A microneedle patch for treating myocardial infarction and a preparation method thereof

Abstract

The present invention relates to a microneedle patch for treating myocardial infarction and a preparation method thereof. In the microneedle patch, the needle tip is solidified by a hydrogel solution I, and the hydrogel solution I contains methacryloyl glucan, safflower polysaccharide, and vascular growth factor mimetic peptide; the substrate comprises an adhesion layer and an anti-fouling layer, and the adhesion layer is solidified by a hydrogel solution II whose main component is methacryloyl glycine; and the anti-fouling layer is solidified by a hydrogel solution III whose main component is polyethylene glycol diacrylate. The microneedle patch of the present invention can not only provide mechanical support to the damaged tissue, effectively ensure the drug delivery depth, but also adhere well to the tissue surface, while avoiding adhesion between the microneedle patch and other tissues and organs in the in vivo environment. Moreover, the vascular growth factor mimetic peptide can promote SPS to exert its antioxidant effect, and can achieve a better myocardial repair effect.

Description

Technical Field

[0001] The present invention relates to the field of medical biomaterials, and in particular to a microneedle patch for treating myocardial infarction and a preparation method thereof. Background Art

[0002] Myocardial infarction (abbreviated as: MI) refers to myocardial necrosis caused by acute and persistent ischemia and hypoxia of the coronary arteries. The repair of the heart after myocardial infarction is divided into three stages, namely the inflammatory stage, the repair stage and the maturation stage. In the inflammatory stage after myocardial infarction, the damaged myocardial tissue will trigger an inflammatory response. Continuous inflammatory response will produce too much ROS, which in turn induces inflammatory response. After the inflammatory stage, the repair stage begins, new blood vessels begin to grow, forming a new microvascular network, and fibrous tissue begins to fill the infarct area. At this time, fibroblasts begin to produce collagen, forming scar tissue to replace necrotic myocardial tissue. Finally, in the maturation stage, the new blood vessels and scar tissue gradually mature and consolidate. Various biomaterials have been used to promote the recovery of cardiac function after myocardial infarction, including nanomaterials, hydrogels and heart patches.

[0003] In general, nanomaterials can achieve selective accumulation in the infarct area by targeting the site of myocardial injury and inflammation; however, strategies based on nanomaterials are limited by potential toxicity and lack of mechanical support in the treatment of myocardial infarction. In addition, although hydrogels injected into the myocardium can directly reach the infarct area and provide support for the ventricular wall, synthetic hydrogels are prone to swell and exert pressure on surrounding tissues; and injectable gels generally have a low modulus and degrade quickly in the body, which cannot achieve long-term therapeutic effects. In recent years, the study of myocardial patches in myocardial tissue engineering has also gained widespread attention. Some biomaterials with adjustable structural properties can be prepared into cardiac patches with good biocompatibility. These patches can provide mechanical support for cell growth and help repair damaged hearts. However, in general, simple cardiac patches lack certain functionality. In order to achieve better therapeutic effects, the patches may be loaded with substances such as stem cells, drugs, and growth factors that promote repair. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a microneedle patch for treating myocardial infarction and a preparation method thereof.

[0005] The specific technical scheme of the present invention is as follows:

[0006] In a first aspect, the present invention provides a microneedle patch for treating myocardial infarction, comprising a substrate and a microneedle tip, wherein the microneedle tip is solidified from a hydrogel solution I, wherein the hydrogel solution I contains methacryloylated dextran (DexMA), safflower polysaccharide (SPS), and a vascular growth factor mimetic peptide; the substrate comprises an adhesion layer and an anti-fouling layer, wherein the adhesion layer is connected to the microneedle tip, is located on the inner side of the substrate, and is solidified from a hydrogel solution II, wherein the main component of the hydrogel solution II is methacryloylated glycine (ACG); the anti-fouling layer is located on the outer side of the substrate, and is solidified from a hydrogel solution III, wherein the main component of the hydrogel solution III is polyethylene glycol diacrylate (PEGDA).

[0007] First, vascular growth factor mimetic peptides have angiogenic activity similar to VEGF, which can activate endothelial cells and reproduce the complex cellular functions of VEGF such as invasion, chemotaxis, capillary sprouting and organization. Secondly, the biological activities of safflower polysaccharide (SPS), such as antioxidant, anti-inflammatory and anti-fibrotic, help to reduce myocardial damage and inflammatory response caused by myocardial infarction and promote myocardial repair and regeneration. In addition, DexMA is a polymer hydrogel with good biocompatibility. The three-dimensional network structure formed by cross-linking can provide a platform for efficient loading and release of biomolecules. After the microneedle penetrates the tissue, micropores are formed on its surface. The drug preparation can slowly diffuse into the deep tissue through the pores for targeted drug delivery; and by forming a membrane structure system with a certain strength, mechanical support can be given to the damaged tissue to prevent heart rupture. The double-layer design of the base adhesion layer and the anti-fouling layer allows the patch to adhere well to the tissue surface, while avoiding adhesion between the microneedle patch and other tissues and organs in the in vivo environment. The microneedle patch of the present invention can not only provide mechanical support to the damaged tissue and effectively ensure the drug delivery depth, but also can adhere well to the tissue surface, while avoiding adhesion between the microneedle patch and other tissues and organs in the in vivo environment.

[0008] Preferably, in terms of weight, the hydrogel solution I comprises 5-20 parts of safflower polysaccharide, 100-300 parts of methacryloyl dextran, and 1-5 parts of vascular growth factor mimetic peptide. In a preferred embodiment, it comprises 20 parts of safflower polysaccharide, 300 parts of methacryloyl dextran, and 5 parts of vascular growth factor mimetic peptide.

[0009] In some embodiments, the vascular growth factor mimetic peptide is a QK polypeptide, which is synthesized based on the VEGF binding region and contains 15 amino acids, with a specific amino acid sequence of KLTWQELYQLKYKGI. It has angiogenic activity similar to VEGF, can activate endothelial cells, and reproduce the complex cell functions of VEGF such as invasion, chemotaxis, capillary sprouting and organization.

[0010] In some embodiments, the safflower polysaccharide (SPS) is prepared by the following method:

[0011] 1) Extraction of safflower polysaccharide: clean safflower petals, dry at 50°C, and grind into powder; then mix safflower powder: distilled water = 60g: 1.2L; after water bath at 80°C for 1-3h, take the precipitate and repeat the above operation, perform secondary extraction, combine the two supernatants, rotary evaporate at 75°C to 1 / 3 of the original solution volume, and take out; slowly add 4 times the volume of anhydrous ethanol, and stir continuously, precipitate at 4°C for 24h, then centrifuge, collect the precipitate, add deionized water to dissolve, and dry at 60°C to obtain crude safflower polysaccharide;

[0012] 2) Purification of safflower polysaccharide: The crude safflower polysaccharide is dissolved in water, frozen at -20°C overnight, and deproteinized after thawing at room temperature. Sevage reagent is added to the melted polysaccharide aqueous solution, vortexed and centrifuged, and the protein is removed repeatedly, followed by centrifugation, and the precipitate is collected, and deionized water is added to the precipitate to re-dissolve to obtain a polysaccharide aqueous solution, and appropriate volumes of anhydrous ethanol, ether, and acetone are added to the polysaccharide aqueous solution in sequence to wash the precipitate, and finally the washed precipitate is dissolved in deionized water, dialyzed, and freeze-dried to obtain the safflower polysaccharide SPS.

[0013] In some embodiments, the methacryloyl dextran (DexMA) is prepared by the following method: mixing dextran, dimethyl sulfoxide and 4-dimethylaminopyridine, stirring, adding glycidyl methacrylate, stirring, dialyzing, and freeze-drying to obtain the methacryloyl dextran. Preferably, dextran: dimethyl sulfoxide: 4-dimethylaminopyridine: glycidyl methacrylate = 5.0 g: 50 mL: 1 g: 1.5 mL.

[0014] Preferably, the hydrogel solution II contains 20 wt % of methacryloylated glycine (ACG) based on the amount of water.

[0015] In some embodiments, the methacryloylated glycine (ACG) is prepared by the following method: dissolving sodium glycine in a NaOH solution under ice bath conditions, then dropping an acryloyl chloride-tetrahydrofuran solution into the solution, reacting, then washing and removing impurities, extracting, drying and concentrating, dissolving the obtained product in water, and freeze-drying to obtain the methacryloylated glycine. Preferably, the concentration of the NaOH solution is 6M, in the acryloyl chloride-tetrahydrofuran solution, acryloyl chloride:tetrahydrofuran = 5.5:10 (volume ratio), sodium glycine: NaOH solution: acryloyl chloride-tetrahydrofuran solution = 5g: 25mL: 15.5mL.

[0016] Preferably, in the hydrogel solution III, the content of polyethylene glycol diacrylate (PEGDA) is 10 wt % based on the amount of water.

[0017] In some embodiments, the polyethylene glycol diacrylate (PEGDA) is prepared by the following method: dissolving polyethylene glycol in anhydrous toluene at 40°C under nitrogen, adding triethylamine after cooling to room temperature, stirring evenly, adding acryloyl chloride dropwise, stirring to react, and then precipitating the obtained polymer in n-hexane, purifying the precipitate, and then dissolving it in water, dialyzing it, and freeze-drying it. Preferably, polyethylene glycol: anhydrous toluene: triethylamine: acryloyl chloride = 8g: 40mL: 1.19mL: 0.81mL.

[0018] Photoinitiator, tartrazine and the like may be further added to the hydrogel solutions I, II and III of the present invention as required.

[0019] The present invention also provides a method for preparing the microneedle patch. The microneedle patch can be prepared by 3D printing and curing. The printing order is: anti-fouling layer, adhesion layer, microneedle tip. After printing is completed, the completely polymerized monomers are removed by water immersion, and the microneedle patch is obtained after drying and demolding.

[0020] The beneficial effects of the present invention are:

[0021] The present invention designs a microneedle patch for myocardial infarction treatment, wherein the needle tip is loaded with safflower polysaccharide and vascular growth factor mimetic peptide, and the substrate has an adhesion layer and an anti-fouling layer, which can provide mechanical support to the damaged tissue, effectively ensure the drug delivery depth, and adhere well to the tissue surface, while avoiding adhesion between the microneedle patch and other tissues and organs in the in vivo environment. Moreover, the vascular growth factor mimetic peptide can promote SPS to exert its antioxidant effect, and can achieve a better myocardial repair effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the microneedle patch for treating myocardial infarction according to the present invention;

[0023] Figure 2 This is a physical picture of the microneedle patch used for myocardial infarction treatment of the present invention;

[0024] Figure 3 The antioxidant capacity analysis results of the microneedle patch of the embodiment of the present invention are shown in FIG. DETAILED DESCRIPTION

[0025] The present invention provides a microneedle patch for treating myocardial infarction, the structure of which is referenced to Figure 1, including a substrate and a microneedle tip, the microneedle tip is solidified by a hydrogel solution I, and the hydrogel solution I includes methacryloyl dextran (DexMA), safflower polysaccharide (SPS), and vascular growth factor mimetic peptide; that is, SPS and vascular growth factor mimetic peptide are introduced into the DexMA hydrogel system, and the biological activities of SPS such as antioxidant, anti-inflammatory and anti-fibrosis can help reduce myocardial damage and inflammatory response caused by myocardial infarction, and promote myocardial repair and regeneration. Mimetic peptides can activate endothelial cells and reproduce complex cell functions such as VEGF invasion, chemotaxis, capillary sprouting and organization, which is safe and effective. Moreover, vascular growth factor mimetic peptides can promote SPS to exert its antioxidant effect, which can further improve the repair effect.

[0026] The substrate includes an anti-fouling layer and an adhesion layer. The adhesion layer is connected to the microneedle tip and is located on the inner side of the substrate. It is solidified from a hydrogel solution II. The main component of the hydrogel solution II is polyethylene glycol diacrylate (ACG). After curing, the patch has good mechanical support and adhesion properties.

[0027] The anti-fouling layer is located on the outside of the substrate and is solidified by the hydrogel solution III. The main component of the hydrogel solution III is polyethylene glycol diacrylate (PEGDA), which can prevent the microneedle patch from adhering to other tissues and organs in the in vivo environment.

[0028] The various structures of the microneedle in the embodiment of the present invention cooperate and support each other, which can not only provide mechanical support to the damaged tissue and effectively ensure the depth of drug delivery, but also adhere well to the tissue surface to avoid adhesion between the microneedle patch and other tissues and organs in the in vivo environment, and has good cardiac repair effect.

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings and embodiments. The preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] Unless otherwise specified, the reagents, materials, and equipment used in the examples of the present invention are all commercially available; the test methods, unless otherwise specified, are all conventional test methods in the art.

[0032] Raw material preparation

[0033] (1) Extraction and purification of safflower polysaccharide (SPS)

[0034] Extraction of safflower polysaccharide: Wash safflower petals with distilled water, dry in a 50℃ oven, grind into powder, and pass through a 60-mesh sieve; add 1.2L distilled water to 60g safflower powder and mix well. Take it out after 1.5h in a water bath at 80℃, take out the precipitate and repeat the above operation, perform secondary extraction, combine the two supernatants, evaporate at 75℃ to 1 / 3 of the original volume, take it out; slowly add 4 times the volume of anhydrous ethanol, and stir continuously, precipitate in a 4℃ refrigerator for 24h, centrifuge at 5000r / min for 10min, collect the precipitate, add deionized water to dissolve, and dry at 60℃.

[0035] Purification of safflower polysaccharide: The extracted polysaccharide was dissolved in water, frozen at -20℃ overnight, and deproteinized after thawing at room temperature. 1 / 3 volume of Sevage reagent (chloroform: n-butanol = 4:1) was added to the melted polysaccharide aqueous solution, and the mixture of polysaccharide solution-chloroform-n-butanol was vortexed for 30s and centrifuged at 5000r / min for 10min. Denatured protein jelly appeared at the interface between the aqueous phase and the solvent phase; the denatured protein at the junction of the water layer and the solvent layer was removed. This method needs to be used repeatedly for more than 5 times to remove the protein. Subsequently, centrifuged at 5000r / min for 10min, the precipitate was collected, and deionized water was added to the precipitate to re-dissolve to obtain a polysaccharide aqueous solution. Appropriate volumes of anhydrous ethanol, ether, and acetone were added to the polysaccharide aqueous solution to wash the precipitate. Finally, the washed precipitate was dissolved in deionized water, placed in a 3500Da dialysis bag, dialyzed with deionized water for 3 days, and then taken out and freeze-dried for 2 days to obtain safflower polysaccharide (SPS).

[0036] (2) Preparation of methacryloylated dextran (DexMA)

[0037] First, weigh 5.0g of dextran, add it to 50mL of dimethyl sulfoxide (DMSO), stir it under magnetic stirring for 1h, and dissolve it into a clear light yellow uniform solution. Then add 1g of 4-dimethylaminopyridine (DMAP) to the dextran solution, continue stirring for 0.5, and dissolve it into a clear light green uniform solution; then, add 1.5mL of glycidyl methacrylate (GMA), stir in the dark for 48h; finally, transfer the reaction solution to a cellulose dialysis bag with a molecular weight cutoff of 14000Da, and dialyze it in deionized water for 3 days to remove by-products. The dialyzed reaction solution was freeze-dried for 48h to obtain methacryloyl dextran (DexMA).

[0038] (3) Synthesis of polyethylene glycol diacrylate (PEGDA)

[0039] 8 g of polyethylene glycol (PEG) was dissolved in 40 mL of anhydrous toluene at 40 ° C under nitrogen atmosphere, and 1.19 mL of triethylamine was added after cooling to room temperature. After stirring evenly, 0.81 mL of acryloyl chloride was added dropwise, and stirred at room temperature for 2 h. The resulting polymer was precipitated in n-hexane, and the precipitate was further purified by toluene and n-hexane three times. Then, the purified polyethylene glycol diacrylate (PEGDA) was dissolved in deionized water and dialyzed (MW: 1000 Da) for 3 days, centrifuged at 10000 rpm for 10 minutes to remove impurities, and the supernatant was freeze-dried and stored at -20 ° C until use.

[0040] (4) Synthesis of methacryloylated glycine (ACG)

[0041] Dissolve 5g of sodium glycinate in 6M NaOH solution (25ml) and stir for 20min in an ice bath. Add 5.5ml of acryloyl chloride to 10ml of tetrahydrofuran, stir and slowly add dropwise to the above solution for 2h, and continue ice bathing for 1h after the addition is complete. Add 10ml of water to the resulting solution, wash three times with ether to remove impurities, adjust the pH of the aqueous phase to 2, add NaCl to saturate, and finally extract with ethyl acetate several times. After drying and concentration, the obtained product is dissolved in 10ml of water and lyophilized to obtain ACG.

[0042] (5) Angiogenic factor mimetic peptide: QK polypeptide, amino acid sequence KLTWQELYQLKYKGI, purchased externally.

[0043] Microneedle patch preparation

[0044] Table 1 Raw material composition of different embodiments and comparative examples

[0045]

[0046] Example 1

[0047] A microneedle patch, the preparation method of which is as follows:

[0048] S1 Preparation of hydrogel solution

[0049] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0050] Hydrogel solution II: 4 g of ACG was dissolved in 20 mL of deionized water to obtain a 20% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesive layer.

[0051] Hydrogel solution I: 20 mg of SPS and 300 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, 5 mg of vascular growth factor mimetic peptide was added to the SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0052] S2 3D curing printing

[0053] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0054] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0055] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0056] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0057] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0058] Example 2

[0059] A microneedle patch, the preparation method of which is as follows:

[0060] S1 Preparation of hydrogel solution

[0061] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0062] Hydrogel solution II: 4 g of ACG was dissolved in 20 mL of deionized water to obtain a 20% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesive layer.

[0063] Hydrogel solution I: 5 mg of SPS and 100 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, 1 mg of vascular growth factor mimetic peptide was added to the SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0064] S2 3D curing printing

[0065] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0066] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0067] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0068] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0069] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0070] Example 3

[0071] A microneedle patch, the preparation method of which is as follows:

[0072] S1 Preparation of hydrogel solution

[0073] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0074] Hydrogel solution II: 4 g of ACG was dissolved in 20 mL of deionized water to obtain a 20% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesive layer.

[0075] Hydrogel solution I: 10 mg of SPS and 200 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, 3 mg of vascular growth factor mimetic peptide was added to the SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0076] S2 3D curing printing

[0077] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0078] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0079] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0080] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0081] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0082] Example 4

[0083] A microneedle patch, the preparation method of which is as follows:

[0084] S1 Preparation of hydrogel solution

[0085] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0086] Hydrogel solution II: 4 g of ACG was dissolved in 20 mL of deionized water to obtain a 20% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesive layer.

[0087] Hydrogel solution I: 20 mg of SPS and 300 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, 1 mg of vascular growth factor mimetic peptide was added to the SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0088] S2 3D curing printing

[0089] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0090] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0091] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0092] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0093] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0094] Example 5

[0095] A microneedle patch, the preparation method of which is as follows:

[0096] S1 Preparation of hydrogel solution

[0097] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0098] Hydrogel solution II: 4 g of ACG was dissolved in 20 mL of deionized water to obtain a 20% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesive layer.

[0099] Hydrogel solution I: 5 mg of SPS and 300 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, 5 mg of vascular growth factor mimetic peptide was added to the SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0100] S2 3D curing printing

[0101] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0102] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0103] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0104] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0105] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0106] Example 6

[0107] A microneedle patch, the preparation method of which is as follows:

[0108] S1 Preparation of hydrogel solution

[0109] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0110] Hydrogel solution II: 4 g of ACG was dissolved in 20 mL of deionized water to obtain a 20% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesive layer.

[0111] Hydrogel solution I: 10 mg of SPS and 300 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, 5 mg of vascular growth factor mimetic peptide was added to the SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0112] S2 3D curing printing

[0113] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0114] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0115] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0116] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0117] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0118] Comparative Example 1

[0119] A microneedle patch, the preparation method of which is as follows:

[0120] S1 Preparation of hydrogel solution

[0121] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0122] Hydrogel solution II: 2 g of ACG was dissolved in 20 mL of deionized water to obtain a 10% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesion layer.

[0123] Hydrogel solution I: 5 mg of vascular growth factor mimetic peptide and 300 mg of DexMA were dissolved in 1 mL of deionized water to form a QK / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0124] S2 3D curing printing

[0125] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0126] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0127] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0128] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0129] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0130] Comparative Example 2

[0131] A microneedle patch, the preparation method of which is as follows:

[0132] S1 Preparation of hydrogel solution

[0133] Hydrogel solution III: 2 g of PEGDA was dissolved in 20 mL of deionized water to obtain a 10% PEGDA solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution III, which was used for curing to prepare an antifouling layer.

[0134] Hydrogel solution II: 2 g of ACG was dissolved in 20 mL of deionized water to obtain a 10% AGC solution, and 12 mg of tartrazine and 20 mg of LAP photoinitiator were added to obtain hydrogel solution II, which was used for curing to prepare an adhesion layer.

[0135] Hydrogel solution I: 20 mg of SPS and 300 mg of DexMA were dissolved in 1 mL of deionized water to form an SPS / DexMA solution, and then 0.6 mg of tartrazine and 1 mg of photoinitiator were added to obtain hydrogel solution I, which was used for curing to prepare microneedle tips.

[0136] S2 3D curing printing

[0137] The prepared hydrogel solution is added into the material tank in sequence. The printing order is anti-fouling layer, adhesion layer, and microneedle tip. After each layer is printed, new solution is added into the material tank.

[0138] Curing conditions of the outer anti-fouling layer of the microneedle substrate: light intensity 15mW / cm 2 , exposure time 15s, base layer exposure time 17s.

[0139] Curing conditions for the inner adhesive layer of the microneedle substrate: light intensity 14mW / cm 2 , exposure time 14s, base layer exposure time 18s.

[0140] Curing conditions of microneedle tip: light intensity 12mW / cm 2 , exposure time 15s, base layer exposure time 15s.

[0141] After printing, soak it in water for 5 minutes to remove the incompletely polymerized monomers. After drying and demoulding, the microneedle patch can be obtained.

[0142] Performance Testing

[0143] The microneedle patches prepared in the examples and comparative examples were tested for performance, and the results are as follows.

[0144] 1. Appearance of microneedles

[0145] Figure 2 An image of a microneedle patch obtained according to an embodiment of the present invention is shown.

[0146] 2. Single needle mechanical properties

[0147] Test method: Place the microneedle patch sample on the sample stage with the tip facing upward, and adjust the sample stage height so that both the upper and lower surfaces are in contact with the fixture. Compress at a constant rate of 0.05 mm / s, and record the compression displacement (L) and load (P) until the set displacement end point. The mechanical strength of a single needle is the ratio of the load to the number of needle tips.

[0148] The test results are shown in Table 1:

[0149] Table 1 Single needle mechanical strength test results of each embodiment and comparative example

[0150]

[0151] As shown in Table 1, safflower polysaccharide is soluble in water. Adding a large amount will destroy the stability of the three-dimensional network structure inside the needle tip formed by methacryloyl dextran, which is not conducive to molding. Adding too little amount cannot achieve a good antioxidant effect. Literature studies have shown that when the mechanical strength of a single needle is greater than 0.04N, it can pierce the stratum corneum and epidermis.

[0152] Examples 1-6 and Comparative Examples 1-2 can all meet this requirement.

[0153] 3. Antioxidant capacity test

[0154] Test method: The antioxidant performance of different embodiments and comparative examples was evaluated by scavenging 1,1-diphenyl-2-pyridylhydrazide (DPPH) free radicals. The mixture of different embodiments and comparative examples and DPPH reagent was stirred and incubated in the dark for 30 minutes, and the remaining DPPH was analyzed by UV-visible spectroscopy. The scavenging rate of DPPH was determined as follows:

[0155] DVC (%) = [(A blank - A positive control) / A blank] × 100%

[0156] D (%) = [[A blank - (A measurement - A control)] / A blank] × 100%

[0157] like Figure 3 As shown in the figure, the efficiency of scavenging free radicals increases with the increase of SPS concentration, indicating that SPS can effectively scavenge free radicals and has a better antioxidant effect. In addition, vascular growth factor mimetic peptide can promote SPS to exert its antioxidant effect and has a certain synergistic effect with SPS.

[0158] 4. Lap-shear tensile bearing strength analysis of the adhesion layer

[0159] Test method: Prepare the bio-ink of the adhesive layer of the microneedle backing according to the proportion in the embodiment, apply the bio-ink on fresh pig skin cut according to the size specified in "YY / T 0729.2-2009 Tissue Adhesive Bonding Performance Test Method Part 1", and then irradiate it under ultraviolet light until the curing is complete, and then compress the bonding part with a force of 1 to 2N. Then place the sample strip in the fixture of the testing machine so that the force direction is the long axis direction of the sample. Load the sample with a crosshead at a speed of 5mm / min until it is destroyed. Record the load at the time of destruction. The test results are shown in Table 3:

[0160] Table 3 Lap-shear tensile bearing strength

[0161]

[0162] As can be seen from Table 3, in Comparative Examples 1 and 2, due to the lower content of ACG and fewer active groups, the adhesion between the tissues is lower, while Examples 1-6 show higher lap-shear tensile bearing strength.

[0163] The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A microneedle patch for treating myocardial infarction, comprising a substrate and a microneedle tip, characterized in that: The microneedle tip is solidified by a hydrogel solution I, wherein the hydrogel solution I contains methacryloylated dextran, safflower polysaccharide, and a vascular growth factor mimetic peptide; The substrate comprises an adhesion layer and an anti-fouling layer, wherein the adhesion layer is connected to the microneedle tip, is located on the inner side of the substrate, and is solidified from a hydrogel solution II, wherein the main component of the hydrogel solution II is methacryloyl glycine; The anti-fouling layer is located on the outside of the substrate and is formed by solidifying the hydrogel solution III, wherein the main component of the hydrogel solution III is polyethylene glycol diacrylate; In terms of weight, the hydrogel solution I comprises 5-20 parts of safflower polysaccharide, 100-300 parts of methacryloyl dextran, and 1-5 parts of vascular growth factor mimetic peptide; The hydrogel solution II comprises 20 wt% of methacryloylated glycine based on the amount of water; In the hydrogel solution III, the content of polyethylene glycol diacrylate is 10 wt % based on the amount of water.

2. The microneedle patch for treating myocardial infarction according to claim 1, characterized in that: The vascular growth factor mimetic peptide is QK polypeptide.

3. The microneedle patch for treating myocardial infarction according to claim 1, characterized in that: The safflower polysaccharide is prepared by the following method: 1) Extraction of safflower polysaccharide: clean the safflower petals, dry at 50℃, and grind into powder; then mix safflower powder: distilled water = 60g: 1.2L; after water bath at 80℃ for 1-3h, take the precipitate and repeat the above operation for secondary extraction, combine the two supernatants, rotary evaporate at 75℃ to 1 / 3 of the original volume, and take out; slowly add 4 times the volume of anhydrous ethanol, and stir continuously, precipitate at 4℃ for 24h, then centrifuge, collect the precipitate, add deionized water to dissolve, and dry at 60℃ to obtain crude safflower polysaccharide; 2) Purification of safflower polysaccharide: the crudely extracted safflower polysaccharide is dissolved in water, frozen at -20°C overnight, and deproteinized after thawing at room temperature: Sevage reagent is added to the melted polysaccharide aqueous solution, vortexed and centrifuged, and the protein is removed repeatedly, followed by centrifugation, and the precipitate is collected, and deionized water is added to the precipitate for re-dissolution to obtain a polysaccharide aqueous solution, and appropriate volumes of anhydrous ethanol, ether, and acetone are added to the polysaccharide aqueous solution in sequence to wash the precipitate, and finally the washed precipitate is dissolved in deionized water, dialyzed, and freeze-dried to obtain the safflower polysaccharide.

4. The microneedle patch for treating myocardial infarction according to claim 1, characterized in that: The methacryloyl dextran is prepared by the following method: Dextran, dimethyl sulfoxide and 4-dimethylaminopyridine are mixed and stirred, glycidyl methacrylate is added, stirred, dialyzed and freeze-dried to obtain the methacryloylated dextran.

5. The microneedle patch for treating myocardial infarction according to claim 1, characterized in that: The polyethylene glycol diacrylate is prepared by the following method: Polyethylene glycol is dissolved in anhydrous toluene at 40° C. under a nitrogen environment, triethylamine is added after cooling to room temperature, acryloyl chloride is added dropwise after stirring evenly, and the reaction is stirred. Then the obtained polymer is precipitated in n-hexane. After the precipitate is purified, it is dissolved in water, dialyzed, and freeze-dried to obtain the polyethylene glycol diacrylate.

6. The method for preparing a microneedle patch for treating myocardial infarction according to any one of claims 1 to 5, characterized in that: The microneedle patch is prepared by 3D printing and curing, and the printing order is: anti-fouling layer, adhesion layer, microneedle tip. After printing, the incompletely polymerized monomers are removed by water immersion, and the microneedle patch is obtained after drying and demoulding.

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