Preparation method and application of antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness

Abstract

The application relates to a preparation method of an antibacterial hydrogel with enhanced antioxidation activity and NIR / pH dual responsiveness, and the preparation method is as follows: hollow copper sulfide nanoparticles are first prepared, the hollow copper sulfide nanoparticles are dispersed into a chitosan solution to obtain a chitosan solution containing the hollow copper sulfide nanoparticles, then a crosslinking agent epigallocatechin gallate (EGCG) solution and a 3-formylphenylboronic acid solution (3-FPBA) are sequentially added for crosslinking, so as to obtain the antibacterial hydrogel with enhanced antioxidation activity and NIR / pH dual responsiveness. The hydrogel is used for wound dressings in biomedical engineering materials. The preparation method is simple, the preparation process is green and safe, higher solid-like performance is exhibited, meanwhile, excellent injectability is maintained, and the hydrogel can play a greater advantage in the healing process of bacterial wound infection.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydrogel, in particular to a preparation method and application of a biomedical material antibacterial hydrogel, and belongs to the technical field of chemistry. BACKGROUND

[0002] Bacterial wound infection is one of the serious threats to public health. Traditional clinical treatment relies too much on antibiotics, which causes the risk of drug-resistant bacteria. In addition, the healing process of the wound (hemostasis, inflammation, proliferation, remodeling) is disturbed and biochemically disordered by inflammatory response, oxidative stress effect, rapid degradation of matrix, etc. Therefore, it is urgent to develop new antibacterial strategies and wound healing materials to combat bacterial infection in a more effective and safer way, while more gently repairing damaged skin and accelerating wound healing. As a kind of wound dressing, the unique three-dimensional network structure of hydrogel not only can absorb wound exudate and maintain a moist environment, but also can release drugs locally and accurately to achieve therapeutic effect. In recent years, photo-thermal hydrogel has attracted widespread attention due to its excellent light responsiveness and heat conversion capacity. However, single photo-thermal therapy (PTT) requires higher temperature to effectively resist bacteria, which may cause secondary damage to the damaged tissue. In order to overcome the above limitations, people pay more attention to the research of combining other antibacterial strategies (such as photodynamic therapy (PDT), chemical dynamic therapy (CDT) or natural medicine treatment, etc.) to work synergistically to achieve excellent therapeutic effect at lower temperature or shorter treatment time. Therefore, it is imperative to develop a multifunctional antibacterial hydrogel dressing platform based on photo-thermal therapy. In the fields of tissue engineering and flexible devices, reversible bonds can be used as cross-linking agents to prepare hydrogels with excellent mechanical properties and healing properties, which is a very promising strategy. For example, a hydrogel that can dissociate at acidic pH and condense at alkaline pH is synthesized by using the complex formed by the catechol structure of halogenated catechol and borate as a cross-linking agent, which shows good self-healing performance and antibacterial activity. However, this halogenated catechol inevitably has the disadvantage of greater cytotoxicity. Therefore, developing a pH-responsive hydrogel dressing containing natural drugs with excellent mechanical properties, self-healing properties and good biocompatibility is conducive to meet the clinical needs of wound treatment. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings and deficiencies of the prior art, and to provide a preparation method of an injectable antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual response characteristics for promoting wound healing at a bacterial infection site, which has good mechanical properties, injectability, adhesion, pH responsiveness, antioxidant activity, and has a wide application prospect.

[0004] The application discloses a preparation method of an antibacterial hydrogel with enhanced antioxidation activity and NIR / pH dual response.

[0005] Further, the preparation steps are as follows:

[0006] A: CuCl2 solution, PVP-K30 are added into deionized water, magnetic stirring is carried out at room temperature, NaOH solution is added, 2 min later, N2H4.H2O is added, 5 min later, Na2S solution is added, hollow copper sulfide nanoparticles are generated by reacting at 75 DEG C for 2 h, finally, 12000 rpm centrifugal separation is carried out for 10 min, twice water washing is carried out for 3 times, and the hollow copper sulfide nanoparticles are collected;

[0007] B: chitosan is dissolved in deionized water, ice acetic acid solution is added under the condition of oscillation to dissolve, then NaOH solution is added, the pH value of the prepared chitosan solution is adjusted to neutral, EGCG and 3-formylphenylboronic acid are dissolved in deionized water respectively to obtain 1.5% EGCG solution and 0.065M 3-formylphenylboronic acid solution respectively;

[0008] C: the copper sulfide nanoparticles obtained in A are uniformly mixed into the chitosan solution obtained in B to prepare 3% chitosan solution containing hollow copper sulfide nanoparticles, then equal volume of EGCG solution and 3-formylphenylboronic acid solution are sequentially added, and the antibacterial hydrogel with enhanced antioxidation activity and NIR / pH dual response characteristics is obtained after mixing for 30 s on a mixer;

[0009] The steps A and B in the above method are not arranged in sequence.

[0010] Further, the concentration of CuCl2 in step A is 0.5 mol / L, the concentration of NaOH solution is 0.01 mM, and the concentration of Na2S solution is 320 mg / mL.

[0011] Further, in step B, the chitosan is dissolved by using 2% ice acetic acid solution, and finally, 3% chitosan solution is prepared.

[0012] Further, in step C, the mass percentage concentration of the hollow copper sulfide nanoparticles in the chitosan solution is 43.75-350 µg / mL.

[0013] The application of an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness for wound dressing in biomedical engineering materials.

[0014] Further, when used as a wound dressing, the concentration of the hollow CuS NPs is 125 μg / mL.

[0015] Further, when used as a wound dressing, an 808nm near-infrared laser irradiation with a power density of less than or equal to 2 W cm -2 .

[0016] The positive beneficial technical effects of the present application are that the preparation method is simple, the gelation time is short, the preparation process is green and safe, the hollow copper sulfide nanoparticles are synthesized, the operation is simple, the photo-thermal effect and biocompatibility of the nanoparticles are excellent, the mechanical properties of the hydrogel due to the loading of the copper sulfide nanoparticles are higher than those of the pure EGCG hydrogel, the hydrogel exhibits higher solid-like properties, and the hydrogel also maintains excellent injectability, under the irradiation of an 808nm near-infrared light, through the synergistic effect of PTT and EGCG, the hydrogel still exhibits strong antibacterial ability even under high-concentration bacteria, and the hydrogel can play a great advantage in the healing process of bacterial wound infection. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a gelation principle diagram of the CuS@EGCG hydrogel and the EGCG hydrogel of the present application.

[0018] Figure 2 is a scanning electron microscope image of the end surface of the EGCG hydrogel of Example 1.

[0019] Figure 3 is a scanning electron microscope image of the end surface of the CuS@EGCG hydrogel of Example 1 and a Cu, S element distribution map of the region.

[0020] Figure 4 is a stress-strain curve diagram of the CuS@EGCG hydrogel and the EGCG hydrogel of Example 2.

[0021] Figure 5 is a self-healing schematic diagram of the CuS@EGCG hydrogel of Example 2.

[0022] Figure 6 is an injectable schematic diagram of the CuS@EGCG hydrogel of Example 2.

[0023] Figure 7Figure 3 is a graph of the photothermal effect of CuS@EGCG hydrogel for Example 3. Water (a), different concentrations of chitosan solution (b), different concentrations of EGCG hydrogel (c), different concentrations of CuS@EGCG hydrogel under 808 laser (2 W / cm2) irradiation (31.25 pg / mL (d), 62.5 pg / mL (e), 100 pg / mL (f), 125 pg / mL (g), 250 pg / mL (h)) of photothermal conversion.

[0024] Figure 8 Figure 4 is a graph of the temperature change of CuS@EGCG hydrogel under different near-infrared irradiation power densities ((a) 0.5, (b) 1, (c) 1.25, (d) 1.5 and (e) 1.75, (f) 2 W / cm 2 ).

[0025] Figure 9 Figure 5 is a graph of the heating and cooling curves of CuS@EGCG hydrogel under near-infrared irradiation (10 min, 2 W / cm 2 ) on / off cycle (3 times).

[0026] Figure 10 Figure 6 is a graph of the ABTS radical scavenging of CuS@EGCG hydrogel and EGCG hydrogel.

[0027] Figure 11 Figure 7 is a graph of the DPPH radical scavenging of CuS@EGCG hydrogel and EGCG hydrogel.

[0028] Figure 12 Figure 8 is a graph of the pH responsiveness verification of CuS@EGCG hydrogel and EGCG hydrogel for Example 3.

[0029] Figure 13 Figure 9 is a graph of the antibacterial property verification of CuS@EGCG hydrogel and EGCG hydrogel for Example 3, part 1.

[0030] Figure 14 Figure 10 is a graph of the antibacterial property verification of CuS@EGCG hydrogel and EGCG hydrogel for Example 3, part 2. DETAILED DESCRIPTION

[0031] In order to more fully explain the implementation of the present application, the implementation examples of the present application are provided, which are only an illustration of the present application and do not limit the scope of the present application.

[0032] In the present application, H-CuSNPs refers to hollow copper sulfide nanoparticles, CuSNPs refers to copper sulfide nanoparticles, H- represents hollow; CuS@EGCG hydrogel refers to the product of the present application, an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness; CS refers to chitosan; 3-FPBA refers to 3-formylphenylboronic acid; EGCG refers to epigallocatechin gallate;

[0033] A method for preparing an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness, the preparation steps are as follows:

[0034] A: CuCl2 solution, PVP-K30 is added to deionized water, the ratio of deionized water to PVP-K30 is 1 mL:9-10 mg; the concentration of CuCl2 is 0.5 mol / L, the ratio of CuCl2 to PVP-K30 is 1 µmol:4.5-5 mg; magnetic stirring at room temperature, add NaOH solution, the concentration of NaOH solution is 0.01 mM, equal volume with deionized water, 2 min later add N2H4·H2O, the ratio of N2H4·H2O to PVP-K30 is 1 µL:37-37.5 mg; 5 min later add Na2S solution, the mass ratio of Na2S to PVP-K30 is 3.5-4:1; react at 75°C for 2 h to generate hollow copper sulfide nanoparticles, finally centrifuge at 12000 rpm for 10 min, wash with double water for 3 times, collect the hollow copper sulfide nanoparticles;

[0035] B: Dissolve chitosan in deionized water, add glacial acetic acid solution under shaking state to dissolve, then add sodium hydroxide solution to adjust the pH value of the prepared chitosan solution to neutral, respectively dissolve EGCG and 3-formylphenylboronic acid in deionized water to obtain 1.5% EGCG solution and 0.065M 3-formylphenylboronic acid solution respectively;

[0036] C: Mix the copper sulfide nanoparticles obtained in A uniformly into the chitosan solution obtained in B to prepare a 3% chitosan solution containing hollow copper sulfide nanoparticles, then add equal volume of EGCG solution and 3-formylphenylboronic acid solution in turn, mix on a mixer for 30 s to obtain an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness;

[0037] The steps A and B in the above method are not in a specific order.

[0038] Further; the concentration of CuCl2 in step A is 0.5 mol / L, the concentration of NaOH solution is 0.01 mM, and the concentration of Na2S solution is 320 mg / mL.

[0039] Further; the chitosan in step B is dissolved by 2% acetic acid solution, and the final preparation is 3% chitosan solution.

[0040] Further; the mass percentage concentration of hollow copper sulfide nanoparticles in solution in step C is 50~200 µg / mL.

[0041] Example 1

[0042] The present embodiment provides an injectable antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual response characteristics, which is prepared by the following steps:

[0043] 1) Preparation and morphology characterization of hollow copper sulfide nanoparticles: 28 μL of CuCl2 solution (0.5 mol / L) and 67.2 mg of PVP-K30 were added to 7 mL of deionized water and magnetically stirred at room temperature. An equal volume of NaOH solution (0.01 mM) was added, 2 min later 1.8 μL of N2H4·H2O was added, 5 min later 56 μL of Na2S solution (concentration of 320 mg / mL) was added, and the reaction was carried out at 75°C for 2 h to generate CuS NPs. Centrifugation at 12000 rpm for 10 min, deionized water washing for 2 times, and collection of hollow CuS NPs.

[0044] 2) Preparation of CuS@EGCG hydrogel and EGCG hydrogel: 0.3 g of chitosan powder was dissolved in acetic acid solution (10 mL, 2% (v / v)) to prepare a 3% (w / v) CS solution, after the chitosan was completely dissolved, a certain amount of 6 M NaOH was added to make the solution pH about 7, then 0.06 g of EGCG, 0.039 g of 3-formylphenylboronic acid was dissolved in 4 mL of ethanol solution (40% (v / v)) respectively to obtain a 0.015 g / mL and 0.065 M solution, the prepared solution was mixed in proportion CS solution:EGCG solution:3-FPBA solution = 5:1:1, then the whole mixture was vortexed for 30 seconds to obtain EGCG hydrogel; The steps for synthesizing CuS@EGCG HY are to add hollow CuS NPs solution to the CS solution to obtain a 3% (w / v) CS solution with different CuS concentrations, and then perform the subsequent steps of mixing with EGCG solution and 3-FPBA solution to complete the preparation.

[0045] Reference is made to Figure 1 The schematic diagram of the gelation principle of CuS@EGCG hydrogel and EGCG hydrogel is shown.

[0046] The CuS@EGCG hydrogel and EGCG hydrogel prepared in Example 1 were observed by scanning electron microscope (SEM) Figure 2 and CuS@EGCG hydrogelFigure 3 characterization, Figure Two The network structure of the hydrogel is shown. Example 2

[0047] Example 2 characterizes the partial mechanical properties of the prepared CuS@EGCG hydrogel and EGCG hydrogel

[0048] (1) Preparation and morphology characterization of hollow copper sulfide nanoparticles: CuCl2 solution (28 μΐ, 0.5 mol / L) and PVP-K30 (67.2 mg) were added to 7 mL of deionized water and magnetically stirred at room temperature. NaOH solution (7 mL, 0.01 mM) was added, and 2 min later, 1.8 μΐ of N2H4-H2O was added. After 5 min, 56 μΐ of Na2S stock solution (320 mg / μΐ) was added, and the reaction was carried out at 75°C for 2 h to generate hollow CuS NPs. The hollow CuS NPs were collected by centrifugation at 12000 rpm for 10 min and washed twice with deionized water.

[0049] (2) Preparation of CuS@EGCG hydrogel and EGCG hydrogel: 0.3 g of chitosan powder was dissolved in acetic acid solution (10 ml, 2% (v / v)) to prepare a 3% (w / v) CS solution. After the chitosan was completely dissolved, a certain amount of 6 M NaOH was added, and the solution pH was about 7. Then EGCG, 3-formylphenylboronic acid was dissolved in 4 mL of ethanol solution (40% (v / v)) to obtain a solution of 0.015 g / mL and 0.065 M, respectively. The prepared solutions were mixed in the ratio CS solution:EGCG solution:3-FPBA solution = 5:1:1, and then the whole mixture was vortexed for 30 seconds to obtain the EGCG hydrogel. The steps for synthesizing CuS@EGCG HY are as follows: hollow CuS NPs solution was added to the CS solution to obtain a 3% (w / v) CS solution with different CuS concentrations, and then the subsequent steps of mixing with EGCG solution, 3-FPBA solution were performed to complete the preparation.

[0050] In the amplitude sweep test, the rheometer (AR2000ex) was used to determine the rheological properties with a fixed frequency sweep (1 Hz). As shown in Figure 4 The storage modulus and loss modulus of the CuS@EGCG hydrogel were higher than those of the EGCG hydrogel; this was due to the higher crosslinking density; among them, the G' and G" of the CuS@EGCG hydrogel intersected at a strain of about 400%, while the strain intersection point of the EGCG hydrogel was about 277%, which reflected that the addition of copper sulfide nanoparticles made the hydrogel have higher mechanical resistance and better solid-like properties.

[0051] Self-healing property and injectability: As shown in FIGS. 1A-1C, the CuS@EGCG hydrogel exhibited self-healing property from a macroscopic perspective; in FIG. 1D, the CuS@EGCG hydrogel was continuously written on a petri dish with a 1 mL syringe. The CuS@EGCG hydrogel could be easily injected through a 0.45 mm needle without clogging and quickly healed, and could adapt to irregular tissue defects. Figure 5 , Figure 6 Figure 6 Example 3

[0052] This example characterizes the photothermal, antioxidant, pH-responsive, and antibacterial properties of the prepared CuS@EGCG hydrogel and EGCG hydrogel.

[0053] (1) Preparation and morphology characterization of hollow copper sulfide nanoparticles: 28 μΐ of CuCl2 solution (0.5 mol / L) and 67.2 mg of PVP-K30 were added to 7 mL of deionized water and magnetically stirred at room temperature. 7 mL of NaOH solution (0.01 mM) was added, and 2 min later, N2H4·H2O was added. After 5 min, 56 μΐ of Na2S solution (concentration of 320 mg / mL) was added, and the reaction was carried out at 75°C for 2 h to generate hollow CuS NPs. The hollow CuS NPs were collected by centrifugation at 12000 rpm for 8 min and deionized water washing twice.

[0054] (2) Preparation of CuS@EGCG hydrogel and EGCG hydrogel: 0.3 g of chitosan powder was dissolved in acetic acid solution (10 ml, 2% (v / v)) to prepare a 3% (w / v) CS solution, and after the chitosan was completely dissolved, a certain amount of 6 M NaOH was added to make the solution pH about 7. Then 0.06 g of EGCG and 0.039 g of 3-formylphenylboronic acid were dissolved in 4 mL of ethanol solution (40% (v / v)) to obtain a solution of 0.015 g / mL and 0.065 M, respectively; the prepared solutions were mixed in a ratio of CS solution:EGCG solution:3-FPBA solution = 5:1:1, and then the whole mixture was vortexed for 30 seconds to obtain the EGCG hydrogel; the step of forming CuS@EGCG HY is to add the hollow CuS NPs solution to the CS solution to obtain a 3% (w / v) CS solution with different CuS concentrations, and then perform the subsequent steps of mixing with the EGCG solution and 3-FPBA solution to complete the preparation.

[0055] See Figure 7 ​​The photothermal performance verification chart of CuS@EGCG hydrogel is shown. As shown in the figure, the photothermal performance of CuS@EGCG hydrogel is closely related to the laser power density and the concentration of H-CuS NPs in the hydrogel. By comparing the temperature curves (h) of CuS@EGCG hydrogel at the concentration of 250 μg mL −1 , it is found that even if the concentration is doubled, the temperature curve is basically consistent and there is no obvious change; therefore, we choose CuS@EGCG hydrogel with H-CuS NPs concentration of 125 μg mL−1 (i.e. 125 μg / mL) for the following condition exploration. Next we explore the effect of different power densities on the hydrogel. As Figure 8 can be seen, under the condition of near-infrared laser power density of 2 W / cm 2 (2 W cm -2 ), the temperature of CuS@EGCG hydrogel increases from 25°C to 53°C after 3 minutes of irradiation; in contrast, less than this power density, it cannot quickly rise above 50℃ in a short time; given that in photothermal therapy, a temperature exceeding 55°C will burn the body and cause secondary damage to the wound, thereby hindering wound treatment, we finally determine the photothermal conditions of CuS@EGCG hydrogel: 808 nm near-infrared laser with a power density of 2 W cm -2 and the concentration of hollow CuS NPs is 125 μg mL −1， The photothermal stability is a very key aspect to consider when evaluating a photothermal agent (PTA). The hydrogel is irradiated at a power density of 2 W cm -2 for 10 min, then the laser is turned off for 5 min, and this heating and cooling cycle is repeated 3 times. As Figure 9 can be seen, the temperature peak changes little and the cooling trend is consistent, indicating that the photothermal performance of CuS@EGCG hydrogel is stable and repeatable in the cycle process.

[0056] Referring to Figure 10 , Figure 11 the anti-oxidation verification chart of CuS@EGCG hydrogel and EGCG hydrogel, the figure shows that compared with EGCG hydrogel, the introduction of H-CuS NPs significantly improves the clearance ability of the hydrogel to ABTS free radicals and DPPH free radicals, and has good biological application prospect.

[0057] Referring to Figure 12The pH response verification diagrams for CuS@EGCG hydrogel and EGCG hydrogel shown illustrate the release rate of EGCG by the two hydrogels at pH values ​​of 4, 5, 6, and 7.4. It can be concluded that at pH values ​​below 7.4, the release rate and release speed of the hydrogels increase as the pH value decreases, which can effectively achieve pH-responsive treatment in response to changes in the environmental pH during wound healing.

[0058] See Figure 13 (Staphylococcus aureus) Figure 14 The graph showing the antibacterial activity of CuS@EGCG hydrogel and EGCG hydrogel (without NIR irradiation) indicates that both hydrogels exhibited limited antibacterial activity, with Staphylococcus aureus survival rates of 87% (EGCG HY) and 80% (CuS@EGCG HY), respectively. The vertical axis represents survival rate, with E. coli survival rates of 82.5% (EGCG HY) and 67.8% (CuS@EGCG HY), respectively. The CuS@EGCG hydrogel showed higher antibacterial performance than the EGCG hydrogel without NIR irradiation, which may be due to the hollow CuSNPs and Cu... 2+ The release of [the substance / material] was observed. Notably, after 3.5 min of near-infrared irradiation (with NIR), the bacterial survival rates in the CuS@EGCG hydrogel group were 0.056% (S. aureus) and 2.35% (E. coli), demonstrating a significant bactericidal effect. This indicates that the synergistic effect of photothermal and chemical antibacterial action facilitates faster and more efficient bacterial killing, thus showing great potential in the field of wound dressings. "control" represents the blank control group.

[0059] After a detailed description of the embodiments of the present invention, those skilled in the art will clearly understand that various changes and modifications can be made without departing from the scope and spirit of the above-mentioned patent applications. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention, and the present invention is not limited to the embodiments of the examples given in the specification.

Claims

1. A method for preparing an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness, characterized in that The preparation method is as follows: first, hollow copper sulfide nanoparticles are prepared, then the hollow copper sulfide nanoparticles are dispersed into a chitosan solution to obtain a chitosan solution containing hollow copper sulfide nanoparticles, then a crosslinking agent epigallocatechin gallate (EGCG) solution and a 3-formylphenylboronic acid (3-FPBA) solution are sequentially added for crosslinking, so as to obtain an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual response; The specific preparation steps are as follows A: CuCl2 solution, PVP-K30 are added into deionized water, and magnetic stirring is carried out at room temperature, NaOH solution is added, 2 min later, N2H4·H2O is added, 5 min later, Na2S solution is added, and hollow copper sulfide nanoparticles are generated after reaction at 75℃ for 2 h, finally, the hollow copper sulfide nanoparticles are collected by centrifugation at 12000 rpm for 10 min, and washed with double-distilled water for 3 times; B: chitosan is dissolved in deionized water, and ice acetic acid solution is added under shaking to dissolve it, then sodium hydroxide solution is added, so that the pH value of the prepared chitosan solution is adjusted to neutral, and EGCG and 3-formylphenylboronic acid are dissolved in deionized water to obtain 1.5% EGCG solution and 0.065M 3-formylphenylboronic acid solution respectively; C: the copper sulfide nanoparticles obtained in A are uniformly mixed into the chitosan solution obtained in B to prepare a 3% chitosan solution containing hollow copper sulfide nanoparticles, then equal volumes of EGCG solution and 3-formylphenylboronic acid solution are sequentially added, and the antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual response characteristics is obtained after mixing on a mixer for 30 s; the G' and G'' of the hydrogel intersect at a strain of about 400%; The steps A and B in the above method are not in a specific order.

2. The method for preparing an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness according to claim 1, characterized in that In step A, the concentration of CuCl2 is 0.5 mol / L, the concentration of NaOH solution is 0.01 mM, and the concentration of Na2S solution is 320 mg / mL.

3. The method for preparing an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness according to claim 1, characterized in that In step B, chitosan is dissolved in 2% ice acetic acid solution, and a 3% chitosan solution is finally prepared.

4. The method of claim 1, wherein the method of preparing an antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness is characterized by In step C, the mass percentage concentration of hollow copper sulfide nanoparticles in the chitosan solution is 43.75~350 µg / mL.

5. Use of the antibacterial hydrogel with enhanced antioxidant activity and NIR / pH dual responsiveness prepared by the preparation method of claim 1, characterized in that: The hydrogel is used for wound dressings in biomedical engineering materials.

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