Photocatalytic hydrogel AGZ-G as well as preparation method and application thereof

Abstract

The invention relates to photocatalytic hydrogel AGZ (at) G as well as a preparation method and application thereof, and belongs to the technical field of biomedical materials. The preparation method of the photocatalytic hydrogel AGZ-G comprises the following steps: mixing silver nitrate, melamine and water to obtain a mixed solution, freeze-drying the mixed solution to obtain freeze-dried powder, heating the freeze-dried powder to 500-600 DEG C, and keeping the temperature for 1.5-4 hours to prepare g-C3N4-Ag; g-C3N4-Ag and water are mixed and subjected to ultrasonic treatment, and g-C3N4 / Ag is prepared; the g-C3N4 / Ag, GOx, a 2-methylimidazole solution and a zinc acetate aqueous solution are mixed to prepare an AGZ composite material; and mixing the AGZ composite material, an oxidized hyaluronic acid aqueous solution and a carboxymethyl chitosan aqueous solution to obtain the photocatalytic hydrogel AGZ (at) G. The photocatalytic hydrogel AGZ (at) G disclosed by the invention has a remarkable promotion effect on wound healing of diabetes mellitus, and has excellent in-vitro antibacterial performance, good in-vitro biological safety and very strong biocompatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical materials, and in particular to a photocatalytic hydrogel AGZ@G and a preparation method and application thereof. Background Art

[0002] Diabetes is a chronic disease caused by absolute or relative insufficient secretion of insulin and impaired utilization, with high blood sugar levels as the main sign. The main symptoms are polydipsia, polyuria, polyphagia and weight loss. Patients with a long course of the disease may develop chronic progressive lesions, functional impairment and failure of tissues and organs such as eyes, kidneys, nerves, heart, and blood vessels, and even acute severe metabolic disorders. At the same time, high blood sugar in the wounds of diabetic patients is prone to bacterial infection, and the complex immune environment makes the wounds protracted and unhealed, so there is a high recurrence rate and disability rate; in addition, chronic wounds are ischemic and hypoxic, excessive oxidative stress, epidermal nerves and blood vessels are damaged, and there are chronic persistent infections and inflammation, making wound healing very difficult.

[0003] The existing treatment methods for wounds mainly include traditional dressings, negative pressure drainage and amputation surgery. Among them, traditional dressings are generally used for ordinary wounds, but not for diabetic wounds; negative pressure drainage and amputation surgery are expensive and inconvenient for patients. Therefore, it is of great significance to develop wound dressings with anti-infection efficacy and the ability to promote the healing of diabetic wounds.

[0004] However, in terms of focusing on wound antibacterial properties, there are relatively few hydrogel dressings with immunomodulatory capabilities in the existing technology, and their biocompatibility is insufficient and their ability to adapt to the complex environment of diabetic wounds is poor. Summary of the invention

[0005] The purpose of the present invention is to provide a photocatalytic hydrogel AGZ@G and a preparation method and application thereof, so as to solve the problems that the existing hydrogel dressings have insufficient antibacterial properties and biocompatibility and poor adaptability to the complex environment of diabetic wounds.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a photocatalytic hydrogel AGZ@G, comprising the following steps:

[0008] (1) mixing silver nitrate, melamine and water to obtain a mixed solution, freeze-drying the mixed solution to obtain a freeze-dried powder, heating the freeze-dried powder to 500-600° C. and maintaining it for 1.5-4 hours to obtain g-C3N4-Ag;

[0009] (2) mixing g-C3N4-Ag and water, ultrasonicating for 18 to 24 hours and then centrifuging to obtain a silver-modified graphite phase carbon nitride nanosheet dispersion;

[0010] (3) mixing the silver-modified graphite phase carbon nitride nanosheet dispersion, glucose oxidase, 2-methylimidazole solution and zinc acetate aqueous solution for 3 to 6 hours, centrifuging, and drying the precipitate for 36 to 60 hours to obtain an AGZ composite material;

[0011] (4) The AGZ composite material and the oxidized hyaluronic acid aqueous solution are ultrasonically mixed to obtain a mixed solution, and the mixed solution and the carboxymethyl chitosan aqueous solution are vortex mixed to obtain the photocatalytic hydrogel AGZ@G.

[0012] Preferably, the mass ratio of silver nitrate and melamine mixed in step (1) is 0.05-0.2:0.2-0.6;

[0013] The mass volume ratio of the silver nitrate and water mixture is 0.05-0.2 g:30-100 mL;

[0014] The freeze-drying temperature in step (1) is -60 to -20°C, and the freeze-drying time is 5 to 10 days.

[0015] Preferably, the mass volume ratio of the mixture of g-C3N4-Ag and water in step (2) is 0.05-0.2g:50-150mL.

[0016] Preferably, the power of the ultrasound in step (2) is 400-600W;

[0017] The centrifugal speed in step (2) is 3000-6000 rpm, and the centrifugal time is 20-50 min.

[0018] Preferably, the mass volume ratio of the glucose oxidase and the silver-modified graphite-phase carbon nitride nanosheet dispersion mixed in step (3) is 200-400 mg: 0.25-0.33 mL;

[0019] The volume ratio of the silver-modified graphite-phase carbon nitride nanosheet dispersion and the 2-methylimidazole solution is 0.25-0.33:5-15;

[0020] The volume ratio of the silver-modified graphite-phase carbon nitride nanosheet dispersion and the zinc acetate aqueous solution is 0.25-0.33:5-15;

[0021] The initial concentration of the 2-methylimidazole solution is 1-2 mol / L;

[0022] The initial concentration of the zinc acetate aqueous solution is 15-30 mmol / L.

[0023] Preferably, the centrifugal speed in step (3) is 6000-10000 rpm, and the centrifugal time is 8-15 min;

[0024] The drying in step (3) is vacuum freeze drying, and the temperature of the vacuum freeze drying is -60 to -20°C.

[0025] Preferably, in step (4), the mass volume ratio of the AGZ composite material, the oxidized hyaluronic acid aqueous solution and the carboxymethyl chitosan aqueous solution is 0.5-2 mg: 0.1-1 mL: 0.1-1 mL;

[0026] The initial concentration of the oxidized hyaluronic acid aqueous solution is 20 to 50 mg / mL;

[0027] The initial concentration of the carboxymethyl chitosan aqueous solution is 40-70 mg / mL.

[0028] Preferably, the power of the ultrasonic mixing in step (4) is 70 to 150 W, and the time of the ultrasonic mixing is 2 to 8 min;

[0029] The vortex mixing time in step (4) is 2 to 8 minutes.

[0030] The present invention also provides the photocatalytic hydrogel AGZ@G prepared by the preparation method.

[0031] The present invention also provides the use of the photocatalytic hydrogel AGZ@G in preparing a preparation for promoting diabetic wound healing.

[0032] The present invention has the following technical effects and advantages:

[0033] The present invention uses zeolite imidazolate framework (ZIF-8) as the framework, obtains AGZ composite material by encapsulating g-C3N4 / Ag and glucose oxidase, and dopes the AGZ composite material into oxidized hyaluronic acid-carboxymethyl chitosan base to prepare photocatalytic hydrogel AGZ@G. The preparation method of the present invention is simple in process, easy to operate and low in cost;

[0034] The photocatalytic hydrogel AGZ@G of the present invention has a strong adaptability to the complex environment of diabetic wounds, can promote the healing of diabetic wounds under photocatalytic conditions, and has excellent in vitro antibacterial properties, good in vitro biosafety and strong biocompatibility. Among them, glucose oxidase, as a natural endogenous oxidoreductase, can catalyze the conversion of glucose in diabetic wounds into gluconic acid and H2O2 to reduce the pH of the wound environment; g-C3N4 / Ag has unique photoelectric properties and stability, and can decompose H2O2 to generate hydroxyl radicals (·OH) under visible light catalysis to achieve antibacterial function; zeolite imidazole ester framework as a MOF material has a high specific surface area and porosity, and can disintegrate and release Zn under acidic conditions. 2+and imidazole for combined antibacterial effects; oxidized hyaluronic acid is complexed with carboxymethyl chitosan through aldehyde groups to construct a hydrogel skeleton with good biocompatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of photocatalytic hydrogel AGZ@G;

[0036] Figure 2 The in vitro antibacterial results of the photocatalytic hydrogel AGZ@G against Staphylococcus aureus BNCC310011 strain;

[0037] Figure 3 The cytotoxicity results of photocatalytic hydrogel AGZ@G on L929 cells;

[0038] Figure 4 The results show that the photocatalytic hydrogel AGZ@G promotes wound healing in type 1 diabetic model mice. DETAILED DESCRIPTION

[0039] The present invention provides a method for preparing a photocatalytic hydrogel AGZ@G, comprising the following steps:

[0040] (1) silver nitrate (AgNO3), melamine and water are mixed to obtain a mixed solution, the mixed solution is freeze-dried to obtain a freeze-dried powder, and the freeze-dried powder is heated to 500-600°C and maintained for 1.5-4 hours to obtain g-C3N4-Ag;

[0041] (2) mixing g-C3N4-Ag and water, ultrasonicating for 18 to 24 hours and then centrifuging to obtain a silver-modified graphite phase carbon nitride nanosheet dispersion (g-C3N4 / Ag);

[0042] (3) mixing g-C3N4 / Ag, glucose oxidase (GOx), 2-methylimidazole solution and zinc acetate aqueous solution for 3 to 6 hours, preferably 4 hours; centrifuging, taking the precipitate and drying it for 36 to 60 hours to obtain an AGZ composite material;

[0043] (4) The AGZ composite material and the oxidized hyaluronic acid aqueous solution are ultrasonically mixed to obtain a mixed solution, and the mixed solution and the carboxymethyl chitosan aqueous solution are vortex mixed to obtain the photocatalytic hydrogel AGZ@G.

[0044] In the present invention, the mass ratio of AgNO3 and melamine mixed in step (1) is 0.05-0.2:0.2-0.6, preferably 0.08-0.15:0.3-0.5, and more preferably 0.1:0.4;

[0045] The mass volume ratio of the AgNO3 and water mixture is 0.05-0.2 g:30-100 mL, preferably 0.08-0.15 g:40-60 mL, and more preferably 0.1 g:50 mL;

[0046] The freeze-drying temperature in step (1) is -60 to -20°C, preferably -40°C; the freeze-drying time is 5 to 10 days, preferably 7 days;

[0047] In step (1), the heating temperature is preferably 550°C; the heating rate is 2-5°C / min, preferably 3°C / min; and the holding time is preferably 2h.

[0048] In the present invention, the mass volume ratio of the mixture of g-C3N4-Ag and water in step (2) is 0.05-0.2 g:50-150 mL, preferably 0.1 g:100 mL.

[0049] In the present invention, the power of the ultrasound in step (2) is 400-600W, preferably 500W; the ultrasound time is preferably 20h;

[0050] The centrifugal speed in step (2) is 3000-6000 rpm, preferably 4000 rpm; the centrifugal time is 20-50 min, preferably 30 min.

[0051] In the present invention, the mass volume ratio of the mixture of GOx and g-C3N4 / Ag in step (3) is 200-400 mg: 0.25-0.33 mL, preferably 225 mg: 0.3 mL;

[0052] The volume ratio of the g-C3N4 / Ag and 2-methylimidazole solution is 0.25-0.33:5-15, preferably 0.3:10;

[0053] The volume ratio of the g-C3N4 / Ag and the zinc acetate aqueous solution is 0.25-0.33:5-15, preferably 0.3:10;

[0054] The initial concentration of g-C3N4 / Ag is 1-5 mg / mL, preferably 3 mg / mL;

[0055] The initial concentration of the 2-methylimidazole solution is 1-2 mol / L, preferably 1.46 mol / L;

[0056] The initial concentration of the zinc acetate aqueous solution is 15-30 mmol / L, preferably 20 mmol / L.

[0057] In the present invention, the centrifugal speed in step (3) is 6000-10000 rpm, preferably 8000 rpm; the centrifugal time is 8-15 min, preferably 10 min;

[0058] The drying in step (3) is vacuum freeze drying, and the vacuum freeze drying temperature is -60 to -20°C, preferably -40°C; the drying time is preferably 48 hours.

[0059] In the present invention, the mass volume ratio of the AGZ composite material, the oxidized hyaluronic acid aqueous solution and the carboxymethyl chitosan aqueous solution mixed in step (4) is 0.5-2 mg: 0.1-1 mL: 0.1-1 mL, preferably 1 mg: 0.5 mL: 0.5 mL;

[0060] The initial concentration of the oxidized hyaluronic acid aqueous solution is 20 to 50 mg / mL, preferably 30 mg / mL;

[0061] The initial concentration of the carboxymethyl chitosan aqueous solution is 40-70 mg / mL, preferably 60 mg / mL.

[0062] In the present invention, the power of the ultrasonic mixing in step (4) is 70 to 150 W, preferably 100 W; the time of the ultrasonic mixing is 2 to 8 min, preferably 3 min;

[0063] The vortex mixing time in step (4) is 2 to 8 minutes, preferably 3 minutes.

[0064] The present invention also provides the photocatalytic hydrogel AGZ@G prepared by the preparation method.

[0065] The present invention also provides the use of the photocatalytic hydrogel AGZ@G in preparing a preparation for promoting diabetic wound healing.

[0066] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0067] In the present invention, the strain number of Staphylococcus aureus is BNCC310011, which was purchased from Henan Industrial Microbial Strain Engineering Technology Research Center; the mouse fibroblast L929 cell line was purchased from Shanghai Cell Center;

[0068] In the present invention, the test mice were male BALB / c mice, weighing 18-20 g, purchased from Changchun Yisi Experimental Animal Technology Co., Ltd.;

[0069] In the present invention, CCK-8 solution was purchased from Beijing Solebow Biotechnology Co., Ltd.;

[0070] Example 1: Preparation of photocatalytic hydrogel AGZ@G

[0071] (1) Preparation of g-C3N4 / Ag: 0.1 g AgNO3 and 0.4 g melamine were dispersed in 50 mL deionized water, freeze-dried at -40 °C for 7 days, and then heated in a crucible. The heating rate was controlled at 3 °C / min using a muffle furnace. When the temperature reached 550 °C, the mixture was heated for 2 h to obtain g-C3N4-Ag. 0.1 g g-C3N4-Ag was dispersed in 100 mL deionized water and ultrasonically mixed at 500 W for 20 h to obtain a suspension. The suspension was then centrifuged at 4000 rpm for 30 min to uniformly disperse g-C3N4-Ag in deionized water to obtain a silver-modified graphite phase carbon nitride nanosheet dispersion (g-C3N4 / Ag), which was diluted with deionized water to a concentration of 3 mg / mL.

[0072] (2) Preparation of AGZ composite material: 0.3 mL 3 mg / mL g-C3N4 / Ag, 225 mg GOx and 10 mL 1.46 mol / L 2-methylimidazole were mixed evenly, and then 10 mL 20 mmol / L zinc acetate aqueous solution was added. After stirring at room temperature for 4 h, the mixture was centrifuged at 8000 rpm for 10 min to obtain a precipitate. The precipitate was washed three times with deionized water and freeze-dried at -40 °C in a vacuum freeze-drying process for 48 h to obtain the AGZ composite material.

[0073] (3) Preparation of photocatalytic hydrogel AGZ@G: 1 mg of AGZ composite material and 0.5 mL of 30 mg / mL oxidized hyaluronic acid aqueous solution were ultrasonically mixed at 100 W for 3 min, and then 0.5 mL of 60 mg / mL carboxymethyl chitosan solution was added and mixed with a vortex mixer for 3 min to obtain photocatalytic hydrogel AGZ@G. Figure 1 shown.

[0074] Comparative Example 1: Preparation of Hydrogel G

[0075] 0.5 mL of 30 mg / mL oxidized hyaluronic acid aqueous solution and 0.5 mL of 60 mg / mL carboxymethyl chitosan solution were mixed with a vortex mixer for 3 min to obtain hydrogel G.

[0076] Experimental Example 1: In vitro antibacterial properties of photocatalytic hydrogel AGZ@G

[0077] The concentration of live bacteria was 10 6CFU / mL of Staphylococcus aureus bacterial solution (No. BNCC310011) was divided into 6 groups, namely, light-shielding + Ctrl group, light-shielding + G group, light-shielding + AGZ@G group, light-irradiation + Ctrl group, light-irradiation + G group, and light-irradiation + AGZ@G group, with 1 mL of bacterial solution in each group; 300 μL of PBS was added to the light-shielding + Ctrl group and the light-irradiation + Ctrl group, respectively; 300 μL of hydrogel G prepared in Comparative Example 1 was added to the light-shielding + G group and the light-irradiation + G group, respectively; and 300 μL of hydrogel G prepared in Comparative Example 1 was added to the light-shielding + AGZ@G group. 300 μL of the photocatalytic hydrogel AGZ@G prepared in Example 1 was added to the G group and the light + AGZ@G group respectively; the light-shielded + Ctrl group, the light-shielded + G group and the light-shielded + AGZ@G group were wrapped with tin foil and irradiated with 50 W visible light for 30 min, and the light + Ctrl group, the light + G group and the light + AGZ@G group were directly irradiated with 50 W visible light for 30 min; after culturing each group at 37°C and 180 rpm for 4 h, the bacterial solution of each group was diluted with PBS for 10 min. 5 The diluted bacterial solution was obtained by multiplying the concentration of the diluted bacterial solution by 20 μL, and 20 μL of each diluted bacterial solution was spread on a nutrient agar plate containing 15 mmol / L glucose. The colonies were counted after culturing for 24 hours. The results were as follows: Figure 2 shown.

[0078] The results showed that compared with the light-avoidance + Ctrl group, the colony counts of Staphylococcus aureus in the light-avoidance + G group and the light-avoidance + AGZ@G group were reduced to 90.29% and 51.67%, respectively; compared with the light-irradiation + Ctrl group, the colony counts of Staphylococcus aureus in the light-irradiation + G group and the light-irradiation + AGZ@G group were reduced to 87.75% and 17.45%, respectively. This indicates that the photocatalytic hydrogel AGZ@G of the present invention has in vitro antibacterial properties, and its in vitro antibacterial properties are even better under photocatalytic conditions.

[0079] Experimental Example 2: Cytotoxicity of Photocatalytic Hydrogel AGZ@G

[0080] 300 μL of PBS, AGZ@G photocatalytic hydrogel prepared in Example 1, and G hydrogel prepared in Comparative Example 1 were added to 1.5 mL of serum-free 1640 medium, respectively. After incubation at 37 °C for 24 h, three groups of culture medium extracts were obtained, namely, Ctrl group, G group, and AGZ@G group. Mouse fibroblast L929 cells were inoculated into a 96-well plate, and 4×10 3After adding each culture medium extract, the cells were cultured in a humidified incubator at 37°C and 5% CO2 + 95% air to obtain each group of cell fluids. The culture wells without L929 cells were used as the zero adjustment groups corresponding to each group of cell fluids. At the 24th, 48th and 72nd hours of culture, 10 μL of CCK-8 solution was added to each culture well. After culturing for 4 hours at 37°C, 5% CO2 and 90% humidity, the OD of each group of cell fluids was determined by an enzyme marker. 450nm The cell survival rate was calculated. Figure 3 As shown;

[0081] The formula for calculating cell viability is:

[0082]

[0083] The results showed that compared with the Ctrl group, the proliferation of L929 cells in the G group and the AGZ@G group was not significantly inhibited, indicating that the photocatalytic hydrogel AGZ@G of the present invention has good in vitro biosafety.

[0084] Experimental Example 3: Photocatalytic hydrogel AGZ@G promotes diabetic wound healing

[0085] Streptozotocin (STZ) was dissolved in a citrate buffer solution with a pH of 4.5. Male BALB / c mice were selected and raised under the conditions of an ambient temperature of 22°C, an ambient relative humidity of 45%, and a light exposure time of 12h / d. After fasting for 12h, the mice were intraperitoneally injected with a dose of 120mg / kg. When the blood glucose concentration of the BALB / c mice was higher than 16.7mmol / L for three consecutive days, the type Ⅰ diabetes model mice were considered to be successfully established. The model mice were divided into four groups after shaving their backs, namely, the Ctrl group, the G group, the AGZ@G group, and the AGZ@G+light group. A sterile dermal biopsy device with a diameter of 8mm was used to make full-thickness skin wounds of the same size on the backs of each model mouse, and a rubber ring was sutured to fix the wound shape to form a wound surface. Then, 10μL of live bacteria with a concentration of 10 6 CFU / mL of Staphylococcus aureus suspension was inoculated into the wounds on the backs of the model mice to form wound infection; on the second day after the formation of wound infection, PBS was applied to the wounds of the model mice in the Ctrl group, the hydrogel G prepared in Comparative Example 1 was applied to the wounds of the model mice in the G group, the photocatalytic hydrogel AGZ@G prepared in Example 1 was applied to the wounds of the model mice in the AGZ@G group and the AGZ@G+illumination group, and the wounds of the model mice in the AGZ@G+illumination group were irradiated with a xenon lamp light source for 30 minutes; the model mice in each group were continued to be raised for 14 days under the conditions of an ambient temperature of 22°C, an ambient relative humidity of 45%, and an illumination time of 12h / d. During this period, optical images of the wounds of the model mice in each group were taken every day to record the wound size. The results are shown in FIG. Figure 4 shown.

[0086] The results showed that the wound area of ​​each group of model mice gradually decreased over time after treatment, and showed different degrees of healing. The wounds of the model mice in the AGZ@G group and the AGZ@G+light group showed significant healing effects; compared with other groups, the wounds of the model mice in the AGZ@G+light group healed faster. On the 14th day after treatment, the wound area recovered to 100%, and new hair had grown in the wound area. This shows that the photocatalytic hydrogel AGZ@G of the present invention has strong biocompatibility, strong adaptability to the complex environment of diabetic wounds, and shows a significant promoting effect on diabetic wound healing under photocatalytic conditions.

[0087] As can be seen from the above examples, the present invention provides a photocatalytic hydrogel AGZ@G and its preparation method and application. The photocatalytic hydrogel AGZ@G prepared by the present invention has a strong adaptability to the complex environment of diabetic wounds, can show a significant effect of promoting diabetic wound healing under photocatalytic conditions, and has excellent in vitro antibacterial properties, good in vitro biosafety and strong biocompatibility.

[0088] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a photocatalytic hydrogel AGZ@G, characterized in that: The steps include: (1) mixing silver nitrate, melamine and water to obtain a mixed solution, freeze-drying the mixed solution to obtain a freeze-dried powder, heating the freeze-dried powder to 500-600° C. and maintaining it for 1.5-4 hours to obtain g-C3N4-Ag; (2) mixing g-C3N4-Ag and water, ultrasonicating for 18 to 24 hours and then centrifuging to obtain a silver-modified graphite phase carbon nitride nanosheet dispersion; (3) mixing the silver-modified graphite phase carbon nitride nanosheet dispersion, glucose oxidase, 2-methylimidazole solution and zinc acetate aqueous solution for 3 to 6 hours, centrifuging, and drying the precipitate for 36 to 60 hours to obtain an AGZ composite material; (4) The AGZ composite material and the oxidized hyaluronic acid aqueous solution are ultrasonically mixed to obtain a mixed solution, and the mixed solution and the carboxymethyl chitosan aqueous solution are vortex mixed to obtain the photocatalytic hydrogel AGZ@G.

2. The preparation method according to claim 1, characterized in that: The mass ratio of silver nitrate and melamine in step (1) is 0.05-0.2:0.2-0.6; The mass volume ratio of the silver nitrate and water mixture is 0.05-0.2 g:30-100 mL; The freeze-drying temperature in step (1) is -60 to -20°C, and the freeze-drying time is 5 to 10 days.

3. The preparation method according to claim 1, characterized in that: The mass volume ratio of the mixture of g-C3N4-Ag and water in step (2) is 0.05-0.2g:50-150mL.

4. The preparation method according to claim 3, characterized in that: The power of the ultrasound in step (2) is 400-600W; The centrifugal speed in step (2) is 3000-6000 rpm, and the centrifugal time is 20-50 min.

5. The preparation method according to claim 1, characterized in that: The glucose oxidase and silver-modified graphite-phase carbon nitride nanosheet dispersion are mixed in a mass volume ratio of 200-400 mg: 0.25-0.33 mL in step (3); The volume ratio of the silver-modified graphite-phase carbon nitride nanosheet dispersion and the 2-methylimidazole solution is 0.25-0.33:5-15; The volume ratio of the silver-modified graphite-phase carbon nitride nanosheet dispersion and the zinc acetate aqueous solution is 0.25-0.33:5-15; The initial concentration of the 2-methylimidazole solution is 1-2 mol / L; The initial concentration of the zinc acetate aqueous solution is 15-30 mmol / L.

6. The preparation method according to claim 5, characterized in that: The centrifugal speed in step (3) is 6000-10000 rpm, and the centrifugal time is 8-15 min; The drying in step (3) is vacuum freeze drying, and the temperature of the vacuum freeze drying is -60 to -20°C.

7. The preparation method according to claim 1, characterized in that: Step (4) The mass volume ratio of the AGZ composite material, the oxidized hyaluronic acid aqueous solution and the carboxymethyl chitosan aqueous solution is 0.5-2 mg: 0.1-1 mL: 0.1-1 mL; The initial concentration of the oxidized hyaluronic acid aqueous solution is 20 to 50 mg / mL; The initial concentration of the carboxymethyl chitosan aqueous solution is 40-70 mg / mL.

8. The preparation method according to claim 7, characterized in that: The power of the ultrasonic mixing in step (4) is 70 to 150 W, and the time of the ultrasonic mixing is 2 to 8 min; The vortex mixing time in step (4) is 2 to 8 minutes.

9. The photocatalytic hydrogel AGZ@G prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the photocatalytic hydrogel AGZ@G according to claim 9 in preparing a preparation for promoting diabetic wound healing.

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