatibility assessment: 0.2 mL of the modified hydrogels prepared in Examples 2, 4, and Comparative Examples 1-2 were solidified at the bottom of 96-well plates and co-cultured with L929 (mouse fibroblasts) and C166 (mouse vascular endothelial cells) for 12 and 24 h respectively to assess the cell compatibility of the hydrogels. Wells with normally cultured cells served as the control group, and wells without added cells served as the blank group. Cell viability was detected using the CCK-8 assay. Cell viability (%) = (experimental group absorbance - control group absorbance) / (control group absorbance - blank group absorbance) × 100%. Results are shown in […]. Figure 2 .

[0033] Macrophage polarization investigation: RAW264.7 cells were cultured with the modified hydrogel prepared in Example 2 for 24 h, and cell phenotype was detected by flow cytometry. Normally cultured cells served as the control group. An inflammation model was constructed by stimulating cells with LPS (lipopolysaccharide) as the LPS group. The results of flow cytometry and the macrophage phenotype M2:M1 ratio are shown in [the table below]. Figure 3 .

[0034] Skin wound healing assessment: Eighteen 6-week-old rats were randomly divided into three groups: a control group, two comparative groups, and two example groups. A skin trauma model was established, and a 2 cm diameter skin incision was made on the back of each rat. Wounds were photographed and recorded on day 0 and day 7 after drug administration. The results are shown in the table below. Figure 4 .

[0035] Figure 1 The results showed that the gel had good fluidity before curing, making it suitable for injection or application to wound sites. After curing with temperature and light, it exhibited good moldability.

[0036] Figure 2 The results showed that the modified hydrogels prepared in Examples 2, 4 and Comparative Examples 1-2 had good cell compatibility and did not produce toxicity to normal physiological cells when used for skin wound repair.

[0037] Figure 3 The results showed that, compared with the LPS group, the modified hydrogel prepared in Example 2 altered the phenotype of RAW264.7 cells after treatment, with an increase in cells in the Q2 region and a decrease in cells in the Q1 region. This indicated that macrophages underwent polarization, transforming from the M1 phenotype to the M2 phenotype. The M2 phenotype can inhibit the release of inflammatory factors, thereby promoting the accelerated transition of skin wounds from the inflammatory stage to the healing stage and improving repair efficiency.

[0038] Figure 4 The results showed that, compared with the control group and the two control groups, the rats in the Example 2 group showed good healing after 7 days of administration, indicating that GDVLNs have a positive effect on skin repair by promoting macrophage polarization.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0040] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A modified hydrogel for skin wound healing, characterized in that, The modified hydrogel comprises the following raw materials in parts by weight: 2-5 parts of drug-loaded GDVLNs, 1-2 parts of chitosan, 0.6-1.5 parts of antioxidant, 0.2 parts of LAP, 1.5 parts of MA, 18 parts of gel matrix, and 100 parts of buffer solution; The drug-loaded GDVLNs comprise the following raw materials: ginseng, resveratrol, baicalin, DSPE-PEG2000, and sucrose. The preparation method of the drug-loaded GDVLNs is as follows: S1: After homogenizing ginseng, differential and ultracentrifugation were performed, and the precipitate was collected to obtain GDVLNs; S2: Resveratrol, baicalin and DSPE-PEG2000 were dissolved and rotary evaporated to obtain a composite film; S3: Hydrate GDVLNs with the composite film to obtain the initial product; S4: Homogenize and ultrafilter the initial product to obtain the ultrafiltrate, add sucrose to it and freeze-dry to obtain drug-loaded GDVLNs.

2. The modified hydrogel for skin wound healing according to claim 1, characterized in that, The mass ratio of ginseng, resveratrol, baicalin, DSPE-PEG2000, and sucrose is 1000:0.7:0.3:1:

2. In step S2, the dissolution process uses a mixed solvent, which is prepared by mixing anhydrous ethanol and chloroform in a volume ratio of 1:

1.

3. The modified hydrogel for skin wound healing according to claim 1, characterized in that, The antioxidant is selected from any one of gallic acid, ferulic acid, and tannic acid; The gel matrix is ​​selected from any one of poloxamer, gelatin, and sodium alginate.

4. A method for preparing a modified hydrogel for skin wound healing according to any one of claims 1-3, characterized in that, The specific preparation method is as follows: Step 1: Dissolve chitosan and antioxidant in 50 parts of buffer solution to obtain a cross-linking solution; Step 2: After modifying the gel matrix with MA, dissolve it in 40 parts of buffer solution to obtain the modified solution; Step 3: Dissolve the drug-loaded GDVLNs in 10 parts of buffer solution and mix with cross-linking solution. Then add LAP to obtain a precursor solution. Mix the precursor solution with the modification solution and gel to obtain a modified hydrogel for skin wound healing.

5. The method for preparing a modified hydrogel for skin wound healing according to claim 4, characterized in that, In step 3, the process of adding LAP is carried out in the dark. The gelation process is regulated by temperature or light.

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