Preparation method of near-infrared response thermoelectric temperature-sensitive supramolecular injectable hydrogel as well as product and application of near-infrared response thermoelectric temperature-sensitive supramolecular injectable hydrogel

Abstract

The invention discloses a preparation method of near-infrared response thermoelectric temperature-sensitive supramolecular injectable hydrogel. The preparation method comprises the following steps: dissolving bismuth nitrate pentahydrate and thioacetamide in deionized water to react to obtain Bi2S3 nano-particles, and putting the Bi2S3 nano-particles into a tannic acid TA aqueous solution to react to obtain Bi2S3 coated TA nano-particles; the preparation method comprises the following steps: adding NIPAM, VI, disulfiram and azodiisobutyronitrile into an organic solvent, dissolving to obtain a mixed solution, and heating to obtain a supramolecular temperature-sensitive polymer PNV; sA, TA, PNV and Bi2S3 at TA are dissolved in normal saline, an obtained mixed solution is injected into a mold, a metal salt solution is sprayed, and the thermoelectric temperature-sensitive supramolecular injectable hydrogel is obtained through a reaction. The invention also discloses application of the injectable hydrogel obtained by the preparation method in preparation of products for repairing skin wounds. The injectable hydrogel provided by the invention completes active contraction and thermal-electric stimulation under single near-infrared energy input, and can be used as a photo-thermal platform to relieve bacterial load and promote repair of infected wounds.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a preparation method of a near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel, and a product and application thereof. Background Art

[0002] As the largest organ in the human body, the skin accounts for about 16% of an individual's body weight and is a key barrier against external mechanical stimulation and the invasion of pathogens and harmful microorganisms. However, when the impact on the skin is too strong, its surface is very likely to be damaged, leading to the formation of wounds. Slow or partial healing of full-thickness wounds imposes a heavy physical and mental burden on patients, and more than $10 billion is spent on treatment each year. At present, the wound repair process is mostly carried out with medical dressings such as gauze, but this traditional dressing is only suitable for surface wounds, cannot promote wound contraction, and is prone to secondary damage when replaced. At the same time, the wound may be infected by external pathogens or contaminated by tiny particles, which reduces the overall healing rate and may even threaten life.

[0003] Nowadays, hydrogels that mimic the natural extracellular matrix structure are promising wound dressings that can promote wound healing. At the same time, injectable hydrogels with good fluidity are widely used to treat deep wound infections or irregular wounds. SA-based wound dressing hydrogels can absorb exudates secreted from the wound, provide a moist environment for the wound, and are conducive to rapid granulation and re-epithelialization in the wound area.

[0004] Antibiotics are currently the most common treatment for bacterial infections, but the clinical abuse of antibiotics has accelerated the emergence of multidrug-resistant bacteria and the formation of bacterial biofilms.

[0005] In recent years, photothermal therapy (PTT) treatment has been used to effectively eradicate bacteria and biofilms by generating hyperthermia due to its broad-spectrum and highly effective antibacterial properties, good controllability, non-invasiveness, and prevention of multidrug-resistant bacteria.

[0006] Thermosensitive PNIPAM hydrogels can shrink rapidly under external auxiliary heating / body temperature, significantly accelerating wound healing. This adjustable contractile mechanical active dressing is adaptable and can be used for scarless wound repair. For example, the PNIPAM-PMMA hydrogel prepared by adding PMAA-Na and gelatin to chemically cross-linked PNIPAM hydrogel using traditional free radical polymerization can effectively promote wound healing (Hu J, Wei T, Zhao H, et al. Mechanically active adhesive and immune regulative dressings for wound closure [J]. Matter, 2021. DOI: 10.1016 / j.matt.2021.06.044.).

[0007] The endogenous electric field spontaneously formed near the wound surface helps the healing process. Most of the current conductive hydrogels directly use external DC power supplies, which are bulky and difficult to carry, which conflicts with the need for long-term treatment. Most wearable self-powered hydrogels require external energy input and conversion into electrical energy output, and some are also heavily dependent on random limb movements. Self-powered hydrogels involving thermoelectricity can spontaneously convert temperature gradients into electrical energy. Without generating much dissipated energy. Despite many expected advantages, thermoelectric hydrogels for wound healing are not commonly used. This is because high-performance thermoelectric materials are usually ionic hydrogels with high chemical toxicity. Hydrogels containing thermoelectric particles with certain biocompatibility have poor performance and require a large temperature difference to achieve the ideal effect. The low temperature gradient generated by the body surface alone is difficult to generate a considerable current. Based on this requirement, nanoparticles with good photothermal conversion efficiency and thermoelectric properties need to be selected to enhance the temperature gradient on the wound surface through single near-infrared light irradiation, while achieving the effects of contraction and enhanced antibacterial effect.

[0008] Therefore, how to provide an injectable hydrogel wound dressing that can simultaneously promote wound contraction and photothermal electrical stimulation is currently a research hotspot in this field. Summary of the invention

[0009] The purpose of the present invention is to provide a preparation method of a near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel, its product and application. The prepared injectable hydrogel can be used as a wound dressing to complete active contraction and thermal-electric stimulation under a single near-infrared energy input, and can be used as a photothermal platform to reduce bacterial load and promote the repair of infected wounds.

[0010] The purpose of the present invention is achieved through the following technical solutions:

[0011] (1) dissolving bismuth nitrate pentahydrate and thioacetamide in deionized water to react to obtain bismuth sulfide Bi2S3 nanoparticles, and adding the Bi2S3 nanoparticles into a tannic acid TA aqueous solution to react to obtain Bi2S3@TA nanoparticles;

[0012] (2) adding N-isopropylacrylamide NIPAM, 1-vinylimidazole VI, disulfiram and azobisisobutyronitrile to an organic solvent, dissolving the resulting mixed solution and heating it to obtain a supramolecular thermosensitive polymer PNV;

[0013] (3) Sodium alginate SA, TA, PNV and Bi2S3@TA were dissolved in physiological saline, the resulting mixture was injected into a mold, and a metal salt solution was sprayed to obtain a thermoelectric temperature-sensitive supramolecular injectable hydrogel.

[0014] In the present invention: Bi2S3 nanoparticles have good biocompatibility and photothermal conversion efficiency, and can be used as thermoelectric materials to realize the mutual conversion of thermal energy and electrical energy, generate large temperature difference power generation under near-infrared irradiation, and apply an electric field on the wound surface to accelerate wound healing; TA is a natural antioxidant, and its combination with Bi2S3 can enhance its performance in removing active oxygen; at the same time, TA can form hydrogen bonds with SA to make the hydrogel an excellent antioxidant platform and provide an excellent anti-inflammatory microenvironment for the wound; the sprayed metal ions can chelate with SA and VI in PNV, which is beneficial to the in situ gelation of the hydrogel and enhances the mechanical properties of the gel.

[0015] Preferably, in step (1), the mass ratio of bismuth nitrate pentahydrate to thioacetamide is 1:1-1:5.

[0016] Preferably, in step (1), the pH value of the aqueous solution after the bismuth nitrate pentahydrate and thioacetamide are dissolved in deionized water is 0-5.

[0017] Preferably, in step (1), bismuth nitrate pentahydrate and an aqueous solution of thioacetamide are reacted continuously in an oil bath at 40-60° C. for 3-12 hours.

[0018] Preferably, in step (1), the mass ratio of Bi2S3 to TA is 1:1-5:1.

[0019] Preferably, in step (1), the pH value of the solution after the Bi2S3 nanoparticles are added to the tannic acid TA aqueous solution is 7-10.

[0020] Preferably, in step (1), the Bi2S3 nanoparticles react with the TA aqueous solution at 25-40°C for 2-6 hours.

[0021] In the present invention, by adjusting the feed ratio of bismuth nitrate pentahydrate to thioacetamide and the reaction conditions, and the feed ratio of Bi2S3 to TA and the reaction conditions, the thickness of the TA shell on the surface of Bi2S3@TA nanoparticles is regulated, and both active oxygen scavenging and thermoelectric performance are taken into account.

[0022] In step (1), the Bi2S3@TA nanoparticles have a core-shell structure, and the surface of the Bi2S3 nanorods is coated with TA; the diameter of the Bi2S3 nanorods is 5-20 nm, and the length is 50-200 nm; the thickness of the TA is 1-5 nm.

[0023] Preferably, in step (1), the Bi2S3@TA nanoparticles need to be centrifugally purified.

[0024] Preferably, in step (2), the feed ratio of NIPAM to VI is 4:1-1:2.

[0025] Preferably, in step (2), the mixed solution is continuously heated at 50-70° C. for 5-8 hours.

[0026] Preferably, in step (2), the PNV is purified by heating, and the precipitant used includes but is not limited to n-hexane and anhydrous ether. Preferably, in step (2), the precipitated PNV needs to be dialyzed for purification and freeze-dried.

[0027] In the present invention, the precipitation temperature and polymerization degree of the thermosensitive supramolecular polymer are adjusted respectively by regulating the feed ratio of NIPAM to VI and the reaction conditions.

[0028] Preferably, in step (3), the mass fraction of SA in the mixed solution is 0.5%-5%.

[0029] Preferably, in step (3), the mass fraction of TA in the mixed solution is 0.5%-2%.

[0030] Preferably, in step (3), the mass fraction of PNV in the mixed solution is 2.5%-10%.

[0031] Preferably, in step (3), the mass fraction of Bi2S3@TA in the mixed solution is 0.01%-0.04%.

[0032] The present invention adjusts the modulus, antioxidant, shrinkage, photothermal and thermoelectric properties of the hydrogel by regulating the mass fractions of SA, TA, PNV and Bi2S3@TA in the mixed solution.

[0033] Preferably, in step (3), the metal salt solution sprayed is selected from CaCl2, CuCl2, CoCl2, ZnCl2 and SrCl2.2+ / Zn 2+ ) can provide excellent antibacterial properties.

[0034] Further preferably, the sprayed metal salt solution is CuCl2.

[0035] Preferably, in step (3), the concentration of the sprayed metal salt solution is 100 mM-2M.

[0036] The present invention also provides a near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel obtained by the preparation method.

[0037] The present invention also provides the use of the above-mentioned near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel in the preparation of skin wound repair products. When the injectable hydrogel provided by the present invention is used as a wound dressing, it can effectively resist bacteria and synergistically promote the repair of infected wounds with the aid of near-infrared irradiation.

[0038] Preferably, the conditions for near infrared irradiation are: 808nm, 1.5W / cm 2 .

[0039] The present invention has the following beneficial effects:

[0040] The preparation method provided by the present invention uses natural polysaccharides as the main components. Through functional design, natural polysaccharide SA, antioxidant TA, thermosensitive supramolecular polymer PNV, thermoelectric particles Bi2S3@TA and metal ions are combined under mild conditions to prepare a near-infrared responsive thermoelectric thermosensitive supramolecular injectable hydrogel wound dressing; at the same time, the uniform dispersion of the thermoelectric particles is ensured in the high-viscosity sodium alginate solution, and sedimentation is not easy to occur.

[0041] The entire system of the hydrogel wound dressing provided by the present invention achieves the effect of synergistically promoting wound repair with active contraction and photothermal-electrical stimulation as the core through a single energy input of near-infrared irradiation; in addition, the addition of natural polyphenols greatly enhances the antioxidant properties of the hydrogel and provides a good anti-inflammatory microenvironment; and the introduction of specific metal ions enables the injectable hydrogel to have normalized antibacterial properties, thereby reducing the bacterial load of infected wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a TEM image of the thermoelectric nanoparticles Bi2S3@TA in an embodiment of the present invention.

[0043] Figure 2 This is the XRD diagram of the thermoelectric nanoparticles Bi2S3@TA in an embodiment of the present invention.

[0044] Figure 3 This is a graph showing the DPPH removal of the thermoelectric nanoparticles Bi2S3@TA in an embodiment of the present invention.

[0045] Figure 4 This is a photothermal performance diagram of the thermoelectric nanoparticle Bi2S3@TA in an embodiment of the present invention.

[0046] Figure 5 Schematic diagram of the synthesis process of the thermosensitive supramolecular polymer PNV in an embodiment of the present invention.

[0047] Figure 6 is the NIPAAM, VI and PNV of the embodiment of the present invention. 1 H-NMR spectrum.

[0048] Figure 7 The UV-Vis graphs and photos of PN, PV and PNV at different temperatures in the embodiments of the present invention are shown.

[0049] Figure 8 This is a time scan diagram of the injectable hydrogel-metal ion in an embodiment of the present invention.

[0050] Fig. 9 This is a strain scanning diagram of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0051] Fig.10 This is a step strain scanning diagram of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0052] Fig.11 This is a flow scan of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0053] Fig.12 This is a temperature shrinkage diagram of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0054] Fig.13 This is a thermoelectric performance diagram of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0055] Fig.14 This is a graph showing the in vitro antibacterial performance of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0056] Fig.15 This is a graph showing the hemolytic performance of the injectable hydrogel SPTP-Cu in an embodiment of the present invention.

[0057] Fig.16 This is a diagram showing the temperature rise after the injectable gel SPTP-Cu in an example of the present invention was injected into an infected mouse model with skin defects.

[0058] Fig.17 This is a diagram of the infected wound repair of the injectable hydrogel SPTP-Cu in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the purpose and technical scheme of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings. The following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in this field or the product instructions are used.

[0060] Example 1

[0061] (1) Preparation of thermoelectric particles Bi2S3@TA

[0062] 500 mg of thioacetamide was dissolved in 4 mL of deionized water, and 6 mL of 250 mg of bismuth nitrate pentahydrate solution was added. The pH of the mixture was adjusted to 0.5 and reacted at 45 °C for 5 h. Bi2S3 nanoparticles were collected and Bi2S3@TA thermoelectric nanoparticles with Bi2S3:TA feed ratios of 5:1, 2.5:1 and 1:1 were prepared, respectively, and named BT 1 , BT 2 and BT 3 .

[0063] like Figure 1 As shown in the figure, the thermoelectric nanoparticles Bi2S3@TA(BT 1 ) TEM image. TEM shows that the prepared Bi2S3 has a nanorod structure with a diameter of 10nm and a length of 60nm. Bi2S3@TA(BT 1 ) has a core-shell structure, the surface of Bi2S3 is coated with TA, and the thickness of the TA shell is 1nm.

[0064] like Figure 2 As shown in the figure, the thermoelectric nanoparticles Bi2S3@TA(BT 1 The XRD pattern of the original TA shows a typical amorphous broad peak, while Bi2S3 and Bi2S3@TA(BT 1 ), indicating that the encapsulation of TA shell did not change the crystal form of Bi2S3.

[0065] like Figure 3 As shown in the figure, the DPPH scavenging graph of the thermoelectric nanoparticle Bi2S3@TA in this embodiment. TA has the best effect in scavenging reactive oxygen species at the same concentration, and the ROS scavenging performance of Bi2S3 coated with TA is enhanced. When the proportion of TA increases, the scavenging effect of Bi2S3@TA is enhanced.

[0066] like Figure 4 As shown in the figure, the thermoelectric nanoparticles Bi2S3@TA(BT 1). As shown in the heating temperature curves of various nanomaterials, Bi2S3, TA and Bi2S3@TA increased by 19.6°C, 1.6°C and 18.1°C, respectively, after continuous near-infrared light irradiation for 300s. The photothermal stability of Bi2S3@TA was demonstrated by five photothermal cycle experiments. The photothermal conversion efficiency of Bi2S3@TA was calculated to be 33.2%, which is higher than that of other melanin substances and some Bi2S3 semiconductor nanomaterials previously reported.

[0067] (2) Preparation of supramolecular thermosensitive polymer PNV

[0068] like Figure 5 The figure shows the synthesis process of the thermosensitive supramolecular polymer PNV in this embodiment, which uses NIPAAM and VI as raw materials to react under certain conditions to generate the supramolecular polymer PNV, wherein DSS is a chain transfer agent, AIBN is a thermal initiator, and DMSO is a solvent.

[0069] Specifically, NIPAAM (28.29 g, 250 mmol), VI (5.88 g, 62.5 mmol), disulfiram (0.37 g, 1.25 mmol) and azobisisobutyronitrile (0.41 g, 2.5 mmol) were added to 25 mL DMSO and ultrasonicated for 10 min to completely dissolve them in the flask. Nitrogen was introduced into the solution for about 30 min to remove oxygen from the solution. The mixed solution was placed in a 70 ° C oil bath and heated for continuous reaction for about 6 h. After the reaction was completed, it was naturally cooled to room temperature. Anhydrous ether with a volume of 10 times the solution was used as a precipitant to precipitate the product. After standing for a period of time, the precipitant was poured out, and after the remaining precipitant evaporated, the product was redissolved in water. After the solution containing the product was dialyzed with an 8000 Da dialysis bag for 48 h, it was filtered using a 45 μm PES filter head. The obtained filtrate was freeze-dried to obtain PNV1. Polymers PNV2 and PNV3 with NIPAAM:VI feed ratios of 2:1 and 1:2 were prepared in a similar manner.

[0070] like Figure 6 As shown, the NIPAAM, VI and PNV (PNV2) in this embodiment 1 H-NMR spectrum. Figure 6 The double bond related peaks of NIPAAM are c (5.61ppm) and d (6.05ppm), and the double bond related peak of VI is A (5.13ppm), but these double bond peaks do not appear in PNV (PNV2). At the same time, two monomer-responsive inactive hydrogen peaks appear in PNV (PNV2), indicating the successful polymerization of NIPAAM and VI.

[0071] like Figure 7As shown, the UV-Vis graphs and photos of PN, PV and PNV at different temperatures in this embodiment. At 25°C, all solutions can remain transparent, but after heating, the polymer solution containing PNIPAAM segments has precipitation phenomenon, and the solution is turbid. And when the proportion of PVI segments increases, the polymer precipitation temperature increases. Based on the platform temperature of the photothermal response, PNV2 is selected as the component of the subsequent hydrogel.

[0072] (3) Preparation of injectable hydrogels

[0073] 0.3g SA, 0.05g TA, 0.5g PNV2 and 2.5mg Bi2S3@TA(BT 1 ) nanoparticles were dissolved in 10 mL of saline and the pH was adjusted to 8 using 0.1 M sodium hydroxide. The resulting solution was injected into the mold and sprayed with a metal ion solution (Cu 2+ or Ca 2+ ), a thermoelectric temperature-sensitive supramolecular injectable hydrogel can be obtained.

[0074] like Figure 8 The time scan of the injectable hydrogel-metal ion in this embodiment is shown in FIG. 2+ In situ curing and forming hydrogel. Spraying Ca 2+ After solution, the modulus of SPTP hydrogel is the highest, and Cu 2 + With Ca 2+ There is no significant difference in the modulus of crosslinking. Based on the antibacterial properties of metal ions, Cu 2+ The subsequent experimental hydrogel is called SPTP-Cu.

[0075] like Fig. 9 The figure shows the strain scanning diagram of the injectable hydrogel SPTP-Cu in this embodiment. The upper limit of the strain of the hydrogel SPTP-Cu can reach 175%, which can withstand the strain in the wound area and can be used as a wound dressing.

[0076] like Fig.10 The figure shows the step strain scanning diagram of the injectable hydrogel SPTP-Cu in this embodiment. The hydrogel SPTP-Cu can withstand multiple step strains and exhibits good and repeatable self-healing properties.

[0077] like Fig.11 The flow scanning diagram and injectable photos of the injectable hydrogel SPTP-Cu in this embodiment are shown in FIG. The viscosity of the spray-coated SPTP-Cu decreases rapidly under shear strain, showing good injectable performance.

[0078] like Fig.12The figure shows the shrinkage of the injectable hydrogel SPTP-Cu in this example. A series of hydrogels were placed on a heating table. During the heating process, the hydrogel containing supramolecular polymers shrank sharply. In addition, a series of hydrogels were heated to 1.5W / cm 2 When exposed to 808nm near-infrared light, the thermosensitive supramolecular hydrogel shrank dramatically as the irradiation time increased. The shrinkage of the hydrogel SPTP-Cu after heating proved that it has the ability to actively shrink and is expected to promote wound repair.

[0079] like Fig.13 The figure shows the thermoelectric performance of the injectable hydrogel SPTP-Cu in this embodiment. Some hydrogels were placed on a heating table. During the heating process, the cold end and hot end of the SPTP-Cu hydrogel containing Bi2S3@TA formed a significant potential difference change. Under ΔT = 25°C, the voltage between the two ends can reach 37mV, and the current can be higher than 1μA, making it possible for thermoelectricity to promote wound repair.

[0080] like Fig.14 The figure shows the in vitro antibacterial performance of the injectable hydrogel SPTP-Cu in this embodiment. The antibacterial effect of the hydrogel SPTP-Cu on Staphylococcus aureus is better than that on Escherichia coli. At the same time, the antibacterial effect is enhanced after being irradiated with near-infrared light, indicating that the hydrogel can be used as an antibacterial platform to reduce the bacterial load in the wound area.

[0081] like Fig.15 The figure shows the hemolysis performance of the injectable hydrogel SPTP-Cu in this embodiment (1. saline, 2.5 mg / mL, 3.10 mg / mL, 4.15 mg / mL, 5.20 mg / mL, 6.2% Triton). The hemolysis rates of the hydrogel SPTP-Cu are all lower than 5%, indicating that the hydrogel has good biocompatibility.

[0082] like Fig.16 The figure shows the temperature rise after the injectable gel SPTP-Cu in this example is injected into the infected mouse model with skin defect (I: normal saline, II: Tegaderm TM , III: SPT-Cu, IV: SPTP-Cu, V: SPTP-Cu+NIR). The temperature of the wound area without NIR irradiation did not change significantly, and the temperature of the wound area loaded with hydrogel was slightly lower, which may be due to the high specific heat capacity of hydrogel. 2 After being exposed to near-infrared light, the irradiated area of ​​the wound can quickly reach above 45°C within 60 seconds, which can reach the precipitation temperature of the supramolecular thermosensitive polymer, making it possible for the area covered by the wound dressing to actively shrink.

[0083] like Fig.17As shown, it is a diagram of the infected wound repair of the injectable hydrogel SPTP-Cu in this embodiment. The scale of the photo is 8 mm. The wound area of ​​the SPTP-Cu+NIR group is smaller than that of the other four groups, and the infected wound is basically completely repaired on Day 12. Similarly, the bacterial survival rate of the SPTP-Cu+NIR group on Day 3 and Day 6 is lower than that of the other four groups, indicating that SPTP-Cu can be used as a photothermal antibacterial platform to reduce the bacterial load in the wound area and promote wound repair.

[0084] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel, characterized in that: The preparation method comprises: (1) dissolving bismuth nitrate pentahydrate and thioacetamide in deionized water to react to obtain bismuth sulfide Bi2S3 nanoparticles, and adding the Bi2S3 nanoparticles into a tannic acid TA aqueous solution to react to obtain Bi2S3@TA nanoparticles; (2) adding N-isopropylacrylamide NIPAM, 1-vinylimidazole VI, disulfiram and azobisisobutyronitrile to an organic solvent, dissolving the resulting mixed solution and heating it to obtain a supramolecular thermosensitive polymer PNV; (3) Sodium alginate SA, TA, PNV and Bi2S3@TA were dissolved in physiological saline, the resulting mixture was injected into a mold, and a metal salt solution was sprayed to obtain a thermoelectric temperature-sensitive supramolecular injectable hydrogel.

2. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 1, characterized in that: In step (1), the mass ratio of bismuth nitrate pentahydrate to thioacetamide is 1:1-1:5; the pH value of the aqueous solution after the bismuth nitrate pentahydrate and thioacetamide are dissolved in deionized water is 0-5; the bismuth nitrate pentahydrate and thioacetamide are continuously reacted in an oil bath at 40-60°C for 3-12h to obtain bismuth sulfide Bi2S3 nanoparticles.

3. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 1, characterized in that: In step (1), the mass ratio of Bi2S3 to TA is 1:1-5:1; the pH value of the Bi2S3 nanoparticles after being added to the tannic acid TA aqueous solution is 7-10; the Bi2S3 nanoparticles and the TA aqueous solution are continuously reacted at 25-40°C for 2-6h to obtain Bi2S3@TA nanoparticles.

4. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 1, characterized in that: In step (1), the Bi2S3@TA nanoparticles have a core-shell structure, and the surface of the Bi2S3 nanorods is coated with TA; the diameter of the Bi2S3 nanorods is 5-20 nm, and the length is 50-200 nm; the thickness of the TA is 1-5 nm.

5. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 1, characterized in that: In step (2), the feed ratio of NIPAM to VI is 4:1-1:2; the mixed solution is continuously heated at 50-70° C. for 5-8 hours to obtain the supramolecular thermosensitive polymer PNV.

6. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 1, characterized in that: In step (3), the mass fraction of SA in the mixed solution is 0.5%-5%, the mass fraction of TA in the mixed solution is 0.5%-2%, the mass fraction of PNV in the mixed solution is 2.5%-10%, and the mass fraction of Bi2S3@TA in the mixed solution is 0.01%-0.04%.

7. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 1, characterized in that: In step (3), the metal salt solution sprayed is selected from CaCl2, CuCl2, CoCl2, ZnCl2 or SrCl2.

8. The method for preparing the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 7, characterized in that: The concentration of the sprayed metal salt solution is 100mM-2M.

9. A near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the near-infrared responsive thermoelectric temperature-sensitive supramolecular injectable hydrogel according to claim 9 in preparing products for skin wound repair.

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