A hydrogel wound dressing for promoting healing of infectious wounds, and its preparation method and application

Abstract

The present invention discloses a hydrogel wound dressing for promoting the healing of infectious wounds. The hydrogel wound dressing comprises the following raw materials: oxymethacrylated hyaluronic acid, aqueous polyurethane, polylysine, cannabidiol, neomycin sulfate, and 2-camphor alcohol. The present invention also provides a method for preparing the hydrogel wound dressing and its use in preparing a product for repairing infectious wounds. The wound dressing of the present invention has a microporous structure, good biocompatibility, and biodegradability, and can be used to stop bleeding, reduce wound infection, and promote cell proliferation and wound healing.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a hydrogel wound dressing for promoting healing of infectious wounds, and a preparation method and application thereof. Background Art

[0002] Modern wound repair research faces multiple technical bottlenecks, particularly the deep tissue damage caused by low-penetration firearm wounds and the irregular, complex wounds resulting from explosive shock waves in battlefield environments. These wounds, due to their complex morphology and the difficulty of achieving effective hemostasis with conventional pressure application, have become a core challenge in trauma medicine. In precision surgery, surgeries involving central nervous systems and solid organs require nanoscale hemostatic precision. Procedures involving cavities such as the nasal cavity, auditory canal, and urinary tract further test the spatial conformability and biocompatibility of hemostatic materials. Analysis of tissue regeneration mechanisms reveals that wound repair follows a sequential progression through the hemostatic-inflammatory phase, the granulation tissue formation phase, and the tissue remodeling phase. Rapid hemostasis within the golden hour after trauma is crucial for shortening the healing cycle. Currently, commonly used dressings in clinical practice often suffer from a disconnect between hemostatic efficacy and repair-promoting functions. The development of dual-functional, integrated medical dressings that combine immediate hemostasis with long-term tissue regeneration induction has become a key research focus in translational medicine.

[0003] Wound dressings with excellent biocompatibility and biodegradability are of great significance for clinical application in vivo. Hyaluronic acid (HA), a naturally occurring linear polysaccharide, is widely distributed in human tissues, particularly in the extracellular matrix (ECM) of the skin. Its excellent biocompatibility, biodegradability, hydrophilicity, and non-immunogenicity make it a crucial material for wound healing. HA promotes cell adhesion, migration, proliferation, and differentiation, and participates in angiogenesis and tissue regeneration. Therefore, it is considered an attractive material for synthesizing biomedical hydrogels for skin wound healing. As a dressing material, water-based polyurethane (PU) has become a star material in the field of wound repair due to its high designability, modularity, and multifunctionality. In particular, water-based polyurethane dressings that mimic the structure of skin combine high designability, elasticity, breathability, and biocompatibility. Polyurethane dressings can adapt to wounds of varying shapes and sizes, providing a moist healing environment while protecting the wound from external microorganisms. In addition, polyurethane dressings usually have a certain mechanical strength and can withstand the friction and pressure in daily activities, reduce secondary damage to the wound, and can be used for full-thickness scar-free healing, showing excellent therapeutic effects.

[0004] Hydrogels similar to ECMs have shown great potential in wound healing, maintaining a moist environment, providing stable mechanical support for the proliferation of new cells, and promoting the exchange of wound substances. Although water-based polyurethane is a promising tissue engineering immune response biomaterial, ordinary water-based polyurethane hydrogels have a hydrated layer on the surface, a dense structure, and no pores, which hinders cell adhesion and growth and is not conducive to the healing of damaged tissues. Summary of the Invention

[0005] One object of the present invention is to provide a hydrogel wound dressing having both good hemostatic and wound healing properties in response to the above technical problems.

[0006] Another object of the present invention is to provide a method for preparing the hydrogel wound dressing.

[0007] Another object of the present invention is to provide applications of the hydrogel wound dressing.

[0008] In order to achieve the above-mentioned purpose of the invention, the present invention provides a hydrogel wound dressing that promotes the healing of infectious wounds, which comprises the following raw materials: oxidized methacrylated hyaluronic acid, aqueous polyurethane, polylysine, cannabidiol, neomycin sulfate, and 2-camphenol.

[0009] Preferably, in the hydrogel, the mass volume concentration of oxidized methacrylated hyaluronic acid is 3-7%, the mass volume concentration of aqueous polyurethane is 3-7%, the mass volume concentration of polylysine is 4-6%, the molar concentration of cannabidiol is 0.5-2 M, the molar concentration of neomycin sulfate is 0.5-2 M, and the molar concentration of 2-camphenol is 0.5-2 M.

[0010] Preferably, the molar ratio of cannabidiol, neomycin sulfate and 2-camphenol is (0.5-2): (0.5-2): (0.5-2), and most preferably is 1:1:1.

[0011] Preferably, the oxidation degree of the oxidized methacrylated hyaluronic acid is 25%-50%.

[0012] Preferably, the solid content of the waterborne polyurethane is 10-20%.

[0013] On the other hand, the present invention also provides a method for preparing the hydrogel wound dressing, comprising the following steps:

[0014] Dissolve oxidized methacrylated hyaluronic acid and aqueous polyurethane in water, add polylysine, then add cannabidiol, neomycin sulfate and 2-hydroxybenzoic acid in sequence, and finally add a photoinitiator and irradiate with ultraviolet light to obtain a hydrogel.

[0015] Preferably, the oxidized methacrylated hyaluronic acid is prepared by the following steps:

[0016] (1) Prepare a hyaluronic acid solution with a mass volume concentration of 1%;

[0017] (2) adding 1% of the volume of the hyaluronic acid solution in methacrylic anhydride, adjusting the pH to 8-9, and reacting for 24 hours;

[0018] (3) Pour the mixed liquid after the reaction into 3 to 5 times the volume of ice ethanol. A precipitate will appear. The precipitate is redissolved, dialyzed, and freeze-dried to obtain methacrylated hyaluronic acid.

[0019] (4) Prepare a methacrylated hyaluronic acid solution with a mass volume concentration of 1%, add 0.5-1% of sodium periodate by mass volume of the hyaluronic acid solution and continue stirring, add 2% of ethylene glycol by volume of the hyaluronic acid solution to terminate the reaction, dialyze, and freeze-dry to obtain oxidized methacrylated hyaluronic acid.

[0020] Preferably, the waterborne polyurethane is prepared by the following steps:

[0021] (1) Take 6 mmol of polyethylene glycol 2000 and 2 mmol of polycaprolactone 2000, dehydrate under vacuum, react at 110°C for 2 hours, then cool to 50°C and maintain for 30-45 minutes;

[0022] (2) Add 19.2 mmol of isophorone diisocyanate, stir for 20 min, add 20 μL of catalyst, stir for 20 min, heat to 75 °C, and react for 2.5 hours; add 6 mmol of chain extender and continue the reaction for 1.5-2 hours;

[0023] (3) After the temperature drops to 50°C, add 12 mmol of 2-hydroxyethyl methacrylate and 3 mmol of triethylamine. Continue the reaction for 21-24 hours, then drop it into 100-200 mL of pure water to obtain a water-based polyurethane with a solid content of 10-20%.

[0024] Preferably, the cannabidiol solution is an ethanol solution of cannabidiol with a molar concentration of 0.5-2M.

[0025] Preferably, the mass volume concentration of the polylysine aqueous solution is 4%-6%.

[0026] Preferably, the neomycin sulfate solution is an aqueous solution of neomycin sulfate with a molar concentration of 0.5-2M.

[0027] Preferably, the 2-bromophenol solution is an ethanol solution of 2-bromophenol with a molar concentration of 0.5-2M.

[0028] Preferably, the photoinitiator is an aqueous solution of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (I2959) with a mass volume concentration of 1%.

[0029] Preferably, the molecular weight of the hyaluronic acid is 150,000-200,000.

[0030] On the other hand, the present invention also provides use of the hydrogel wound dressing in preparing a product for repairing infected wounds.

[0031] To accelerate wound healing and prevent chronic inflammation, this invention covalently crosslinks aqueous polyurethane with oxidized methacrylated hyaluronic acid (OHAMA) and incorporates the natural antibacterial polymer polylysine (PL) to construct a three-dimensional porous oxidized methacrylated hyaluronic acid-aqueous polyurethane-polylysine (OHAMA-PU-PL) hydrogel with inherent immunomodulatory properties. Cannabidiol (CBD), neomycin sulfate (NS), and 2-camphenol (2-B) are also loaded into the hydrogel, producing analgesic, anti-inflammatory, and antibacterial effects. The wound dressing of this invention exhibits a microporous structure, excellent biocompatibility, and biodegradability, and can be used to promote wound healing. Furthermore, the hydrogel dressing of this invention features a simple preparation method, requiring no additional solvents or specialized equipment to complete the reaction. This provides a new approach to the rapid production of natural polymer hydrogels, successfully resolving the dilemma of complex functionality and simple preparation in the field of wound dressings. The resulting hydrogel dressing exhibits excellent wound healing properties, reducing wound infection, promoting cell proliferation, and promoting wound healing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The water absorption of different hydrogels at different time points is shown.

[0033] Figure 2 The viscosity of different hydrogels is shown. (A) Viscosity in the frequency range of 0.1 to 10 Hz; (B) Viscosity in the shear stress range of 0.1 to 100%.

[0034] Figure 3 The adhesion strength of different hydrogels on pig skin is shown.

[0035] Figure 4 The pH value changes of the hydrogel extract are shown.

[0036] Figure 5 The drug release of cannabidiol of Example 13 over time is shown.

[0037] Figure 6 Images of colonies of different samples after 24 hours of culture are shown.

[0038] Figure 7The results of cytotoxicity experiments are shown. (A) Images and hemolysis rates of different samples after incubation with blood cells; (B) Cell viability of different samples after 24 hours of incubation with CCK8; (C) Live-dead staining images of different samples after incubation with 3T3 cells.

[0039] Figure 8 Figure 3 shows gene expression levels and cell wound healing assay results after RAW 246.7 cells were treated with hydrogel extract. (A) Gene expression levels; (B) 3T3 cell migration and cell wound healing rate after 24 hours of culture.

[0040] Figure 9 Figure 2 shows the healing status, healing rate, and weight change of dorsal wounds in mice over time. (A) Healing status; (B) Healing rate; (C) Weight change of mice during treatment. Values ​​are mean ± standard deviation (SD) (n = 3), *p < 0.05, **p < 0.01, ***p < 0.001.

[0041] Figure 10 Shown are the results of H&E and Masson staining analysis of skin tissue sections from different treatment groups on day 0, day 5, and day 10 of treatment. DETAILED DESCRIPTION

[0042] To facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the present disclosure more thorough and comprehensive.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] Example 1

[0045] Prepare oxidized methacrylated hyaluronic acid-waterborne polyurethane-polylysine (OHAMA-PU-PL) hydrogels according to the following steps:

[0046] 1. Preparation of Oxidized Methacrylated Hyaluronic Acid (OHAMA)

[0047] (1) Weigh 1.0 g of hyaluronic acid (HA) (molecular weight can be 150,000 to 200,000, and HA with a molecular weight of 150,000 is used in this example), add 100 mL of purified water, and stir magnetically for 2 hours to completely dissolve and defoam the HA to obtain a hyaluronic acid solution with a mass volume concentration of 1% (w / v%, g / mL).

[0048] (2) Add 10 mL (1% of the volume of the hyaluronic acid solution) of methacrylic anhydride (MAA), then adjust the pH to 8 with a 10 M NaOH aqueous solution and react for 24 hours.

[0049] (3) The mixed liquid after the reaction was poured into 300 mL (3 times the volume of the hyaluronic acid solution) of ice ethanol. A precipitate appeared. The precipitate was re-dissolved in 100 mL of pure water and dialyzed in a dialysis bag (Da=3500) for 3 days. The precipitate was freeze-dried to obtain methacrylated hyaluronic acid (HAMA).

[0050] (4) Weigh 1.0 g of HAMA and add 100 mL of purified water. After magnetic stirring to completely dissolve it, add 0.5 g of sodium periodate (NaIO4) and continue stirring for 4 hours. Then, add 2 mL of ethylene glycol to terminate the reaction. Dialyze the solution with a dialysis bag (Da = 3500) for 3 days and freeze-dry to obtain oxidized methacrylated hyaluronic acid (OHAMA) with an oxidation degree of 50% (the oxidation degree can be 25% to 50%, and the amount of sodium periodate added can be adjusted according to the desired oxidation degree). After drying, store at -20°C.

[0051] 2. Preparation of waterborne polyurethane (PU)

[0052] (1) 6 mmol of polyethylene glycol 2000 (PEG 2000) and 2 mmol of polycaprolactone 2000 (PCL 2000) were placed in a three-necked flask, vacuum-dehydrated, reacted at 110 °C for 2 hours, and then cooled to 50 °C and maintained for 40 minutes.

[0053] (2) Add 19.2 mmol of isophorone diisocyanate (IPDI) and stir for 20 minutes. Add 20 μL of dibutyltin dilaurate (DBTDL) and stir for 20 minutes. Then, heat to 75°C and react for 2.5 hours. Add 6 mmol of the chain extender 2,2-bis(hydroxymethyl)propionic acid (DMPA) and continue the reaction for 1.5 hours.

[0054] (3) After the temperature dropped to 50°C, 12 mmol of 2-hydroxyethyl methacrylate (HEMA) and 3 mmol of triethylamine were added. After the reaction was continued for 21 hours, the mixture was added dropwise to 100 mL of purified water (stirred at 1000 rpm / min with an overhead stirrer for 1 hour) to obtain a waterborne polyurethane (PU) with a solid content of 20%. The solid content of the waterborne polyurethane suitable for the present invention can be between 10% and 20%, which can be adjusted by changing the amount of purified water added.

[0055] 3. Prepare 6% (w / v%, g / mL) oxymethacrylated hyaluronic acid-waterborne polyurethane (OHAMA-PU) solution:

[0056] Weigh 240 mg of oxidized methacrylated hyaluronic acid solid and dissolve it in 4 mL of water and 1 mL of aqueous polyurethane (solid content 20%).

[0057] 4. Prepare 4% (w / v%, g / mL) polylysine (PL) solution:

[0058] Weigh 120 mg of polylysine solid into a vial, dissolve in 3 mL of purified water, and adjust the pH to 8 by adding 1 M NaOH aqueous solution for later use.

[0059] 5. Preparation of hydrogel

[0060] 1 mL of 6% OHAMA-PU solution was placed in a vial, 200 μL of 4% polylysine solution was added, and the solution was stirred to dissolve. Then, 10 μL of 1% photoinitiator I2959 (photoinitiator 2959, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone) was added, and the solution was exposed to UV light for 1 hour to observe the gel formation.

[0061] Example 2

[0062] The present embodiment provides a hydrogel. The only difference between the preparation method of the hydrogel and that of Example 1 is the concentration of the OHAMA-PU solution in step (3), i.e., a 4% OHAMA-PU solution is used (200 mg of oxidized methacrylated hyaluronic acid solid is placed on a plate and dissolved in 4 mL of water and 1 mL of aqueous polyurethane).

[0063] Example 3

[0064] The present embodiment provides a hydrogel. The only difference between the preparation method of the hydrogel and that of Example 1 is the concentration of the OHAMA-PU solution in step (3), i.e., a 5% OHAMA-PU solution is used (250 mg of oxidized methacrylated hyaluronic acid solid is placed in a plate and dissolved with 4 mL of water and 1 mL of aqueous polyurethane).

[0065] Example 4

[0066] The present embodiment provides a hydrogel. The only difference between the preparation method of the hydrogel and that of Example 1 is the concentration of the OHAMA-PU solution in step (3), i.e., a 6% OHAMA-PU solution is used (300 mg of oxidized methacrylated hyaluronic acid solid is placed in a plate and dissolved with 4 mL of water and 1 mL of aqueous polyurethane).

[0067] Example 5

[0068] The present embodiment provides a hydrogel. The only difference between the preparation method of the hydrogel and that of Example 1 is the concentration of the OHAMA-PU solution in step (3), i.e., a 7% OHAMA-PU solution is used (350 mg of oxidized methacrylated hyaluronic acid solid is placed in a plate and dissolved with 4 mL of water and 1 mL of aqueous polyurethane).

[0069] Example 6

[0070] The embodiment of the present invention provides a hydrogel, and the only difference between the preparation method of the hydrogel and that of Example 1 is that the illumination time in step (5) is 30 minutes.

[0071] Example 7

[0072] The embodiment of the present invention provides a hydrogel, and the only difference between the preparation method of the hydrogel and that of Example 1 is that the illumination time in step (5) is 2 hours.

[0073] Example 8

[0074] The embodiment of the present invention provides a hydrogel, and the only difference between the preparation method of the hydrogel and that of Example 1 is that the illumination time in step (5) is 3 hours.

[0075] Example 9

[0076] The embodiment of the present invention provides a hydrogel, and the only difference between the preparation method of the hydrogel and that of Example 1 is that the illumination time in step (5) is 4 hours.

[0077] Example 10

[0078] The embodiment of the present invention provides a hydrogel, and the only difference between the preparation method of the hydrogel and that of Example 1 is that the illumination time in step (5) is 5 hours.

[0079] Example 11

[0080] A novel hemostatic hydrogel, the preparation steps of which are as follows:

[0081] (1) Preparation of 6% (w / v%, g / mL) OHAMA-PU solution: Weigh 240 mg of oxymethacrylated hyaluronic acid solid and place it on a plate. Dissolve it in 4 mL of water and 1 mL of aqueous polyurethane.

[0082] (2) Preparation of 4% (w / v%, g / mL) polylysine solution: Weigh 120 mg of polylysine solid into a vial and dissolve in 3 mL of purified water.

[0083] (3) Preparation of 1 M (1 mol / L) cannabidiol solution: Weigh 315 mg of CBD solid into a vial and dissolve in 1 mL of ethanol.

[0084] (4) Preparation of 1% (w / v%, g / mL) I2959 solution: Weigh 10 mg of I2959 solid into a vial and dissolve in 1 mL of water for later use.

[0085] (5) Add 200 μL of 4% polylysine solution to 1 mL of 6% OHAMA-PU solution and mix well. Then, add 20 μL of 1 M cannabidiol, 20 μL of 1 M neomycin sulfate, and 20 μL of 1 M 2-benzyl alcohol in sequence and continue to mix well. Finally, add 100 μL of 1% I2959 solution and mix well. Then, transfer the sol to a mold and expose it under ultraviolet light for 1 hour. Observe the gel formation to obtain a hydrogel wound dressing.

[0086] Example 12

[0087] A novel hemostatic hydrogel, the preparation steps of which are as follows:

[0088] (1) Preparation of 6% (w / v%, g / mL) OHAMA-PU solution: Weigh 240 mg of oxymethacrylated hyaluronic acid solid and place it on a plate. Dissolve it in 4 mL of water and 1 mL of aqueous polyurethane.

[0089] (2) Preparation of 4% (w / v%, g / mL) polylysine solution: Weigh 120 mg of polylysine solid into a vial and dissolve in 3 mL of purified water.

[0090] (3) Preparation of 1 M (1 mol / L) cannabidiol solution: Weigh 315 mg of CBD solid into a vial and dissolve in 1 mL of ethanol.

[0091] (4) Preparation of 1 M (1 mol / L) 2-bromophenol mixed solution: Weigh 154 mg of 2-bromophenol and dissolve it in 1 mL of anhydrous ethanol.

[0092] (5) Preparation of 1% (w / v%, g / mL) I2959 solution: Weigh 10 mg of I2959 solid into a vial and dissolve in 1 mL of water for later use.

[0093] (6) Add 200 μL of 4% polylysine solution to 1 mL of 6% OHAMA-PU solution and mix well. Then, add 20 μL of 1 M cannabidiol, 20 μL of 1 M neomycin sulfate, and 20 μL of 1 M 2-benzyl alcohol in sequence and continue to mix well. Finally, add 100 μL of 1% I2959 solution and mix well. Then, transfer the sol to a mold and expose it under ultraviolet light for 1 hour. Observe the gel formation to obtain a hydrogel wound dressing.

[0094] Example 13

[0095] A novel hemostatic hydrogel, the preparation steps of which are as follows:

[0096] (1) Preparation of 6% (w / v%, g / mL) OHAMA-PU solution: Weigh 240 mg of oxymethacrylated hyaluronic acid solid and place it on a plate. Dissolve it in 4 mL of water and 1 mL of aqueous polyurethane.

[0097] (2) Preparation of 4% (w / v%, g / mL) polylysine solution: Weigh 120 mg of polylysine solid into a vial and dissolve in 3 mL of purified water.

[0098] (3) Preparation of 1 M (1 mol / L) cannabidiol solution: Weigh 315 mg of CBD solid into a vial and dissolve in 1 mL of ethanol.

[0099] (4) Preparation of 1 M (1 mol / L) 2-bromophenol mixed solution: Weigh 154 mg of 2-bromophenol and dissolve it in 1 mL of anhydrous ethanol.

[0100] (5) Preparation of 1 M (1 mol / L) neomycin sulfate solution: Weigh 712 mg of neomycin sulfate (NS) and dissolve it in 1 mL of purified water.

[0101] (6) Preparation of 1% (w / v%, g / mL) I2959 solution: Weigh 10 mg of I2959 solid into a vial and dissolve in 1 mL of water for later use.

[0102] (7) Add 200 μL of 4% polylysine solution to 1 mL of 6% OHAMA-PU solution and mix well. Then, add 20 μL of 1 M cannabidiol, 20 μL of 1 M neomycin sulfate, and 20 μL of 1 M 2-benzyl alcohol in sequence and continue to mix well. Finally, add 100 μL of 1% I2959 solution and mix well. Then, transfer the sol to a mold and expose it under ultraviolet light for 1 hour. Observe the gel formation to obtain a hydrogel wound dressing.

[0103] In the present invention, covalent cross-linking is first used to obtain a stable hydrogel basic framework, and polylysine is introduced into the hydrogel network using a Schiff base reaction. Drug molecules such as cannabidiol, neomycin sulfate, and 2-camphor are then added. The hydrogen bonds formed between amino groups and hydroxyl groups are used to strengthen the cross-linking strength of the hydrogel three-dimensional network, resulting in a dressing-type hydrogel product that can be used to promote wound healing.

[0104] The present invention's effect examples verify the antibacterial properties and biocompatibility of the hydrogel dressings prepared in Example 1 and Example 13, specifically including the following parts:

[0105] Performance Testing

[0106] The antibacterial properties and cytotoxicity tests of the hydrogel were conducted according to GB / B 31402-2015 and YY / T 1911-2023 respectively.

[0107] As shown in Table 1, the gelation of the hydrogels changes with the concentrations of the OHAMA-PU solution and PL, and another influencing factor is the illumination time. Comparison and final evaluation confirmed that the best gelation was achieved when the OHAMA-PU concentration was 6%, the PL concentration was 4%, and the illumination time was 1 hour.

[0108] Therefore, the subsequent performance studies will be conducted using the hydrogels in Examples 1 and 13.

[0109] Table 1: Comparison of hydrogel gelation time in various examples

[0110]

[0111] By measuring the change of water absorption of freeze-dried hydrogel over time, Figure 1 As can be seen from the results, the freeze-dried samples of the hydrogels of Examples 1 and 13 absorbed water very quickly, rapidly expanding to approximately 5 times their dry weight within 15 minutes, and reaching equilibrium with water expansion of approximately 20 times within 60 minutes.

[0112] When the storage modulus (G′) is greater than the loss modulus (G′′), the hydrogel is in a gel state. Figure 2 As shown in Figure 2, after the hydrogel undergoes gelation, with the increase of angular frequency and shear stress, G′ is always greater than G′′, indicating that the hydrogel can stably appear in a gel state ( Figure 3 , A, B). This demonstrates that the hydrogel possesses excellent mechanical properties, maintaining its convenience and integrity. Adhesion is crucial for wounds; good adhesion ensures that the formed gel adheres firmly to the surface of bleeding tissue without falling off.

[0113] Adhesion tests were performed on different samples. Figure 3 It can be seen that the OHAMA-PU-PL hydrogel of Example 1 has good adaptability and tissue adhesion properties to pig skin; and the adhesion reaches 1.38 kPa.

[0114] During the wound healing stage, the hydrogel's response to changes in the pH of the skin environment affects the wound healing ability. By measuring the pH changes of OHAMA-PU-PL (Example 1) and OHAMA-PU-PL-CBD-NS-(2-B) (Example 13) hydrogels in physiological saline and buffer solution PBS (7.4) over time, it was found that the pH of both hydrogels gradually decreased with time ( Figure 4 This may be due to the release of acidic PL in the hydrogel system, which will help improve the antibacterial ability of infected wounds. Figure 5 It can be seen that the drug cannabidiol (CBD) in the hydrogel component can be released continuously and stably in a normal saline environment, which will help the drug to continuously environment wounds and inhibit the occurrence of bacterial inflammation.

[0115] Antibacterial hydrogels have the ability to inhibit bacterial growth. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were selected as bacterial models, and the OD value counting method was used to investigate the antibacterial effect of the hydrogels (Table 2; Figure 6 ). It can be found that the OHAMA-PU-PL hydrogel of Example 1 has certain antibacterial properties, and the OHAMA-PU-PL-CBD-NS-(2-B) of Example 13 has good antibacterial properties against both model bacteria due to the introduction of antibiotics.

[0116] Table 2. OD600 values ​​of Staphylococcus aureus and Escherichia coli after 24 hours of culture in different samples

[0117]

[0118] In the cytotoxicity experiment, it was observed that the test substance had a significant effect on cell growth. When the test substance was diluted to different concentrations, the cell survival rate reached about 100%, indicating that at this concentration, the substance had a weak cytotoxic effect ( Figure 7 , B, C). The experimental results indicate that the hydrogel extract has no obvious cytotoxicity at different dilution concentrations. In the hemolysis experiment, it was found that the hydrogel has good blood compatibility ( Figure 7 , A).

[0119] Subsequently, the gene expression level of macrophages (RAW 246.7) was detected by fluorescence quantitative PCR, and it was found that the hydrogel group (Example 1, Example 13) promoted the activation of RAW 246.7 to M1, which was beneficial to increase the level of inflammation in the early stage of wound healing, thereby improving the body's bactericidal ability ( Figure 8 , A).

[0120] In the cell scratch test, it was found that the hydrogel groups (Example 1, Example 11, Example 12, Example 13) all had the function of promoting cell migration ( Figure 8 , B), which will help improve wound healing ability.

[0121] To determine whether the hydrogels could aid wound healing, the hydrogels were applied to partial-thickness wounds in mice ( Figure 9 , A). After 10 days of treatment, the control group (3M dressing group) showed obvious suppuration on the third day, which lasted until the seventh day. On the tenth day, irregular red scars appeared around the wound on the skin surface. The wound healing rate was 65.76%. This was due to the presence of pus around the wound, which hindered wound healing. Compared with the untreated group, the hydrogel group showed no signs of suppuration and infection during the treatment period; the healing rate also increased significantly by 89.62±3.30% (p<0.01) and 85.68±1.25% (p<0.01), with obvious healing ( Figure 9 , A, B). In addition, the OHAMA-PU-PL group (Example 1) had residual hydrogel film on the skin surface on the fifth day of treatment; debridement can easily cause secondary damage to the wound. Fortunately, the film on the wound surface can be absorbed by itself over time. During the treatment period, there was no significant change in the weight of mice in the control group (3M) and the drug-added group (Example 13). Figure 9 , C); The body weight of mice in the OHAMA-PU-PL group (Example 1) increased significantly on days 3 and 5, consistent with wound healing. This may be because the improvement in wound healing helps increase the mice's daily motivation to eat. In summary, both the OHAMA-PU-PL group and the drug-addition group effectively treat infected wounds.

[0122] Figure 10 The results of H&E and Masson staining analysis of skin tissue sections from different treatment groups on treatment days 0, 5, and 10 are shown. Bacterial infection can cause severe inflammatory reactions at the wound site, leading to infiltration of inflammatory cells. Therefore, H&E staining is often used to observe the inflammatory state of the wound site. The inflammatory cells are usually characterized by a large nucleus. Figure 10It can be seen that there is still a large amount of inflammatory cell infiltration in the control group on the 5th day, but the inflammatory cell infiltration in Example 1 and Example 13 is relatively small, as indicated by blue arrows. On the 10th day, the epidermis of Example 1 and Example 13 groups was basically formed, and there was almost no inflammatory cell infiltration, which was similar to the state of tissue section staining of healthy mice. However, there was still some inflammatory cell infiltration in the blank control group. The formation of collagen plays a key role in the wound healing process. It can promote cell migration and serve as the basis for extracellular matrix deposition in the wound healing growth stage. Masson staining can be used to evaluate the formation of collagen, and its collagen is stained blue. Figure 10 As shown, no significant collagen deposition was observed in the skin tissue of the control group after 5 days of healing. However, collagen deposition was higher in the gel groups of Examples 1 and 13. By day 10, the epidermis and dermis in each group had essentially formed, with substantial collagen deposition. Furthermore, the treatment groups had a higher number of hair follicles and an orderly stacked collagen fiber structure, indicating that the treatment method has a positive effect on healing. These observations indicate that the material is beneficial in reducing inflammation and scarring, accelerating healing.

Claims

1. A hydrogel wound dressing that promotes healing of infectious wounds, characterized in that The invention comprises the following raw materials: oxidized methacrylated hyaluronic acid, water-based polyurethane, polylysine, cannabidiol, neomycin sulfate and 2-camphenol.

2. The hydrogel wound dressing according to claim 1, characterized in that In the hydrogel, the mass volume concentration of oxidized methacrylated hyaluronic acid is 3-7%, the mass volume concentration of aqueous polyurethane is 3-7%, the mass volume concentration of polylysine is 4-6%, the molar concentration of cannabidiol is 0.5-2 M, the molar concentration of neomycin sulfate is 0.5-2 M, and the molar concentration of 2-camphenol is 0.5-2 M.

3. The hydrogel wound dressing according to claim 1, characterized in that The molar ratio of cannabidiol, neomycin sulfate and 2-camphenol is (0.5-2): (0.5-2): (0.5-2).

4. The hydrogel wound dressing according to claim 1, characterized in that The degree of oxidation of oxidized methacrylated hyaluronic acid is 25%-50%.

5. The hydrogel wound dressing according to claim 1, characterized in that The solid content of waterborne polyurethane is 10-20%.

6. The method for preparing the hydrogel wound dressing according to any one of claims 1 to 5, characterized in that The method comprises the following steps: Dissolve oxidized methacrylated hyaluronic acid and aqueous polyurethane in water, add polylysine, then add cannabidiol, neomycin sulfate and 2-camphenol in sequence, and finally add a photoinitiator and irradiate with ultraviolet light to obtain a hydrogel.

7. The preparation method according to claim 6, characterized in that The oxidized methacrylate hyaluronic acid is prepared by the following steps: (1) Prepare a hyaluronic acid solution with a mass volume concentration of 1%; (2) adding 1% of the volume of the hyaluronic acid solution in methacrylic anhydride, adjusting the pH to 8-9, and reacting for 24 hours; (3) Pour the mixed liquid after the reaction into 3 to 5 times the volume of ice ethanol. A precipitate will appear. The precipitate is redissolved, dialyzed, and freeze-dried to obtain methacrylated hyaluronic acid. (4) Prepare a methacrylated hyaluronic acid solution with a mass volume concentration of 1%, add 0.5-1% of sodium periodate by mass volume of the hyaluronic acid solution and continue stirring, add 2% of ethylene glycol by volume of the hyaluronic acid solution to terminate the reaction, dialyze, and freeze-dry to obtain oxidized methacrylated hyaluronic acid.

8. The preparation method according to claim 6, characterized in that The waterborne polyurethane is prepared by the following steps: (1) Take 6 mmol of polyethylene glycol 2000 and 2 mmol of polycaprolactone 2000, dehydrate under vacuum, react at 110°C for 2 hours, then cool to 50°C and maintain for 30-45 minutes; (2) Add 19.2 mmol of isophorone diisocyanate, stir for 20 min, add 20 μL of catalyst, stir for 20 min, heat to 75 °C, and react for 2.5 hours; add 6 mmol of chain extender and continue the reaction for 1.5-2 hours; (3) After the temperature drops to 50°C, add 12 mmol of 2-hydroxyethyl methacrylate and 3 mmol of triethylamine. Continue the reaction for 21-24 hours, then drop it into 100-200 mL of pure water to obtain a water-based polyurethane with a solid content of 10-20%.

9. The preparation method according to claim 6, characterized in that The molecular weight of the hyaluronic acid in the hydrogel is 150,000-200,000.

10. Use of the hydrogel wound dressing according to any one of claims 1 to 5 in preparing a product for repairing infected wounds.

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