Medical composite hydrogel and its preparation method and application

Abstract

The present invention relates to the technical field of hydrogels, and in particular to a medical composite hydrogel and its preparation method and application. The preparation method includes: using a hydrothermal method to compound attapulgite powder and transition metal sulfide under high-temperature conditions to form a TMDC / PGS composite material; the content of TMDC in the TMDC / PGS composite material is 90-97.5 wt%; mixing a hydrogel solution with a TSPBA solution to obtain a reaction base solution; adding the TMDC / PGS composite material to the reaction base solution and performing treatment under the conditions of heating and ultrasonic waves to obtain a medical composite hydrogel. The medical composite hydrogel of the present invention not only has the characteristics of injectability, low toxicity and antibacterial property, but also has the functions of promoting wound healing, promoting epidermal, vascular and nerve regeneration, anti-inflammatory and antioxidant, and is particularly suitable for application in promoting the repair of wounds of diabetic patients.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogels, and particularly relates to a medical composite hydrogel, a preparation method thereof, and an application thereof. Background Art

[0002] Hydrogel materials are a class of polymer materials with a three-dimensional network structure that can absorb and retain a large amount of water. Due to their good biocompatibility, excellent flexibility and other properties, hydrogel materials are increasingly widely used in the field of medical dressings. Hydrogel materials can provide barrier protection for wounds, prevent external bacteria from invading, reduce the risk of infection. In addition, they can maintain a moist environment for the wound and promote wound healing. However, there are still the following problems in the application of hydrogel medical dressings:

[0003] On the one hand, existing hydrogel materials have the problem of excessive fluidity, which makes it difficult to precisely control during use, affecting the stability and convenience of the dressing. And the binding strength with the skin is also relatively low, and it is easy to fall off during the movement of the patient, resulting in the exposure of the wound and increasing the risk of infection.

[0004] On the other hand, the functionality of existing hydrogel materials is relatively single and it is difficult to meet the needs of patients with more complex conditions. Taking the repair of chronic wounds in diabetic patients as an example:

[0005] The repair of diabetic chronic wounds is one of the difficult problems that need to be urgently solved in clinical practice. Generally, it is considered that the reason why diabetic chronic wounds are difficult to heal lies in their unique wound microenvironment: severely imbalanced oxidative stress levels and bacterial infections will exacerbate wound hypoxia, inhibit angiogenesis, re-epithelialization and extracellular matrix synthesis to damage the healing process. However, existing hydrogel medical dressings cannot meet the needs of wound recovery, and the wounds often still linger and are difficult to heal.

[0006] In summary, although existing hydrogel materials have certain application values in the field of medical dressings, there are obvious deficiencies in terms of fluidity and functionality. How to improve the above properties of hydrogel materials to expand their application in medical dressings has attracted more and more attention from those skilled in the art. Summary of the Invention

[0007] To solve or partially solve the problems existing in the related art, the present invention provides a medical composite hydrogel, a preparation method thereof, and an application thereof.

[0008] The present invention provides a preparation method of a medical composite hydrogel, which includes:

[0009] Step a), using a hydrothermal method, compounding attapulgite powder and transition metal sulfide under high temperature conditions to form a TMDC / PGS composite material; the content of TMDC in the TMDC / PGS composite material is 90-97.5 wt%.

[0010] Step b): Mix the hydrogel solution with the TSPBA solution to obtain a reaction base solution;

[0011] Step c): Add the TMDC / PGS composite material to the reaction base solution and perform treatment under heating and ultrasonic conditions to obtain a medical composite hydrogel.

[0012] Further, in the step a), the attapulgite powder is prepared according to the following method:

[0013] Calcine the attapulgite, the calcination temperature is 200 - 450 °C, the time is 2 - 4 h, and the heating rate is 5 - 20 °C / min;

[0014] Treat the calcined attapulgite with a 2 - 5 mol / L HCl solution for 3 - 5 h;

[0015] Wash, dry and grind the acid - treated attapulgite to obtain attapulgite powder.

[0016] Further, the step a) is specifically:

[0017] Ultrasonically disperse the attapulgite powder and transition metal sulfide in absolute ethanol to obtain a mixed dispersion; the transition metal sulfide in the mixed dispersion accounts for 90 - 97.5 wt% of the total mass of the attapulgite powder and transition metal sulfide;

[0018] Perform heat treatment on the mixed dispersion, the heat treatment temperature is 180 - 260 °C, the time is 24 - 36 h, and the heating rate is 5 - 20 °C / min;

[0019] Wash, centrifuge and vacuum - dry the product obtained after heat treatment to obtain the TMDC / PGS composite material.

[0020] Further, in the step b), the concentration of the hydrogel solution is 5 - 30 wt%, and the concentration of the TSPBA solution is 5 - 30 wt%; the mixing volume ratio of the hydrogel solution to the TSPBA solution is 1 - 5:1.

[0021] Further, in the step c), the mixing ratio of the TMDC / PGS composite material to the reaction base solution is 1 - 5 mg:1 mL.

[0022] Further, in the step c), the heating is water - bath heating, the temperature is 70 - 90 °C, and the time is 10 - 30 min.

[0023] Further, the hydrogel solution is a polyvinyl alcohol solution, an alginate solution, a chitosan solution, a gelatin solution, a hyaluronic acid solution, a polyethylene glycol solution, a polyacrylamide solution, a carboxymethyl cellulose solution, or a methyl cellulose solution; and / or,

[0024] The transition metal sulfide is MoS2.

[0025] Further, the content of TMDC in the TMDC / PGS composite material is 92.5 - 95 wt%.

[0026] The present invention also provides a medical composite hydrogel, which includes: a TSPBA - modified polymer, a TMDC / PGS composite material, and water.

[0027] Further, the medical dressing has at least one of the following functions: promoting wound healing, promoting epidermal, vascular, and nerve regeneration, antibacterial, anti - inflammatory, and antioxidant.

[0028] The medical composite hydrogel and its preparation method provided by the present invention can have the following beneficial effects:

[0029] 1), The present invention first prepares a TMDC / PGS composite material by a hydrothermal method, and finally cross - links HG, TSPBA, and the TMDC / PGS composite material to form a medical composite hydrogel. The HG is modified by forming a borate ester bond through the cross - linking of the boric acid bond of TSPBA and the hydroxyl group of HG, thereby forming an optimized hydrogel, which better plays the role of a physical barrier and increases the ability to inhibit oxidative stress reactions. The combination of TMDC and PGS can not only increase the specific surface area of TMDC, improve its light absorption rate, enhance the photothermal reaction and photodynamic reaction capabilities, but also reduce the toxicity of the material. Therefore, the introduction of the TMDC / PGS composite material enhances the antibacterial performance of the hydrogel, while promoting the functions of wound epidermal regeneration and blood vessel reconstruction / endowing the hydrogel with stable physical properties such as viscosity and elasticity.

[0030] 2), By the method of the present invention, an oxidation microenvironment and a photodynamic antibacterial dual - controlled intelligent inorganic / organic hybrid hydrogel can be constructed, synergistically exerting the advantages of inorganic materials and organic materials, and being able to simultaneously solve the two key problems of bacterial infection and oxidative stress that affect chronic wound healing; the wound microenvironment can be controllably adjusted according to the wound situation by controlling the light irradiation duration, which has important clinical value for promoting the skin regeneration of chronic non - healing wounds. Moreover, the prepared composite hydrogel has injectability, can form a gel in situ at the wound site, effectively isolate the wound from the environment, and reduce the infection risk; at the same time, for wounds with characteristics such as easy infection at diabetic wound sites, the TMDC / PGS composite material in the gel can efficiently and controllably antibacterial, and finally the combination of the two realizes the treatment of complex wounds such as diabetes.

[0031] 3), Experimental results show that the medical composite hydrogel prepared by the present invention not only has the characteristics of injectability, low toxicity and antibacterial property, but also has the functions of promoting wound healing, promoting epidermal, vascular and nerve regeneration, anti-inflammatory and antioxidant, and is particularly suitable for promoting the repair of wounds in diabetic patients.

[0032] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] By describing the exemplary embodiments of the present invention in more detail in conjunction with the accompanying drawings, the above and other objects, features and advantages of the present invention will become more obvious. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0034] Figure 1 is a physical picture of the injectability test in the embodiment of the present invention;

[0035] Figure 2 is a physical picture of the rheological visibility experiment in the embodiment of the present invention;

[0036] Figure 3 is a graph showing the relationship between temperature and time of four medical composite hydrogels in the embodiment of the present invention;

[0037] Figure 4 is a graph showing the relationship between viscosity and time of four medical composite hydrogels in the embodiment of the present invention;

[0038] Figure 5 is a scanning electron microscope picture of the medical composite hydrogel in the completely cured state corresponding to Example 3 of the present invention;

[0039] Figure 6 is a graph showing the proportion of inorganic elements of the medical composite hydrogel in the completely cured state corresponding to Example 3 of the present invention;

[0040] Figure 7 is a physical photograph of the mechanical elasticity test in the embodiment of the present invention;

[0041] Figure 8 is a microscope picture of the cell scratch experiment in the embodiment of the present invention;

[0042] Figure 9 is a fluorescence staining picture of the cell viability / cytotoxicity test in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "the", and "said" used in the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0045] It should be understood that although the terms "first", "second", "third", etc. may be used in the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0046] The embodiments of the present invention provide a preparation method of a medical composite hydrogel, which includes the following steps:

[0047] Step a): Using the hydrothermal method, attapulgite powder and transition metal sulfide are compounded under high-temperature conditions to form a TMDC / PGS composite material; the content of TMDC in the TMDC / PGS composite material is 90-97.5 wt%.

[0048] Step b): Mixing the hydrogel solution with the TSPBA solution to obtain a reaction base solution;

[0049] Step c): Adding the TMDC / PGS composite material to the reaction base solution and treating it under the conditions of heating and ultrasonic waves to obtain a medical composite hydrogel.

[0050] The inventive concept of this application is as follows:

[0051] N1-(4-Bromobenzyl)-N3-(4-bromophenyl)-N1,N1,N3,N3-tetramethylpropane-1,3-diamine TSPBA was used as a crosslinking agent to crosslink with a hydrogel HG (such as PVA, etc.). TSPBA is a compound containing methacryloyloxy and phenol-like structures, with polymerizability and crosslinkability. The phenylboronic acid functional groups it has can also endow the material with molecular recognition and response capabilities. During the crosslinking reaction process, the boronic acid bonds of TSPBA and the hydroxyl groups of HG crosslink to form borate ester bonds to modify HG, thereby forming an optimized hydrogel HG-TSPBA, increasing the stability and rheological properties of the hydrogel. In addition, due to the introduction of TSPBA, the hydrogel not only has the original biocompatibility and water solubility, but also increases the ability to inhibit oxidative stress reactions.

[0052] On this basis, the inventors of the present application further considered compounding with other functional materials for modification to endow the hydrogel with more properties, such as antibacterial, antioxidant and other properties, so that it can be applied to the repair of more patient wounds. For the selection of functional materials, the inventors of the present application first considered using transition metal dichalcogenides TMDC. As a classic light absorber, TMDC eliminates bacteria through photothermal reactions and photodynamic reactions, is applied to the treatment of infected wounds, and has good biocompatibility. However, the inventors of the present application found through research that when TMDC is compounded with the hydrogel HG-TSPBA, there is a problem of high toxicity. In addition, its improvement effect on antibacterial and antioxidant properties is not ideal, and the wound healing ability and blood vessel regeneration ability also need to be improved.

[0053] In order to improve the above problems, the present application considered adding other functional composite materials additionally, but the effects were not ideal. Then the inventors of the present application found through research that after compounding TMDC with palygorskite PGS and then compounding with the hydrogel HG-TSPBA, not only can the above problems be solved, but also the hydrogel can be endowed with better viscosity and the bonding strength with the wound tissue can be improved. Specifically: Palygorskite PGS is also a kind of nanomaterial, which is rich in reserves in our country, has rich resources, low price, and convenient material taking. It is mainly composed of SiO2, and SiO2 has a "needle tip" morphology, which can kill bacteria adhering to the surface and inhibit the reproduction of bacteria. And after PGS is compounded with TMDC, the specific surface area of TMDC can be increased, its light absorption rate can be improved, the photothermal reaction and photodynamic reaction capabilities can be enhanced, and in addition, the toxicity of the material can be reduced. Palygorskite also has rheological properties. When palygorskite encounters water, it can quickly swell and disperse to form an irregular fiber network, and finally form a dispersion with high viscosity and high stability with rheological properties. Therefore, the introduction of palygorskite also increases the viscosity of the hydrogel system.

[0054] On this basis, the TMDC / PGS composite material is uniformly dispersed in HG and TSPBA, and then crosslinked to obtain a medical composite hydrogel.

[0055] The above step a) is a step of preparing the TMDC / PGS composite material using attapulgite powder and transition metal sulfide as raw materials. The inventor has found through research that the ratio of the two materials in the TMDC / PGS composite material affects the rheological properties, antibacterial properties, and tissue repair promotion properties of the finally formed medical composite hydrogel. When the content of TMDC in the TMDC / PGS composite material is 90 - 97.5 wt%, the properties of the obtained medical composite hydrogel are better.

[0056] This step is specifically preferably as follows:

[0057] The attapulgite powder and transition metal sulfide are ultrasonically dispersed in absolute ethanol to obtain a mixed dispersion; the transition metal sulfide in the mixed dispersion accounts for 90 - 97.5 wt% of the total mass of the attapulgite powder and transition metal sulfide;

[0058] The mixed dispersion is subjected to heat treatment at a temperature of 180 - 260 °C for a time of 24 - 36 h, and the heating rate is 5 - 20 °C / min;

[0059] The product obtained after heat treatment is washed, centrifuged, and vacuum dried to obtain the TMDC / PGS composite material.

[0060] Ultrasonically dispersing the attapulgite powder and transition metal sulfide in absolute ethanol can ensure the uniform mixing of the two materials and form a stable mixed dispersion. Ultrasonic dispersion helps to break up agglomerates and better disperse the powder. The attapulgite powder and transition metal sulfide can be separately dispersed in absolute ethanol, and then the two dispersions are mixed in proportion; or the attapulgite powder and transition metal sulfide can be first mixed in proportion and then dispersed in absolute ethanol.

[0061] After obtaining the mixed dispersion, hydrothermal compounding is carried out immediately. High - temperature conditions can promote the interaction between attapulgite and transition metal sulfide, thereby enhancing the structural stability of the composite material. At the same time, heat treatment also helps to remove the solvent and promote the curing of the material. The more preferred conditions for heat treatment are: temperature 200 - 230 °C, time 2 - 3 h, heating rate 8 - 12 °C / min. The most preferred conditions for heat treatment are: temperature 300 °C, time 2 h, heating rate 10 °C / min.

[0062] Washing and centrifuging the product after heat treatment can remove impurities such as solvents that may remain during the reaction process; vacuum drying is to remove the moisture in the composite material and isolate oxygen to prevent side reactions from occurring, and finally obtain a dry TMDC / PGS composite material.

[0063] The attapulgite powder used in this step is preferably prepared as follows:

[0064] The attapulgite is calcined at a temperature of 200 - 450 °C for 2 - 4 h with a heating rate of 5 - 20 °C / min;

[0065] The calcined attapulgite is acid-treated with a 2 - 5 mol / L HCl solution for 3 - 5 h;

[0066] The acid-treated attapulgite is washed, dried and ground to obtain the attapulgite powder.

[0067] After heat treatment, attapulgite has properties such as strong adsorption performance and thermal stability. In addition, calcining attapulgite can remove the organic matter, moisture and other volatile impurities therein, thus purifying the material. In addition, calcination can also change the crystal structure and surface properties of attapulgite, improve its activity and surface area, expand its pore size, thereby enhancing its adsorption capacity and cation exchange capacity, which is beneficial to subsequent acid treatment and the composite with transition metal sulfides. The calcination temperature is more preferably 290 - 320 °C, the time is more preferably 2 - 3 h, and the heating rate is more preferably 8 - 12 °C / min. Most preferably, the calcination temperature is 300 °C, the time is 2 h, and the heating rate is 10 °C / min.

[0068] Subsequent acid treatment can remove the metal oxides and other impurities on the surface and inside the pores of attapulgite, increase its surface active sites, and thus improve its binding ability with transition metal sulfides. The concentration of the HCl solution is more preferably 2 mol / L, and the treatment time is more preferably 3 h. To improve the treatment efficiency, this step is preferably carried out under stirring conditions.

[0069] After acid treatment, washing is carried out to remove the residual hydrochloric acid of attapulgite, and drying is used to remove moisture; after grinding, powdery attapulgite is obtained, increasing the specific surface area, which is beneficial to the composite with transition metal sulfides.

[0070] Step b) is the step of mixing the hydrogel solution with the TSPBA solution to obtain the reaction base solution, providing the basic matrix and reaction environment for the subsequent preparation of the composite hydrogel. In this step, the concentration of the hydrogel solution is preferably 5-30 wt%, and the concentration of the TSPBA solution is preferably 5-30 wt%; the mixing volume ratio of the hydrogel solution to the TSPBA solution is 1-5:1. Those skilled in the art can understand that the solvents of both the hydrogel solution and the TSPBA solution are water. The ratio of the TMDC / PGS composite material, HG, and TSPBA has an impact on the rheological properties of the final composite gel and functions such as antibacterial promotion of tissue repair. Further, the mixing ratio of the TMDC / PGS composite material and the reaction base solution is 1-5 mg: 1 mL.

[0071] TSPBA can be prepared by the precipitation method, specifically: using 4-(bromomethyl)phenylboronic acid and tetramethylpropylenediamine as reactants, reacting in DMF under heating conditions. After the reaction is complete, adding tetrahydrofuran to the reaction system to promote the precipitation of the product. After separating the solid product, washing and drying are carried out to obtain TSPBA. The molar ratio of 4-(bromomethyl)phenylboronic acid to tetramethylpropylenediamine is preferably 1-6:1, and the heating temperature is preferably 45-70 °C. Most preferably, the molar ratio of 4-(bromomethyl)phenylboronic acid to tetramethylpropylenediamine is preferably 3-3.1:1, and the heating temperature is preferably 60 °C.

[0072] Step c) is the step of mixing the TMDC / PGS composite material with the reaction base solution and treating it under heating and ultrasonic conditions to prepare the medical composite hydrogel. Heating can promote the cross-linking reaction and help improve the dispersion uniformity of the TMDC / PGS composite material in the hydrogel matrix. The heating method preferably uses water bath heating, the heating temperature is preferably 70-90 °C, and the time is preferably 10-30 min. Most preferably, the heating temperature is 90 °C and the time is 15 min. Ultrasonic treatment can enhance the dispersion of the TMDC / PGS composite material in the reaction base solution, reduce agglomeration, and promote uniform mixing. In addition, ultrasound can also generate local high temperature and high pressure through cavitation, further promoting the progress of the chemical reaction.

[0073] The material of the above hydrogel HG is preferably polyvinyl alcohol, alginate, chitosan, gelatin, hyaluronic acid, polyethylene glycol, polyacrylamide, carboxymethyl cellulose or methyl cellulose; and / or, the above transition metal dichalcogenide TMDC is MoS2. Further preferably, the material of the hydrogel HG is PVA and the TMDC is MoS2. In this case, the content of MoS2 in the TMDC / PGS composite material is preferably 92.5-95 wt%, the concentration of the PVA solution is preferably 13-16 wt%, the concentration of the TSPBA solution is preferably 4-6 wt%, the mixing volume ratio of the PVA solution to the TSPBA solution is preferably 2-4:1, and the mixing ratio of the TMDC / PGS composite material to the reaction base liquid is preferably 4-5 mg:1 mL. Most preferably, the content of MoS2 in the TMDC / PGS composite material is 92.5 wt%, the concentration of the PVA solution is 15 wt%, the concentration of the TSPBA solution is preferably 3 wt%, the mixing volume ratio of the PVA solution to the TSPBA solution is 3:1, and the mixing ratio of the TMDC / PGS composite material to the reaction base liquid is 5 mg:1 mL.

[0074] Step c) Through the treatment of ultrasonic and heating, a uniform and stable medical composite hydrogel TMDC / PGS@HG-TSPBA can be obtained, in which the TMDC / PGS composite material is uniformly distributed in the hydrogel HG-TSPBA, endowing the hydrogel with better rheological properties, higher adhesion strength to tissues, and better tissue regeneration, antibacterial, anti-inflammatory and antioxidant properties.

[0075] The composite hydrogel obtained after heating in step c) has good fluidity. After standing at room temperature for a period of time, the hydrogel continues to solidify, the fluidity weakens, and the adhesion strength increases. Those skilled in the art can select the specific application method of the composite hydrogel according to actual needs. For example: if it is for injection, it can be taken out for injection immediately after heating. At this time, the composite hydrogel has good fluidity, which is convenient for filling and injection. After injection, wait for 10-20 minutes for the composite hydrogel to solidify completely and firmly adhere to the wound surface. If it is used for non-injection purposes such as plasters, it can be taken out and left to stand for 10-20 minutes after heating, and then adhered to the wound surface after the composite hydrogel has solidified completely.

[0076] Another embodiment of the present invention also provides a medical composite hydrogel, comprising: a TSPBA-modified polymer, a TMDC / PGS composite material, and water. It can be prepared according to the method described in the above embodiment. The medical composite hydrogel has the following advantages:

[0077] The medical composite hydrogel has excellent rheological properties, injectability, high adhesion strength to organs such as the epidermis, heart, and liver, can deform accordingly with the deformation of the attached object, and is not easy to fall off;

[0078] The medical composite hydrogel has low toxicity and mild usage conditions;

[0079] The medical composite hydrogel has excellent antibacterial, anti-inflammatory and antioxidant properties. In addition, it also has good effects on promoting tissue healing and promoting angiogenesis.

[0080] Another embodiment of the present invention also provides an application of the above-mentioned medical composite hydrogel in a medical dressing. The medical dressing has at least one of the following functions: promoting wound healing, promoting the regeneration of epidermis, blood vessels and nerves, antibacterial, anti-inflammatory and antioxidant. It is particularly suitable for use in promoting the repair of wounds in diabetic patients.

[0081] As can be seen from the above, the medical composite hydrogel and its preparation method provided by the embodiments of the present invention have the following advantages:

[0082] 1) First, the TMDC / PGS composite material is prepared by a hydrothermal method in the present invention. Finally, HG, TSPBA and the TMDC / PGS composite material are crosslinked to form a medical composite hydrogel. HG is modified by forming a borate ester bond through the crosslinking of the boric acid bond of TSPBA and the hydroxyl group of HG, so as to form an optimized hydrogel, better play the physical barrier role, and increase the ability to inhibit oxidative stress reactions. The combination of TMDC and PGS can not only increase the specific surface area of TMDC, improve its light absorption rate, enhance the photothermal reaction and photodynamic reaction ability, but also reduce the toxicity of the material. Therefore, the introduction of the TMDC / PGS composite material improves the antibacterial performance of the hydrogel while reducing the toxicity of the material.

[0083] 2) By the method of the present invention, an oxidation microenvironment and a photodynamic antibacterial dual-controlled intelligent inorganic / organic hybrid hydrogel can be constructed, synergistically exerting the advantages of inorganic materials and organic materials, and being able to simultaneously solve the two key problems of bacterial infection and oxidative stress that affect chronic wound healing; the wound microenvironment can be controllably adjusted according to the wound situation by controlling the light irradiation time, which has important clinical value for promoting the skin regeneration of chronic non-healing wounds. Moreover, the prepared composite hydrogel has injectability, can form a gel in situ at the wound site, effectively isolate the wound from the environment, and reduce the risk of infection; at the same time, for wounds with characteristics such as easy infection at diabetic wound sites, the TMDC / PGS composite material in the gel can efficiently and controllably antibacterial, and finally the combination of the two realizes the treatment of complex wounds such as diabetes.

[0084] 3) Experiments have proved that the medical composite hydrogel prepared by the present invention not only has the characteristics of injectability, low toxicity and antibacterial, but also has the functions of promoting wound healing, promoting the regeneration of epidermis, blood vessels and nerves, antibacterial, anti-inflammatory and antioxidant, and is particularly suitable for use in promoting the repair of wounds in diabetic patients.

[0085] The technical solution of the present invention will be further described below in conjunction with specific embodiments:

[0086] In the following examples, MoS2 is M888682 nano-molybdenum disulfide purchased from Macklin, and its specifications are: ≥99.5%, 100nm, cas: 1317-33-5.

[0087] In the following examples, attapulgite is purchased from Jiangsu Xuyi Attapulgite Co., Ltd.

[0088] In the following examples, TSPBA is prepared according to the following method:

[0089] 9.2 mmol of 4-(bromomethyl)phenylboronic acid and 3 mmol of tetramethylpropylenediamine (TMPA) were placed in a 100 mL round-bottom flask, 40 mL of N,N-dimethylformamide (DMF) was added thereto, and the temperature of the reaction system was adjusted to 60 °C and reacted overnight. After the reaction was completed, when the reaction system was cooled to room temperature, 400 mL of tetrahydrofuran was added to the system, and a white solid was precipitated. It was filtered by a sintered funnel, washed three times with 240 mL of tetrahydrofuran, and the filter cake was collected, placed in a vacuum drying oven and dried to obtain TSPBA.

[0090] In the following examples, the attapulgite powder PGS is prepared according to the following method:

[0091] Take attapulgite and put it into a clean ceramic crucible. After covering it, place it in the center of the muffle furnace. Heat it to 300 °C at a heating rate of 10 °C / min and heat-treat it for 2 h. After the temperature drops to room temperature, take it out. Add the calcined attapulgite to the prepared 3 mol / L HCl solution, stir continuously for 3 h. After the reaction is completed, centrifuge the attapulgite and wash it with deionized water several times until the pH is neutral. Finally, dry it in an oven at 60 °C for 8 h and grind it into powder to obtain the attapulgite powder PGS that has been completely heat-treated and acid-treated.

[0092] Example 1

[0093] 1). Preparation of MoS2 / PGS composite material: Dissolve PGS and MoS2 in 20 ml of absolute ethanol respectively, and ultrasonically treat them to make them completely dispersed. Mix the dispersions and stir well. The percentage M1 of PGS in the total solid mass (the total mass of PGS and MoS2) in the mixed dispersion is 2.5%, and the percentage M2 of MoS2 in the total solid mass (the total mass of PGS and MoS2) is 97.5%;

[0094] Add the mixed dispersion to a 100 mL reaction kettle and keep it at 220 °C in a muffle furnace for 24 hours. After the product is washed and centrifuged several times, it is freeze-dried for standby.

[0095] 2) Preparation of composite hydrogel: Take 397.2 mg of PVA and place it in 2.25 mL of deionized water to prepare a 15 wt% PVA aqueous solution. Then take 39.6 mg of TSPBA and place it in 0.75 ml of deionized water to prepare a 5 wt% TSPBA aqueous solution. The PVA aqueous solution and the TSPBA aqueous solution are mixed at a volume ratio of 3:1 to obtain a reaction base solution;

[0096] Add 15 mg of the MoS2 / PGS composite material prepared in step 1) to the reaction base solution, place it in a water bath at 90 °C, and heat for 15 min to form 3 ml of PVA-TSPBA@PGS / MoS2 medical composite hydrogel.

[0097] Examples 2 - 4

[0098] The difference from Example 1 is in step 1): The percentage M1 of PGS in the total solid mass and the percentage M2 of MoS2 in the total solid mass in the mixed dispersion are different. The M1 and the percentage M2 of TMDC in the total solid mass of Examples 1 - 4 are listed in Table 1:

[0099] Table 1 Contents of M1 and M2 in Examples 1 - 4

[0100]

[0101]

Injectability test

[0102] Add the freshly prepared medical composite hydrogels of Examples 1 - 4 into syringes respectively, and inject out the shape of the Chinese character "Tian". The results are Figure 1 as shown.

[0103] It can be Figure 1 seen that: The medical composite hydrogels prepared in Examples 1 - 4 all have injectability, and the injectability of the composite hydrogels in Examples 2 and 3 is the best.

[0104]

Rheological visibility experiment

[0105] Observe the initial state (i.e., the state just taken out after heating in a water bath at 90 °C for 15 min), the intermediate state (the state after standing at room temperature for 3 minutes), and the fully cured state (the state after being fully cured at room temperature for 18 minutes) of the medical composite hydrogel prepared in Example 3. The physical pictures are as Figure 2 shown.

[0106] It can be Figure 2 seen that: The medical composite hydrogel material has fluidity in the early stage, gradually has viscosity during the gelation process, and finally becomes a colloid with strong adhesion.

[0107] The application composite hydrogels corresponding to Examples 1-4 were labeled as follows:

[0108] Example 1: 2.5% PGS / 97.5% MoS2@PVA-TSPBA;

[0109] Example 2: 5% PGS / 95% MoS2@PVA-TSPBA;

[0110] Example 3: 7.5% PGS / 92.5% MoS2@PVA-TSPBA;

[0111] Example 4: 10% PGS / 90% MoS2@PVA-TSPBA

[0112] The above four materials were subjected to photothermal performance testing, rheological performance testing, qualitative analysis, mechanical elasticity testing, and viscoelasticity testing of viscera. Specifically as follows:

[0113]

Photothermal performance testing

[0114] After the medical composite hydrogels prepared in Examples 1-4 were placed at room temperature for 18-20 min to cure completely, the relationship between the temperature and time of the four medical composite hydrogels was tested. The test results are as Figure 3 shown. It can be seen from Figure 3 that: The medical composite hydrogels prepared in Examples 1-4 all have the ability of photothermal conversion. As time goes by, the temperature increases. The highest temperature of the four groups of materials is lower than 50 °C. This temperature shows mildness and safety for animal experiments and human applications. Among them, the medical composite hydrogel corresponding to Example 3 has the highest highest temperature, indicating that its photothermal conversion ability is the strongest.

[0115]

Rheological performance testing

[0116] 1. After the medical composite hydrogels prepared in Examples 1-4 were placed at room temperature for 18-20 min to cure completely, the relationship between the viscosity and time of the four medical composite hydrogels was tested. The test results are as follows: After the four medical composite hydrogels were cured, the viscosity was basically stable. Among them, the viscosity of the medical composite hydrogel corresponding to Example 3 was the most moderate.

[0117] 2. Take the medical composite hydrogels in the initial state prepared in Examples 1-4 and test the relationship between their storage modulus G' and loss modulus G'' with time. When the storage modulus is greater than the loss modulus, it means that the sample tends to be in a solid state and has elasticity; when the loss modulus is greater than the storage modulus, it means that the sample tends to be in a liquid state and has injectability. The test results are as follows: The viscosities of the four medical composite hydrogel materials changed from a liquid state to a solid state over time. Among them, the transition time of the medical composite hydrogel corresponding to Example 3 was moderate.

[0118] As can be seen from the above, among the four medical composite hydrogel materials, the medical composite hydrogel corresponding to Example 3 has the best rheological properties. It has injectability in the early stage, meeting the injectable operation requirements of the experiment. In the later stage, it has solid viscoelasticity, is not easily deformed and does not easily flow away after covering the wound.

[0119]

Qualitative Analysis

[0120] 1. Morphology Analysis:

[0121] Figure 5 The scanning electron microscope image of the medical composite hydrogel in the completely cured state corresponding to Example 3 is shown. From Figure 5 it can be seen that the morphology of the finished medical composite hydrogel material is porous.

[0122] 2. Inorganic Component Analysis:

[0123] The inorganic element proportion diagram of the medical composite hydrogel in the completely cured state corresponding to Example 3 is as Figure 6 shown.

[0124] From Figure 6 it can be seen that the main elements in the inorganic components of the medical composite hydrogel are Mo, S, Si, and O. The element proportions are accurate and evenly distributed, indicating that the preparation of PGS / MoS2 in the finished material is successful.

[0125]

Mechanical Elasticity Test

[0126] The medical composite hydrogel in the completely cured state corresponding to Example 3 is attached to the surface of the human index finger, and the index finger is bent. Observe the bonding state between the medical composite hydrogel and the skin tissue. The test results are as Figure 7 shown.

[0127] From Figure 7 it can be seen that the medical composite hydrogel corresponding to Example 3 has good adhesion, elasticity and mobility at the joint.

[0128]

Viscosity Test on Organs

[0129] The medical composite hydrogel in the completely cured state corresponding to Example 3 is respectively attached to the following organs of mice: heart, liver, spleen, lung, kidney, brain, bone, muscle; observe the bonding state between the medical composite hydrogel and different organs. The test results are as follows: The medical composite hydrogel corresponding to Example 3 has good viscosity with different organs.

[0130] The following is a comparative experiment on the performance of the medical composite hydrogel prepared in the embodiments of the present application in terms of application in combination with the comparative examples:

[0131] Comparative Example 1

[0132] Take 397.2 mg of PVA and place it in 2.25 mL of deionized water to prepare a 15 wt% PVA aqueous solution. Then take 39.6 mg of TSPBA and place it in 0.75 mL of deionized water to prepare a 5 wt% TSPBA aqueous solution. Mix the PVA aqueous solution and the TSPBA aqueous solution in a volume ratio of 3:1 to obtain a reaction base solution;

[0133] Place the reaction base solution in a 90 °C water bath and heat for 15 min to form 3 mL of medical hydrogel.

[0134] Comparative Example 2

[0135] Take 397.2 mg of PVA and place it in 2.25 mL of deionized water to prepare a 15 wt% PVA aqueous solution. Then take 39.6 mg of TSPBA and place it in 0.75 mL of deionized water to prepare a 5 wt% TSPBA aqueous solution. Mix the PVA aqueous solution and the TSPBA aqueous solution in a volume ratio of 3:1 to obtain a reaction base solution;

[0136] Add 13.8 mg of MoS2 to the reaction base solution, place it in a 90 °C water bath, and heat for 15 min to form 3 mL of medical composite hydrogel.

[0137] Label the hydrogels corresponding to Example 3, Comparative Example 1, and Comparative Example 2 as follows: Example 3: PVA-TSPBA@MoS2 / PGS;

[0138] Comparative Example 1: PVA-TSPBA

[0139] Comparative Example 2: PVA-TSPBA@MoS2

[0140] After the medical composite hydrogel prepared in Example 3, the medical hydrogel prepared in Comparative Example 1, and the medical composite hydrogel prepared in Comparative Example 2 are cured completely at room temperature for 18 - 20 min, the following analysis and performance comparison tests are carried out:

[0141]

Analysis of organic components

[0142] Perform Fourier transform infrared spectroscopy tests on the hydrogels corresponding to Example 3, Comparative Example 1, and Comparative Example 2. The test results are as follows: Peaks can be detected in the relevant functional groups for all three groups of materials (3300 cm -1 represents the hydroxyl group OH, 1711 cm -1 represents the acyl group C=O, 1650 cm -1 represents the aromatic ring, 1300 cm -1 represents the C-O bond, 1086 cm -1 represents the C-H bond, proving that the organic component PVA-TSPBA in the three groups of materials is successfully prepared.

[0143]

Cell Scratch Assay

[0144] The wound healing promotion of three groups of hydrogel materials was simulated by the extraction method: scratches were made on the culture dish covered with mouse L929 cells (mouse fibroblasts) to simulate wounds, and the cell distribution at 0 h, 12 h, and 36 h was observed. The test results are as Figure 8 shown.

[0145] As Figure 8 can be seen: compared with Comparative Examples 1 and 3, the scratched area of the medical composite hydrogel material corresponding to Example 3 was significantly covered with cells after 36 h, showing a significant ability to promote wound healing.

[0146]

Cell Viability / Cytotoxicity Test

[0147] Three groups of hydrogel materials were co-cultured with mouse L929 cells (mouse fibroblasts) by the extraction method, and the cell viability / cytotoxicity at 24 h was observed. Live cells were labeled with a green fluorescent dye, and dead cells were labeled with a red fluorescent dye. The test results are as Figure 9 shown. The figure shows the results of three channels: "Live" (live cells), "Dead" (dead cells), and "Merge" (merged image).

[0148] As Figure 9 can be seen: there were more viable cells and fewer dead cells in the PVA-TSPBA group of hydrogel materials, showing low cytotoxicity. In the PVA-TSPBA@MoS2 group of hydrogel materials, the viable cells were significantly reduced and the dead cells were significantly increased, showing high cytotoxicity. In the PVA-TSPBA@MoS2 / PGS group of hydrogel materials, there were more viable cells and fewer dead cells, indicating that after adding PGS to the material, the cytotoxicity of PVA-TSPBA@MoS2 / PGS was reduced and modified.

[0149]

Antioxidant Experiment

[0150] L929 cells were induced to generate oxidative stress and were exposed to three groups of hydrogel material samples. DCFH-DA probe was used to label the ROS in the cells, and the green fluorescence intensity represents the ROS concentration. The antioxidant effect of the materials was judged by comparing the fluorescence intensities of each group of cells. The experimental results are as follows: the DCFH-DA fluorescence intensity of the PVA-TSPBA@MoS2 / PGS group of hydrogel materials was the weakest, indicating the strongest antioxidant ability.

[0151]

Antibacterial Experiment

[0152] After culturing Staphylococcus aureus, it was cultured on the surface of the control group (normal saline) and three groups of hydrogel material samples respectively, and NIR irradiation was carried out. NIR +and without NIR irradiation - After 10 minutes, the growth of bacteria was observed by naked eyes and scanning electron microscope to judge the antibacterial properties of the samples. The antibacterial effects are as follows: the PVA-TSPBA@MoS2 / PGS group hydrogel material has the best antibacterial effect under NIR irradiation.

[0153]

Wound healing experiment

[0154] Diabetic mice (purchased from Spefox Biotech Co., Ltd.) were anesthetized with isoflurane; a full-thickness skin wound with a diameter of 6 mm was made on the back of the diabetic mice using a wound puncher. Then 15 µL of Staphylococcus aureus solution (1×108 CFU / mL) was dropped on the wound surface and infected for 24 h to establish a bacterial infection wound model.

[0155] Normal saline (control group) and three groups of hydrogel materials were applied on the wound surface of four groups of diabetic mice respectively.

[0156] The observation time points were set as 0 days, 3 days, 7 days, 10 days, 12 days, and 14 days, and the changes in the wound surface at each time point were recorded.

[0157] On the third day, secretion samples were collected from the wound surface. The secretion samples were inoculated into the culture medium for bacterial culture and the growth of bacteria was observed. After 24 hours, the bacterial growth was as follows: The antibacterial effect of Example 1 group was significantly better than that of the other three groups.

[0158] On the 14th day, wound tissues were taken for HE pathological staining, Masson pathological staining and immunofluorescence. On the 14th day, the heart, liver, spleen, lung and kidney organs of the mice were taken for pathological examination. The test results are as follows:

[0159] The PVA-TSPBA@MoS2 / PGS group hydrogel material promoted the healing of infected wounds in diabetic mice best.

[0160] The PVA-TSPBA@MoS2 / PGS group hydrogel material has the best antibacterial effect on infected wounds in diabetic mice.

[0161] In the PVA-TSPBA@MoS2 / PGS group of hydrogel materials, wound scar healed, keratinocytes were visible in the epidermis, and collagen deposition was visible under the epidermis, indicating that this material promoted the healing of infected wounds in diabetic mice best; in the PVA-TSPBA@MoS2 group of hydrogel materials, epidermal healing trends were observed, and a large amount of granulation tissue was regenerated; in the PVA-TSPBA group of hydrogel materials, scab formation was observed, and necrotic tissue and secretions were present under the scab; in the Control group, scab formation was observed, and a large amount of necrotic tissue and secretions were present under the scab.

[0162] It can be seen that for the PVA-TSPBA@MoS2 / PGS hydrogel material, the fluorescence signals of the epidermis, blood vessels, and nerves are the highest, indicating that its ability to promote the regeneration of the epidermis, blood vessels, and nerves is the strongest.

[0163] None of the three hydrogel materials showed obvious organ toxicity, indicating reliable biosafety.

[0164] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing a medical composite hydrogel, characterized in that: include: Step a), ultrasonically dispersing attapulgite powder and transition metal sulfide in anhydrous ethanol to obtain a mixed dispersion; the transition metal sulfide in the mixed dispersion accounts for 90-97.5wt% of the total mass of the attapulgite powder and the transition metal sulfide; heat-treating the mixed dispersion at a temperature of 180-260°C, a time of 24-36h, and a heating rate of 5-20°C / min; washing, centrifuging and vacuum drying the product obtained after the heat treatment to obtain a TMDC / PGS composite material; The transition metal sulfide is MoS2; Step b), mixing the hydrogel solution with the TSPBA solution to obtain a reaction base solution; the concentration of the hydrogel solution is 5-30wt%, and the concentration of the TSPBA solution is 5-30wt%; The mixing volume ratio of the hydrogel solution to the TSPBA solution was 1-5:1; The hydrogel solution is a polyvinyl alcohol solution, an alginate solution, a chitosan solution, a gelatin solution, a hyaluronic acid solution, a polyethylene glycol solution, a polyacrylamide solution, a carboxymethyl cellulose solution or a methyl cellulose solution; Step c), adding the TMDC / PGS composite material to the reaction base liquid, the mixing ratio of the TMDC / PGS composite material and the reaction base liquid is 1-5 mg:1 mL, and treating under heating and ultrasonic conditions to obtain a medical composite hydrogel.

2. The preparation method according to claim 1, characterized in that: In the step a), the attapulgite powder is prepared according to the following method: The attapulgite is calcined at a temperature of 200-450°C for 2-4 hours at a heating rate of 5-20°C / min. The calcined attapulgite is treated with an acid using a 2-5 mol / L HCl solution for 3-5 h; The acid-treated attapulgite is washed, dried and ground to obtain attapulgite powder.

3. The preparation method according to claim 1, characterized in that: In the step c), the heating is carried out in a water bath at a temperature of 70-90° C. for a time of 10-30 min.

4. The preparation method according to claim 1, characterized in that: The content of TMDC in the TMDC / PGS composite material is 92.5-95wt%.

5. A medical composite hydrogel, characterized in that: It is prepared according to the method described in any one of claims 1 to 4, and comprises: TSPBA modified high molecular polymer, TMDC / PGS composite material, and water.

6. Use of the medical composite hydrogel according to claim 5 in medical dressings, characterized in that: The medical dressing has at least one of the following functions: promoting wound healing, promoting epidermal, blood vessel and nerve regeneration, antibacterial, anti-inflammatory and anti-oxidative.

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