Acellular matrix hydrogel microneedle with biological activity and preparation method thereof

Abstract

The invention provides an extracellular matrix hydrogel microneedle with biological activity and a preparation method of the extracellular matrix hydrogel microneedle, and belongs to the technical field of medicines. The preparation method of the extracellular matrix hydrogel microneedle with biological activity comprises the following steps: carrying out ultrasonic treatment on methacrylated porcine small intestinal submucosa (SISMA) to prepare hydrogel, adding a photoinitiator into the prepared hydrogel, injecting into a microneedle mold, and concentrating and curing to obtain the extracellular matrix hydrogel microneedle. The hydrogel microneedle disclosed by the invention has good biological activity and better swelling property, and has a good prospect in biological medicine.

Description

Technical Field

[0001] The invention belongs to the field of medical technology, and specifically relates to a bioactive acellular matrix hydrogel microneedle and a preparation method thereof. Background Art

[0002] Microneedles are a needle tip array with a length of 0.2mm-2.0mm that can penetrate the epidermal stratum corneum with minimal stimulation of pain nerves, providing a transdermal delivery solution for non-lipid-soluble, non-small molecule drugs.

[0003] There are many types of microneedle drug delivery technologies, which mainly include surface coating technology, hollow microneedle technology, soluble microneedle technology and hydrogel microneedle technology. Among them, hydrogel microneedles are a new type of microneedle, which uses hydrogels with high biocompatibility as materials, penetrates the stratum corneum by using the mechanical strength of the gel scaffold in a dry state, and absorbs tissue fluid and then swells and slowly releases drugs under the skin by using the hydrophilic properties of the hydrogel. Compared with other microneedle technologies, hydrogel microneedles have the advantages of large drug loading, high biocompatibility and controllable drug release, and have therefore become a hot spot in microneedle technology.

[0004] At present, most of the materials used for the preparation of hydrogel microneedles are polyvinyl alcohol (PVA), polyethylene glycol (PEG), methacrylic anhydride gelatin (GelMA), methacryloyl hyaluronic acid (HAMA). The materials have a single composition and do not contain biologically active substances. They can only play the role of a simple drug carrier and cannot promote tissue repair by themselves. At the same time, the existing hydrogel microneedle materials are mostly compounds with relatively small molecular weight, and the swelling properties (including swelling speed, swelling rate, etc.) have certain limitations.

[0005] The preparation of hydrogel microneedles usually requires the use of hydrogel materials with high concentration and high fluidity to ensure the mechanical properties and surface morphology of the microneedles. The current technical solutions for preparing microneedles with bioactive materials such as extracellular matrix (ECM) usually only improve the hydrophilicity of ECM through enzymatic digestion and chemical modification. The hydrophilicity of the final ECM material is still limited, and it is often impossible to form a high-concentration, high-fluidity solution, and thus cannot meet the needs of microneedle preparation. At the same time, most of the ECM materials obtained by existing ECM preparation technologies are difficult to dissolve due to their rich collagen components, and have poor fluidity, making them difficult to use in the preparation of microneedles.

[0006] Therefore, in order to obtain microneedles with biological activity and better swelling properties, it is also necessary to explore a method for preparing modified decellularized matrix materials (SISMA) with excellent solubility and fluidity. Summary of the invention

[0007] The object of the present invention is to provide an extracellular matrix for preparing microneedles.

[0008] A bioactive acellular matrix hydrogel microneedle made of methacrylylated porcine small intestinal submucosa material;

[0009] The methacrylated porcine small intestinal submucosa material is a small intestinal submucosa grafted with methacrylic anhydride, and the methacrylic anhydride grafting rate is 40-90%.

[0010] Preferably, the methacrylic anhydride grafting rate is 40 to 90%.

[0011] Preferably, the methacrylic anhydride grafting rate is 80%.

[0012] Preferably, it is prepared by reacting small intestinal submucosal layer with methacrylic anhydride in an alkaline aqueous solution.

[0013] Preferably, the molar ratio of the free amino groups in the small intestinal submucosal layer to methacrylic anhydride is 1:(5-100).

[0014] Preferably, the molar ratio of the free amino groups in the small intestinal submucosal layer to methacrylic anhydride is 1:20.

[0015] Preferably, the alkaline aqueous solution is an aqueous solution with a pH of 8-10.

[0016] Preferably, the reaction conditions are: 0-50° C. for 1-24 h.

[0017] Preferably, the reaction conditions are: 0-20° C. for 20-24 hours, 20-35° C. for 10-20 hours, and 35-50° C. for 1-10 hours.

[0018] Preferably, the amino content of the small intestinal submucosal layer is 400-800 μM.

[0019] Preferably, the small intestinal submucosa is the small intestinal submucosa that has been defatted, decellularized and digested.

[0020] Preferably, it is prepared by the following method:

[0021] (1) mixing the methacrylylated porcine small intestinal submucosal material with a photoinitiator to obtain a mixed solution, injecting the mixed solution into a microneedle mold, removing bubbles, and concentrating in an oven;

[0022] The mass volume fraction of the photoinitiator in the mixed solution is 0.05%-1%;

[0023] (2) The concentrated SISMA in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0024] Preferably, the photoinitiator is LAP or I2959.

[0025] Preferably, in step (1), the oven concentration temperature is 20°C to 50°C; the oven concentration time is 12h to 72h; and the light curing time is 15s to 1min.

[0026] The present invention also provides a method for preparing the hydrogel microneedle, comprising the following steps:

[0027] (1) mixing the methacrylylated porcine small intestinal submucosal material with a photoinitiator to obtain a mixed solution, injecting the mixed solution into a microneedle mold, removing bubbles, and concentrating in an oven;

[0028] The mass volume fraction of the photoinitiator in the mixed solution is 0.05%-1%;

[0029] (2) The concentrated SISMA in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0030] The present invention also provides use of the hydrogel microneedle in preparing a drug delivery carrier.

[0031] The present invention provides an ECM hydrogel microneedle and a preparation method thereof, so that the microneedle can act as a drug delivery carrier and have the activities of promoting angiogenesis, regulating immune stress, and promoting collagen deposition. At the same time, the rich collagen network structure of the ECM material is used to improve the swelling performance of the microneedle and improve its drug delivery efficiency.

[0032] Obviously, according to the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, other various forms of modification, replacement or change may be made.

[0033] The following is a further detailed description of the above contents of the present invention through specific implementation methods in the form of embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. All technologies implemented based on the above contents of the present invention belong to the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the overall view of SISMA microneedle under low-power microscope (1mm);

[0035] Figure 2 This is the side of the SISMA microneedle under a high-power microscope (200 μm);

[0036] Figure 3 Images of angiogenesis of different hydrogel microneedles;

[0037] Figure 4The statistical histograms of vascular intersections, mesh numbers, node numbers and total length of vascular trunks of HUVEC cells after treatment with different hydrogel microneedles, ns: P>0.05; *: P<0.05; **: P<0.01; ***: P<0.001; ****: P<0.0001;

[0038] Figure 5 The expression of inflammatory genes in RAW264.7 cells after treatment with different hydrogel microneedles; ns: P>0.05; **: P<0.01; ***: P<0.001; ****: P<0.0001

[0039] Figure 6 The experimental results of NIH-3T3 cell migration after treatment with different hydrogel microneedles;

[0040] Figure 7 Results of NIH-3T3 cell proliferation assay after treatment with different hydrogel microneedles;

[0041] Figure 8 The experimental results of the swelling properties of SISMA hydrogel microneedles are shown;

[0042] Fig. 9 This is the relationship between the raw material ratio and the grafting rate of the modified small intestinal submucosal layer in Experimental Example 1. DETAILED DESCRIPTION

[0043] LAP phenyl (2,4,6-trimethylbenzoyl) phosphate lithium salt;

[0044] I2959: 2-Hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone;

[0045] The raw materials and equipment used in the present invention are all known products, which are obtained by purchasing commercially available products.

[0046] The raw material porcine small intestinal submucosa (SIS) of the present invention can be prepared by the following method:

[0047] 1) Take fresh pig small intestine, rinse the contents with water, rub it with salt and rinse it with water three times. Use a scalpel to cut the small intestine open and cut it into 10-20 cm long segments;

[0048] 2) Use a tongue depressor to scrape off the muscular layer and serosal layer of the small intestine and store in normal saline at 4°C;

[0049] 3) Rinse with deionized water, filter and immerse in a mixture of chloroform and methanol (chloroform: methanol = 1:1) at room temperature overnight;

[0050] 4) After repeated washing with deionized water, place in 0.25% trypsin solution and treat at 4°C overnight;

[0051] 5) rinse with deionized water 10 times and then treat with 0.5% SDS for at least 4 h;

[0052] 6) After washing, freeze-dry at -70°C for 24 hours to obtain the SIS membrane.

[0053] 7) The SIS film is crushed using a ball mill at low temperature to obtain SIS powder.

[0054] 8) Digest the SIS powder with pepsin solution and freeze-dry it again for later use.

[0055] Example 1. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0056] 1. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) material

[0057] (1) Dissolve SIS in ultrapure water at a ratio of 1%, keep stirring, and after it is fully dissolved, add NaOH to adjust the pH to 9.

[0058] (2) After adding methacrylic anhydride (MA) dropwise in batches, NaOH was added to adjust the pH to a range of 8 to 9. The molar ratio of free amino groups (from SIS) to MA was 1:20, and a mixed solution was obtained by ultrasonic treatment (ultrasonic power 100 W, 4°C, 3h). Dialysis and freeze-drying were used for later use. In this embodiment, the method for calculating the amount of MA is as follows: first, the free amino group content after SIS digestion is determined by the OPA method, and based on this, the actual amount of MA is deduced according to the amount of free amino substances: the amount of MA substances is equal to 1:20.

[0059] 2. Preparation of SISMA hydrogel microneedles using microneedle molds

[0060] (1) SISMA mixed with photoinitiator LAP was injected into a silicone resin (PDMS) microneedle mold. The concentration of LAP in the mixed solution was 0.25% (g / ml). The mixture was degassed under negative pressure and concentrated in an oven at 20°C for 12 h.

[0061] (2) The concentrated SISMA (LAP-405 nm, irradiation for 55 s) in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0062] Example 2: Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0063] The preparation method of this embodiment is the same as that of Example 1, except that the preparation method of SISMA is different. SISMA of this embodiment is prepared according to the following method:

[0064] Dissolve SIS in an ice-water bath at a ratio of 0.25% for 4-6 hours. After SIS is dissolved, add free amino groups and methacrylic anhydride (MA) at a molar ratio of 1:20, adjust the pH value to 9-10, and react in an ice-water bath for 24 hours. Dialyze and freeze-dry for later use.

[0065] Example 3. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0066] The preparation method of this embodiment is the same as that of Example 1, except that the preparation method of SISMA is different. SISMA of this embodiment is prepared according to the following method:

[0067] Dissolve SIS at a ratio of 0.5% at room temperature, add free amino groups and methacrylic anhydride (MA) at a molar ratio of 1:20, adjust the pH value to 9-10, and react at 25°C for 12 hours. Dialyze and freeze-dry for later use.

[0068] Example 4. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0069] The preparation method of this embodiment is the same as that of embodiment 1, except that the method of preparing SISMA hydrogel microneedles by microneedle molds is different, specifically:

[0070] (1) SISMA mixed with photoinitiator LAP was injected into a silicone resin (PDMS) microneedle mold. The concentration of LAP in the mixed solution was 0.25% (g / ml). The mixture was degassed under negative pressure and concentrated in an oven at 50°C for 24 hours.

[0071] (2) The concentrated SISMA (LAP-405 nm, irradiation for 1 min) in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0072] Example 5. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0073] The preparation method of this embodiment is the same as that of embodiment 1, except that the method of preparing SISMA hydrogel microneedles by microneedle molds is different, specifically:

[0074] (1) SISMA mixed with photoinitiator LAP was injected into a silicone resin (PDMS) microneedle mold. The concentration of LAP in the mixed solution was 0.25% (g / ml). The mixture was degassed under negative pressure and concentrated in an oven at 30°C for 48 hours.

[0075] (2) The concentrated SISMA (LAP-405 nm, irradiation for 30 s) in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0076] (3) Scanning electron microscopy to detect microneedle surface morphology

[0077] SEM detection of microneedle surface morphology Figure 1 , Figure 2 .

[0078] Example 6. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0079] The preparation method of this embodiment is the same as that of embodiment 1, except that the method of preparing SISMA hydrogel microneedles by microneedle molds is different, specifically:

[0080] (1) SISMA mixed with photoinitiator I2959 was injected into a silicone resin (PDMS) microneedle mold. The concentration of LAP in the mixed solution was 0.25% (g / ml). The mixture was degassed under negative pressure and concentrated in an oven at 20°C for 72 hours.

[0081] (2) The concentrated SISMA (I2959-365 nm, irradiation for 25 s) in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0082] Example 7. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0083] The preparation method of this embodiment is the same as that of embodiment 1, except that the method of preparing SISMA hydrogel microneedles by microneedle molds is different, specifically:

[0084] (1) SISMA mixed with photoinitiator I2959 was injected into a silicone resin (PDMS) microneedle mold. The concentration of LAP in the mixed solution was 0.25% (g / ml). The mixture was degassed under negative pressure and concentrated in an oven at 50°C for 24 hours.

[0085] (2) The concentrated SISMA (I2959-365 nm, irradiation for 1 min) in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0086] Example 8. Preparation of methacrylylated porcine small intestinal submucosa (SISMA) hydrogel microneedles

[0087] The preparation method of this embodiment is the same as that of embodiment 1, except that the method of preparing SISMA hydrogel microneedles by microneedle molds is different, specifically:

[0088] (1) SISMA mixed with photoinitiator LAP or I2959 was injected into a silicone resin (PDMS) microneedle mold. The concentration of LAP or I2959 in the mixed solution was 0.25% (g / ml). The mixture was degassed under negative pressure and concentrated in an oven at 30°C for 48 hours.

[0089] (2) The concentrated SISMA (I2959-365 nm, irradiation for 30 s) in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

[0090] The following experimental examples demonstrate the beneficial effects of the hydrogel microneedles prepared by the present invention.

[0091] Experimental Example 1: Performance test of SISMA hydrogel microneedle of the present invention:

[0092] 1. Experimental methods

[0093] (1) Sample preparation

[0094] Referring to Example 5, SISMA hydrogel microneedles and GelMA hydrogel microneedles were prepared. Among them, the preparation method of GelMA hydrogel microneedles is the same as that of SISMA hydrogel microneedles, except that SISMA in the raw material is replaced by GelMA. The preparation method of GelMA is as follows: dissolve gelatin at a ratio of 0.5% in a warm water bath for 1 to 4 hours, and after it is completely dissolved, free amino groups and methacrylic anhydride (MA) are added in a molar ratio of 1:20, and the pH value is adjusted to the range of 9 to 10, and reacted in an ice water bath for 24 hours. Dialyze and freeze-dry for use. Prepare SISMA hydrogel microneedles and GelMA hydrogel microneedle extracts according to the national standard GB / T 16886.12-2017.

[0095] (1) Determination of the angiogenesis-promoting ability of SISMA hydrogel microneedles

[0096] To verify whether SISMA hydrogel microneedles have biological activity, we verified the angiogenesis-promoting ability of SISMA hydrogel microneedles and compared them with GelMA hydrogel microneedles.

[0097] The test was performed according to the following steps: 1) Matrigel: Place a 24-well plate on an ice plate and add 30 μL of Matrigel to each well to ensure that the bottom of the well is evenly covered. After balancing on the ice plate for 5 minutes, place it in a 37°C incubator for 15 minutes to form a gel. 2) Cell inoculation and treatment: Take logarithmic human umbilical vein endothelial cells (HUVEC), digest them, and resuspend the cells with SISMA hydrogel microneedles and GelMA hydrogel microneedle extract to prepare cell extracts. Resuspend the cells with HUVEC complete culture medium as the control group, add 100,000 cells to each well of the 24-well plate covered with Matrigel, and culture it in a 37°C incubator for 8 hours. 3) Tube formation observation: After culturing the culture medium for 8 hours, observe the cells under an optical microscope and collect images. Image analysis was performed using Image J software.

[0098] (2) SISMA hydrogel microneedle immunomodulation assay

[0099] The anti-inflammatory properties of SISMA hydrogel microneedles were verified using mouse mononuclear macrophage leukemia cells (RAW264.7) and compared with GelMA hydrogel microneedles.

[0100] RAW264.7 culture medium: 90% α-MEM culture medium + 10% fetal bovine serum (FBS) + 100 U / mL penicillin (P) and 100 μg / mL streptomycin (S).

[0101] RAW264.7 in the logarithmic growth phase were taken to prepare a cell suspension, and 100,000 cells / well were plated into a 6-well plate. After overnight attachment, the cells were treated with 100 ng / mL lipopolysaccharide (LPS) for 4 hours to simulate the inflammatory microenvironment. Subsequently, SISMA hydrogel microneedles and GelMA hydrogel microneedle extracts were replaced, and a control group without LPS stimulation was set up. After 48 hours of culture, RNA was extracted using Promega's RNA kit (LS1040); reverse transcription was performed using the Promega reverse transcription kit (A2791); finally, TaKaRa's TB Green Premix Ex Taq∥ reagent (RR820A) was used to perform qPCR experiments using a two-step method to measure the expression of inflammatory genes Il-6, Cd86, and Il-1β.

[0102] (3) Determination of the ability of SISMA hydrogel to promote fibroblast migration

[0103] The ability of SISMA hydrogel microneedles to promote fibroblast migration was measured and compared with that of GelMA hydrogel microneedles.

[0104] Mouse embryonic fibroblasts (NIH-3T3) were used as a cell model, and the culture medium was 90% high-glucose DMEM medium + 10% FBS + 100U / mL P + 100μg / mL S. NIH-3T3 cells in the logarithmic phase were prepared into a cell suspension without FBS, and 200μL of the cell suspension without FBS was inoculated in the upper chamber of the Transwell, 50,000 cells / well; 700μL of SISMA hydrogel microneedles and GelMA hydrogel microneedle extract were added to the lower chamber. After 24h of culture, the culture medium was removed, the cells were washed 3 times with PBS, and the cells were fixed with 10% neutral formaldehyde for 30min, washed 3 times with PBS, and stained with crystal violet for 1h. The crystal violet was cleaned with PBS, and the cells in the upper chamber were gently wiped with a cotton swab. Subsequently, an optical microscope was used to observe and collect pictures.

[0105] (4) Determination of the ability of SISMA hydrogel microneedles to promote fibroblast proliferation

[0106] The ability of SISMA hydrogel microneedles to promote fibroblast proliferation was measured and compared with that of GelMA hydrogel microneedles.

[0107] NIH-3T3 was used as a cell model, and the culture medium was the same as above. The proliferation ability of NIH-3T3 cells was verified by CCK-8 experiment.

[0108] NIH-3T3 cells in the logarithmic phase were prepared as a cell suspension, and 3,000 NIH-3T3 cells were inoculated in each well of a 96-well plate for three time points. After the cells adhered to the wall, the SISMA hydrogel microneedles and GelMA hydrogel microneedle extracts were replaced at 2d, 4d, and 6d, respectively. At 1d, 3d, and 7d, the conditioned medium was removed, and 110 μL of high-glucose DMEM medium containing 10% CCK-8 was added to each well. The culture was incubated at 37°C in the dark for 1.5h, and then 100 μL of the incubation solution was added to a new 96-well plate. The absorbance value was measured at a wavelength of 450nm using an ELISA reader.

[0109] (5) Determination of swelling properties of SISMA hydrogel microneedles

[0110] The swelling properties of SISMA hydrogel microneedles were measured.

[0111] Take SISMA hydrogel microneedles and GelMA hydrogel microneedles, weigh and record the initial weight. After adding 5mL PBS to fully soak, wipe off the excess water on the surface with filter paper and weigh and record. Swelling rate calculation: Let M0 be the initial mass and M1 be the mass after full soaking, then the swelling rate formula is:

[0112]

[0113] 2. Experimental results

[0114] The results of angiogenesis-promoting ability assay were as follows Figure 3 and Figure 4 As shown, SISMA hydrogel microneedles had better angiogenesis ability compared with the control group and GelMA hydrogel microneedle group.

[0115] Immunomodulatory assay results Figure 5 As shown in the figure, compared with the LPS and GelMA hydrogel microneedle groups, SISMA hydrogel microneedle can downregulate the expression of inflammatory factors Il-6 and CD86. Compared with the LPS group, SISMA microneedle can reduce the expression of inflammatory factor Il-1β

[0116] The results of fibroblast migration ability assay were as follows Figure 6As shown, compared with GelMA hydrogel microneedles, SISMA hydrogel microneedles have a stronger ability to promote NIH-3T3 migration.

[0117] The results of fibroblast proliferation assay were as follows Figure 7 As shown in the figure, on the 5th day, the OD value of SISMA hydrogel microneedles was larger than that of the Control group, and there was a statistical difference (P<0.05). Compared with the GelMA hydrogel microneedles, the OD value of SISMA hydrogel microneedles was larger. For SISMA hydrogel microneedles, the OD value increased with time, indicating that SISMA hydrogel microneedles themselves have the ability to promote the proliferation of NIH-3T3.

[0118] The swelling properties test results are as follows Figure 6 As shown, compared with GelMA hydrogel microneedles, SISMA hydrogel microneedles absorbed PBS liquid faster and had a higher swelling rate within the same time.

[0119] It can be seen from the above experimental data that the SISMA hydrogel microneedle provided by the present invention has excellent angiogenesis-promoting ability, immunomodulatory function, ability to promote fibroblast migration and proliferation, and good swelling performance.

[0120] Experimental Example 2 Optimal ratio of small intestinal submucosal layer to methacrylic anhydride

[0121] (1) Experimental methods

[0122] The grafting rate of SISMA is closely related to the mechanical properties of the hydrogel. In this experimental example, the grafting rate is used as an indicator to optimize the dosage ratio of the small intestinal submucosal layer and methacrylic anhydride in the preparation process of SISMA.

[0123] The preparation method of SISMA in this experimental example is consistent with that in Example 1, except that the mass molar ratio of free amino group to MA is set to 1:5, 1:20 and 1:100 respectively. The grafting rate of the prepared SISMA is tested by the o-phthalaldehyde (OPA) method.

[0124] (2) Experimental results

[0125] The results are as follows Fig. 9 As shown, when the molar ratio of free amino group to MA is 1:20, the prepared SISMA has the highest grafting rate, which can reach an average of 70%-90%.

[0126] In summary, the hydrogel microneedles made of modified decellularized matrix material (SISMA) provided by the present invention have good biological activity and better swelling properties, and have good prospects in biomedicine.

Claims

1. A bioactive acellular matrix hydrogel microneedle, characterized in that: It is made from methacrylylated porcine small intestinal submucosa material; The methacrylated porcine small intestinal submucosa material is a small intestinal submucosa grafted with methacrylic anhydride, and the methacrylic anhydride grafting rate is 40-90%.

2. The hydrogel microneedle according to claim 1, characterized in that The methacrylic anhydride grafting rate is 40 to 90%.

3. The hydrogel microneedle according to claim 2, characterized in that: The methacrylic anhydride grafting rate is 80%.

4. The hydrogel microneedle according to any one of claims 1 to 3, characterized in that: It is prepared by reacting the small intestinal submucosal layer with methacrylic anhydride in an alkaline aqueous solution.

5. The hydrogel microneedle according to claim 4, characterized in that: The molar ratio of the free amino groups in the small intestinal submucosal layer to methacrylic anhydride is 1:(5-100).

6. The hydrogel microneedle according to claim 5, characterized in that The molar ratio of the free amino groups in the small intestinal submucosal layer to methacrylic anhydride is 1:

20.

7. The hydrogel microneedle according to claim 4, characterized in that: The alkaline aqueous solution is an aqueous solution with a pH of 8-10.

8. The hydrogel microneedle according to claim 4, characterized in that: The reaction conditions are: 0-50° C. for 1-24 h.

9. The hydrogel microneedle according to claim 8, characterized in that The reaction conditions are: 0-20° C. for 20-24 hours, 20-35° C. for 10-20 hours, and 35-50° C. for 1-10 hours.

10. The hydrogel microneedle according to claim 4, characterized in that: The amino content of the small intestinal submucosal layer is 400-800 μM.

11. The hydrogel microneedle according to claim 10, characterized in that: The small intestinal submucosa is the small intestinal submucosa that has been defatted, decellularized and digested.

12. The hydrogel microneedle according to claim 1, characterized in that: Prepared by the following method: (1) mixing the methacrylylated porcine small intestinal submucosal material with a photoinitiator to obtain a mixed solution, injecting the mixed solution into a microneedle mold, removing bubbles, and concentrating in an oven; The mass volume fraction of the photoinitiator in the mixed solution is 0.05%-1%; (2) The concentrated SISMA in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

13. The hydrogel microneedle according to claim 12, characterized in that: The photoinitiator is LAP or I2959.

14. The hydrogel microneedle according to claim 12, characterized in that: In step (1), the oven concentration temperature is 20° C. to 50° C.; the oven concentration time is 12 h to 72 h; and the light curing time is 5 s to 1 min.

15. The method for preparing the hydrogel microneedle according to any one of claims 1 to 14, characterized in that: The steps include: (1) mixing the methacrylylated porcine small intestinal submucosal material with a photoinitiator to obtain a mixed solution, injecting the mixed solution into a microneedle mold, removing bubbles, and concentrating in an oven; The mass volume fraction of the photoinitiator in the mixed solution is 0.05%; (2) The concentrated SISMA in the mold is photocured and demolded to obtain SISMA hydrogel microneedles.

16. Use of the hydrogel microneedle according to any one of claims 1 to 14 in preparing a drug delivery carrier.

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