Chitosan methacrylic acid hydrogel microneedle patch loaded with vascular endothelial growth factor and antibacterial peptide as well as preparation method and application of chitosan methacrylic acid hydrogel microneedle patch

Abstract

The invention discloses a vascular endothelial growth factor (VEGF) and antibacterial peptide (AMP) loaded chitosan methacrylic acid (CSMA) hydrogel microneedle patch as well as a preparation method and application thereof, the microneedle patch takes CSMA hydrogel as a main body material, the CSMA hydrogel is crosslinked and cured through ultraviolet light, and the microneedle patch has the characteristics of simplicity and convenience in preparation and stable material performance. The microneedle patch can continuously and stably release VEGF and AMP, promote wound healing and inhibit bacterial infection. Experiments show that the hydrogel microneedle is non-toxic to cells, has good biocompatibility and biodegradability, and also has excellent antibacterial performance. The invention provides an efficient and safe novel treatment tool for repairing infectious wounds.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical materials, and specifically relates to a chitosan methacrylate (CSMA) hydrogel microneedle patch loaded with vascular endothelial growth factor (VEGF) and antimicrobial peptide (AMP), and a preparation method and application thereof. Background Art

[0002] Wound repair is an important topic in the field of global public health. Its complexity lies in the fact that infectious wounds are often accompanied by problems such as local microenvironment imbalance, colonization of pathogenic microorganisms and obstructed vascular regeneration. In severe cases, they can induce systemic infection and even multiple organ failure. The traditional dressings widely used in clinical practice (such as gauze, ointments and synthetic polymer dressings) have significant defects: the mechanical compatibility of rigid matrix materials with skin tissue is poor, which can easily cause secondary damage; most products lack water-containing properties, resulting in wound dehydration or accumulation of exudate; more importantly, existing dressings mostly adopt a passive isolation protection mode, which can neither achieve accurate delivery of therapeutic drugs nor simultaneously meet the dual needs of antibacterial and anti-inflammatory and angiogenesis. Studies have shown that the biological basis of wound healing depends on the formation of a functional microvascular network, while persistent infection will disrupt the repair process. Therefore, the development of new intelligent dressings with active therapeutic functions, biocompatibility and biomimetic structures has become a research focus in this field.

[0003] In recent years, hydrogel materials have shown unique advantages in the field of wound repair due to their three-dimensional network structure, high water content and extracellular matrix-like properties. Among them, chitosan (CS)-based hydrogels have attracted much attention due to their natural antibacterial properties, degradability and epithelialization-promoting effects, but their defects such as insufficient mechanical strength and poor molding controllability limit their clinical applications. CSMA hydrogels obtained by methacrylation modification, while retaining the inherent biological activity of chitosan, introduce photosensitive cross-linking groups, which not only significantly improves the mechanical properties of the material, but also can achieve precise microstructure regulation through ultraviolet light curing. At the same time, microneedle transdermal drug delivery technology breaks through the skin barrier in a minimally invasive way, and can deliver active ingredients to the dermis in a targeted manner, effectively overcoming the problems of low bioavailability and short action time of traditional drug delivery methods. However, existing microneedle systems generally have bottleneck problems such as single function (only focusing on antibacterial or healing promotion), low drug loading efficiency (especially for protein growth factors and polypeptide antibacterial agents), and preparation process damage to active ingredients (such as high temperature and high pressure or organic solvent treatment). Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a hydrogel microneedle system based on methacrylated chitosan (CSMA) in view of the deficiencies in the prior art. The system is loaded with vascular endothelial growth factor (VEGF) and antimicrobial peptide (AMP) through covalent cross-linking technology, and is suitable for the repair and treatment of infectious wounds, so as to break through the single function limitation of traditional dressings.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for preparing a chitosan methacrylate (CSMA) hydrogel microneedle patch loaded with vascular endothelial growth factor (VEGF) and antimicrobial peptide (AMP), comprising the following steps: S1. Preparation of chitosan methacrylate (CSMA): The chitosan is dispersed in a pre-cooled acetic acid solution, and the chitosan solution is prepared after ultrasonic treatment; the monomer is slowly added dropwise in a nitrogen-protected thermostatic reactor at a molar ratio of chitosan to methacrylic anhydride of 1:0.7-0.9, and N-methylmorpholine (NMM) is used to catalyze the reaction; a hydroquinone inhibitor is added to terminate the reaction after aging; the reaction solution is centrifuged to remove unreacted monomers; S2. Purification and freeze-drying: The supernatant obtained in step S1 is dialyzed with a NaCl solution and a phosphate buffer solution in sequence, and the dialyzate is freeze-dried by programmed method to obtain chitosan methacrylate (CSMA) freeze-dried powder; S3. Preparation of microneedle patch: The chitosan methacrylate (CSMA) freeze-dried powder obtained in step S2 is re-dissolved in deionized water to prepare a chitosan methacrylate prepolymer solution, a photoinitiator is added, and vascular endothelial growth factor (VEGF) and antimicrobial peptide (AMP) are mixed; the mixed solution is then injected into the microneedle mold treated with oxygen plasma, centrifuged to complete the perfusion and remove the excess solution, and then cured under ultraviolet light. After demolding, it is washed with PBS buffer and dried to obtain the microneedle mold.

[0006] Specifically, in step S1, chitosan is dispersed in a precooled 1.2-1.8% (v / v) acetic acid aqueous solution, and solubilized by ultrasonic treatment at 40-50 kHz and 150-200 W for 15-20 minutes at 2-4°C to prepare a 2.8-3.2% (w / v, g / ml) chitosan solution; the low temperature environment is 8-12°C; the methacrylic anhydride is added twice, with the first addition having a molar ratio of 1:0.5-0.6, and the remaining monomers are added after 1-2 hours of reaction.

[0007] Specifically, in step S1, after 1.8-2.2% (w / v, g / ml) N-methylmorpholine is used for catalytic reaction for 2.5-3 hours, 0.04-0.06% (w / v, g / ml) hydroquinone inhibitor is added, and the reaction is terminated by ripening at 32-38° C. for 1-2 hours. The reaction solution is centrifuged at 4800-5200 rpm to remove unreacted monomers.

[0008] Specifically, in step S2, the supernatant is dialyzed with a 0.1 M NaCl solution at pH 4.7-4.9 for 12 hours and a 0.01 M phosphate buffer at pH 5.4-5.6 for 34-38 hours, and the conductivity of the final product is controlled to be ≤2.5 μS / cm; the NaCl solution is replaced every 1.5-2.5 hours; the phosphate buffer is replaced every 3.5-4.5 hours; and the dialysis uses a dialysis membrane with a molecular weight cutoff of 12-15 kDa.

[0009] Specifically, in step S2, the programmed freeze-drying method is: after equilibration at 4°C, the temperature is reduced to -18~-22°C at a rate of 0.4-0.6°C / min and maintained for 3-5 hours, then reduced to -43~-47°C at a rate of 0.8-1.2°C / min for pre-freezing, and freeze-dried at a vacuum degree of ≤10 Pa for 70-74 hours to obtain CSMA freeze-dried powder with a degree of substitution ≥86%.

[0010] Specifically, in step S3, the concentration of the chitosan methacrylic acid prepolymer solution is 4.2-4.8% (w / v, g / ml), and the photoinitiator is phenyl-2,4,6-trimethylbenzoyl lithium phosphinate; in the mixed solution, the concentration of phenyl-2,4,6-trimethylbenzoyl lithium phosphinate photoinitiator is 0.12-0.18% (w / v, g / ml), the concentration of the mixed vascular endothelial growth factor is 80-120 μg / mL, and the concentration of the antimicrobial peptide is 40-160 μg / mL.

[0011] Preferably, the mixed vascular endothelial growth factor may be, but is not limited to, Recombinant VEGF165, purchased from Shanghai Bio-Tech Biotechnology Co., Ltd.

[0012] Preferably, the antimicrobial peptide may be, but is not limited to, Tet-213, purchased from MedChemExpress.

[0013] Specifically, in step S3, the power of the oxygen plasma treatment is 50-60 W, the time is 90-100 seconds, and the contact angle of the PDMS mold surface after the oxygen plasma treatment is ≤30°.

[0014] Specifically, in step S3, the perfusion is completed by centrifugation at 2400-2600 rpm for 14-16 minutes; after removing the excess solution, the perfusion is completed at an intensity of 18-22 mW / cm2 The microneedle patch was cured by irradiating it with 360-370 nm ultraviolet light for 40-50 seconds. After demolding, it was washed and dried with PBS buffer of pH 7.2-7.4 to obtain a microneedle patch with a needle tip height of 580-920 μm and a base thickness of 220-280 μm.

[0015] Furthermore, the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide prepared by the above preparation method is also within the protection scope of the present invention. Preferably, the microneedle array is a close-packed structure, the needle tip cone angle is 28-32°, and the distance between adjacent needle tips is 380-420 μm.

[0016] Furthermore, the present invention also claims to protect the use of the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide in the preparation of infectious wound repair drugs.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention has successfully developed a drug-loaded hydrogel microneedle for the repair of infectious wounds. The methacrylated chitosan hydrogel microneedle is used as a drug carrier. It not only exhibits excellent biocompatibility and blood compatibility, but also can effectively stop bleeding. The hydrogel has no toxic side effects and has good potential for mass-production and repeated preparation.

[0018] (2) The drug-loaded hydrogel microneedles provided by the present invention form chemical bonds through the reaction of methacrylic anhydride with the amino and hydroxyl groups in chitosan. The reaction principle is clear and the operation process is simple. There is no need to undergo complex multiple chemical reactions, which greatly reduces costs and significantly improves repeatability.

[0019] (3) The preparation method of the drug-loaded hydrogel microneedles of the present invention is highly flexible. By adjusting the addition ratio of methacrylated chitosan and PEGDA, the mechanical properties of the drug-loaded hydrogel microneedles can be precisely controlled, so that they can better adapt to the needs of different wound environments.

[0020] (4) The present invention adds AMP and VEGF to the hydrogel microneedles. These two components exist in the gaps inside the hydrogel microneedles formed after photocuring and cross-linking, which can effectively prevent bacterial infection of wounds and promote wound healing, providing strong support for the repair of infectious wounds.

[0021] (5) The drug-loaded hydrogel microneedles provided by the present invention also have excellent extensibility. In addition to being able to load VEGF and AMP, they can also easily load other bioactive substances, such as antibiotics, anti-inflammatory drugs, etc., to meet the specific needs of different wound repairs, showing broad application prospects.

[0022] (6) The present invention innovatively constructs a CSMA hydrogel microneedle system: by optimizing the photocrosslinking parameters, the mechanical strength and swelling characteristics of the microneedles can be controlled and regulated; while the PEGDA network is used to enhance the structural stability, its hydrophilic chain can improve the loading efficiency of VEGF and AMP; the CSMA component gives the system inherent antibacterial activity, combined with the synergistic bactericidal effect of AMP to form a double antibacterial barrier; the sustained release of VEGF continuously promotes angiogenesis. This microneedle system breaks through the single functional limitation of traditional dressings and realizes the synergistic effect of infection control, vascular reconstruction and wound microenvironment regulation for the first time, providing an innovative solution for the comprehensive treatment of complex infectious wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0024] Figure 1 This is a diagram of the dual-drug synergistic action mechanism of the microneedle patch of the present invention, demonstrating that AMP / VEGF release achieves an antibacterial-angiogenic coupling effect.

[0025] Figure 2 Schematic diagram of CSMA synthesis path.

[0026] Figure 3 The actual picture shows CSMA gel before and after polymerization under ultraviolet light.

[0027] Figure 4 The contact angle change comparison chart of the PDMS mold treated with oxygen plasma (>100° before treatment, ≤30° after treatment).

[0028] Figure 5 Characterization of the morphology of the microneedle array.

[0029] Figure 6 For in vitro antibacterial property verification, fluorescent staining patterns were shown.

[0030] Figure 7 To verify the in vitro antibacterial performance, a statistical chart of the inhibition rate is shown.

[0031] Figure 8 These are actual photos of the wound healing rate during the repair process of infected wounds in rats. DETAILED DESCRIPTION

[0032] The present invention can be better understood with reference to the following examples.

[0033] The experimental methods used in the following examples are conventional methods unless otherwise specified, and the reagents, methods and equipment used are conventional reagents, methods and equipment in the art unless otherwise specified. The preparation process of the microneedle patch of the present invention is as follows: S1. Preparation of chitosan methacrylate (CSMA): The chitosan is dispersed in a pre-cooled acetic acid solution, and the chitosan solution is prepared after ultrasonic treatment; the monomer is slowly added dropwise in a nitrogen-protected thermostatic reactor at a molar ratio of chitosan to methacrylic anhydride of 1:0.7-0.9, and N-methylmorpholine (NMM) is used to catalyze the reaction; a hydroquinone inhibitor is added to terminate the reaction after aging; the reaction solution is centrifuged to remove unreacted monomers; S2. Purification and freeze-drying: The supernatant obtained in step S1 is dialyzed with a NaCl solution and a phosphate buffer solution in sequence, and the dialyzate is freeze-dried by programmed method to obtain chitosan methacrylate (CSMA) freeze-dried powder; S3. Preparation of microneedle patch: The chitosan methacrylate (CSMA) freeze-dried powder obtained in step S2 is re-dissolved in deionized water to prepare a chitosan methacrylate prepolymer solution, a photoinitiator is added, and vascular endothelial growth factor (VEGF) and antimicrobial peptide (AMP) are mixed; the mixed solution is then injected into the microneedle mold treated with oxygen plasma, centrifuged to complete the perfusion and remove the excess solution, and then cured under ultraviolet light. After demolding, it is washed with PBS buffer and dried to obtain the microneedle mold.

[0034] The microneedle patch of the present invention has the following characteristics: Figure 1 The dual-drug synergistic mechanism shown can enable AMP / VEGF release to achieve an antibacterial-angiogenic coupling effect.

[0035] Example 1: CSMA synthesis path verification 2.8% (w / v, g / ml) chitosan was dissolved in a precooled 1.5% (v / v) acetic acid solution, and after being ultrasonically treated at 40 kHz for 15 minutes, it was transferred to a nitrogen-protected reactor. The monomer was added twice at a molar ratio of chitosan to methacrylic anhydride of 1:0.8 at 10°C. The first addition was a molar ratio of 1:0.5, and the remaining monomer was added after 1.5 hours. 2.0% (w / v, g / ml) N-methylmorpholine was used to catalyze the reaction for 3 hours. After the reaction was terminated, the precipitate was removed by centrifugation at 5000 rpm, and the supernatant was dialyzed with 0.1 M NaCl solution at pH 4.8 for 12 hours (with a 2-hour interval between changes) and 0.01 M phosphate buffer at pH 5.5 for 36 hours (with a 4-hour interval between changes). The conductivity of the final product was ≤2.3 μS / cm. The reaction pathway is as follows Figure 2 shown.

[0036] Example 2: Visual verification of photopolymerization process Take 4.5% (w / v, g / ml) CSMA prepolymer solution, add 0.15% (w / v, g / ml) phenyl-2,4,6-trimethylbenzoyl lithium phosphinate photoinitiator, inject it into the PDMS mold treated with oxygen plasma (50 W, 90 seconds), and irradiate it under 365 nm ultraviolet light (intensity 20 mW / cm²) for 45 seconds. The obtained CSMA gel before and after polymerization under ultraviolet light is as follows: Figure 3 As shown. Before polymerization, the solution was in a transparent and flowing state ( Figure 3 After solidification, a solid gel is formed ( Figure 3 Down).

[0037] Example 3: Optimization and verification of wettability of PDMS mold by oxygen plasma treatment The surface of the PDMS microneedle mold was treated with 50 W oxygen plasma for 90 seconds, and the wettability changes before and after treatment were measured by a contact angle meter. Figure 4 As shown. The contact angle of the untreated mold surface is 105.3°±3.5° ( Figure 4 Left), showing strong hydrophobicity; after treatment, the contact angle dropped to 27.9°±2.1° ( Figure 4 Right) to achieve hydrophilic modification.

[0038] Example 4: Preparation and morphology characterization of drug-loaded microneedle arrays The CSMA freeze-dried powder was re-dissolved in deionized water to prepare a 4.5% (w / v, g / ml) CSMA prepolymer solution, and 0.15% (w / v, g / ml) phenyl-2,4,6-trimethylbenzoylphosphinate lithium photoinitiator was added, and VEGF (100 μg / mL) and AMP (100 μg / mL) were mixed; the mixed solution was injected into the PDMS microneedle mold treated with oxygen plasma, and the injection was completed by centrifugation at 2500 rpm for 15 minutes; after removing the excess solution, it was irradiated under 365 nm ultraviolet light (intensity 20 mW / cm²) for 45 seconds to cure, and after demolding, it was washed and dried with pH 7.2 PBS buffer to obtain a microneedle patch with a needle tip height of 700 μm and a base thickness of 250 μm. The actual picture of the microneedle array was taken by stereo microscope ( Figure 5 ), clearly showing the hexagonal close-packed structure, the height of a single microneedle tip was measured to be 700±20 μm, and the distance between adjacent tips was measured to be 400±10 μm.

[0039] Example 5: Preparation and morphology characterization of blank microneedle array The CSMA lyophilized powder was re-dissolved in deionized water to prepare a 4.5% (w / v, g / ml) CSMA prepolymer solution, and 0.15% (w / v, g / ml) phenyl-2,4,6-trimethylbenzoylphosphinate lithium photoinitiator was added, without adding VEGF and AMP; the mixed solution was injected into the PDMS microneedle mold treated with oxygen plasma and centrifuged at 2500 rpm for 15 minutes to complete the perfusion; after removing the excess solution, the mixture was irradiated under 365nm ultraviolet light (intensity 20 mW / cm²) for 45 seconds to cure, and after demolding, it was washed and dried with PBS buffer at pH 7.2 to obtain a microneedle patch with a needle tip height of 700 μm and a base thickness of 250 μm.

[0040] Example 6: In vitro antibacterial performance verification The microneedles prepared in Example 4 were recorded as drug-loaded microneedles (MN@drug group). The microneedles prepared in Example 5 were recorded as blank microneedles (MN group). The prepared blank microneedles (MN group) and drug-loaded microneedles (MN@drug group) were co-cultured with Staphylococcus aureus and Escherichia coli for 24 hours, respectively, and the untreated bacterial solution was used as the control group (Control). Fluorescence staining results ( Figure 6 ) showed that the bacteria in the Control group showed dense green fluorescence (live bacteria), the green fluorescence density in the MN group was significantly reduced, and the green fluorescence in the MN@drug group almost disappeared, which directly showed the strong antibacterial effect of the drug-loaded microneedles, and the blank microneedles also had a certain effect. The antibacterial rate was determined by the plate colony counting method ( Figure 7 ), the inhibition rate of the MN group against Staphylococcus aureus was over 60%, and the inhibition rate against Escherichia coli was over 70%; the inhibition rate of the MN@drug group against both bacteria was over 95%.

[0041] Example 7: Rat infection wound repair experiment The microneedles prepared in Example 4 were recorded as drug-loaded microneedles (Combine group). The microneedles prepared in Example 5 were recorded as blank microneedles (MN group). A full-thickness skin defect model with a diameter of 8 mm infected by MRSA was established (n=24) and divided into three groups: Control group, MN group, and Combine group. The Control group was only treated with PBS buffer, and the other two groups were treated with corresponding microneedles on the wound surface. The wound area was recorded daily after surgery ( Figure 8 ), the healing rate of the Combine group reached more than 95% on the 9th day, which was significantly higher than that of the control group (about 60%) and the blank microneedle group (about 85%).

[0042] The present invention provides a chitosan methacrylic acid hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptides, and a preparation method and application thereof. There are many methods and approaches to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A method for preparing a chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide, characterized in that: The steps include: S1. Preparation of chitosan methacrylic acid: Dispersing chitosan in a precooled acetic acid solution, and preparing a chitosan solution after ultrasonic treatment; slowly adding monomers in a nitrogen-protected thermostatic reactor at a molar ratio of chitosan to methacrylic anhydride of 1:0.7-0.9, and using N-methylmorpholine to catalyze the reaction; adding a hydroquinone inhibitor to terminate the reaction after aging; and removing unreacted monomers from the reaction solution by centrifugation; S2. Purification and freeze-drying: The supernatant obtained in step S1 is dialyzed with NaCl solution and phosphate buffer solution in sequence, and the dialyzate is freeze-dried by programmed method to obtain chitosan methacrylic acid freeze-dried powder; S3. Preparation of microneedle patch: The chitosan methacrylate freeze-dried powder obtained in step S2 is redissolved in deionized water to prepare a chitosan methacrylate prepolymer solution, a photoinitiator is added, and vascular endothelial growth factor and antimicrobial peptide are mixed; the mixed solution is then injected into the microneedle mold treated with oxygen plasma, centrifuged to complete the perfusion and remove the excess solution, and then cured under ultraviolet light. After demolding, the mixture is washed with PBS buffer and dried to obtain the microneedle mold.

2. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S1, chitosan is dispersed in a precooled 1.2-1.8% (v / v) acetic acid aqueous solution, and solubilized by ultrasonic treatment at 40-50 kHz and 150-200 W for 15-20 minutes at 2-4°C to prepare a 2.8-3.2% (w / v) chitosan solution; the low temperature environment is 8-12°C; the methacrylic anhydride is added twice, with the first addition having a molar ratio of 1:0.5-0.6, and the remaining monomers are added after the reaction for 1-2 hours.

3. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S1, after 1.8-2.2% (w / v) N-methylmorpholine is used for catalytic reaction for 2.5-3 hours, 0.04-0.06% (w / v) hydroquinone inhibitor is added, and the reaction is terminated by ripening at 32-38° C. for 1-2 hours. The reaction solution is centrifuged at 4800-5200 rpm to remove unreacted monomers.

4. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S2, the supernatant is dialyzed with 0.1 M NaCl solution at pH 4.7-4.9 for 12 hours and 0.01 M phosphate buffer at pH 5.4-5.6 for 34-38 hours, and the conductivity of the final product is controlled to be ≤2.5 μS / cm; the NaCl solution is replaced every 1.5-2.5 hours; the phosphate buffer is replaced every 3.5-4.5 hours; and the dialysis uses a dialysis membrane with a molecular weight cutoff of 12-15 kDa.

5. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S2, the programmed freeze-drying method is: after equilibration at 4°C, the temperature is reduced to -18~-22°C at a rate of 0.4-0.6°C / min and maintained for 3-5 hours, then the temperature is reduced to -43~-47°C at a rate of 0.8-1.2°C / min for pre-freezing, and freeze-dried at a vacuum degree of ≤10Pa for 70-74 hours to obtain CSMA freeze-dried powder with a degree of substitution ≥86%.

6. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S3, the concentration of the chitosan methacrylic acid prepolymer solution is 4.2-4.8% (w / v), and the photoinitiator is phenyl-2,4,6-trimethylbenzoyl lithium phosphinate; in the mixed solution, the concentration of phenyl-2,4,6-trimethylbenzoyl lithium phosphinate photoinitiator is 0.12-0.18% (w / v), the concentration of the mixed vascular endothelial growth factor is 80-120 μg / mL, and the concentration of the antimicrobial peptide is 40-160 μg / mL.

7. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S3, the power of the oxygen plasma treatment is 50-60 W, the time is 90-100 seconds, and the contact angle of the PDMS mold surface after the oxygen plasma treatment is ≤30°.

8. The method for preparing the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 1, characterized in that: In step S3, the perfusion was completed by centrifugation at 2400-2600 rpm for 14-16 minutes; after removing the excess solution, the perfusion was completed at an intensity of 18-22 mW / cm 2 The microneedle patch was cured by irradiating it with 360-370 nm ultraviolet light for 40-50 seconds. After demolding, it was washed and dried with PBS buffer of pH 7.2-7.4 to obtain a microneedle patch with a needle tip height of 580-920 μm and a base thickness of 220-280 μm.

9. The chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The microneedle array has a densely packed structure, with a needle tip cone angle of 28-32° and a distance between adjacent needle tips of 380-420 μm.

10. Use of the chitosan methacrylate hydrogel microneedle patch loaded with vascular endothelial growth factor and antimicrobial peptide according to claim 9 in the preparation of infectious wound repair drugs.

Images