Preparation method and application of soluble difunctional conductive microneedle patch

Abstract

The invention relates to the technical field of biological materials, in particular to a preparation method and application of a soluble difunctional conductive microneedle patch. A preparation method of a soluble bifunctional conductive microneedle patch comprises the following steps: (1) adding low molecular weight hyaluronic acid M and catalase into deionized water to prepare an HA-CAT solution; (2) adding N, N-dimethylformamide and methacrylic anhydride into the low-molecular-weight hyaluronic acid solution, adjusting the pH value, and adding salt to prepare methacrylated hyaluronic acid; and (3) dissolving a photoinitiator and methacrylated hyaluronic acid in deionized water, adding the black phosphorus nanosheets to prepare an HAMA-BP solution, filling the needle tip part with the HAMA-BP solution, and filling the substrate part with the HA-CAT solution to obtain the black phosphorus / HAMA / BP composite probe. The conductive microneedle patch has excellent mechanical performance and biocompatibility, ROS can be removed to generate oxygen, the electrophysiological requirement of the heart is met, and the black phosphorus nanosheet responds to the change of the pH value and continuously releases and plays a role in removing active oxygen in an anoxic environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomaterials, in particular to a preparation method and application of a soluble dual-functional conductive microneedle patch. BACKGROUND

[0002] Acute myocardial infarction (AMI), also known as myocardial infarction, is a life-threatening disease caused by acute obstruction of the coronary artery, leading to insufficient blood supply to the corresponding myocardial region, resulting in myocardial necrosis. Acute myocardial infarction is a major cause of death and disability worldwide. After myocardial infarction, myocardial cells in the coronary occlusion site lose a large amount of cells due to acute ischemia-reperfusion injury, ultimately leading to heart failure.

[0003] Currently, the therapy for heart failure after myocardial infarction is limited, and the only effective treatment for end-stage is heart transplantation. However, heart transplantation still faces many challenges such as shortage of donors, high surgical risk and technical requirements, and immune rejection after transplantation, and therefore cannot be widely used in clinical practice. Microneedle patches are medical devices that deliver drugs by breaking through the stratum corneum of the skin with micron-sized needles. The core technology includes high drug loading material preparation and physical penetration technology. Microneedle patches, as an effective transdermal drug delivery device, can create a micron-sized drug delivery channel without pain, enhancing the effect of active substances or drugs on the heart. Soluble microneedle patches are an innovative transdermal drug delivery technology that uses micron-sized needle arrays to penetrate the stratum corneum of the skin and deliver drugs or active ingredients painlessly. Soluble microneedle patches are made of soluble and degradable polymer materials, which release and remove excess reactive oxygen species generated after myocardial infarction after the degradation of the polymer materials. The conductive properties of black phosphorus nanosheets with high biocompatibility can enhance myocardial electrical signal conduction and promote the recovery of electrical physiological function in the infarct area. Combined with modified methacrylated hyaluronic acid, it provides mechanical support for the myocardium. Therefore, there is a need to provide a biodegradable conductive microneedle patch with sustained-release effect. SUMMARY

[0004] The present application provides a preparation method and application of a biodegradable conductive microneedle patch with sustained-release effect for reversing ventricular remodeling after myocardial infarction.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of a soluble dual-functional conductive microneedle patch, comprising the following steps: (1) Add low molecular weight hyaluronic acid M and catalase to deionized water, mix uniformly, and stand to remove bubbles to prepare a HA-CAT solution, which is ready for use; (2) adding N,N-dimethylformamide and methacrylic anhydride to the low molecular weight hyaluronic acid solution, then adjusting the pH value, adding salt, and finally filtering, dialyzing, and freeze-drying to obtain methacrylated hyaluronic acid; the methacryl groups (containing carbon-carbon double bonds C=C) on the methacrylic anhydride are grafted to the skeleton of the hyaluronic acid molecule; (3) dissolving the photoinitiator and the methacrylated hyaluronic acid in deionized water, adding black phosphorus nanosheets to obtain a HAMA-BP solution, filling the tip of a mold with the HAMA-BP solution, filling the base of the mold with the HA-CAT solution, vacuum drying, and demolding to obtain the product.

[0006] Preferably, in step (1), the low molecular weight hyaluronic acid M has a molecular weight of 100,000-200,000; and the mass ratio of the low molecular weight hyaluronic acid M to the catalase is 10-20:1.

[0007] Preferably, in the HA-CAT solution, the mass concentration of the low molecular weight hyaluronic acid M is 75-100 mg / mL, and the mass concentration of the catalase is 5-10 mg / mL. Further preferably, the mass concentration of the low molecular weight hyaluronic acid M is 75 mg / mL, and the mass concentration of the catalase is 5 mg / mL.

[0008] Preferably, in step (2), the low molecular weight hyaluronic acid N is dissolved in deionized water to obtain a low molecular weight hyaluronic acid solution, N,N-dimethylformamide is slowly added, and after uniform stirring, methacrylic anhydride is added, then NaOH is added to adjust the pH value to 8-9, NaCl is added, and stirring is performed until complete dissolution, finally, anhydrous ethanol is added, the solution is filtered at least once, then washed with anhydrous ethanol, the washed solution is dialyzed, and then placed in a freeze dryer, and after freeze-drying for 48-72 h, methacrylated hyaluronic acid is obtained.

[0009] Further preferably, the low molecular weight hyaluronic acid N has a molecular weight of 20 Kda-40 Kda, and the mass concentration of the low molecular weight hyaluronic acid N in the low molecular weight hyaluronic acid solution is 15-25 mg / mL.

[0010] Still further preferably, the mass ratio of the low molecular weight hyaluronic acid N to the methacrylic anhydride is 1.2-1.4:1, and the volume ratio of the N,N-dimethylformamide to the deionized water is 55-70%; and the molecular weight of the methacrylated hyaluronic acid retained after filtration is ≥8000 Da.

[0011] Preferably, in step (3), the methyl acrylate hyaluronic acid is dissolved in deionized water containing a photoinitiator, black phosphorus nanosheet is added and stirred to completely dissolve, to obtain a HAMA-BP solution, then the HAMA-BP solution is filled into the tip of the PDMS mold, the excess part is scraped off, the HA-CAT solution is filled into the base of the PDMS mold, the excess part is scraped off, vacuum is drawn at least once, each time for 5-30 min, and after drying at room temperature, the mold is demolded by ultraviolet irradiation to obtain the product.

[0012] Preferably, in step (3), the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoyl phosphonate, the mass concentration of the photoinitiator in the HAMA-BP solution is 0.1-1.0 mg / mL, the mass concentration of the methyl acrylate hyaluronic acid is 50-100 mg / mL, and the mass concentration of the black phosphorus nanosheet is 0.1-5 mg / mL.

[0013] A soluble bifunctional conductive microneedle patch is prepared by the above method.

[0014] The soluble bifunctional conductive microneedle patch is used for preparing a drug for preventing and / or treating myocardial infarction.

[0015] Beneficial effects: The conductive microneedle patch comprises a base part and a tip part, wherein the microneedle base part is prepared by mixing low-molecular hyaluronic acid (HA) and catalase (CAT) to form a self-crosslinked HA-CAT, the low-molecular hyaluronic acid is naturally degradable, the HA-CAT as the base part can be quickly degraded to avoid tissue adhesion caused by the base part, and the catalase can decompose excess ROS generated by ischemia and hypoxia after myocardial infarction into H2O and O2. The microneedle tip part is prepared by mixing HAMA (methyl acrylate hyaluronic acid) modified from low-molecular hyaluronic acid and black phosphorus nanosheet (BP), and a photoinitiator is added for photocuring and crosslinking to delay degradation.

[0016] The microneedle technology is used to target drug delivery, and the natural product hyaluronic acid is used as the base part, which is quickly degraded to release CAT to decompose excess active oxygen into oxygen, thereby relieving the hypoxic environment caused by the microenvironment disorder after myocardial infarction. The methyl acrylate hyaluronic acid is used as the microneedle array, the modified hyaluronic acid is chemically crosslinked, the internal structure is more stable, and the degradation is delayed. The black phosphorus has conductivity, can meet the electrical physiological requirements of the heart, and can improve the mechanical strength, thereby providing mechanical support for the weak ventricular wall.

[0017] The conductive microneedle patch provided by the application has excellent mechanical properties and biocompatibility, removes ROS to generate oxygen, meets the electrophysiological needs of the heart, and the slowly degradable microneedle array makes the black phosphorus nanosheet respond to the change of pH value and the continuous release in the hypoxic environment to play the role of removing active oxygen. The microneedle patch is fixed in the myocardial infarction area, which not only meets the electrophysiological function of the myocardium, but also helps to release the drug and exert the pharmacodynamic effect, and at the same time provides excellent mechanical support for the weak myocardial tissue. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of this application are used to provide further understanding of the application, the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute an improper limitation on the application. Among them: Figure 1 It is the Fourier infrared spectrum of methylacrylated hyaluronic acid (HAMA) and low molecular weight hyaluronic acid (molecular weight is 20Kda-40Kda, HA); Figure 2 It is a scanning electron microscope image of black phosphorus nanosheet, wherein the (right) figure is an enlarged view of the (left) figure; Figure 3 It is a quantitative diagram of hydrogen peroxide removal rate; Figure 4 It is a scanning electron microscope image of the microneedle patch prepared in Example 1; Figure 5 It is a mechanical property curve diagram of the microneedle patch prepared in Example 1; Figure 6 It is a biocompatibility CCK8 statistical diagram of the microneedle patch prepared in Example 1; Figure 7 It is an alpha-actinin immunofluorescence diagram of the microneedle patch prepared in Example 1; Figure 8 It is a FLUO-4 immunofluorescence diagram of the microneedle patch prepared in Example 1; Figure 9 It is a FLUO-4 immunofluorescence intensity quantitative statistical diagram of the microneedle patch prepared in Example 1; Figure 10 It is a degradation diagram of the microneedle patch prepared in Example 1. DETAILED DESCRIPTION

[0019] The application will be described in detail below with reference to the drawings and in conjunction with embodiments. Various examples are provided by way of explanation of the application but are not meant to limit the application. It will be apparent to those skilled in the art that modifications and variations can be made in the present application without departing from the scope or spirit of the application. For example, features shown or described as part of one embodiment can be used in another embodiment to yield still a further embodiment. It is intended that all such additional embodiments come within the scope of the embodiments of the present application and that of its claims.

[0020] A preparation method of a soluble bifunctional conductive microneedle patch, comprising the following steps: (1) adding low molecular weight hyaluronic acid M and catalase into deionized water, uniformly mixing and then standing to remove bubbles to prepare a HA-CAT solution, for standby use; wherein the molecular weight of the low molecular weight hyaluronic acid M is 100000-200000; the mass ratio of the low molecular weight hyaluronic acid M to the catalase is 10-20:1; in the HA-CAT solution, the mass concentration of the low molecular weight hyaluronic acid M is 75-100 mg / mL, and the mass concentration of the catalase is 5-10 mg / mL.

[0021] (2) dissolving low molecular weight hyaluronic acid N in deionized water to prepare a low molecular weight hyaluronic acid solution, slowly adding N,N-dimethylformamide, uniformly stirring, then adding methacrylic anhydride, then adding NaOH to adjust the pH value to 8-9, then adding NaCl, stirring until completely dissolved, finally adding anhydrous ethanol, filtering at least once, then washing with anhydrous ethanol, dialyzing the washed solution, placing it in a freeze dryer, freeze-drying for 48-72 h, and then preparing methacrylated hyaluronic acid. Wherein the molecular weight of the low molecular weight hyaluronic acid N is 20Kda-40Kda, the mass concentration of the low molecular weight hyaluronic acid N in the low molecular weight hyaluronic acid solution is 15-25 mg / mL. The mass ratio of the low molecular weight hyaluronic acid N to the methacrylic anhydride is 1.2-1.4:1, the volume ratio of the N,N-dimethylformamide solution is 55-70%, and the molecular weight of the methacrylated hyaluronic acid retained after filtration is ≥8000 Da.

[0022] (3) The methylacrylated hyaluronic acid is dissolved in deionized water containing a photoinitiator, 1 mg of black phosphorus nanosheet is added to the above solution and stirred to completely dissolve, to prepare a HAMA-BP solution, then 50 μL of the HAMA-BP solution is filled into the tip of a PDMS mold, the excess part is scraped off, 200 μL of the HA-CAT solution is filled into the base of the PDMS mold, the excess part is scraped off, vacuum is repeatedly drawn for 3 times, each time for 15 min, air blowing is carried out at room temperature overnight, and UV irradiation is used for demolding to obtain the product. In the HAMA-BP solution, the mass concentration of the photoinitiator is 0.1-1.0 mg / mL, the mass concentration of the methylacrylated hyaluronic acid is 50-100 mg / mL, and the mass concentration of the black phosphorus nanosheet is 0.1-5 mg / mL.

[0023] Example 1 A preparation method of a soluble bifunctional conductive microneedle patch, comprising the following steps: (1) 75 mg of low molecular weight hyaluronic acid M (molecular weight is 100000-200000) is added into 1 mL of deionized water containing 5 mg of catalase, stirred for 5 min, and mixed uniformly, left to stand for 10 min to remove bubbles to prepare a HA-CAT solution, for standby use.

[0024] (2) 4 g of low molecular weight hyaluronic acid N (molecular weight is 20 Kda-40 Kda) is fully dissolved in 200 mL of deionized water, 133.3 mL of N,N-dimethylformamide is slowly added dropwise, uniformly stirred by magnetic stirring, then 4.8 mL of methacrylic anhydride solution is added, 1 mol of NaOH is used to adjust the pH value to 8, the change of the pH value is monitored in real time, the magnetic stirring is carried out at a speed of 300 rpm for 24 h, then 9.8 g of NaCl is added, the stirring is continuously carried out until completely dissolved, 500 mL of anhydrous ethanol is added, the solution is filtered twice and washed with anhydrous ethanol, the washed solution is added into a dialysis bag, deionized water dialysis is carried out for 3 days, then the solution is placed in a freeze dryer, and freeze-drying is carried out for 72 h to prepare methylacrylated hyaluronic acid, wherein the molecular weight of the methylacrylated hyaluronic acid retained after filtration is ≥8000 Da.

[0025] (3) 50 mg of methylacrylated hyaluronic acid is dissolved in 1 mL of deionized water containing 0.5 mg of lithium phenyl-2,4,6-trimethylbenzoyl phosphinic acid salt, 1 mg of black phosphorus nanosheet is added to the above solution and stirred to completely dissolve to prepare a HAMA-BP solution; 50 μL of the HAMA-BP solution is filled into the tip of a PDMS mold, the excess part is scraped off, 200 μL of the HA-CAT solution is filled into the base of the PDMS mold, the excess part is scraped off, vacuum is repeatedly drawn for 3 times, each time for 15 min, air blowing is carried out at room temperature overnight, and UV irradiation is used for demolding to obtain the product.

[0026] Comparative Example 1 A preparation method of a soluble bifunctional conductive microneedle patch, comprising the following steps: The preparation method of the comparative example is different from that of Example 1 as follows: 50 mg of methacrylated hyaluronic acid is dissolved in 1 mL of deionized water containing 0.5 mg of a photoinitiator (lithium phenyl-2,4,6-trimethylbenzoyl phosphinate) to prepare a HAMA solution; 50 μL of the HAMA solution is filled into the tip part of the PDMS mold, and the excess part is scraped off, then 200 μL of HA-CAT is filled into the base part of the PDMS mold, and the excess part is scraped off, and vacuum is repeatedly drawn for 3 times, each time for 15 min, and the room temperature blast cabinet is used overnight, and the UV irradiation is demolded to obtain the product.

[0027] Characterization and analysis (1) The characteristic peaks of low molecular weight hyaluronic acid (molecular weight of 200 Kda-400 Kda) and methacrylated hyaluronic acid prepared in Example 1 are analyzed by Fourier infrared spectroscopy, and the steps are as follows: After drying the sample to be tested, it is ground and mixed with potassium bromide (KBr), usually in a ratio of 1:100, and pressed into a transparent sheet on a tablet press. Before testing the sample, background correction is needed, and a blank sheet is used as the background to record the background spectrum. Place the prepared sample on the sample holder, ensuring that the sample surface is flat and free of contamination. Adjust the sample holder position so that the sample is in the center of the light beam, ensuring that the light beam can uniformly irradiate the sample. Set the scanning range to 4000-400 cm⁻¹, usually with a resolution of 4 cm⁻¹, and record the characteristic peak corresponding to the methacryl group introduced into the hyaluronic acid.

[0028] Figure 1 The characteristic peaks of methacrylated hyaluronic acid (HAMA) are analyzed by Fourier infrared spectroscopy, and compared with hyaluronic acid (HA). Both of them have characteristic peaks at 1715-1720 cm -1 , which proves that the synthesis of methacrylated hyaluronic acid is successful.

[0029] (2) A certain amount of black phosphorus nanosheet is dropped into a silicon wafer, and the sample is scanned by a scanning microscope after ensuring that there is no water in the sample. Figure 2 It can be seen that the black phosphorus nanosheet has a layered wrinkled structure, and the size is about 500 nm.

[0030] (3) 100 mmol of hydrogen peroxide solution and black phosphorus nanosheets (BP) with concentrations of 0, 10, 20, 30, 40, and 50 μg / mL were incubated in 2 mL of PBS for 24 h, and the hydrogen peroxide concentration was detected using a hydrogen peroxide kit. Figure 3 The ability of black phosphorus nanosheets (BP) to scavenge hydrogen peroxide was quantitatively analyzed, and Figure 3It can be seen that the removal rate of hydrogen peroxide increases with the increase of the concentration of black phosphorus nanosheet (BP).

[0031] (4) After drying the HA-CAT / HAMA-BP, a certain amount of sample is taken and placed on the conductive glue, gold is sprayed, and a scanning microscope is used for morphology characterization. Figure 4 The microneedle patch prepared in Example 1 is characterized by Figure 4 It can be seen that the microneedle patch prepared by the application has uniform length, good morphology and flat base.

[0032] (5) In order to evaluate whether the addition of black phosphorus nanosheet will affect the mechanical properties of microneedles, the mechanical properties of HA-CAT / HAMA and HA-CAT / HAMA-BP are analyzed, and the influence of the addition of black phosphorus on the mechanical properties is evaluated by measuring the force-displacement curve.

[0033] Figure 5 The mechanical properties of the microneedle patch are characterized by Figure 5 It can be seen that the strength of the microneedle patch is 0.41N / needle, which is sufficient to penetrate the myocardial tissue.

[0034] (6) In order to evaluate the cytotoxicity of HA-CAT / HAMA-BP, CCK8 method is used to explore the toxicity of microneedle patch to H9C2 cells, and H9C2 cells are inoculated in 96-well plates at a density of 6x10 3 cells per well, 100 muL of DMEM medium containing H9C2 cells is added to each well, and the culture is incubated at 37 DEG C, 5% CO2 for 24 hours. Then co-culture for 1, 3 and 7 days, and use CCK-8 kit to detect the proliferation of cells cultured for 1, 3 and 7 days.

[0035] Figure 6 The biocompatibility of the microneedle patch is characterized by CCK-8 kit, and the cell viability of 1, 3 and 7 days is detected by Figure 6 It can be seen that the microneedle patch of 1, 3 and 7 days has no statistical significance compared with the blank group, which indicates that the microneedle patch has good biocompatibility.

[0036] (7) In order to evaluate the conductive performance of the microneedle patch, the myocardial cell calcium ion fluorescent probe Fluo-4 participates in the myocardial electrical signal transmission and calcium signal regulation, and alpha-actinin is the key protein of myocardial cell skeleton, mainly located in Z disc, although it does not directly participate in electrical conduction, but through maintaining the structure of sarcomere and ion channel positioning, indirectly regulating the conductive performance of myocardium, and the electrical conduction ability has a significant influence on both, after co-culturing the microneedle patch with myocardial cells, FLUO-4 detection and alpha-actinin immunofluorescence staining detection are carried out.

[0037] Figure 7The conductivity of the microneedle patch was assessed by α-actinin immunofluorescence staining. Figure 7 It can be seen that the fluorescence intensity of the microneedle patch group was significantly higher than that of the control group.

[0038] Figure 8 The conductivity of the microneedle patch was assessed using FLUO-4 immunofluorescence staining. Figure 8 It can be seen that, compared with the control group, the calcium ion concentration of the microneedle patch group prepared by the present invention is increased. Figure 9 Quantitative analysis of the fluorescence intensity of FLUO-4 revealed an increase in the fluorescence intensity of the microneedle patch.

[0039] (8) In order to evaluate the degradation performance of the microneedle patch, the prepared microneedle patch was placed in a dish containing PBS. The base began to degrade in 30 seconds and the base was basically completely degraded in 90 seconds, with the needle tip dispersed in PBS.

[0040] Figure 10 The biodegradability of microneedle patches was analyzed, by Figure 10 It can be seen that substrate degradation and needle tip diffusion are visible in PBS after 120 seconds.

[0041] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a soluble bi-functional conductive microneedle patch, characterized in that, The method comprises the following steps: (1) adding low molecular weight hyaluronic acid M and catalase into deionized water, mixing uniformly to prepare HA-CAT solution, and reserving; (2) adding N,N-dimethylformamide and methacrylic anhydride into the low molecular weight hyaluronic acid solution, then adjusting pH value, adding salt, and finally filtering, dialyzing, freeze-drying to prepare methacrylated hyaluronic acid; (3) dissolving photoinitiator and the methacrylated hyaluronic acid in deionized water, adding black phosphorus nanosheet to prepare HAMA-BP solution, then filling the HAMA-BP solution into the tip part of the mold, filling the above-mentioned HA-CAT solution into the base part of the mold, vacuum drying and demolding to obtain.

2. The method for preparing the soluble bifunctional conductive microneedle patch according to claim 1, characterized in that, In step (1), the molecular weight of the low molecular weight hyaluronic acid M is 100000-200000; the mass ratio of the low molecular weight hyaluronic acid M to catalase is 10-20:

1.

3. The method of claim 1 or 2, wherein the method is characterized by, In the HA-CAT solution, the mass concentration of the low molecular weight hyaluronic acid M is 75-100 mg / mL, and the mass concentration of the catalase is 5-10 mg / mL.

4. The method of claim 1 or 3, wherein the method is characterized by, In step (2), the low molecular weight hyaluronic acid N is dissolved in deionized water to prepare a low molecular weight hyaluronic acid solution, N,N-dimethylformamide is slowly added dropwise, and after stirring uniformly, methacrylic anhydride is added, then NaOH is added to adjust the pH value to 8-9, NaCl is added, stirring until completely dissolved, finally, anhydrous ethanol is added, filtered at least once, then washed with anhydrous ethanol, the washed solution is dialyzed, placed in a freeze dryer, freeze-dried for 48-72 h to prepare methacrylated hyaluronic acid.

5. The method for preparing the soluble bifunctional conductive microneedle patch according to claim 4, characterized in that, The molecular weight of the low molecular weight hyaluronic acid N is 200Kda-400Kda, and the mass concentration of the low molecular weight hyaluronic acid N in the low molecular weight hyaluronic acid solution is 15-25 mg / mL.

6. The method of claim 4 or 5, wherein the method further comprises the step of: The mass ratio of the low molecular weight hyaluronic acid N to methacrylic anhydride is 1.2-1.4:1, and the volume ratio of N,N-dimethylformamide to deionized water is 55-70%; the molecular weight of the methacrylated hyaluronic acid retained after filtration is ≥8000 Da.

7. The method of making a dissolvable bi-functional conductive microneedle patch according to claim 1 or 3 or 4, wherein, In step (3), the above-mentioned methacrylated hyaluronic acid is dissolved in deionized water containing a photoinitiator, black phosphorus nanosheet is added and stirred to completely dissolve to prepare HAMA-BP solution, then the HAMA-BP solution is filled into the tip part of the PDMS mold, the excess part is scraped off, the above-mentioned HA-CAT solution is filled into the base part of the PDMS mold, the excess part is scraped off, vacuum is drawn at least once, each time for 5-30 min, dried at room temperature, then ultraviolet irradiation demolding is performed to obtain.

8. The method of claim 1 or 7, wherein the method is characterized by, In step (3), the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoyl phosphonate, the mass concentration of the photoinitiator in the HAMA-BP solution is 0.1-1.0 mg / mL, the mass concentration of the methacrylated hyaluronic acid is 50-100 mg / mL, and the mass concentration of the black phosphorus nanosheet is 0.1-5 mg / mL.

9. A soluble bi-functional conductive microneedle patch, characterized by, The conductive microneedle patch is prepared by the method of claim 1 or 3 or 4 or 7.

10. Use of the soluble bifunctional conductive microneedle patch according to claim 9 for the preparation of a medicament for preventing and / or treating myocardial infarction.

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