Conductive hydrogel with visible light excitation photoelectric effect for promoting skin regeneration in sun and preparation method of conductive hydrogel

Abstract

The invention discloses a conductive hydrogel used for promoting skin regeneration in the sun and having a photoelectric effect excited by visible light and a preparation method of the conductive hydrogel. N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy) methyl butyrate grafted methacrylated hyaluronic acid is selected as a hydrogel matrix material; the hydrogel is endowed with a photoelectric effect through bonding of a Schiff base reaction and a visible light response gold nanorod / nitrogen carbide sheet layer, and the injectable bionic hydrogel which has adjustable mechanical properties and tissue adhesion, can be initiated by visible light and has a photoelectric stimulation effect and electrical conductivity is constructed. The invention innovatively provides a research strategy of'promoting regeneration of refractory wounds in the sun ', and the constructed conductive bionic hydrogel which can be triggered by visible light and has a photoelectric stimulation effect can realize the strategy. And a new thought and an experimental basis are provided for building a new generation of biological materials with an electrical stimulation effect to repair the regeneration of refractory wounds such as full-thickness skin defects and the like.

Description

Technical Field

[0001] This invention belongs to the field of intelligent biomaterials technology for regenerative medicine, and relates to a conductive hydrogel material and its preparation method, particularly a conductive hydrogel for promoting skin regeneration by visible light-excited photoelectric effect and its preparation method. Background Technology

[0002] Difficult-to-heal wounds, such as diabetic skin defects, pressure injuries, and residual wounds after extensive burns, pose a significant challenge to clinical treatment. These wounds often experience stagnant healing processes due to persistent infection, impaired blood supply, neuropathy, and cellular dysfunction, resulting in the wound remaining in the inflammatory or proliferative phase, making effective repair difficult with conventional dressings or growth factor therapy. Full-thickness skin defects not only expose patients to the risks of infection, amputation, and even death but also impose a heavy socioeconomic burden [Manoj Puthia. A dual-action peptide-containing hydrogel targets woundinfection and inflammation. Science translational medicine, 2020;12, 1-15]. While current mainstream tissue-engineered scaffolds and active dressings can provide physical barriers and a moisturizing microenvironment, their effectiveness in actively regulating the wound microenvironment and restarting endogenous repair processes is limited. Therefore, developing intelligent biomaterials capable of actively intervening, dynamically responding, and precisely regulating the healing microenvironment has become an urgent need in the fields of regenerative medicine and wound repair.

[0003] Recent studies have shown that endogenous bioelectric signals play a crucial role in tissue development and wound repair. After skin injury, a direct current electric field perpendicular to the wound edge is generated, guiding the directional migration and proliferation of epithelial cells, fibroblasts, and vascular endothelial cells—a process known as electrochemotaxis. Exogenous application of electrical stimulation within a safe range has been shown to mimic this physiological electric field, effectively promoting angiogenesis, collagen deposition, and re-epithelialization, showing unique therapeutic potential, especially for chronic, difficult-to-heal wounds [Xia Gong. Polymer Hydrogel-Based Multifunctional Theranostics for Managing Diabetic Wounds. Advanced Functional Materials, 2024;34]. However, current electrical stimulation therapies largely rely on bulky external devices and percutaneous electrodes, resulting in poor portability, imprecise stimulation sites, susceptibility to infection, and low patient compliance. Combining the healing-promoting effects of electrical stimulation with implantable wound dressings to develop localized, self-powered, and programmable integrated electroactive scaffolds is a crucial breakthrough for its clinical translation.

[0004] Visible light-responsive materials offer an innovative pathway to non-invasive and precise local electrical stimulation. By designing functional materials that can directly convert light energy (especially highly penetrating visible light) into electrical signals, it is hoped that an integrated "photo-controlled electrical stimulation" platform can be constructed [Z. Jiang. Enhanced migration of neural stem cells by microglia grown on a three-dimensional graphene scaffold, ACS Applied Materials & Interfaces, 2016; 8, 25069-25077]. Among these, noble metal nanomaterials (such as gold nanorods) and semiconductor nanomaterials (such as graphitic carbon nitride) have attracted widespread attention due to their efficient photothermal and photoelectric conversion properties. However, how to stably and uniformly integrate these nanofunctional units into a three-dimensional hydrogel network with good biocompatibility and mechanical adaptability, and achieve effective transmission and biological utilization of photoexcited electrical signals at the wound site, remains a technical challenge. Furthermore, traditional photosensitive hydrogels mostly rely on ultraviolet light triggering, which has weak tissue penetration and poses a potential risk of cell damage. Therefore, developing intelligent hydrogels based on visible light response and possessing both tissue integration and photoelectric conversion functions has significant scientific and application value for realizing a safe and convenient new treatment model of "sun exposure to promote healing". Summary of the Invention

[0005] The purpose of this invention is to provide a conductive hydrogel with a visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, and its preparation method. This invention uses N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy)methyl butyrate (NB)-grafted methacryloyl hyaluronic acid (HAMA) as the hydrogel matrix material (HAMA-NB). The hydrogel is endowed with a photoelectric effect by bonding visible light-responsive gold nanorods / nitrogen carbide sheets (Au NRs / g-C3N4) via a Schiff base reaction, constructing an injectable biomimetic hydrogel with tunable mechanical properties, tissue adhesion, visible light-excited photoelectric stimulation, and conductivity. This research innovatively proposes a research strategy of "promoting the regeneration of difficult-to-heal wounds through sun exposure." The constructed conductive biomimetic hydrogel with a visible light-excited photoelectric stimulation effect can realize this strategy. The hydrogel serves as a skin tissue scaffold material, and electrical stimulation is used to accelerate the regeneration of difficult-to-heal wounds. This study can provide new ideas and experimental basis for constructing a new generation of biomaterials with electrostimulation effects to repair refractory wounds such as full-thickness skin defects.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for preparing a conductive hydrogel with visible light-induced photoelectric effect for promoting skin regeneration during sun exposure includes: selecting biocompatible methacryloyl hyaluronic acid (HAMA) monomer as the base material, and obtaining HAMA-NB by grafting the photosensitive group N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy)butyrate (NB). HAMA can be crosslinked under ultraviolet light to rapidly shape the hydrogel, and the photogenerated aldehyde group of NB endows the hydrogel with good tissue adhesion. Subsequently, HAMA-NB is composited with Au NRs / g-C3N4 nanosheets that can be photo-induced by visible light, and HAMA-NB@Au NRs / g-C3N4 biomimetic hydrogel is prepared by ultraviolet light irradiation. In this process, the photogenerated aldehyde group of NB undergoes a Schiff base reaction with the amino group on g-C3N4 to bond Au NRs / g-C3N4. NRs / g-C3N4 sheets can be uniformly dispersed in hydrogel. The uniformly dispersed g-C3N4 sheets can act as an electron conductor, making the hydrogel conductive and improving its mechanical properties, thereby constructing a composite biomimetic hydrogel that has tunable mechanical properties, tissue adhesion, photoelectric effect induced by visible light, and conductivity.

[0008] Furthermore, in the above technical solution, the preparation method specifically includes:

[0009] Au NRs dispersion was mixed with g-C3N4 nanosheets and stirred thoroughly to obtain Au NRs / g-C3N4 composite nanosheets; HAMA-NB was dissolved in deionized water to obtain HAMA-NB solution;

[0010] HAMA-NB solution and Au NRs / g-C3N4 composite nanosheets were mixed to obtain a hydrogel precursor solution. A photoinitiator was added, and the hydrogel was generated in situ by UV crosslinking.

[0011] Furthermore, the preparation method of the HAMA-NB is as follows:

[0012] HAMA was dissolved in 2-(N-morpholine)ethanesulfonic acid-hydrate buffer solution, and NB was dissolved in dimethyl sulfoxide (DMSO). The two solutions were mixed, and 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM) was added under continuous stirring. After the reaction was completed, the mixture was dialyzed against 0.1M sodium chloride solution (pH=3.5) for 2 days, followed by dialyzed against deionized water for 2 days. After freeze-drying, HAMA-NB was obtained and stored in the dark in a sealed container.

[0013] Furthermore, the mass ratio of HAMA, NB, and DMTMM is 1:0.06:1.2.

[0014] Furthermore, the concentration of HAMA-NB is 5~40 mg / mL, the concentration ratio of Au NRs / g-C3N4 to HAMA-NB is 1:40~1:4, and the mass ratio of Au NRs to g-C3N4 is 0.1:100~5:100.

[0015] Furthermore, in preparing the substrate material HAMA, the hyaluronic acid HA can be replaced with one or more of the following: sodium alginate, carboxymethyl cellulose, pectin, polyacrylic acid, polymethacrylic acid, polyglutamic acid, gelatin, collagen, modified silk fibroin, etc., which have a large number of carboxyl groups.

[0016] This system uses N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy)butyrate methyl ester (NB) grafted with methacryloyl hyaluronic acid (HAMA) as the hydrogel matrix material (HAMA-NB). Visible light-responsive gold nanorods / nitrogen carbide sheets (Au NRs / g-C3N4) are bonded through Schiff base reaction to impart photoelectric effects to the hydrogel, thus constructing an injectable biomimetic hydrogel with tunable mechanical properties, tissue adhesion, visible light-induced photoelectric stimulation effect, and conductivity.

[0017] In this system, the small molecule NB on the hydrogel matrix material HAMA-NB has the property of generating aldehyde groups under ultraviolet light stimulation. The photogenerated aldehyde groups can undergo Schiff base reactions to bond with the amino groups on the g-C3N4 nanosheets. This property allows the nanosheets to be uniformly dispersed in the hydrogel and can improve the mechanical properties of the hydrogel. The photogenerated aldehyde group property of NB endows the hydrogel with adhesive properties. The introduction of gold nanorods / nitrogen carbide sheets (Au NRs / g-C3N4) endows the hydrogel material with electrical conductivity and visible light responsiveness.

[0018] The prepared hydrogel material possesses tunable mechanical properties, tissue adhesion, NIR-induced photoelectric effect, and conductivity, making it highly suitable as an injectable hydrogel material for tissue regeneration. More importantly, its ability to generate a photoelectric effect upon visible light stimulation supports a research strategy of "sun exposure to promote the healing of difficult-to-heal wounds." The treatment of difficult-to-heal wounds includes one or more of the following: full-thickness skin defects, diabetic wounds, and burn wounds.

[0019] The technical solutions of this invention involve multi-field interdisciplinary research: 1) Biomedical materials, focusing on tissue engineering scaffolds and novel wound dressings for wound repair; 2) Functional polymers and smart hydrogels, the core of which lies in constructing a biomimetic gel network with visible light responsiveness, injectability, tissue adhesion, and conductivity, based on photosensitive polymers (such as o-nitrobenzene-modified hyaluronic acid) and dynamic cross-linking chemistry (such as Schiff base reactions); 3) Nanotechnology and nanobiomaterials, by introducing visible light responsive nanocomponents such as gold nanorods and graphitic carbon nitride nanosheets, endowing materials with efficient photoelectric conversion capabilities, realizing the conversion of sunlight / visible light energy into local electrical signals that regulate cell behavior; 4) Photobio-effects and physical therapy, based on the regeneration promotion principle of endogenous electric fields, using exogenous light control to generate targeted electrical stimulation, thereby non-invasively accelerating the re-epithelialization, vascularization, and remodeling of skin tissue. This technology is essentially a next-generation active dressing that integrates a "light-electricity-biology" cascade response, representing a deep integration of tissue engineering, nanomedicine, and bioelectronics.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] Benefit 1: Innovative "sun exposure to promote healing" strategy, achieving non-invasive and efficient wound regeneration.

[0022] This invention innovatively proposes a non-invasive treatment strategy of "sun exposure to promote the healing of difficult-to-heal wounds." Through a Schiff base reaction, visible light-responsive Au NRs / g-C3N4 are bonded to the HAMA-NB hydrogel matrix, endowing the material with visible light-excited photoelectric effects and conductivity. No additional complex equipment is required; continuous electrical stimulation can be triggered solely by natural light, precisely targeting the wound microenvironment to accelerate cell proliferation, angiogenesis, and collagen remodeling. This effectively addresses the drawbacks of traditional electrical stimulation therapies, such as reliance on external power sources, cumbersome operation, and high invasiveness. It provides a convenient and efficient repair solution for difficult-to-heal wounds such as full-thickness skin defects, significantly improving the feasibility of clinical application and patient compliance.

[0023] Benefit 2: The biomimetic design combines multiple functional characteristics, adapting to the complex needs of wound repair.

[0024] The hydrogel uses methacrylamide hyaluronic acid (HAMA) as a matrix, grafting NB molecules to achieve stable binding with the hydrogel via a Schiff base reaction. The constructed hydrogel material not only possesses mechanical properties matching skin tissue but also exhibits excellent tissue adhesion and biocompatibility, allowing it to closely adhere to the wound surface and avoid secondary damage. Simultaneously, the material combines electrical conductivity and visible light responsiveness, converting light energy into bioelectrical signals to simulate the physiological electrical environment in vivo. This bidirectionally regulates the wound immune microenvironment and repair-related signaling pathways, overcoming the limitations of traditional hydrogels that only provide physical support and lack active repair functions. This achieves a functional integration of "scaffold support - electrical stimulation repair - biocompatibility."

[0025] Benefit 3: Injectable formulations and modular design expand clinical application scenarios and translational potential.

[0026] This invention utilizes an injectable hydrogel formulation, allowing for minimally invasive filling of irregular wounds. It adapts to skin defects of varying locations and shapes, overcoming the limitations of traditional bulk repair materials that struggle to fit complex wounds. Its modular design allows for flexible adjustment of the HAMA-NB concentration and Au NRs / g-C3N4 ratio, enabling precise control of mechanical properties and photoelectric response efficiency to meet the repair needs of different types of wounds, such as acute wounds and chronic ulcers. The material preparation process does not introduce toxic reagents, ensuring high biosafety. Furthermore, the core components, such as hyaluronic acid and gold nanorods, are commonly used clinical biomaterials, facilitating large-scale production and quality control. This lays a solid foundation for the clinical translation of next-generation electrostimulation-effect biomaterials and has broad application prospects. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the preparation process of the present invention and the promotion of regeneration of intractable skin by visible light-induced photoelectric stimulation.

[0028] Figure 2Examples 1: HA, HAMA, and HAMA-NB 1 Results of molecular structure characterization by 1H NMR (500 MHz);

[0029] Figure 3 The transmission electron microscopy (TEM) test results of Au NRs, g-C3N4 and Au NRs / g-C3N4 in Example 1 are shown in the lower right figure, which is the elemental distribution map of the white box area in the lower left figure.

[0030] Figure 4 The results of the compression modulus test for HAMA, HAMA-NB, and HAMA-NB@Au NRs / g-C3N4 in Example 1 are shown.

[0031] Figure 5 The photoelectric effect test results of HAMA-NB@Au NRs / g-C3N4 in Example 1 under visible light stimulation and without visible light stimulation are shown.

[0032] Figure 6 The results of the scratch experiment on HUVECs cells under different light intensities are shown in Example 1.

[0033] Figure 7 This is the result of an experiment in Example 1 showing how HAMA-NB@Au NRs / g-C3N4 (abbreviated as A@HN) hydrogel promotes the repair of full-thickness skin defects in SD rats under visible light stimulation. Detailed Implementation

[0034] To better understand the present invention, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0035] HA, MA, NB, Au ARs and g-C3N4 are all commercially available drugs that can be purchased directly. All drugs should be stored in a cool, dry place away from light.

[0036] The HAMA-NB involved in this invention can be obtained through preparation, specifically by the following method:

[0037] Preparation of HAMA: HA (molecular weight (Mw) approximately 1000 kDa) was dissolved in PBS to prepare a 1% w / v homogeneous solution, yielding an HA solution. Then, methacrylic anhydride (MA) was added to the HA solution at a concentration of 0.1 mL / g HA. NaOH was added to adjust the pH to 8.0, and the mixture was continuously stirred at 4°C for 48 h to form a HAMA solution. The HAMA solution was then dialyzed against deionized water for 3 days, frozen overnight, lyophilized, and stored at −20°C for further use.

[0038] Preparation of HAMA-NB: First, 1 g of HAMA was dissolved in 2-(N-morpholine)ethanesulfonic acid hydrate (MES, 0.01 mol / L, 100 mL; pH=5.3) buffer solution and reacted at 35 °C. After the HAMA was completely dissolved, 60 mg of NB was dissolved in 10 mL of dimethyl sulfoxide (DMSO) and added to the reaction system. Then, 4-(4,6-dimethoxy-triazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM, totaling 1.2 g) was added in three portions, with an interval of 0.5–1 hour between each addition. After the last addition, the reaction continued for 3 hours. The entire process was carried out under stirring. Finally, the sample was dialyzed with 0.1M sodium chloride solution (pH=3.5) for 2 days, then dialyzed with deionized water for 2 days, and then freeze-dried to obtain HAMA-NB, which was stored in the dark in a sealed container.

[0039] Example 1

[0040] 1) Au NRs and g-C3N4 nanosheets were mixed at a mass ratio of 1:100 and stirred thoroughly to obtain Au NRs / g-C3N4 composite nanosheets;

[0041] 2) Dissolve HAMA-NB in ​​deionized water with thorough stirring to prepare a HAMA-NB solution with a concentration of 20 mg / mL;

[0042] 3) Prepare a hydrogel precursor solution by mixing HAMA-NB solution and Au NRs / g-C3N4 composite nanosheets at a mass ratio of 10:1. Add photoinitiator lithium phenyl-2,4,6-trimethylbenzylphosphine (LAP, 0.1wt%) and generate hydrogel in situ by UV crosslinking.

[0043] like Figure 1 The diagram shown illustrates the preparation process of the present invention and the promotion of regeneration of intractable skin by visible light-induced photoelectric stimulation.

[0044] In Example 1, the degree of methacrylic anhydride substitution of HAMA and the degree of nitrobenzyl substitution of HAMA-NB were determined by 1H nuclear magnetic resonance (1H NMR-500 M), as follows: Figure 2 As shown, this demonstrates the successful preparation of HAMA-NB. Figure 3As shown, TEM results confirm that Au NRs were successfully loaded onto the surface of g-C3N4 nanosheets, successfully preparing Au NRs / g-C3N4 composite nanosheets. The mechanical properties of the hydrogel were mainly determined using a universal tensile testing machine, which tested its compressive modulus and cyclic compression characteristics, such as... Figure 4 As shown, the mechanical properties of HAMA-NB are significantly higher than those of HAMA hydrogel, and the mechanical properties of HAMA-NB@AuNRs / g-C3N4 hydrogel with added Au NRs / g-C3N4 composite nanosheets are further improved. The photoelectric effect and conductivity were tested using IV, such as... Figure 5 As shown, HAMA-NB@Au NRs / g-C3N4 exhibited a significant photocurrent under visible light stimulation, demonstrating its excellent photoelectric effect and conductivity. These tests indicate that the prepared hydrogel material possesses tunable mechanical properties, tissue adhesion, photoelectric stimulation induced by visible light, and conductivity. Scratch assays, conducted by seeding HUVECs cells onto the Au NRs / g-C3N4 composite nanosheet film, demonstrated that the photogenerated charge facilitates cell migration. Figure 6 Experiments on full-thickness skin defect repair in SD rats demonstrated that HAMA-NB@Au NRs / g-C3N4 hydrogel, which exhibits visible light-induced photoelectric stimulation, effectively promotes wound repair. Figure 7 The effect is significantly better than that of HAMA-NB hydrogel material (HN for short).

[0045] Example 2

[0046] 1) Au NRs and g-C3N4 nanosheets were mixed at a mass ratio of 5:100 and stirred thoroughly to obtain Au NRs / g-C3N4 composite nanosheets;

[0047] 2) Dissolve HAMA-NB in ​​deionized water with thorough stirring to prepare a HAMA-NB solution with a concentration of 40 mg / mL;

[0048] 3) Prepare a hydrogel precursor solution by mixing HAMA-NB solution and Au NRs / g-C3N4 composite nanosheets at a mass ratio of 4:1. Add photoinitiator lithium phenyl-2,4,6-trimethylbenzylphosphine (LAP, 0.1wt%) and generate hydrogel in situ by UV crosslinking.

[0049] The degree of methacrylic anhydride substitution of HAMA and the degree of nitrobenzyl substitution of HAMA-NB were determined by 1H NMR (1H NMR-500 M), confirming the successful preparation of HAMA-NB. TEM testing confirmed the successful loading of Au NRs onto the surface of g-C3N4 nanosheets, successfully preparing Au NRs / g-C3N4 composite nanosheets. The mechanical properties of the hydrogel were mainly tested using a universal tensile testing machine to determine its compressive modulus and cyclic compression characteristics. The mechanical properties of HAMA-NB were significantly higher than those of HAMA hydrogel, and the mechanical properties of HAMA-NB@Au NRs / g-C3N4 hydrogel with added AuNRs / g-C3N4 composite nanosheets were further improved. Photoelectric effect and conductivity were tested using IV. Under visible light stimulation, HAMA-NB@Au NRs / g-C3N4 exhibited a significant photocurrent, demonstrating its good photoelectric effect and conductivity. The above tests demonstrate that the prepared hydrogel material possesses tunable mechanical properties, tissue adhesion, photoelectric stimulation induced by visible light, and electrical conductivity. Scratch assays, inoculated with HUVECs cells on the surface of AuNRs / g-C3N4 composite nanosheets, showed that photogenerated charge promotes cell migration. Full-thickness skin defect repair experiments in SD rats demonstrated that the HAMA-NB@AuNRs / g-C3N4 hydrogel with visible light-induced photoelectric stimulation effectively promotes wound repair.

[0050] Example 3

[0051] 1) Au NRs and g-C3N4 nanosheets were mixed at a mass ratio of 0.1:100 and stirred thoroughly to obtain Au NRs / g-C3N4 composite nanosheets;

[0052] 2) Dissolve HAMA-NB in ​​deionized water with thorough stirring to prepare a HAMA-NB solution with a concentration of 5 mg / mL;

[0053] 3) A hydrogel precursor solution was prepared by mixing HAMA-NB solution and Au NRs / g-C3N4 composite nanosheets at a mass ratio of 40:1. A photoinitiator, lithium phenyl-2,4,6-trimethylbenzylphosphine (LAP, 0.1 wt%), was added, and the hydrogel was generated in situ by UV crosslinking. The relationship between the material ratio and mechanical properties, tissue adhesion and photoelectric effect was studied.

[0054] The degree of methacrylic anhydride substitution of HAMA and the degree of nitrobenzyl substitution of HAMA-NB were determined by 1H NMR (1H NMR-500 M), confirming the successful preparation of HAMA-NB. TEM testing confirmed the successful loading of Au NRs onto the surface of g-C3N4 nanosheets, successfully preparing Au NRs / g-C3N4 composite nanosheets. The mechanical properties of the hydrogel were mainly tested using a universal tensile testing machine to determine its compressive modulus and cyclic compression characteristics. The mechanical properties of HAMA-NB were significantly higher than those of HAMA hydrogel, and the mechanical properties of HAMA-NB@Au NRs / g-C3N4 hydrogel with added AuNRs / g-C3N4 composite nanosheets were further improved. Photoelectric effect and conductivity were tested using IV. Under visible light stimulation, HAMA-NB@Au NRs / g-C3N4 exhibited a significant photocurrent, demonstrating its good photoelectric effect and conductivity. The above tests demonstrate that the prepared hydrogel material possesses tunable mechanical properties, tissue adhesion, photoelectric stimulation induced by visible light, and electrical conductivity. Scratch assays, inoculated with HUVECs cells on the surface of AuNRs / g-C3N4 composite nanosheets, showed that photogenerated charge promotes cell migration. Full-thickness skin defect repair experiments in SD rats demonstrated that the HAMA-NB@AuNRs / g-C3N4 hydrogel with visible light-induced photoelectric stimulation effectively promotes wound repair.

[0055] The embodiments described above are merely some preferred embodiments of the present invention, and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, characterized in that, Using methacrylamide hyaluronic acid (HAMA) monomer as the base material, HAMA-NB was obtained by grafting the photosensitive group N-(2-aminoethyl)-4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy)methyl butyrate (NB). Subsequently, HAMA-NB was composited with Au NRs / g-C3N4 nanosheets, and HAMA-NB@Au NRs / g-C3N4 biomimetic hydrogel was prepared by UV irradiation. In this process, the photogenerated aldehyde group of NB and the amino group on g-C3N4 undergo Schiff base reaction to bond, which enables Au NRs / g-C3N4 nanosheets to be uniformly dispersed in the hydrogel. This constructed a composite biomimetic hydrogel with tunable mechanical properties, tissue adhesion, photoelectric effect induced by visible light, and conductivity.

2. The method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 1, is characterized in that... include: Au NRs dispersion was mixed with g-C3N4 nanosheets and stirred thoroughly to obtain Au NRs / g-C3N4 composite nanosheets; HAMA-NB was dissolved in deionized water to obtain HAMA-NB solution; A hydrogel precursor solution was obtained by mixing HAMA-NB solution and Au NRs / g-C3N4 composite nanosheets. A photoinitiator was added, and the hydrogel was generated in situ by UV crosslinking.

3. The method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 2, is characterized in that... The preparation method of the HAMA-NB is as follows: HAMA was dissolved in 2-(N-morpholine)ethanesulfonic acid-hydrate buffer solution, and NB was dissolved in dimethyl sulfoxide (DMSO). The two solutions were mixed, and 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride (DMTMM) was added under continuous stirring. After the reaction was completed, the mixture was dialyzed against 0.1M sodium chloride solution (pH=3.5) for 2 days, followed by dialyzed against deionized water for 2 days. After freeze-drying, HAMA-NB was obtained and stored in the dark in a sealed container.

4. The method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 3, is characterized in that... The mass ratio of HAMA, NB, and DMTMM is 1:0.06:1.

2.

5. A method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 2, characterized in that... The concentration of the HAMA-NB solution is 5~40 mg / mL.

6. A method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 2, characterized in that... The mass ratio of Au NRs to g-C3N4 nanosheets is 0.1:100 to 5:

100.

7. A method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 2, characterized in that... The mass ratio of Au NRs / g-C3N4 composite nanosheets to HAMA-NB is 1:40 to 1:

4.

8. A method for preparing a conductive hydrogel with visible light-excited photoelectric effect for promoting skin regeneration through sun exposure, as described in claim 1, characterized in that... In preparing the substrate material HAMA, the hyaluronic acid HA is replaced with one or more of sodium alginate, carboxymethyl cellulose, pectin, polyacrylic acid, polymethacrylic acid, polyglutamic acid, gelatin, collagen, and modified silk fibroin.

9. A conductive hydrogel for promoting skin regeneration through sun exposure, characterized by a visible light-excited photoelectric effect, wherein... It is prepared by the method described in any one of claims 1-8.

10. The application of the conductive hydrogel as described in claim 9 in the preparation of wound treatment dressings, characterized in that, The wound is one or more of the following: full-thickness skin defect, diabetic wound, and burn wound.

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