Composite dressing with time response and function synergy and preparation and application thereof

Abstract

The present application belongs to the technical field of biomedical materials, and relates to a composite dressing with time sequence response and function synergy and a preparation and application thereof. The composite dressing is a double-layer composite structure, comprising a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nano fiber membrane layer. The PVA-GOx-MnO2 hydrogel precursor solution is prepared by adding glucose oxidase and MnO2 nanoparticles into a polyvinyl alcohol solution under ice bath conditions. During preparation, the temperature-sensitive micro-nano fiber membrane is placed on or immersed in the PVA-GOx-MnO2 hydrogel precursor solution, and after cross-linking treatment, the composite dressing is obtained by demolding. The application is used as a chronic wound repair material for diabetes. The present application solves the problems of weak microenvironment regulation ability and mismatched drug release timing of the existing diabetic wound dressing. The preparation method is simple, and the application significantly improves the healing efficiency and treatment safety of diabetic wounds.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomedical materials, and relates to a composite dressing with time sequence response and functional synergy as well as preparation and application thereof. BACKGROUND

[0002] Diabetes is a metabolic disease characterized by chronic hyperglycemia. In recent years, with the change of lifestyle and the aggravation of population aging, its incidence continues to rise. According to the statistics of International Diabetes Federation (IDF), the number of global diabetic patients has reached 643 million by 2025, and is expected to exceed 800 million by 2050. Among them, diabetic chronic wounds (such as diabetic foot ulcers) as one of its serious complications have become an important clinical problem leading to amputation and death. Diabetic wounds have characteristics such as long healing cycle, susceptibility to infection, and high recurrence rate, mainly due to factors such as local high-sugar environment, inflammatory response disorder, enhanced oxidative stress, and decreased angiogenesis. These adverse microenvironments significantly inhibit cell proliferation, migration, and neovascularization, severely affecting the tissue repair process, making it difficult for traditional treatment methods to achieve ideal therapeutic effects. At present, the commonly used treatment methods in clinical practice mainly include debridement, anti-infection treatment, negative pressure drainage, and external dressings and drugs. However, the existing treatment methods generally have the following problems: lack of systematic regulation of the microenvironment; external drugs are easily washed away by exudate, making it difficult to maintain an effective concentration for a long time; the timing of drug release does not match the wound repair stage, resulting in low angiogenesis efficiency and limited treatment effect.

[0003] In recent years, hydrogel dressings have been widely used in chronic wound management due to their good water retention performance, biocompatibility, and ability to load multiple active ingredients. Through structural design, hydrogels can achieve sustained release, controlled release, and even responsive drug delivery, showing great advantages in promoting wound healing. However, existing hydrogel dressings still have some significant limitations: most of the dressings have single functions and lack effective intervention for the complex microenvironment of diabetic wounds such as high sugar, hypoxia, and oxidative stress; at the same time, the drug release mechanism is mainly passive diffusion, which is difficult to dynamically and accurately control the timing according to the stage of wound repair, resulting in low drug utilization rate and unstable treatment effect.

[0004] To solve the above problems, the existing technology has made many explorations. For example: the multifunctional hydrogel dressings disclosed in patents CN118717902A, CN117815438A, CN117084970A, etc. improve the microenvironment of diabetic wounds by integrating antioxidant, anti-inflammatory, and pro-repair functional modules. However, the multiple functions of these dressings lack timing control, and cannot achieve progressive intervention of "first regulation, then treatment".

[0005] Patents CN120025564A, CN119606872A, etc. focus on constructing a responsive drug release system, and use pH, ROS, temperature and other microenvironment stimuli to achieve controllable release of drugs. Although this technology can achieve "dynamic regulation", it is essentially a passive response to existing microenvironment changes and does not actively improve the microenvironment.

[0006] In summary, although existing dressings have made some progress in the treatment of diabetic chronic wounds, they still generally face limited local microenvironment regulation ability, mismatched drug release timing, and low pro-angiogenic efficiency, resulting in overall treatment effects that are difficult to meet clinical needs.

[0007] Therefore, it is of great significance to study a composite dressing with time sequence response and functional synergy and its preparation and application to solve the problems existing in the prior art. SUMMARY

[0008] The purpose of the present application is to solve the problems existing in the prior art and provide a composite dressing with time sequence response and functional synergy and its preparation and application.

[0009] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0010] A composite dressing with time sequence response and functional synergy is a double-layer composite structure, comprising a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nano fiber membrane layer.

[0011] The PVA-GOx-MnO2 hydrogel is obtained by cross-linking treatment of a PVA-GOx-MnO2 hydrogel precursor solution, and the PVA-GOx-MnO2 hydrogel precursor solution is prepared by adding glucose oxidase (GOx) and MnO2 nanoparticles to a polyvinyl alcohol (PVA) solution under ice bath conditions; wherein the main role of PVA is to form a three-dimensional network structure of the hydrogel to load GOx and MnO2 nanoparticles and maintain their catalytic activity.

[0012] The temperature-sensitive micro-nano fiber membrane is a temperature-sensitive micro-nano fiber membrane loaded with pro-angiogenic drugs.

[0013] As a preferred technical solution:

[0014] The temperature-sensitive micro-nano fiber membrane loaded with pro-angiogenic drugs is obtained by electrospinning after polyacrylonitrile, double fatty acid phase change material and pro-angiogenic drugs are sequentially added to N,N-dimethylformamide to prepare a spinning solution.

[0015] The diameter of the micro-nano fiber membrane loaded with the pro-angiogenic drug is 0.5-48 microns.

[0016] The application further provides a preparation method of the composite dressing with time sequence response and function synergy.

[0017] As a preferred technical solution,

[0018] The preparation method of the composite dressing with time sequence response and function synergy is as follows:

[0019] (1) preparing a PVA-GOx-MnO2 hydrogel precursor solution: dissolving polyvinyl alcohol in deionized water under heating and stirring at 70-120 DEG C until completely dissolved to obtain a polyvinyl alcohol solution, and then adding glucose oxidase and MnO2 nanoparticles under ice bath conditions (-4-4 DEG C) after the solution is cooled, and stirring uniformly to obtain the PVA-GOx-MnO2 hydrogel precursor solution;

[0020] (2) preparing a double fatty acid phase change material: mixing lauric acid and stearic acid, and stirring uniformly under heating at 80-120 DEG C, and then cooling, grinding and drying in sequence to obtain the double fatty acid phase change material;

[0021] (3) preparing a spinning solution: adding polyacrylonitrile, the double fatty acid phase change material obtained in step (2) and the pro-angiogenic drug into N,N-dimethylformamide in sequence, and stirring uniformly to obtain the spinning solution;

[0022] (4) preparing a micro-nano fiber membrane loaded with the pro-angiogenic drug: electrospinning the spinning solution obtained in step (3) to obtain the micro-nano fiber membrane loaded with the pro-angiogenic drug;

[0023] (5) injecting the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) into a mold, and placing or immersing the micro-nano fiber membrane loaded with the pro-angiogenic drug obtained in step (4) in the PVA-GOx-MnO2 hydrogel precursor solution, and then performing multiple freeze-thaw cycle treatments to obtain the composite dressing with time sequence response and function synergy after demolding;

[0024] The temperature-sensitive micro-nano fiber membrane is immersed in a PVA-GOx-MnO2 hydrogel precursor solution, and there are two implementation methods, ① pressing immersion method: the temperature-sensitive micro-nano fiber membrane is placed above the PVA-GOx-MnO2 hydrogel precursor solution, the temperature-sensitive micro-nano fiber membrane is gently pressed into the PVA-GOx-MnO2 hydrogel precursor solution by using tweezers, so that the fiber membrane is completely immersed in the solution, and then a freeze-thaw forming process is performed, so that the temperature-sensitive micro-nano fiber membrane is stably embedded in the PVA-GOx-MnO2 hydrogel structure; ② distribution pouring method: part of the PVA-GOx-MnO2 precursor solution is first injected into the mold, then the temperature-sensitive micro-nano fiber membrane is placed on the solution surface, and then the remaining PVA-GOx-MnO2 precursor solution is poured on the temperature-sensitive micro-nano fiber membrane, and the whole is formed and combined through a cyclic freeze-thaw process.

[0025] The preparation method of the composite dressing with time sequence response and function synergy as described above, the polyvinyl alcohol in step (1) has a degree of polymerization of 1700±50, an alcoholysis degree of 88-99.8%, and a concentration of the polyvinyl alcohol solution of 5-25 wt%; the PVA-GOx-MnO2 hydrogel precursor solution contains 0.01-2 wt% of glucose oxidase and 0.02-0.06 wt% of MnO2 nanoparticles.

[0026] The temperature reached by the photothermal effect of MnO2 is closely related to the content of MnO2 in the hydrogel precursor solution. Experiments show that when the content is 0.02 wt%, the local temperature can be increased to above 38℃ under near-infrared light (NIR) irradiation, and when the content is 0.06 wt%, the local temperature can be increased to above 50℃ under NIR irradiation. In addition, the content used should match the phase change temperature of the phase change material to ensure the controlled release of the drug. In addition, the drug release experiment (Example 6) also verifies the feasibility of the present application. Figure 4

[0027] The preparation method of the composite dressing with time sequence response and function synergy as described above, the polyvinyl alcohol in step (1) has a degree of polymerization of 1700±50, an alcoholysis degree of 88-99.8%, and a concentration of the polyvinyl alcohol solution of 5-25 wt%; the PVA-GOx-MnO2 hydrogel precursor solution contains 0.01-2 wt% of glucose oxidase and 0.02-0.06 wt% of MnO2 nanoparticles.

[0028] The concentration of the potassium permanganate solution is 5-30 mg / mL, the concentration of the ascorbic acid solution is 5-35 mg / mL, and the volume ratio of the potassium permanganate solution to the ascorbic acid solution is 1-3:3-1. ​

[0029] The reaction time is 0.5-6h.

[0030] The preparation method of the composite dressing with time sequence response and function synergy as described above, the mass ratio of lauric acid to stearic acid in step (2) is 5-3:1-2, and the phase change temperature of the double fatty acid phase change material is 38-50 DEG C. The phase change temperature range of the double fatty acid phase change material is set to 38-50 DEG C, which is based on the following: ① Ensure that the drug is not released when not triggered, and maintain the controlled release function. The local temperature of diabetic chronic wound is usually 35-37 DEG C, if the phase change temperature is lower than the wound temperature, the phase change material will melt after the dressing is attached to the wound, resulting in drug release, which cannot achieve the design goal of "on-demand release" and "stage response". Therefore, the phase change temperature should be slightly higher than the local temperature of the wound; ② Ensure the safety and comfort of clinical use: if the phase change temperature is set too high (> 50 DEG C), the local tissue temperature will be too high, which may cause thermal injury, even cause skin burns or local inflammatory reaction, and affect wound healing. Therefore, the upper limit of the phase change temperature is set to 50 DEG C, which takes into account the treatment efficiency and patient comfort.

[0031] The preparation method of the composite dressing with time sequence response and function synergy as described above, the concentration of polyacrylonitrile in the spinning solution of step (3) is 15-25wt%, the concentration of double fatty acid phase change material is 5-15wt%, and the concentration of pro-angiogenic drug is 1-10wt%.

[0032] The pro-angiogenic drug is not a specific pro-angiogenic drug, but refers to all drugs or bioactive substances that can promote local tissue angiogenesis, including but not limited to deferoxamine (DFO), curcumin, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), etc. Those skilled in the art can select other drugs or active ingredients with pro-angiogenic effect to replace or supplement according to actual treatment needs, which should fall within the scope of the present application.

[0033] The preparation method of the composite dressing with time sequence response and function synergy as described above, the electrospinning process parameters in step (4) are as follows: ambient temperature 20-40 DEG C, relative humidity 20-60%, needle size 14-20G, voltage 8-20kV, receiving distance 10-20cm, spinning rate 0.1-2mL / h, and drum speed 100-200rpm.

[0034] The use of the composite dressing with time sequence response and function synergy as claimed in any one of the above for a chronic wound repair material of diabetes. The two-layer structure in the composite dressing realizes ordered connection and function synergy in time sequence and local spatial area, and constructs a multi-stage treatment path with time-space cascade effect. The composite dressing can preferentially improve the local microenvironment after contacting the wound, and trigger the release of pro-angiogenic drugs under near-infrared light irradiation, realize the whole process treatment from microenvironment regulation to vascular regeneration, and significantly improve the healing efficiency and treatment safety of diabetic wounds.

[0035] Invention principle:

[0036] The present application not only solves the problems of weak microenvironment regulation ability, mismatched drug release timing and low pro-angiogenic efficiency of existing diabetic wound dressings, but also realizes a whole process intervention system from basic support to advanced repair by integrating the "cascade catalysis-photothermal response-function synergy" mechanism. Specifically:

[0037] As shown in Figure 1 The PVA-GOx-MnO2 hydrogel layer in the composite dressing of the present application can spontaneously perform cascade catalysis after contacting the chronic wound of diabetes: glucose oxidase (GOx) catalyzes high-concentration glucose in the local wound to generate gluconic acid and H2O2, and then MnO2 nanoparticles further catalyze H2O2 to decompose into oxygen and water, realizing the removal of high-sugar environment, oxygen supply and the relief of oxidative stress in the local wound, thereby improving the basic conditions for tissue repair and providing a good microenvironment support for subsequent pro-angiogenic therapy. The pro-angiogenic drugs are loaded in the temperature-sensitive micro-nano fiber membrane, and under near-infrared light irradiation, the photothermal effect of MnO2 can make the temperature-sensitive material melt, realizing the controlled release of pro-angiogenic drugs. This mechanism avoids the passive diffusion behavior of drugs in traditional dressings, ensures that the drugs are released only at the right time, improves drug utilization and reduces the risk of toxicity, and embodies stronger treatment accuracy and safety.

[0038] That is, the present application constructs a multi-stage treatment system driven by "time-space cascade effect" through functional partition design: the first stage: the hydrogel layer removes glucose, supplies oxygen and relieves oxidative stress; the second stage: under external near-infrared light irradiation, the photothermal effect of MnO2 triggers the release of drugs from the temperature-sensitive micro-nano fiber membrane, promoting angiogenesis; this progressive treatment strategy effectively improves the matching degree and functional synergy of each stage of treatment, providing a safer and more effective treatment option for patients with chronic wounds of diabetes.

[0039] If there is no microenvironment regulation in the first stage, i.e. lack of improvement of the local high-sugar, hypoxia and oxidative stress of the chronic wound of diabetes, the pro-angiogenic therapy in the second stage will be adversely affected:

[0040] ①Diabetic chronic wounds have obvious stage characteristics of healing. In the inflammatory stage, the local microenvironment is usually in a state of high glucose, hypoxia, enhanced oxidative stress and increased levels of inflammatory factors. If the pro-angiogenic drugs are directly released at this stage, due to the limited cell activity and the difficulty in activating the corresponding pathway, the drugs are difficult to play the expected effect, and even the local waste or toxicity accumulation may be caused by drug inactivation or premature release, affecting the safety of treatment;

[0041] ②The improvement of the microenvironment is the prerequisite for promoting angiogenesis. The first stage reduces the glucose, oxygen and oxidative stress through the cascade catalytic reaction of the hydrogel layer, and provides a good foundation for tissue repair for subsequent treatment. Only after the completion of this stage, the wound enters the proliferation stage suitable for angiogenesis, and the drug release triggered at this time can achieve efficient pro-angiogenic effect.

[0042] Therefore, the present application proposes a progressive treatment strategy of "improving the microenvironment first and then triggering drug release", which ensures that the drug is released only at the appropriate time, thereby significantly improving the drug efficacy and treatment safety, which is one of the key innovations of the present application that distinguishes it from the prior art.

[0043] Compared with the prior art, the present application systematically constructs an orderly treatment path of "improving the microenvironment first and then triggering pro-angiogenesis", which achieves significant technical effects:

[0044] Active regulation of the microenvironment: using PVA-GOx-MnO2 hydrogel layer, through cascade catalytic reaction, the local high glucose, oxygen and oxidative stress are actively removed, and an ideal tissue repair foundation is created for subsequent treatment.

[0045] External controllable precise drug release: the pro-angiogenic drugs are encapsulated in the temperature-sensitive micro-nano fiber membrane containing double fatty acid phase change material, and under NIR irradiation, the photothermal effect generated by MnO2 triggers the drug release, realizing the on-demand and controllable release of the drug.

[0046] Functional synergy and time sequence response: the two-layer structure promotes step by step, realizing the whole process intervention from basic support to advanced repair, effectively solving the problem of improper drug release timing and unstable efficacy in the prior art.

[0047] Compared with the prior art, the present application has the following beneficial effects:

[0048] (1) The composite dressing with time sequence response and functional synergy of the present application not only solves the problems of weak microenvironment regulation ability, mismatched drug release timing and low pro-angiogenic efficiency of the existing diabetic wound dressings, but also realizes the whole process intervention system from basic support to advanced repair through the integration of "cascade catalysis-photothermal response-functional synergy" mechanism.

[0049] (2) The composite dressing with time sequence response and functional synergy of the application can spontaneously perform cascade catalytic reaction after contacting with diabetic chronic wounds: glucose oxidase (GOx) catalyzes high-concentration glucose in the local wound to generate gluconic acid and H2O2, and then MnO2 nanoparticles further catalyze H2O2 to decompose into oxygen and water, so as to realize the removal of high-sugar environment in the local wound, oxygen supply and the relief of oxidative stress, thereby improving the basic conditions for tissue repair and providing good microenvironment support for subsequent pro-angiogenesis.

[0050] (3) The preparation method of the composite dressing with time sequence response and functional synergy of the application, through functional partition design, constructs a multi-stage treatment system driven by'spatiotemporal cascade effect', and this progressive treatment strategy effectively improves the matching degree and functional synergy of each stage of treatment, so as to provide a safer and more effective treatment option for diabetic chronic wound patients.

[0051] (4) The application of the composite dressing with time sequence response and functional synergy of the application, the composite dressing can improve the local microenvironment after contacting with the wound, and trigger the release of pro-angiogenic drugs under near-infrared light irradiation, realize the whole process treatment from microenvironment regulation to blood vessel regeneration, and significantly improve the healing efficiency and treatment safety of diabetic wounds. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 It is a schematic diagram of the action mechanism of the composite dressing with time sequence response and functional synergy of the application;

[0053] Figure 2 It is a microstructure electron microscope graph of the composite dressing prepared in Example 3 of the application;

[0054] Figure 3 It is a graph of in-vitro drug release curve of the composite dressing prepared in Example 3 of the application;

[0055] Figure 4 It is a graph of cytotoxicity test results of the composite dressing prepared in Examples 1-7 of the application;

[0056] Figure 5 It is a graph of in-vitro angiogenesis of the composite dressing prepared in Example 3 of the application. DETAILED DESCRIPTION

[0057] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the appended claims of the application.

[0058] The performance index of the present application relates to the test method as follows:

[0059] In vitro drug release behavior test: the composite dressing sample is soaked in PBS solution (0.01M, pH = 7.4), and irradiated for 30min using NIR (wavelength 808nm, light intensity 1W / cm 2 ) before sampling. Take out 2mL solution at the set time point, and measure the absorbance value of the solution at the characteristic peak by ultraviolet visible spectrophotometer. The drug concentration in the solution at each sampling time point is obtained by the standard equation, the cumulative drug release rate is calculated and the drug release curve is drawn, and the calculation formula is: i Ci is the drug concentration obtained by the ith test, m is the mass of the composite dressing (μg), a is the mass of the drug (μg), and b is the mass of the other components in the composite dressing (μg).

[0060] Cytotoxicity test: before testing, the composite dressing sample is sterilized in an alcohol fumigation jar for 24h. Human umbilical vein endothelial cells (HUVECs) are inoculated in a 24-well plate at a density of 80000 cells / well, and 3 replicates are set for each group. After 4h of culture, the cells without sample are used as the control group, and the cells with sample are used as the experimental group. After incubation, the cells are washed with PBS for 3 times, CCK-8 reagent is added, and the cells are incubated at 37℃ in the dark for 2h. The absorbance at 450nm is measured by an enzyme marker, and the cell survival rate is calculated.

[0061] In vitro angiogenesis test: the composite dressing is used as the sample, the matrigel (manufacturer: Solarbio, product number: M8370) is melted at 4℃ for 12h, and the gun head and 24-well plate are pre-cooled in the refrigerator. The cell climbing sheet is placed in the well plate, 130μL matrigel is added to the well plate using the pre-cooled gun head and is flattened, and the well plate is placed in the incubator for 30min to make the matrigel completely solidified. The well plate is taken out, the cells are inoculated at a density of 40000 cells / well, and the sample is placed. After irradiation for 30min using NIR (wavelength 808nm, light intensity 1W / cm 2 ), the well plate is incubated in the incubator for 8h, and then taken out for photography. The cells without sample are used as the control group, and the cells with sample are used as the experimental group.

[0062] Example 1

[0063] A preparation method of a composite dressing with time sequence response and functional synergy, the specific steps are as follows:

[0064] (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution:

[0065] (1.1) Synthesis of MnO2 nanoparticles:​

[0066] Potassium permanganate and ascorbic acid were dissolved in deionized water respectively to obtain a potassium permanganate solution with a concentration of 21 mg / mL and an ascorbic acid solution with a concentration of 23.5 mg / mL, and the ascorbic acid solution was added to the potassium permanganate solution under stirring at a speed of 1000 r / min for 1 h. After the reaction, centrifugation, ethanol washing 4 times, deionized water washing 2 times, and drying at 90℃ for 12 h were sequentially performed to obtain MnO2 nanoparticles with an average particle size of 17±0.4 nm;

[0067] The volume ratio of the potassium permanganate solution to the ascorbic acid solution was 1:1.

[0068] (1.2) A polyvinyl alcohol with a model number of 1797 was dissolved in deionized water under heating and stirring at 90℃ until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8 wt%;

[0069] (1.3) After the polyvinyl alcohol solution was cooled, glucose oxidase (manufacturer: Shanghai Yuan Ye Biological Technology Co., Ltd., product number: S10021) and MnO2 nanoparticles were added under ice bath conditions at -2℃, and a PVA-GOx-MnO2 hydrogel precursor solution was obtained after stirring uniformly;

[0070] The addition amount of glucose oxidase in the PVA-GOx-MnO2 hydrogel precursor solution was 0.05 wt%, and the addition amount of MnO2 nanoparticles was 0.04 wt%.

[0071] (2) Preparation of a double fatty acid phase change material: lauric acid and stearic acid were mixed and stirred uniformly under heating at 90℃, and then sequentially cooled at room temperature, ground, and dried at 25℃ to obtain a double fatty acid phase change material;

[0072] The mass ratio of lauric acid to stearic acid was 4:1, and the phase change temperature of the double fatty acid phase change material was 40℃.

[0073] (3) Preparation of a spinning solution: polyacrylonitrile (manufacturer: Shanghai Maikelin Biological Technology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and deferoxamine were sequentially added to N,N-dimethylformamide and stirred uniformly to obtain a spinning solution.

[0074] In the spinning solution, the concentration of polyacrylonitrile was 21 wt%, the concentration of the double fatty acid phase change material was 9 wt%, and the concentration of deferoxamine was 5 wt%.

[0075] (4) Preparation of temperature-sensitive micro-nano fiber membrane: the spinning solution obtained in step (3) is used for electrospinning, and after spinning is completed, the fiber membrane is placed in a vacuum oven at 30°C and dried for 10h to obtain a temperature-sensitive micro-nano fiber membrane; the average diameter of the fibers in the temperature-sensitive micro-nano fiber membrane is 2.1±0.3μm;

[0076] The electrospinning process parameters are: ambient temperature 25°C, relative humidity 50%, needle size 18G, voltage 10kV, receiving distance 18cm, spinning rate 1mL / h, and drum rotation speed 140rpm;

[0077] (5) 0.3mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) is injected into a 1cm diameter circular mold, and the temperature-sensitive micro-nano fiber membrane obtained in step (4) is cut into a 1cm diameter disc, immersed in the PVA-GOx-MnO2 hydrogel precursor solution, and subjected to 3 freeze-thaw cycle treatments to obtain a composite dressing with time sequence response and functional synergy after demolding;

[0078] The freezing temperature during freeze-thaw cycle treatment is-20°C, the freezing time is 20h, the thawing temperature is 25°C, and the thawing time is 4h.

[0079] The finally prepared composite dressing with time sequence response and functional synergy is a double-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nano fiber membrane layer; the temperature-sensitive micro-nano fiber membrane is a temperature-sensitive micro-nano fiber membrane loaded with the pro-angiogenic drug deferoxamine; the composite dressing with time sequence response and functional synergy is used as a diabetic chronic wound repair material; the cumulative drug release amount of the composite dressing with time sequence response and functional synergy within 48h is 47.75%, which can realize controllable release of the pro-angiogenic drug; as shown in the figure, Figure 4 The cell survival rate of the experimental group is 108.9%, indicating that the sample has no cytotoxicity to HUVECs.

[0080] Example 2

[0081] A preparation method of a composite dressing with time sequence response and functional synergy, the specific steps are as follows:

[0082] (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution:

[0083] (1.1) Synthesis of MnO2 nanoparticles:

[0084] Potassium permanganate and ascorbic acid were dissolved in deionized water to obtain a potassium permanganate solution with a concentration of 13 mg / mL and an ascorbic acid solution with a concentration of 5 mg / mL, respectively. The ascorbic acid solution was added to the potassium permanganate solution under stirring at a speed of 1000 r / min, and the reaction was allowed to proceed for 1 h. After the reaction, centrifugation, ethanol washing (4 times), deionized water washing (2 times), and drying at 90℃ for 12 h were sequentially performed to obtain MnO2 nanoparticles with an average particle size of 12±0.6 nm.

[0085] The volume ratio of the potassium permanganate solution to the ascorbic acid solution was 1:3.

[0086] (1.2) Polyvinyl alcohol with a model number of 1797 was dissolved in deionized water under heating and stirring at 90℃ until complete dissolution to obtain a polyvinyl alcohol solution with a concentration of 8 wt%;

[0087] (1.3) After the polyvinyl alcohol solution was cooled, glucose oxidase (manufacturer: Shanghai Yuan Ye Biological Technology Co., Ltd., product number: S10021) and MnO2 nanoparticles were added under ice bath conditions at -2℃. After stirring, a PVA-GOx-MnO2 hydrogel precursor solution was obtained.

[0088] The addition amount of glucose oxidase in the PVA-GOx-MnO2 hydrogel precursor solution was 0.05 wt%, and the addition amount of MnO2 nanoparticles was 0.04 wt%.

[0089] (2) Preparation of a double fatty acid phase change material: lauric acid and stearic acid were mixed and stirred uniformly under heating at 90℃. After room temperature cooling, grinding, and drying at 25℃, a double fatty acid phase change material was obtained.

[0090] The mass ratio of lauric acid to stearic acid was 4:1, and the phase change temperature of the double fatty acid phase change material was 40℃.

[0091] (3) Preparation of a spinning solution: polyacrylonitrile (manufacturer: Shanghai Maikelin Biological Technology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and deferoxamine were sequentially added to N,N-dimethylformamide and stirred uniformly to obtain a spinning solution.

[0092] In the spinning solution, the concentration of polyacrylonitrile was 21 wt%, the concentration of the double fatty acid phase change material was 9 wt%, and the concentration of deferoxamine was 5 wt%.

[0093] (4) Preparation of a temperature-sensitive micro-nano fiber membrane: electrospinning was performed using the spinning solution obtained in step (3). After spinning was completed, the fiber membrane was placed in a vacuum oven at 30℃ and dried for 10 h to obtain a temperature-sensitive micro-nano fiber membrane. The average diameter of the fibers in the temperature-sensitive micro-nano fiber membrane was 2.1±0.3 μm.

[0094] The electrospinning process parameters are: ambient temperature 25℃, relative humidity 50%, needle specification 18G, voltage 10kV, receiving distance 18cm, spinning rate 1mL / h, and drum rotation speed 140rpm;

[0095] (5) 0.3mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) was injected into a 1cm-diameter circular mold, and the temperature-sensitive micro-nanofiber membrane obtained in step (4) was cut into a 1cm-diameter circular piece, which was immersed in the PVA-GOx-MnO2 hydrogel precursor solution and subjected to 3 freeze-thaw cycle treatments, to obtain a composite dressing with time sequence response and functional synergy after demolding;

[0096] In the freeze-thaw cycle treatment, the freezing temperature is -20℃, the freezing time is 20h, the thawing temperature is 25℃, and the thawing time is 4h.

[0097] The finally obtained composite dressing with time sequence response and functional synergy is a double-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nanofiber membrane layer; the temperature-sensitive micro-nanofiber membrane is a temperature-sensitive micro-nanofiber membrane loaded with the pro-angiogenic drug deferoxamine; the composite dressing with time sequence response and functional synergy is used as a diabetic chronic wound repair material; the drug cumulative release amount of the composite dressing with time sequence response and functional synergy within 48h is 46.54%, and the controlled release of the pro-angiogenic drug can be achieved. As shown in FIG. 2, the cell survival rate of the experimental group is 112.5%, indicating that the sample has no cytotoxicity to HUVECs. Figure 4

[0098] Example 3

[0099] A preparation method of a composite dressing with time sequence response and functional synergy, and the specific steps are as follows:

[0100] (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution:

[0101] (1.1) Synthesis of MnO2 nanoparticles:

[0102] Potassium permanganate and ascorbic acid were dissolved in deionized water to obtain a potassium permanganate solution with a concentration of 21mg / mL and an ascorbic acid solution with a concentration of 23.5mg / mL, and the ascorbic acid solution was added to the potassium permanganate solution under stirring at a rotation speed of 1000r / min for 1h. After the reaction, centrifugation, 4 times of anhydrous ethanol washing, 2 times of deionized water washing, and 90℃ drying for 12h were sequentially performed to obtain MnO2 nanoparticles with an average particle size of 17±0.4nm;

[0103] ​The volume ratio of the potassium permanganate solution to the ascorbic acid solution is 1:1.

[0104] (1.2) Dissolve polyvinyl alcohol with model number 1797 in deionized water under heating and stirring conditions at 90 °C until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8 wt%;

[0105] (1.3) After the polyvinyl alcohol solution is cooled, add glucose oxidase (manufacturer: Shanghai Yuan Ye Biological Technology Co., Ltd., product number: S10021) and MnO2 nanoparticles under ice bath conditions at -2 °C, and after uniform stirring, obtain a PVA-GOx-MnO2 hydrogel precursor solution;

[0106] In the PVA-GOx-MnO2 hydrogel precursor solution, the addition amount of glucose oxidase is 0.05 wt%, and the addition amount of MnO2 nanoparticles is 0.04 wt%;

[0107] (2) Prepare a double fatty acid phase change material: mix lauric acid and stearic acid, and stir uniformly under heating conditions at 90 °C, and then sequentially cool at room temperature, grind, and dry at 25 °C to obtain a double fatty acid phase change material;

[0108] In the double fatty acid phase change material, the mass ratio of lauric acid to stearic acid is 4:1, and the phase change temperature is 40 °C;

[0109] (3) Prepare a spinning solution: add polyacrylonitrile (manufacturer: Shanghai Maikelin Biochemical Technology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and deferoxamine in sequence into N,N-dimethylformamide, and stir uniformly to obtain a spinning solution;

[0110] In the spinning solution, the concentration of polyacrylonitrile is 18 wt%, the concentration of the double fatty acid phase change material is 12 wt%, and the concentration of deferoxamine is 5 wt%;

[0111] (4) Prepare a temperature-sensitive micro-nano fiber membrane: use the spinning solution obtained in step (3) to perform electrospinning, and after spinning is completed, place the fiber membrane in a vacuum oven at 30 °C and dry for 10 h to obtain a temperature-sensitive micro-nano fiber membrane; the average diameter of the fibers in the temperature-sensitive micro-nano fiber membrane is 1.4 ± 0.2 μm;

[0112] The electrospinning process parameters are: ambient temperature 25 °C, relative humidity 50%, needle size 18G, voltage 10 kV, receiving distance 18 cm, spinning rate 1 mL / h, and drum rotation speed 140 rpm;

[0113] (5) Inject 0.3 mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) into a circular mold with a diameter of 1 cm. Cut the thermosensitive micro / nanofiber membrane obtained in step (4) into a circular piece with a diameter of 1 cm, immerse it in the PVA-GOx-MnO2 hydrogel precursor solution, and perform 3 freeze-thaw cycles. After demolding, a composite dressing with time-response and functional synergy is obtained.

[0114] The freeze-thaw cycle treatment involved a freezing temperature of -20℃, a freezing time of 20 hours, a thawing temperature of 25℃, and a thawing time of 4 hours.

[0115] The final composite dressing with time-responsive and functional synergistic effects is a two-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro / nanofiber membrane layer; the temperature-sensitive micro / nanofiber membrane is a temperature-sensitive micro / nanofiber membrane loaded with the angiogenic drug deferoxamine; the composite dressing with time-responsive and functional synergistic effects is used as a material for repairing chronic diabetic wounds.

[0116] like Figure 2 As shown, the final composite dressing with time-response and functional synergy is a two-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a thermosensitive micro / nanofiber membrane layer; the thermosensitive micro / nanofiber membrane is a thermosensitive micro / nanofiber membrane loaded with pro-angiogenic drugs; the composite dressing with time-response and functional synergy is used as a material for repairing chronic diabetic wounds.

[0117] like Figure 3 As shown, the composite dressing with time-response and functional synergy enables controlled release of pro-angiogenic drugs, with a cumulative drug release of 81.31% within 48 hours. This indicates that under NIR irradiation, MnO2 nanoparticles can absorb light energy and convert it into heat energy, triggering a phase transition in the phase change material within the fiber membrane, thereby releasing the drug. This result verifies the reliability of the drug release mechanism of the sample and avoids the "burst release" or "premature release" problems commonly found in traditional dressings.

[0118] like Figure 4 As shown, the cell survival rate in the experimental group was 118.4%, indicating that the sample had no cytotoxicity to HUVECs.

[0119] like Figure 5 As shown, after 8 hours of cell incubation, the control group failed to form tubular structures, while the experimental group clearly exhibited tubular structures. This is because the angiogenesis-promoting drugs within the sample were released under NIR irradiation, effectively promoting angiogenesis. These results indicate that the composite dressing prepared in Example 3 can achieve faster and more efficient vascularization of damaged tissue during the healing process of diabetic wounds, providing strong support for tissue repair and regeneration.

[0120] Example 4

[0121] A preparation method of a composite dressing with time sequence response and function synergy, the specific steps are as follows:

[0122] (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution:

[0123] (1.1) Synthesis of MnO2 nanoparticles:

[0124] Dissolve potassium permanganate and ascorbic acid in deionized water respectively to obtain a potassium permanganate solution with a concentration of 21 mg / mL and an ascorbic acid solution with a concentration of 23.5 mg / mL. Under stirring conditions at a speed of 1000 r / min, add the ascorbic acid solution to the potassium permanganate solution and react for 1 h. After the reaction is completed, sequentially perform centrifugation, 4 times of anhydrous ethanol washing, 2 times of deionized water washing, and 90℃ drying for 12 h to obtain MnO2 nanoparticles with an average particle size of 17±0.4 nm;

[0125] wherein the volume ratio of the potassium permanganate solution to the ascorbic acid solution is 1:1;

[0126] (1.2) Dissolve polyvinyl alcohol of model 1797 in deionized water under heating and stirring conditions at 90℃ until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8wt%;

[0127] (1.3) After the polyvinyl alcohol solution is cooled, add glucose oxidase (manufacturer: Shanghai Yuan Ye Biological Technology Co., Ltd., product number: S10021) and MnO2 nanoparticles under ice bath conditions at -2℃. After stirring uniformly, obtain a PVA-GOx-MnO2 hydrogel precursor solution;

[0128] wherein the addition amount of glucose oxidase in the PVA-GOx-MnO2 hydrogel precursor solution is 0.05wt%, and the addition amount of MnO2 nanoparticles is 0.04wt%;

[0129] (2) Preparation of double fatty acid phase change material: mix lauric acid and stearic acid, stir uniformly under heating conditions at 90℃, sequentially cool at room temperature, grind, and dry at 25℃ to obtain a double fatty acid phase change material;

[0130] wherein the mass ratio of lauric acid to stearic acid is 5:1.5, and the phase change temperature of the double fatty acid phase change material is 43℃;

[0131] (3) Preparation of spinning solution: sequentially add polyacrylonitrile (manufacturer: Shanghai Maikelin Biological Technology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and deferoxamine to N,N-dimethylformamide, stir uniformly, and obtain a spinning solution;

[0132] The concentration of polyacrylonitrile in the spinning solution is 21wt%, the concentration of the double fatty acid phase change material is 9wt%, and the concentration of deferoxamine is 5wt%;

[0133] (4) Preparation of a temperature-sensitive micro-nano fiber membrane: the spinning solution obtained in step (3) is used for electrospinning, and after spinning is completed, the fiber membrane is placed in a vacuum oven at 30°C and dried for 10h to obtain a temperature-sensitive micro-nano fiber membrane; the average diameter of the fibers in the temperature-sensitive micro-nano fiber membrane is 2±0.4μm;

[0134] The electrospinning process parameters are: ambient temperature 25°C, relative humidity 50%, needle specification 18G, voltage 10kV, receiving distance 18cm, spinning rate 1mL / h, and drum rotation speed 140rpm;

[0135] (5) 0.3mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) is injected into a 1cm-diameter circular mold, the temperature-sensitive micro-nano fiber membrane obtained in step (4) is cut into a 1cm-diameter circular piece, and the circular piece is immersed in the PVA-GOx-MnO2 hydrogel precursor solution and subjected to 3 freeze-thaw cycle treatments to obtain a composite dressing with time sequence response and functional synergy after demolding;

[0136] The freezing temperature during the freeze-thaw cycle treatment is -20°C, the freezing time is 20h, the thawing temperature is 25°C, and the thawing time is 4h.

[0137] The finally obtained composite dressing with time sequence response and functional synergy is a double-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nano fiber membrane layer; the temperature-sensitive micro-nano fiber membrane is a temperature-sensitive micro-nano fiber membrane loaded with the pro-angiogenic drug deferoxamine; and the composite dressing with time sequence response and functional synergy is used as a chronic wound repair material for diabetes.

[0138] The cumulative drug release amount of the composite dressing with time sequence response and functional synergy within 48h is 45.73%, and the controlled release of the pro-angiogenic drug can be achieved. As shown in Figure 4 the cell survival rate of the experimental group is 109.2%, indicating that the sample has no cytotoxicity to HUVECs.

[0139] Example 5

[0140] A preparation method of a composite dressing with time sequence response and functional synergy, and the specific steps are as follows:

[0141] (1) Preparation of a PVA-GOx-MnO2 hydrogel precursor solution:

[0142] (1.1) Synthesis of MnO2 nanoparticles:

[0143] Dissolve potassium permanganate and ascorbic acid in deionized water respectively to obtain a potassium permanganate solution with a concentration of 21 mg / mL and an ascorbic acid solution with a concentration of 23.5 mg / mL, add the ascorbic acid solution to the potassium permanganate solution under stirring at a speed of 1000 r / min, and react for 1 h, then perform centrifugation, ethanol washing 4 times, deionized water washing 2 times, and drying at 90℃ for 12 h in sequence to obtain MnO2 nanoparticles with an average particle size of 17±0.4 nm;

[0144] The volume ratio of the potassium permanganate solution to the ascorbic acid solution is 1:1.

[0145] (1.2) Dissolve polyvinyl alcohol with a model number of 1797 in deionized water under heating and stirring at 90℃ until complete dissolution to obtain a polyvinyl alcohol solution with a concentration of 8 wt%;

[0146] (1.3) After the polyvinyl alcohol solution is cooled, add glucose oxidase (manufacturer: Shanghai Yuan Ye Biotechnology Co., Ltd., product number: S10021) and MnO2 nanoparticles under ice bath conditions at -2℃, and stir uniformly to obtain a PVA-GOx-MnO2 hydrogel precursor solution;

[0147] The addition amount of glucose oxidase in the PVA-GOx-MnO2 hydrogel precursor solution is 0.05 wt%, and the addition amount of MnO2 nanoparticles is 0.04 wt%.

[0148] (2) Prepare a double fatty acid phase change material: mix lauric acid and stearic acid, stir uniformly under heating at 90℃, cool at room temperature, grind, and dry at 25℃ in sequence to obtain a double fatty acid phase change material;

[0149] The mass ratio of lauric acid to stearic acid is 4:1, and the phase change temperature of the double fatty acid phase change material is 40℃.

[0150] (3) Prepare a spinning solution: add polyacrylonitrile (manufacturer: Shanghai Maikelin Biotechnology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and curcumin (manufacturer: Shanghai Yuan Ye Biotechnology Co., Ltd., product number: S35425) to N,N-dimethylformamide in sequence, stir uniformly, and obtain a spinning solution;

[0151] In the spinning solution, the concentration of polyacrylonitrile is 18 wt%, the concentration of the double fatty acid phase change material is 12 wt%, and the concentration of curcumin is 5 wt%.

[0152] (4) Preparation of temperature-sensitive micro-nano fiber membrane: the spinning solution obtained in step (3) is used for electrospinning, and after spinning is completed, the fiber membrane is placed in a vacuum oven at 30°C and dried for 10h to obtain a temperature-sensitive micro-nano fiber membrane; the average diameter of the fibers in the temperature-sensitive micro-nano fiber membrane is 1.6±0.4μm;

[0153] The electrospinning process parameters are: ambient temperature 25°C, relative humidity 50%, needle size 18G, voltage 10kV, receiving distance 18cm, spinning rate 1mL / h, and drum rotation speed 140rpm;

[0154] (5) 0.3mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) is injected into a 1cm diameter circular mold, and the temperature-sensitive micro-nano fiber membrane obtained in step (4) is cut into a 1cm diameter disc and placed in the PVA-GOx-MnO2 hydrogel precursor solution for 3 freeze-thaw cycle treatments, and after demolding, a composite dressing with time sequence response and functional synergy is obtained;

[0155] The freeze-thaw cycle treatment is carried out at a freezing temperature of-20°C for 20h, and a thawing temperature of 25°C for 4h.

[0156] The finally prepared composite dressing with time sequence response and functional synergy is a double-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nano fiber membrane layer; the temperature-sensitive micro-nano fiber membrane is a temperature-sensitive micro-nano fiber membrane loaded with the pro-angiogenic drug curcumin; and the composite dressing with time sequence response and functional synergy is used as a diabetic chronic wound repair material.

[0157] The composite dressing with time sequence response and functional synergy has a cumulative drug release amount of 79.64% within 48h, and can achieve controllable release of the pro-angiogenic drug. As shown in Figure 4 The cell survival rate of the experimental group is 121.6%, indicating that the sample has no cytotoxicity to HUVECs.

[0158] Example 6

[0159] A preparation method of a composite dressing with time sequence response and functional synergy, the specific steps are as follows:

[0160] (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution:

[0161] (1.1) Synthesis of MnO2 nanoparticles:

[0162] Potassium permanganate and ascorbic acid were dissolved in deionized water to obtain a potassium permanganate solution with a concentration of 5 mg / mL and an ascorbic acid solution with a concentration of 18 mg / mL, respectively. The ascorbic acid solution was added to the potassium permanganate solution under stirring at a speed of 400 r / min, and the reaction was allowed to proceed for 6 h. After the reaction, centrifugation, ethanol washing (4 times), deionized water washing (2 times), and drying at 90℃ for 12 h were sequentially performed to obtain MnO2 nanoparticles with an average particle size of 10.5±0.5 nm.

[0163] The volume ratio of the potassium permanganate solution to the ascorbic acid solution was 3:1.

[0164] (1.2) Polyvinyl alcohol with a model number of 1788 was dissolved in deionized water under heating and stirring at 70℃ until complete dissolution to obtain a polyvinyl alcohol solution with a concentration of 5 wt%;

[0165] (1.3) After the polyvinyl alcohol solution was cooled, glucose oxidase (manufacturer: Shanghai Yuan Ye Biological Technology Co., Ltd., product number: S10021) and MnO2 nanoparticles were added under ice bath conditions at -2℃. After stirring, a PVA-GOx-MnO2 hydrogel precursor solution was obtained.

[0166] The addition amount of glucose oxidase in the PVA-GOx-MnO2 hydrogel precursor solution was 0.01 wt%, and the addition amount of MnO2 nanoparticles was 0.02 wt%.

[0167] (2) Preparation of a double fatty acid phase change material: lauric acid and stearic acid were mixed and stirred uniformly under heating at 80℃. After room temperature cooling, grinding, and drying at 25℃, a double fatty acid phase change material was obtained.

[0168] The mass ratio of lauric acid to stearic acid was 5:1, and the phase change temperature of the double fatty acid phase change material was 38℃.

[0169] (3) Preparation of a spinning solution: polyacrylonitrile (manufacturer: Shanghai Maikelin Biological Technology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and deferoxamine were sequentially added to N,N-dimethylformamide and stirred uniformly to obtain a spinning solution.

[0170] In the spinning solution, the concentration of polyacrylonitrile was 15 wt%, the concentration of the double fatty acid phase change material was 15 wt%, and the concentration of deferoxamine was 1 wt%.

[0171] (4) Preparation of a temperature-sensitive micro-nano fiber membrane: electrospinning was performed using the spinning solution obtained in step (3). After spinning was completed, the fiber membrane was placed in a vacuum oven at 30℃ and dried for 10 h to obtain a temperature-sensitive micro-nano fiber membrane. The fiber diameter in the temperature-sensitive micro-nano fiber membrane was 0.7±0.2 μm.

[0172] The electrospinning process parameters are: ambient temperature 20℃, relative humidity 60%, needle specification 20G, voltage 20kV, receiving distance 20cm, spinning rate 0.1mL / h, and drum rotation speed 100rpm.

[0173] (5) 0.3mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) was injected into a 1cm-diameter circular mold, and the temperature-sensitive micro-nanofiber membrane obtained in step (4) was cut into a 1cm-diameter disc and placed on the PVA-GOx-MnO2 hydrogel precursor solution, and then subjected to 3 freeze-thaw cycles to obtain a composite dressing with time sequence response and functional synergy after demolding;

[0174] In the freeze-thaw cycle, the freezing temperature is -20℃, the freezing time is 20h, the thawing temperature is 25℃, and the thawing time is 4h.

[0175] The finally obtained composite dressing with time sequence response and functional synergy is a double-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro-nanofiber membrane layer; the temperature-sensitive micro-nanofiber membrane is a temperature-sensitive micro-nanofiber membrane loaded with the pro-angiogenic drug deferoxamine; and the composite dressing with time sequence response and functional synergy is used as a diabetic chronic wound repair material.

[0176] The cumulative drug release amount of the composite dressing with time sequence response and functional synergy within 48h is 89.56%, and the controlled release of the pro-angiogenic drug can be achieved. As shown in Table 1, the cell survival rate of the experimental group is 110.5%, indicating that the sample has no cytotoxicity to HUVECs. Figure 4

[0177] Example 7

[0178] A preparation method of a composite dressing with time sequence response and functional synergy, and the specific steps are as follows:

[0179] (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution:

[0180] (1.1) Synthesis of MnO2 nanoparticles:

[0181] Potassium permanganate and ascorbic acid were dissolved in deionized water to obtain a potassium permanganate solution with a concentration of 30mg / mL and an ascorbic acid solution with a concentration of 35mg / mL, and the ascorbic acid solution was added to the potassium permanganate solution under stirring at a rotation speed of 3000r / min for 0.5h. After the reaction, centrifugation, 4 times of anhydrous ethanol washing, 2 times of deionized water washing, and 90℃ drying for 12h were sequentially performed to obtain MnO2 nanoparticles with an average particle size of 24.2±0.6nm; ​

[0182] wherein the volume ratio of the potassium permanganate solution to the ascorbic acid solution is 1:1;

[0183] (1.2) Dissolve polyvinyl alcohol with model number 1799 in deionized water under the condition of heating and stirring at 120℃ until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 25wt%;

[0184] (1.3) After the polyvinyl alcohol solution is cooled, add glucose oxidase (manufacturer: Shanghai Yuan Ye Biotechnology Co., Ltd., product number: S10021) and MnO2 nanoparticles under the condition of an ice bath at -2℃, and after stirring uniformly, obtain a PVA-GOx-MnO2 hydrogel precursor solution;

[0185] wherein the addition amount of glucose oxidase in the PVA-GOx-MnO2 hydrogel precursor solution is 2wt%, and the addition amount of MnO2 nanoparticles is 0.06wt%;

[0186] (2) Prepare a double fatty acid phase change material: mix lauric acid and stearic acid, and stir uniformly under the condition of heating at 120℃, and then sequentially cool at room temperature, grind, and dry at 25℃ to obtain a double fatty acid phase change material;

[0187] wherein the mass ratio of lauric acid to stearic acid is 3:2, and the phase change temperature of the double fatty acid phase change material is 50℃;

[0188] (3) Prepare a spinning solution: add polyacrylonitrile (manufacturer: Shanghai Maikelin Biotechnology Co., Ltd., product number: P823208), the double fatty acid phase change material obtained in step (2), and deferoxamine in sequence into N,N-dimethylformamide, stir uniformly, and obtain a spinning solution;

[0189] In the spinning solution, the concentration of polyacrylonitrile is 25wt%, the concentration of the double fatty acid phase change material is 5wt%, and the concentration of deferoxamine is 10wt%;

[0190] (4) Prepare a temperature-sensitive micro-nano fiber membrane: use the spinning solution obtained in step (3) to perform electrospinning, after the spinning is completed, place the fiber membrane in a vacuum oven at 30℃ and dry for 10h to obtain a temperature-sensitive micro-nano fiber membrane; the average diameter of the fibers in the temperature-sensitive micro-nano fiber membrane is 48±0.5μm;

[0191] The electrospinning process parameters are: ambient temperature 40℃, relative humidity 20%, needle specification 14G, voltage 8kV, receiving distance 10cm, spinning rate 2mL / h, and drum rotation speed 200rpm;

[0192] (5) Inject 0.3 mL of the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) into a circular mold with a diameter of 1 cm. Cut the thermosensitive micro / nanofiber membrane obtained in step (4) into 1 cm circular pieces, place them on the PVA-GOx-MnO2 hydrogel precursor solution, and perform 3 freeze-thaw cycles. After demolding, a composite dressing with time-response and functional synergy is obtained.

[0193] The freeze-thaw cycle treatment involved a freezing temperature of -20℃, a freezing time of 20 hours, a thawing temperature of 25℃, and a thawing time of 4 hours.

[0194] The final composite dressing with time-responsive and functional synergistic effects is a two-layer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro / nanofiber membrane layer; the temperature-sensitive micro / nanofiber membrane is a temperature-sensitive micro / nanofiber membrane loaded with the angiogenic drug deferoxamine; the composite dressing with time-responsive and functional synergistic effects is used as a material for repairing chronic diabetic wounds.

[0195] The composite dressing, exhibiting both time-responsive and functional synergistic effects, achieved a cumulative drug release of 41.26% within 48 hours, enabling controlled release of pro-angiogenic drugs. For example... Figure 4 As shown, the cell viability of the composite dressing prepared in this embodiment is 98.74%, indicating that the sample has no cytotoxicity to HUVECs.

Claims

1. A composite dressing with time-response and functional synergy, characterized in that: It has a bilayer composite structure, including a PVA-GOx-MnO2 hydrogel layer and a temperature-sensitive micro / nanofiber membrane layer; PVA-GOx-MnO2 hydrogel is obtained by cross-linking a PVA-GOx-MnO2 hydrogel precursor solution. The PVA-GOx-MnO2 hydrogel precursor solution is prepared by adding glucose oxidase and MnO2 nanoparticles to a polyvinyl alcohol solution under ice bath conditions. The thermosensitive micro / nanofiber membrane is a thermosensitive micro / nanofiber membrane loaded with angiotensin-promoting drugs. The thermosensitive micro / nanofiber membrane loaded with angiotensin-promoting drugs is obtained by electrospinning after sequentially adding polyacrylonitrile, a di-fatty acid phase change material and angiotensin-promoting drugs into N,N-dimethylformamide to prepare a spinning solution.

2. The composite dressing with time-response and functional synergy according to claim 1, characterized in that, The diameter of the fibers in the thermosensitive micro / nanofiber membrane loaded with angiogenic drugs ranges from 0.5 to 48 μm.

3. A method for preparing a composite dressing with temporal response and functional synergy as described in claim 1 or 2, characterized in that: Thermosensitive micro / nanofiber membranes loaded with angiogenic drugs obtained by electrospinning were placed on or immersed in a PVA-GOx-MnO2 hydrogel precursor solution. After cross-linking treatment, the membranes were demolded to obtain a composite dressing with time-responsive and functional synergistic effects.

4. The method for preparing a composite dressing with time-response and functional synergy according to claim 3, characterized in that, The specific steps are as follows: (1) Preparation of PVA-GOx-MnO2 hydrogel precursor solution: Polyvinyl alcohol was dissolved in deionized water and heated and stirred at 70~120℃ until completely dissolved to obtain a polyvinyl alcohol solution. After the solution was cooled, glucose oxidase and MnO2 nanoparticles were added under ice bath conditions and stirred evenly to obtain PVA-GOx-MnO2 hydrogel precursor solution. (2) Preparation of dual fatty acid phase change material: Lauric acid and stearic acid are mixed and stirred evenly under heating conditions of 80~120℃, and then cooled, ground and dried in sequence to obtain dual fatty acid phase change material; (3) Preparation of spinning solution: Polyacrylonitrile, the di-fatty acid phase change material obtained in step (2) and the angiogenesis drug are added to N,N-dimethylformamide in sequence and stirred evenly to obtain spinning solution; (4) Preparation of thermosensitive micro / nanofiber membrane loaded with pro-angiogenic drugs: electrospinning was performed using the spinning solution obtained in step (3) to obtain a thermosensitive micro / nanofiber membrane loaded with pro-angiogenic drugs. (5) Inject the PVA-GOx-MnO2 hydrogel precursor solution obtained in step (1) into the mold, place the thermosensitive micro / nanofiber membrane loaded with angiogenic drugs obtained in step (4) on the PVA-GOx-MnO2 hydrogel precursor solution or immerse it in the PVA-GOx-MnO2 hydrogel precursor solution, perform multiple freeze-thaw cycles, and obtain a composite dressing with time-response and functional synergy after demolding.

5. The method for preparing a composite dressing with time-response and functional synergy according to claim 4, characterized in that, In step (1), the degree of polymerization of polyvinyl alcohol is 1700±50, the degree of alcoholysis is 88~99.8%, and the concentration of polyvinyl alcohol solution is 5~25wt%; the amount of glucose oxidase added in the PVA-GOx-MnO2 hydrogel precursor solution is 0.01~2wt%, and the amount of MnO2 nanoparticles added is 0.02~0.06wt%.

6. The method for preparing a composite dressing with time-response and functional synergy according to claim 4, characterized in that, In step (1), the particle size of MnO2 nanoparticles is 10~25nm. The synthesis method of MnO2 nanoparticles is as follows: potassium permanganate and ascorbic acid are dissolved in deionized water to obtain potassium permanganate solution and ascorbic acid solution. Under stirring conditions of 400~3000r / min, ascorbic acid solution is added to potassium permanganate solution. After the reaction is completed, MnO2 nanoparticles are obtained by centrifugation, washing and drying. The concentration of potassium permanganate solution is 5~30 mg / mL, the concentration of ascorbic acid solution is 5~35 mg / mL, and the volume ratio of potassium permanganate solution to ascorbic acid solution is 1~3:3~1; The reaction time is 0.5~6h.

7. The method for preparing a composite dressing with time-response and functional synergy according to claim 4, characterized in that, In step (2), the mass ratio of lauric acid to stearic acid is 5~3:1~2, and the phase transition temperature of the dual fatty acid phase change material is 38~50℃.

8. The method for preparing a composite dressing with time-response and functional synergy according to claim 4, characterized in that, In the spinning solution of step (3), the concentration of polyacrylonitrile is 15~25wt%, the concentration of difatty acid phase change material is 5~15wt%, and the concentration of angiogenesis drug is 1~10wt%.

9. A method for preparing a composite dressing with temporal response and functional synergy according to claim 4, characterized in that, The electrospinning process parameters in step (4) are: ambient temperature 20~40℃, relative humidity 20~60%, needle size 14~20G, voltage 8~20kV, receiving distance 10~20cm, spinning rate 0.1~2mL / h, and roller speed 100~200rpm.

10. The application of a composite dressing with time-response and functional synergy as described in claim 1 or 2, characterized in that: Used as a material for repairing chronic wounds in diabetic patients.

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