Near-infrared light responsive hydrogel, preparation method thereof and application thereof in wound repair

Abstract

This invention discloses a near-infrared photoresponsive hydrogel, its preparation method, and its application in wound repair. The method includes the following steps: S1, modifying chitosan with 1,3-propanesulfonate lactone to prepare sulfonated chitosan; S2, mixing sulfonated chitosan solution, chitosan solution, genipin solution, and NaOH solution to prepare a hydrogel solution; S3, blending MXene, MOF, and the hydrogel solution to prepare a near-infrared photoresponsive hydrogel. The composite hydrogel provided by this invention utilizes the biomimetic structure and good biocompatibility of sulfonated chitosan, combined with the photothermal properties of MXene and the catalytic and ion-release characteristics of MOF, to achieve a dual function of broad-spectrum and highly effective antibacterial activity and multi-pathway promotion of skin tissue regeneration. This provides a novel integrated solution for the treatment of infected wounds, combining anti-infection, promotion of vascularization, and re-epithelialization.

Description

Technical Field

[0001] This invention relates to the fields of nanomaterials and biomedicine, and in particular to a near-infrared photoresponsive hydrogel, its preparation method, and its application in wound repair. Background Technology

[0002] As the body's first line of defense against harmful external substances, the skin is easily damaged in daily life, leading to wounds. If a wound is exposed to air for an extended period, pathogens from the environment can invade and colonize the wound. Improper treatment can easily result in bacterial infection, causing severe tissue damage and inflammation, and may even develop into a chronic wound. This not only causes persistent pain for patients but can also lead to severe consequences such as excruciating pain, necessary amputation, or even death. Currently, traditional treatment for such infections mainly relies on antibiotics. However, the overuse and abuse of antibiotics have led to the emergence of various drug-resistant strains, posing a significant challenge to clinical treatment. Faced with the increasingly complex microbial infection problems in the clinical environment and the urgent need for efficient wound healing, developing novel multifunctional antibacterial dressings to improve the treatment effect of infected wounds has become an urgent task.

[0003] Hydrogels, due to their excellent physicochemical properties, show great potential for application in wound dressings. Their characteristics include high water content (70%-99%), a three-dimensional network structure, biomimetic properties similar to the extracellular matrix, tunable mechanical properties, good permeability, and excellent wound exudate absorption capacity. However, most traditional hydrogels require the introduction of chemical cross-linking agents to achieve gelation, which may adversely affect their biocompatibility and bioactivity. Since wound morphology is often irregular, treatment methods that can precisely conform to the wound are particularly important, highlighting the significant value of injectable hydrogels in achieving efficient, comprehensive wound treatment. Therefore, utilizing dynamic Schiff base reactions to achieve gelation and leveraging the high permeability of hydrogels for drug delivery holds significant potential for promoting skin tissue regeneration.

[0004] Chitosan has been widely used in medical and food fields due to its broad-spectrum antibacterial properties, non-toxicity, good biodegradability, and biocompatibility. However, the presence of numerous hydrogen bonds and acetamino groups in the chitosan molecule leads to its high crystallinity and poor solubility, limiting its application in certain scenarios. Therefore, it is necessary to modify the structure of chitosan to obtain derivatives with better performance. Sulfonated chitosan (SCS) is a water-soluble derivative of chitosan, with a structure similar to glycosaminoglycans in the extracellular matrix and also possessing heparin-like properties. Studies have confirmed that SCS not only has antioxidant activity but can also induce angiogenesis in vitro and significantly enhance the bioactivity of vascular endothelial growth factor (VEGF). These properties make SCS an ideal wound dressing material. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a near-infrared photoresponsive hydrogel, its preparation method, and its application in wound repair. This invention constructs an injectable, multi-responsive smart composite hydrogel and dressing by loading MXene nanosheets and MOF nanomaterials onto a hydrogel network formed by cross-linking sulfonated chitosan / chitosan / genipin. This composite hydrogel utilizes the biomimetic structure and good biocompatibility of sulfonated chitosan, combined with the photothermal properties of MXene and the catalytic and ion-release characteristics of MOF, to achieve the dual functions of broad-spectrum and highly effective antibacterial activity and multi-pathway promotion of skin tissue regeneration. It can significantly accelerate the healing process of infected wounds by promoting angiogenesis, regulating inflammatory responses, and enhancing cell migration, providing a novel integrated solution for the treatment of infected wounds that combines anti-infection, promotion of vascularization, and re-epithelialization.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In its first aspect, the present invention provides a method for preparing a near-infrared photoresponsive hydrogel, comprising the following steps: S1. Sulfonated chitosan was prepared by modifying chitosan with 1,3-propanesulfonate lactone. S2. A hydrogel solution is prepared by mixing sulfonated chitosan solution, chitosan solution, genipin solution and NaOH solution. S3. MXene, MOF and hydrogel solution are blended to prepare MXene / MOF-loaded composite hydrogel, namely the near-infrared photoresponsive hydrogel.

[0007] Preferably, step S1 specifically includes: Chitosan was added to an acetic acid solution and heated and stirred until completely dissolved. Then, 1,3-propanesulfonate lactone was added dropwise to the solution, and the reaction was carried out under a nitrogen atmosphere with heating and stirring. After the reaction was completed, the product was cooled, poured into anhydrous ethanol, stirred, centrifuged to collect the precipitate, washed and dried to obtain sulfonated chitosan. Preferably, step S2 specifically includes: Prepare sulfonated chitosan solution and chitosan solution, mix the sulfonated chitosan solution and chitosan solution, add genipin solution and NaOH solution to the resulting mixture to prepare hydrogel solution.

[0008] Preferably, step S3 specifically includes: MOF powder was added to the MXene solution and ultrasonically dispersed to obtain an MXene / MOF composite dispersion. The MXene / MOF dispersion was added to the hydrogel solution prepared in step S2, stirred evenly, and allowed to stand overnight at room temperature to obtain a composite hydrogel, namely the near-infrared photoresponsive hydrogel.

[0009] Preferably, the preparation method of the near-infrared photoresponsive hydrogel includes the following steps: S1. Preparation of sulfonated chitosan: Add 0.5-2g of chitosan to 40-160 mL of acetic acid solution with a concentration of 1-4wt%, heat and stir until completely dissolved, then add 1-4g of 1,3-propanesulfonate lactone dropwise to the solution, and stir the reaction under nitrogen atmosphere at 40-80°C for 3-12 hours; cool to room temperature, pour the product into anhydrous ethanol, stir, centrifuge to collect the precipitate, wash it with anhydrous ethanol several times by centrifugation, and then vacuum dry for 12-48 hours to obtain sulfonated chitosan, denoted as SCS; S2. Preparation of hydrogel solution: Prepare sulfonated chitosan solution and chitosan solution, each with a mass fraction of 1-4 wt%, and mix them at a volume ratio of sulfonated chitosan solution: chitosan solution = 1:(1-4) to obtain a mixture with a total volume of 1.5-6 mL; add 30-120 μL of genipin solution with a mass fraction of 0.75-3 wt% and 250-1000 μL of NaOH solution with a concentration of 0.5-2 M to the mixture in sequence, adjust the pH of the system to 5-7, and prepare a hydrogel solution, denoted as SCS Gel; S3. Loading MXene / MOF to prepare composite hydrogels: Add 10-40 mg of MOF powder to 0.5-2 mL of MXene solution with a concentration of 5-20 mg / mL, and ultrasonically disperse for 5-20 minutes to obtain an MXene / MOF composite dispersion; Add 60-240 μL of MXene / MOF dispersion to the hydrogel solution prepared in step S2, stir evenly, and let stand overnight at room temperature to obtain the composite hydrogel, namely the near-infrared photoresponsive hydrogel, denoted as M / M-SCS Gel.

[0010] Preferably, the preparation method of the near-infrared photoresponsive hydrogel includes the following steps: S1. Preparation of sulfonated chitosan: 1 g of chitosan was added to 80 mL of 2 wt% acetic acid solution and heated and stirred until completely dissolved. Then, 2 g of 1,3-propanesulfonate lactone was added dropwise to the solution. The reaction was carried out under nitrogen atmosphere and stirred at 60°C for 6 h. After cooling to room temperature, the product was poured into anhydrous ethanol, stirred, and the precipitate was collected by centrifugation. After washing with anhydrous ethanol by centrifugation several times, the product was dried under vacuum for 24 h to obtain sulfonated chitosan, denoted as SCS. S2. Preparation of hydrogel solution: Prepare a sulfonated chitosan solution and a chitosan solution, both with a mass fraction of 2 wt%, and mix them at a volume ratio of 1:2 to obtain a total volume of 3 mL. Add 60 μL of a 1.5 wt% genipin solution and 500 μL of a 1 M NaOH solution to the mixture, adjust the pH of the system to 6, and prepare a hydrogel solution, denoted as SCS Gel. S3. Loading MXene / MOF to prepare composite hydrogels: Add 20 mg of MOF powder to 1 mL of MXene solution with a concentration of 10 mg / mL, and sonicate for 10 minutes to obtain an MXene / MOF composite dispersion; Add 120 μL of MXene / MOF dispersion to the hydrogel solution prepared in step S2, stir evenly, and let stand overnight at room temperature to obtain the composite hydrogel, namely the near-infrared photoresponsive hydrogel, denoted as M / M-SCS Gel.

[0011] In a second aspect, the present invention provides a near-infrared photoresponsive hydrogel, which is prepared by the method described above.

[0012] A third aspect of the present invention provides the application of the near-infrared photoresponsive hydrogel described above in wound repair.

[0013] In a fourth aspect, the present invention provides the application of the near-infrared photoresponsive hydrogel described above in the preparation of wound repair formulations.

[0014] A fifth aspect of the present invention provides a wound repair dressing comprising the near-infrared photoresponsive hydrogel as described above.

[0015] The beneficial effects of this invention are: (1) The near-infrared photoresponsive hydrogel provided by the present invention combines the photothermal effect of MXene with the catalytic and ion release properties of MOF. While achieving broad-spectrum and efficient antibacterial effects, it can also promote the vascularization and re-epithelialization of skin tissue through multiple pathways, thus solving the problem of difficulty in achieving both anti-infection and tissue regeneration. (2) The near-infrared photoresponsive hydrogel constructed in this invention is not only injectable, but also has multiple response characteristics (such as photothermal response, ion release and catalytic function), which can realize dynamic and precise treatment of infected wounds, breaking through the limitation of the single function of traditional dressings. (3) This invention combines biomimetic structural carriers (sulfonated chitosan / chitosan hydrogel), functional nanomaterials and bio-crosslinking technology to form a comprehensive treatment platform integrating anti-infection, angiogenesis and re-epithelialization functions, providing a more systematic and efficient repair strategy for infected wounds. Attached Figure Description

[0016] Figure 1 Fourier transform infrared (FTIR) spectra of chitosan and sulfonated chitosan. Figure 2 Scanning electron microscope (SEM) images of SCS Gel and M / M-SCS Gel; Figure 3 Antibacterial effects and antibacterial rates of different materials against S. aureus and E. coli; Figure 4 Test results of corresponding wound marks and wound healing rate (n = 5) after hydrogel treatment; Figure 5 H&E and Masson trichrome stained scan images of wound tissue on day 7. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0018] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0019] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0020] Example 1 A near-infrared photoresponsive hydrogel is prepared by the following steps: S1. Preparation of sulfonated chitosan: 1 g of chitosan (CS) was added to 80 mL of 2 wt% acetic acid solution and heated and stirred until completely dissolved. Then, 2 g of 1,3-propanesulfonate lactone was added dropwise to the solution. The mixture was stirred at 60°C under a nitrogen atmosphere for 6 h. After cooling to room temperature, the product was poured into pre-cooled anhydrous ethanol and stirred vigorously to precipitate a white product. The precipitate was collected by centrifugation and washed repeatedly with anhydrous ethanol to remove unreacted 1,3-propanesulfonate lactone. The solid was then dried in a vacuum drying oven for 24 h to obtain sulfonated chitosan, denoted as SCS. S2. Preparation of hydrogel solution: Prepare a sulfonated chitosan solution and a chitosan solution (using deionized water) both with a mass fraction of 2 wt%, and mix them at a volume ratio of 1:2 to obtain a total volume of 3 mL. Add 60 μL of a genipin solution (using a 2 wt% aqueous acetic acid solution) and 500 μL of a 1 M NaOH solution to the mixture, and adjust the pH of the system to 6 to prepare a hydrogel solution, denoted as SCS Gel. S3. Loading MXene / MOF to prepare composite hydrogels: 20 mg of MOF powder was added to 1 mL of MXene solution with a concentration of 10 mg / mL (deionized water as solvent), and ultrasonically dispersed for 10 minutes to obtain an MXene / MOF composite dispersion. Add 120 μL of MXene / MOF dispersion to the hydrogel solution prepared in step S2, stir evenly, and let stand overnight at room temperature to complete the gelation process, thereby obtaining the composite hydrogel, namely the near-infrared photoresponsive hydrogel, denoted as M / M-SCS Gel.

[0021] The MXene solution was prepared by the following method: Two g of lithium fluoride (LiF) was added to a polytetrafluoroethylene-lined container containing 20 mL of 9 mol L⁻¹ hydrochloric acid (HCl) solution, and the mixture was magnetically stirred for 30 min. Then, 1 g of Ti₃AlC₂ MAX phase powder was slowly added. The reaction was carried out at 40°C with continuous stirring for 36 h. After the reaction, the resulting slurry was transferred to a 50 mL centrifuge tube and washed repeatedly at 3500 rpm using deionized water and anhydrous ethanol as washing media until the pH of the supernatant reached approximately 6. The washed precipitate was then vacuum dried to obtain multilayer MXene nanosheets.

[0022] Take 0.1 mg of the prepared multilayer MXene nanosheets and place them in a centrifuge tube. Add 10 mL of deionized water. Under a nitrogen (N2) atmosphere, sonicate the suspension for 30 min. After sonication, centrifuge the suspension at 3000 rpm for 1 h and collect the dark green supernatant containing few or single-layer MXene nanosheets, which is the MXene solution.

[0023] The MOF powder was prepared by the following method: 1.62 g of ferric chloride hexahydrate (FeCl3·6H2O), 0.68 g of copper chloride dihydrate (CuCl2·2H2O), 1.0 g of terephthalic acid (H2BDC), and 0.7 g of polyvinylpyrrolidone (PVP, K30) were dissolved sequentially in 70 mL of N,N-dimethylformamide (DMF). The mixed solution was transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene, sealed, and placed in an oven at 120 °C for 6 hours. After the reaction, the mixture was allowed to cool naturally to room temperature. The resulting product was collected by centrifugation (3000 rpm) and washed three times sequentially with DMF and anhydrous methanol to remove unreacted raw materials and impurities. The final precipitate was dried under vacuum at 60 °C for 12 hours to obtain MOF powder.

[0024] Performance characterization and testing 1. Figure 1 Fourier transform infrared spectra of chitosan (CS) and sulfonated chitosan (SCS) demonstrate the successful preparation of sulfonated chitosan. Figure 2 Scanning electron microscope (SEM) images of SCS gel and M / M-SCS gel.

[0025] 2. Antibacterial performance test Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922) were used to represent Gram-positive and Gram-negative bacteria, respectively, and the antibacterial activity of the composite hydrogel was evaluated using the plate spread method. First, Luria-Bertani (LB) broth and Luria-Bertani agar were used as culture media. The bacteria were incubated in an incubator at 37°C and 200 rpm for 24 hours in LB broth. To observe the antibacterial effect, 2 μL of M / M-SCS gel was mixed with 1 mL of bacterial suspension (10... 7 Mix (CFU / mL), incubate at 180 rpm at room temperature for 12 h, dilute 100 times, spread 30 μL of bacterial mixture evenly on LB agar plates, incubate at 37℃ for 24 hours, and then take colony images with a digital camera.

[0026] The experiment was divided into the following groups: The blank control group (treated with PBS only), the SCS Gel group (treated with SCS-Gel hydrogel solution prepared in step S2 of Example 1), and the M / M-SCS Gel group (treated with composite hydrogel M / M-SCS Gel prepared in step S3 of Example 1) were all tested under conditions of no infrared (NIR-) and infrared (NIR+) light.

[0027] Test results are as follows Figure 3 As shown, compared with the PBS group and the SCS Gel group, the M / M-SCS Gel group has significant antibacterial ability. Especially under NIR irradiation, the antibacterial ability of the M / M-SCS Gel group is further enhanced, and it can achieve an antibacterial rate of nearly 100% against E. coli and S. aureus.

[0028] 3. Wound healing test in mouse model This study used a mouse full-thickness skin infection model to evaluate the in vivo antibacterial properties and wound healing effect of hydrogels. Seven-week-old SD mice weighing 17-20 g were selected, and the experiment was performed under anesthesia and aseptic conditions. First, the backs of the mice were shaved and disinfected to create a circular full-thickness skin defect with a diameter of 6 mm. Then, 50 μL of Staphylococcus aureus suspension (10...) was inoculated. 6 (CFU / mL). A stable infection model was confirmed 48 hours after inoculation.

[0029] Mice were randomly divided into three groups: a blank control group (treated with PBS only), an SCS Gel group (using the SCS-Gel hydrogel solution prepared in step S2 of Example 1), and an M / M-SCS Gel group (using the composite hydrogel M / M-SCS Gel prepared in step S3 of Example 1). Experiments were conducted under conditions of no infrared light (NIR-) and infrared light (NIR+), respectively. The infrared light (NIR+) group received 808 nm near-infrared light (power density 1.5 W / cm²) irradiation on the wound for 10 minutes after drug administration. Digital images of the wound were taken on days 0, 1, 3, 5, and 7 post-treatment, and the wound healing area was measured and calculated using ImageJ software.

[0030] On day 7 post-treatment, wound exudate was gently scraped with sterile cotton swabs soaked in PBS for bacterial culture and colony count. Five biological replicates were prepared for each group, and subsequent histological evaluation was performed. To conduct histopathological and collagen deposition analysis, mice were sacrificed on day 7, and full-thickness skin tissue around the wound was collected. After fixation with 4% paraformaldehyde, the tissue was dehydrated, embedded in paraffin, and sectioned for hematoxylin-eosin staining and Masson's trichrome staining, respectively.

[0031] All animal procedures in this experiment were approved by the Animal Ethics Committee of the Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (Approval No.: 2025-C008).

[0032] Test results are as follows Figure 4 and Figure 5 As shown, Figure 4 and Figure 5 M / M-SCS Gel(-) and M / M-SCS Gel(+) represent applying infrared light and not applying infrared light, respectively.

[0033] Test results are as follows Figure 4 and Figure 5 As shown, wound healing was significantly enhanced in the M / M-SCS Gel(-) and M / M-SCS Gel(+) groups after 7 days of treatment, while the infected wounds in the control group did not heal completely. Quantitative analysis showed that on day 7, the wound area decreased by 92.6% and 99.1% in the M / M-SCS Gel(-) and M / M-SCS Gel(+) groups, respectively.

[0034] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A method for preparing a near-infrared photoresponsive hydrogel, characterized in that, Includes the following steps: S1. Sulfonated chitosan was prepared by modifying chitosan with 1,3-propanesulfonate lactone. S2. A hydrogel solution is prepared by mixing sulfonated chitosan solution, chitosan solution, genipin solution and NaOH solution. S3. MXene, MOF and hydrogel solution are blended to prepare MXene / MOF-loaded composite hydrogel, namely the near-infrared photoresponsive hydrogel.

2. The method for preparing near-infrared photoresponsive hydrogel according to claim 1, characterized in that, Step S1 is as follows: Chitosan was added to an acetic acid solution and heated and stirred until completely dissolved. Then, 1,3-propanesulfonate lactone was added dropwise to the solution, and the reaction was carried out under a nitrogen atmosphere with heating and stirring. After the reaction was completed, the product was cooled, poured into anhydrous ethanol, stirred, centrifuged to collect the precipitate, washed, and dried to obtain sulfonated chitosan.

3. The method for preparing near-infrared photoresponsive hydrogel according to claim 1, characterized in that, Step S2 is as follows: Prepare sulfonated chitosan solution and chitosan solution, mix the sulfonated chitosan solution and chitosan solution, add genipin solution and NaOH solution to the resulting mixture to prepare hydrogel solution.

4. The method for preparing near-infrared photoresponsive hydrogel according to claim 1, characterized in that, Step S3 is as follows: MOF powder was added to the MXene solution and ultrasonically dispersed to obtain an MXene / MOF composite dispersion. The MXene / MOF dispersion was added to the hydrogel solution prepared in step S2, stirred evenly, and allowed to stand overnight at room temperature to obtain a composite hydrogel, namely the near-infrared photoresponsive hydrogel.

5. The method for preparing the near-infrared photoresponsive hydrogel according to claim 1, characterized in that, Includes the following steps: S1. Preparation of sulfonated chitosan: Add 0.5-2g of chitosan to 40-160 mL of acetic acid solution with a concentration of 1-4wt%, heat and stir until completely dissolved, then add 1-4g of 1,3-propanesulfonate lactone dropwise to the solution, and stir the reaction under nitrogen atmosphere at 40-80°C for 3-12 hours; cool to room temperature, pour the product into anhydrous ethanol, stir, centrifuge to collect the precipitate, wash it with anhydrous ethanol several times by centrifugation, and then vacuum dry for 12-48 hours to obtain sulfonated chitosan, denoted as SCS; S2. Preparation of hydrogel solution: Prepare sulfonated chitosan solution and chitosan solution, each with a mass fraction of 1-4 wt%, and mix them at a volume ratio of sulfonated chitosan solution: chitosan solution = 1:(1-4) to obtain a mixture with a total volume of 1.5-6 mL; add 30-120 μL of genipin solution with a mass fraction of 0.75-3 wt% and 250-1000 μL of NaOH solution with a concentration of 0.5-2 M to the mixture in sequence, adjust the pH of the system to 5-7, and prepare a hydrogel solution, denoted as SCS Gel; S3. Loading MXene / MOF to prepare composite hydrogels: Add 10-40 mg of MOF powder to 0.5-2 mL of MXene solution with a concentration of 5-20 mg / mL, and ultrasonically disperse for 5-20 minutes to obtain an MXene / MOF composite dispersion; Add 60-240 μL of MXene / MOF dispersion to the hydrogel solution prepared in step S2, stir evenly, and let stand overnight at room temperature to obtain the composite hydrogel, namely the near-infrared photoresponsive hydrogel, denoted as M / M-SCS Gel.

6. The method for preparing near-infrared photoresponsive hydrogel according to claim 1, characterized in that, Includes the following steps: S1. Preparation of sulfonated chitosan: 1 g of chitosan was added to 80 mL of 2 wt% acetic acid solution and heated and stirred until completely dissolved. Then, 2 g of 1,3-propanesulfonate lactone was added dropwise to the solution. The reaction was carried out under nitrogen atmosphere and stirred at 60°C for 6 h. After cooling to room temperature, the product was poured into anhydrous ethanol, stirred, and the precipitate was collected by centrifugation. After washing with anhydrous ethanol by centrifugation several times, the product was dried under vacuum for 24 h to obtain sulfonated chitosan, denoted as SCS. S2. Preparation of hydrogel solution: Prepare a sulfonated chitosan solution and a chitosan solution, both with a mass fraction of 2 wt%, and mix them at a volume ratio of 1:2 to obtain a total volume of 3 mL. Add 60 μL of a 1.5 wt% genipin solution and 500 μL of a 1 M NaOH solution to the mixture, adjust the pH of the system to 6, and prepare a hydrogel solution, denoted as SCS Gel. S3. Loading MXene / MOF to prepare composite hydrogels: Add 20 mg of MOF powder to 1 mL of MXene solution with a concentration of 10 mg / mL, and sonicate for 10 minutes to obtain an MXene / MOF composite dispersion; Add 120 μL of MXene / MOF dispersion to the hydrogel solution prepared in step S2, stir evenly, and let stand overnight at room temperature to obtain the composite hydrogel, namely the near-infrared photoresponsive hydrogel, denoted as M / M-SCS Gel.

7. A near-infrared photoresponsive hydrogel, characterized in that, It is prepared by the method described in any one of claims 1-8.

8. The application of the near-infrared photoresponsive hydrogel as described in claim 8 in wound repair.

9. The application of the near-infrared photoresponsive hydrogel as described in claim 8 in the preparation of wound repair formulations.

10. A wound repair dressing, characterized in that, It includes the near-infrared photoresponsive hydrogel as described in claim 8.

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