Double-response collagen-based conductive hydrogel, medicine and preparation and application methods of double-response collagen-based conductive hydrogel and medicine

Abstract

The invention discloses a double-response collagen-based conductive hydrogel, a medicine and a preparation and application method of the double-response collagen-based conductive hydrogel. The preparation method of the double-response collagen-based conductive hydrogel comprises the following steps: carrying out chemical modification on polysaccharide through 3-aminophenylboronic acid, and then carrying out sodium periodate oxidation treatment to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer; the preparation method comprises the following steps: performing hydrazide modification on collagen through adipic acid dihydrazide, and performing free radical polymerization with aniline to obtain a hydrazide collagen grafted polyaniline copolymer; the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer are subjected to crosslinking, and the double-response collagen-based conductive hydrogel capable of responding to glucose and the pH value is obtained. Compared with single-response conductive hydrogel, the hydrogel can specifically respond to the microenvironment of chronic diabetic wound surfaces and release antibacterial and anti-inflammatory drugs, and high-quality healing of chronic wounds such as diabetic foot ulcers and the like is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogel dressings, and in particular to a collagen-based conductive hydrogel capable of dual-responsive drug release in terms of glucose concentration and pH value. Background Art

[0002] Currently, electrical stimulation therapy has been successfully applied in the clinical treatment of chronic diabetic wounds. However, the application of electrical stimulation therapy in the wound healing process requires the use of large electrical equipment, which brings inconvenience to patients. In addition, metal electrodes face problems such as difficulty in adapting to irregular wound shapes and easy corrosion, which has an adverse effect on the rapid healing of chronic diabetic wounds and the improvement of wound healing quality.

[0003] Conductive hydrogels have a three-dimensional porous structure, are hydrophilic, and have controllable chemical and physical properties. Similar to the extracellular matrix, they are a favorable matrix for cell growth, migration, and proliferation. If conductive hydrogels are used to implement electrical stimulation therapy in the treatment of chronic wounds, the current coverage can be expanded to the entire wound, overcoming many of the defects of electrode electrical stimulation.

[0004] However, in the prior art, ion conductive hydrogels have poor electrical conductivity, and electronic conductive hydrogels have the problem of poor water solubility and difficulty in dispersion of conductive polymers, making it difficult to obtain stable and good electrical stimulation treatment effects.

[0005] On the other hand, the physiological environment of diabetic chronic wounds is complex and changeable, and different medications and treatment strategies are required at different healing stages. However, existing technologies also lack therapeutic media that can flexibly adjust treatment plans according to the microenvironment in which they are located and enable high-quality wound healing through wound immune regulation. Summary of the invention

[0006] In view of the defects of the prior art, the purpose of the present invention is to provide a collagen-based conductive hydrogel, a drug and a preparation and application method thereof which are sensitive to both glucose concentration and pH value and can release active substances accordingly.

[0007] The technical solution of the present invention is as follows:

[0008] A method for preparing a dual-responsive collagen-based conductive hydrogel, comprising:

[0009] (1) preparing a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer, comprising: chemically modifying a polysaccharide with 3-aminophenylboronic acid to obtain a polysaccharide grafted aminophenylboronic acid copolymer, and subjecting the polysaccharide to sodium periodate oxidation treatment to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer;

[0010] (2) preparing a hydrazide collagen grafted polyaniline copolymer, comprising: performing hydrazide modification on collagen by adipic acid dihydrazide to obtain hydrazide collagen, and performing free radical polymerization on the hydrazide collagen and aniline to obtain a hydrazide collagen grafted polyaniline copolymer;

[0011] (3) preparing a collagen-based conductive hydrogel, comprising cross-linking the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer to obtain a dual-responsive collagen-based conductive hydrogel that can respond to both glucose and pH value.

[0012] According to some preferred embodiments of the present invention, the preparation of the polysaccharide grafted aminophenylboronic acid copolymer comprises:

[0013] Dissolving 2 parts by weight of polysaccharide in phosphate buffer to obtain a polysaccharide solution having a concentration of 1.5 to 2.5 wt %;

[0014] Adding 0.6 to 1 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.3 to 0.6 parts by weight of N-hydroxysuccinimide to the polysaccharide solution, and then adding 3-aminophenylboronic acid in a molar ratio of 1:(1 to 2) to the polysaccharide solution, reacting at room temperature for 12 to 36 hours, performing dialysis with a molecular cutoff of 3500Da, and freeze-drying to obtain the polysaccharide-grafted aminophenylboronic acid copolymer;

[0015] The polysaccharide grafted aminophenylboronic acid copolymer is dissolved in deionized water to obtain a polysaccharide grafted aminophenylboronic acid copolymer solution with a concentration of 1.5-2.5wt%. Under acidic conditions, sodium periodate is added to the polysaccharide grafted aminophenylboronic acid copolymer solution at a molar ratio of 1:(1-2) to the polysaccharide grafted aminophenylboronic acid copolymer. The solution is reacted in the dark for 4-8 hours, and dialyzed with a molecular retention capacity of 3500Da and freeze-dried to obtain the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer.

[0016] According to some preferred embodiments of the present invention, the preparation of the hydrazide collagen grafted polyaniline copolymer comprises:

[0017] Dissolving 1 part by weight of collagen in a phosphate buffer to obtain a collagen solution with a concentration of 0.5 to 1.5 wt %;

[0018] Add 4 to 6 parts by weight of adipic acid dihydrazide to the collagen solution, mix and clarify, then add 0.2 to 0.6 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 to 0.4 parts by weight of N-hydroxysuccinimide, react at room temperature for 12 to 36 hours, perform dialysis with a molecular cutoff of 8000 to 14000 Da, and freeze-dry to obtain the hydrazide collagen;

[0019] The hydrazide collagen is dissolved in a hydrochloric acid solution to obtain a hydrazide collagen solution with a concentration of 1.5 to 2.5 wt%, to which 0.02 to 0.1 parts by mass of aniline are added, and the mixture is reacted at room temperature for 30 to 90 minutes. Ammonium persulfate is then added at a molar ratio of 1:1 to aniline, and the mixture is reacted at room temperature for 12 to 36 hours. Dialysis with a molecular retention capacity of 8000 to 14000 Da and freeze-drying are performed to obtain the hydrazide collagen grafted polyaniline copolymer.

[0020] According to some preferred embodiments of the present invention, the preparation of the collagen-based conductive hydrogel comprises:

[0021] The dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer are mixed to obtain the collagen-based conductive hydrogel, wherein the mass ratio of the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer to the hydrazide collagen grafted polyaniline copolymer is 1:(1-8).

[0022] According to some preferred embodiments of the present invention, the concentration of the phosphate buffer is 0.01 mol / L.

[0023] According to some preferred embodiments of the present invention, the concentration of the hydrochloric acid is 0.1 mol / L.

[0024] According to some preferred embodiments of the present invention, the polysaccharide is selected from one or more of hyaluronic acid, sodium hyaluronate, alginic acid, sodium alginate, carboxymethyl cellulose, sodium carboxymethyl cellulose, chondroitin sulfate, xanthan gum, guar gum, carrageenan, konjac glucomannan, and starch.

[0025] The present invention further provides a dual-responsive collagen-based conductive hydrogel prepared according to the above preparation method.

[0026] The dual-responsive collagen-based conductive hydrogel obtained by the present invention contains a dynamic acylhydrazone bond generated by a hydrazide group and an amino group, which is completely opened under acidic conditions, so it has pH responsiveness. At the same time, it can dynamically construct phenylboronic acid and a diol structure to form a boronate ester bond. When glucose is present, glucose competes with the diol structure for the opportunity to combine with phenylboronic acid, resulting in the disconnection of the boronate ester bond, the disintegration of the material network, and the generation of sugar responsiveness. Therefore, the dual-responsive collagen-based conductive hydrogel is sensitive to both pH value and glucose / blood sugar, and can polymerize or disintegrate the material network under pH changes and glucose concentration changes, and further realize the controlled release of the material internal filling material.

[0027] The collagen in the dual-responsive collagen-based conductive hydrogel obtained by the present invention is widely derived from mammalian skin, Achilles tendon, cartilage and other tissues, has good biocompatibility, low immunogenicity, hemostasis, and easy processability, and is rich in amino functional groups. The hydrogel constructed by the invention has good injectability and is suitable for irregularly shaped skin wounds. It can greatly reduce the risk of secondary injury and infection of the wound and improve the safety and durability of the material.

[0028] The raw material polyaniline selected by the present invention is a conductive polymer with stable conductivity, good processability, biocompatibility, intrinsic antioxidant and antibacterial properties, and is a good material for constructing conductive hydrogel.

[0029] The present invention further provides a dual-responsive drug-releasing collagen-based conductive hydrogel drug, which contains the dual-responsive collagen-based conductive hydrogel and a loaded drug, wherein the loaded drug is selected from antioxidant active substances and / or anti-inflammatory drugs.

[0030] According to some preferred embodiments of the present invention, the loaded drug includes an antioxidant active substance whose mass is 0.1 to 0.5% of the mass of the dual-responsive collagen-based conductive hydrogel and an anti-inflammatory drug whose mass is 0.1 to 0.5% of the mass of the dual-responsive collagen-based conductive hydrogel.

[0031] According to some preferred embodiments of the present invention, the antioxidant active substance is selected from one or more of gallic acid, tannic acid, anthocyanin, proanthocyanidin, luteolin, and epigallocatechin gallate; the anti-inflammatory drug is selected from one or more of aspirin, indomethacin, diclofenac, metformin hydrochloride, and gliquidone.

[0032] The present invention further provides a method for preparing the dual-responsive drug-releasing collagen-based conductive hydrogel drug, which comprises:

[0033] Obtaining the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer;

[0034] Obtaining the hydrazide collagen grafted polyaniline copolymer;

[0035] The loaded drug is added to the hydrazide collagen grafted polyaniline copolymer, and after being evenly mixed, the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer is added to obtain the dual-responsive drug-releasing collagen-based conductive hydrogel drug.

[0036] The present invention further provides an application method of the above-mentioned collagen-based conductive hydrogel or the collagen-based conductive hydrogel drug with dual-responsive drug release, which is to use it in the preparation of a medicament for treating diabetic wounds.

[0037] The present invention has the following beneficial effects:

[0038] (1) The preparation method of the present invention grafts polyaniline onto the hydrazide collagen molecular chain by free radical polymerization, which can effectively solve the problem of poor water solubility and difficulty in dispersion of polyaniline, increase the amount of polyaniline added in the hydrogel, and greatly enhance the conductive properties of the collagen material;

[0039] (2) The present invention endows the hydrogel with superior compressive resistance and adhesion properties through the dual dynamic cross-linking network of acylhydrazone bond / boronate bond. The acylhydrazone bond / phenylboronate bond network is sensitive to both pH value and glucose concentration and has dual-factor response capability. Compared with the single-response conductive hydrogel, it can specifically respond to the microenvironment of chronic diabetic wounds and release antibacterial and anti-inflammatory drugs, and can more efficiently regulate the immune microenvironment of the wound surface, thereby promoting high-quality healing of chronic wounds such as diabetic foot ulcers.

[0040] (3) The conductive hydrogel obtained by the present invention is an injectable hydrogel constructed based on dynamic covalent cross-linking, which can be applied to irregularly shaped skin wounds, greatly reducing the risk of secondary injury and infection of the wounds, and improving the safety and durability of the hydrogel dressing. At the same time, it has electrochemical activity similar to that of human skin tissue, and shows significant advantages in the treatment of chronic wounds with poor regenerative ability, and is an ideal material for the development of skin tissue engineering scaffolds. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a SEM photo of the collagen-based conductive hydrogel drug obtained in Example 1;

[0042] Figure 2 The application effect display diagram of the collagen-based conductive hydrogel drug obtained in Example 1, wherein (a) is the injectability display, and (b) is its adhesion state on the skin;

[0043] Figure 3 This is a diagram showing the effect of collagen-based conductive hydrogel drugs filling irregular tissue damage obtained in Example 1;

[0044] Figure 4 A comparison chart of the adhesion performance of the collagen-based conductive hydrogel and the hydrogel drug obtained in Example 1 with the ungrafted polyaniline hydrogel;

[0045] Figure 5 The conductivity comparison diagram of the collagen-based conductive hydrogel and the hydrogel drug obtained in Example 1 and the ungrafted polyaniline hydrogel;

[0046] Figure 6 The cumulative release curves of metformin hydrochloride of the collagen-based conductive hydrogel drug under different conditions were obtained for Example 1, wherein (a) is different pH conditions and (b) is different glucose concentrations. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0048] Example 1

[0049] The collagen-based conductive hydrogel drug with dual-responsive drug release was prepared by the following steps:

[0050] (1) Preparation of dialdehyde polysaccharide grafted aminophenylboronic acid copolymer:

[0051] 2 parts by weight of sodium hyaluronate was dissolved in a phosphate buffer solution (pH 5.7) with a concentration of 0.01 mol / L to prepare a polysaccharide solution with a mass fraction of 2%;

[0052] 0.8 parts by mass of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.5 parts by mass of N-hydroxysuccinimide were added to the polysaccharide solution, and the mixture was stirred at room temperature for 30 minutes. Then, 3-aminophenylboronic acid was added at a molar ratio of 1:1 to the polysaccharide, and the mixture was stirred and reacted at room temperature for 24 hours. Dialysis with a molecular cutoff of 3500 Da and freeze-dried to obtain a polysaccharide-grafted aminophenylboronic acid copolymer.

[0053] 2 parts by weight of the polysaccharide grafted aminophenylboronic acid copolymer were dissolved in deionized water to obtain a polysaccharide grafted aminophenylboronic acid copolymer solution with a mass fraction of 2%, the pH value of the solution was adjusted to 3.0, sodium periodate was added in a molar ratio of 1:1 to the polysaccharide grafted aminophenylboronic acid copolymer, the reaction was carried out in the dark for 6 hours, and dialysis with a molecular cutoff of 3500Da was performed, and freeze-dried to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer;

[0054] (2) Preparation of hydrazide collagen grafted polyaniline copolymer:

[0055] 1 mass part of collagen was dissolved in 0.01 mol / L phosphate buffer (pH 5.7) to prepare a collagen solution with a mass fraction of 1%;

[0056] Add 5 parts by weight of adipic acid dihydrazide to the collagen solution, stir and mix to obtain a clear and transparent solution, then add 0.5 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.3 parts by weight of N-hydroxysuccinimide, stir at room temperature for 24 hours, perform dialysis with a molecular cutoff of 8000 to 14000 Da, and freeze-dry to obtain hydrazide collagen;

[0057] 2 parts by mass of hydrazide collagen were dissolved in a 0.1 mol / L hydrochloric acid solution to obtain a 2% hydrazide collagen solution, and then 0.06 parts by mass of aniline were added, and the mixture was stirred at room temperature for 60 minutes. Ammonium persulfate was then added at a molar ratio of 1:1 to aniline, and the mixture was stirred and reacted at room temperature for 24 hours. Dialysis with a molecular cutoff of 8000 to 14000 Da and freeze-dried to obtain a hydrazide collagen grafted polyaniline copolymer.

[0058] (3) Preparation of collagen-based conductive hydrogel drugs with dual-responsive drug release:

[0059] Gallic acid, an antioxidant active substance, and metformin hydrochloride, an anti-inflammatory drug, are added to hydrazide collagen grafted polyaniline copolymer, mixed evenly, and then dialdehyde polysaccharide grafted aminophenylboronic acid copolymer is added to prepare a collagen-based conductive hydrogel drug with pH / glucose dual-responsive drug release; wherein the mass ratio of dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and hydrazide collagen grafted polyaniline copolymer is 1:6, the mass fraction of the antioxidant active substance loaded in the collagen-based conductive hydrogel drug is 0.2% of the mass of the hydrogel, and the mass fraction of the anti-inflammatory drug loaded is 0.2% of the mass of the hydrogel.

[0060] Figure 1 This is a SEM photo of the collagen-based conductive hydrogel drug for dual-response drug release of gallic acid, an antioxidant active substance, and metformin hydrochloride, an anti-inflammatory drug, obtained in Example 1. It can be seen that the obtained collagen-based conductive hydrogel has a three-dimensional network structure, a uniform and complete through-hole structure, and a concentrated pore size distribution between 15 and 25 μm. The loose and porous structure is conducive to the exchange and transportation of water, gas, nutrients and metabolic waste, and is suitable for the adhesion and proliferation of cells such as fibroblasts and vascular endothelial cells.

[0061] Figure 2 (a) is the injectable property of the obtained collagen-based conductive hydrogel drug (wherein Hydrogel represents collagen-based conductive hydrogel, and PBS buffer represents 0.01 M phosphate buffer at pH 7.4), Figure 2 (b) shows its adhesion on the skin. It can be seen that the dual dynamic covalent crosslinking of acylhydrazone bond / boronate bond in the conductive hydrogel makes it injectable and maintains a good gel state in a liquid environment. It can still maintain tight adhesion on the finger under the flushing of water flow.

[0062] Figure 3 This is a diagram showing the filling effect of the obtained collagen-based conductive hydrogel drug on irregular tissue damage through injection (wherein Tissue represents tissue). It can be seen that it achieves complete coverage of irregular tissue defects and can effectively exert the therapeutic effect of the hydrogel.

[0063] Figure 4 This is a comparison chart of the adhesion properties of collagen-based conductive hydrogels measured by overlap shear experiments (wherein, G represents collagen-based hydrogels without polyaniline grafting and without drug loading, GP represents collagen-based conductive hydrogels grafted with polyaniline but without drug loading, and GPd represents collagen-based conductive hydrogels grafted with polyaniline and loaded with drugs). The testing method is: fresh pig skin is used to simulate human skin tissue, and two pig skins are bonded face to face using collagen-based conductive hydrogels. The bonding strength of the hydrogel is measured using an electronic universal testing machine. It can be seen that the bonding strength of the hydrogel is about 25 kPa, which has good tissue adhesion properties and can effectively prevent the material from falling off due to daily activities.

[0064] Figure 5 The conductivity comparison chart of collagen-based conductive hydrogels (where G represents collagen-based hydrogels without polyaniline grafting and drug loading, GP represents collagen-based conductive hydrogels with polyaniline grafting but without drug loading, and GPd represents collagen-based conductive hydrogels with polyaniline grafting and drug loading). It can be seen that the conductivity of collagen-based conductive hydrogel drugs can reach 68.3mS / cm. The good conductivity of the hydrogel helps the tissue around the wound to rebuild the endogenous electric field, guide the migration, proliferation and differentiation of tissue cells, and promote wound healing.

[0065] Figure 6 The cumulative release curve of metformin hydrochloride from collagen-based conductive hydrogel drugs under different conditions, where (a) is different pH conditions and (b) is different glucose concentrations. The test method is: soak the collagen-based conductive hydrogel drug in phosphate buffers with different pH values ​​or different glucose concentrations, and take the buffer solution within a predetermined time to calculate the release amount of metformin hydrochloride. It can be found from the figure that the obtained collagen-based conductive hydrogel can release the anti-inflammatory drug metformin hydrochloride faster under pH 5.5 or high sugar environment, and has the ability to respond to pH / glucose stimulation and drug release. When chronic wounds become infected and acidic or face a high blood sugar microenvironment, the hydrogel can release drugs faster, and has a good application prospect in inducing high-quality healing of diabetic chronic wounds.

[0066] Example 2

[0067] The collagen-based conductive hydrogel drug with dual-responsive drug release was prepared by the following steps:

[0068] (1) Preparation of dialdehyde polysaccharide grafted aminophenylboronic acid copolymer:

[0069] 2 parts by mass of sodium alginate was dissolved in a phosphate buffer solution (pH 5.7) with a concentration of 0.01 mol / L to prepare a polysaccharide solution with a mass fraction of 2%;

[0070] 0.6 parts by mass of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.3 parts by mass of N-hydroxysuccinimide were added to the polysaccharide solution, and the mixture was stirred at room temperature for 60 minutes. Then, 3-aminophenylboronic acid was added at a molar ratio of 1:2 to the polysaccharide, and the mixture was stirred and reacted for 36 hours at room temperature. Dialysis with a molecular cutoff of 3500 Da and freeze-dried were performed to obtain a polysaccharide-grafted aminophenylboronic acid copolymer.

[0071] 2 parts by weight of the polysaccharide grafted aminophenylboronic acid copolymer were dissolved in deionized water to obtain a polysaccharide grafted aminophenylboronic acid copolymer solution with a mass fraction of 2%, the pH value of the solution was adjusted to 3.0, sodium periodate was added at a molar ratio of 1:4 to the polysaccharide grafted aminophenylboronic acid copolymer, the reaction was carried out in the dark for 8 hours, and dialysis with a molecular cutoff of 3500Da was performed, and freeze-dried to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer;

[0072] (2) Preparation of hydrazide collagen grafted polyaniline copolymer:

[0073] 1 mass part of collagen was dissolved in 0.01 mol / L phosphate buffer (pH 5.7) to prepare a collagen solution with a mass fraction of 1%;

[0074] 6 parts by weight of adipic acid dihydrazide were added to the collagen solution, and the mixture was stirred to obtain a clear and transparent solution. 0.4 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.2 parts by weight of N-hydroxysuccinimide were added, and the mixture was stirred at room temperature for 36 hours. The mixture was dialyzed at a molecular cutoff of 8000 to 14000 Da, and freeze-dried to obtain hydrazide collagen.

[0075] 2 parts by mass of hydrazide collagen were dissolved in a 0.1 mol / L hydrochloric acid solution to obtain a 2% hydrazide collagen solution, and then 0.1 parts by mass of aniline were added, and the mixture was stirred at room temperature for 60 minutes. Ammonium persulfate was then added at a molar ratio of 1:1 to aniline, and the mixture was stirred and reacted at room temperature for 12 hours. Dialysis with a molecular cutoff of 8000 to 14000 Da and freeze-dried to obtain a hydrazide collagen grafted polyaniline copolymer.

[0076] (3) Preparation of collagen-based conductive hydrogel drugs with dual-responsive drug release:

[0077] Tannic acid, an antioxidant active substance, and aspirin, an anti-inflammatory drug, are added to hydrazide collagen grafted polyaniline copolymer, mixed evenly, and then dialdehyde polysaccharide grafted aminophenylboronic acid copolymer is added to prepare a collagen-based conductive hydrogel drug with pH / glucose dual-responsive drug release; wherein the mass ratio of dialdehyde polysaccharide grafted aminophenylboronic acid copolymer to hydrazide collagen grafted polyaniline copolymer is 1:2, the mass fraction of the antioxidant active substance loaded in the collagen-based conductive hydrogel drug is 0.4% of the mass of the hydrogel, and the mass fraction of the anti-inflammatory drug loaded is 0.4% of the mass of the hydrogel.

[0078] Example 3

[0079] The collagen-based conductive hydrogel drug with dual-responsive drug release was prepared by the following steps:

[0080] (1) Preparation of dialdehyde polysaccharide grafted aminophenylboronic acid copolymer:

[0081] 2 parts by mass of xanthan gum were dissolved in a phosphate buffer solution (pH 5.7) with a concentration of 0.01 mol / L to prepare a polysaccharide solution with a mass fraction of 2%;

[0082] Add 1 part by mass of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.6 part by mass of N-hydroxysuccinimide to the polysaccharide solution, stir at room temperature for 60 minutes, then add 3-aminophenylboronic acid at a molar ratio of 1:1 to the polysaccharide, continue stirring and reacting at room temperature for 12 hours, perform dialysis with a molecular cutoff of 3500Da, and freeze-dry to obtain a polysaccharide-grafted aminophenylboronic acid copolymer;

[0083] 2 parts by weight of the polysaccharide grafted aminophenylboronic acid copolymer were dissolved in deionized water to obtain a polysaccharide grafted aminophenylboronic acid copolymer solution with a mass fraction of 2%, the pH value of the solution was adjusted to 3.0, sodium periodate was added in a molar ratio of 1:1 to the polysaccharide grafted aminophenylboronic acid copolymer, the reaction was carried out in the dark for 4 hours, and dialysis with a molecular cutoff of 3500Da was performed, and freeze-dried to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer;

[0084] (2) Preparation of hydrazide collagen grafted polyaniline copolymer:

[0085] 1 mass part of collagen was dissolved in 0.01 mol / L phosphate buffer (pH 5.7) to prepare a collagen solution with a mass fraction of 1%;

[0086] Add 4 parts by weight of adipic acid dihydrazide to the collagen solution, stir and mix to obtain a clear and transparent solution, then add 0.2 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 parts by weight of N-hydroxysuccinimide, stir at room temperature for 36 hours, perform dialysis with a molecular cutoff of 8000 to 14000 Da, and freeze-dry to obtain hydrazide collagen;

[0087] 2 parts by mass of hydrazide collagen were dissolved in a 0.1 mol / L hydrochloric acid solution to obtain a 2% hydrazide collagen solution, and then 0.08 parts by mass of aniline were added, and the mixture was stirred at room temperature for 90 minutes. Ammonium persulfate was then added at a molar ratio of 1:1 to aniline, and the mixture was stirred and reacted at room temperature for 36 hours. Dialysis with a molecular cutoff of 8000 to 14000 Da and freeze-dried to obtain a hydrazide collagen grafted polyaniline copolymer.

[0088] (3) Preparation of collagen-based conductive hydrogel drugs with dual-responsive drug release:

[0089] The antioxidant active substance proanthocyanidin and the anti-inflammatory drug gliquidone are added to the hydrazide collagen grafted polyaniline copolymer, mixed evenly, and then the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer is added to prepare the collagen-based conductive hydrogel drug with pH / glucose dual-responsive drug release; wherein the mass ratio of the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer is 1:1, the mass fraction of the antioxidant active substance loaded in the collagen-based conductive hydrogel drug is 0.3% of the mass of the hydrogel, and the mass fraction of the anti-inflammatory drug loaded is 0.3% of the mass of the hydrogel.

[0090] After testing, the dual-responsive collagen-based conductive hydrogel drugs prepared in Examples 2 and 3 have similar structures and properties to those in Example 1.

[0091] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a dual-responsive collagen-based conductive hydrogel, characterized in that: It includes: (1) preparing a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer, comprising: chemically modifying a polysaccharide with 3-aminophenylboronic acid to obtain a polysaccharide grafted aminophenylboronic acid copolymer, and subjecting the polysaccharide to sodium periodate oxidation treatment to obtain a dialdehyde polysaccharide grafted aminophenylboronic acid copolymer; (2) preparing a hydrazide collagen grafted polyaniline copolymer, comprising: performing hydrazide modification on collagen by adipic acid dihydrazide to obtain hydrazide collagen, and performing free radical polymerization on the hydrazide collagen and aniline to obtain a hydrazide collagen grafted polyaniline copolymer; (3) preparing a collagen-based conductive hydrogel, comprising cross-linking the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer to obtain a dual-responsive collagen-based conductive hydrogel that can respond to both glucose and pH value.

2. The preparation method according to claim 1, characterized in that: in, The preparation of the polysaccharide grafted aminophenylboronic acid copolymer comprises: Dissolving 2 parts by weight of polysaccharide in phosphate buffer to obtain a polysaccharide solution having a concentration of 1.5 to 2.5 wt %; Adding 0.6 to 1 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.3 to 0.6 parts by weight of N-hydroxysuccinimide to the polysaccharide solution, and then adding 3-aminophenylboronic acid in a molar ratio of 1:(1 to 2) to the polysaccharide solution, reacting at room temperature for 12 to 36 hours, performing dialysis with a molecular cutoff of 3500Da, and freeze-drying to obtain the polysaccharide-grafted aminophenylboronic acid copolymer; The polysaccharide grafted aminophenylboronic acid copolymer is dissolved in deionized water to obtain a polysaccharide grafted aminophenylboronic acid copolymer solution with a concentration of 1.5-2.5wt%, and under acidic conditions, sodium periodate is added to the polysaccharide grafted aminophenylboronic acid copolymer solution at a molar ratio of 1:(1-2) to the polysaccharide grafted aminophenylboronic acid copolymer, reacted for 4-8 hours in the dark, dialyzed with a molecular cutoff of 3500Da, and freeze-dried to obtain the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer; and / or, The preparation of the hydrazide collagen grafted polyaniline copolymer comprises: Dissolving 1 part by weight of collagen in a phosphate buffer to obtain a collagen solution with a concentration of 0.5 to 1.5 wt %; Add 4 to 6 parts by weight of adipic acid dihydrazide to the collagen solution, mix and clarify, then add 0.2 to 0.6 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 to 0.4 parts by weight of N-hydroxysuccinimide, react at room temperature for 12 to 36 hours, perform dialysis with a molecular cutoff of 8000 to 14000 Da, and freeze-dry to obtain the hydrazide collagen; The hydrazide collagen is dissolved in a hydrochloric acid solution to obtain a hydrazide collagen solution with a concentration of 1.5 to 2.5 wt %, 0.02 to 0.1 parts by mass of aniline is added thereto, and the mixture is reacted at room temperature for 30 to 90 min, and then ammonium persulfate is added at a molar ratio of 1:1 to aniline, and the mixture is reacted at room temperature for 12 to 36 h, and the mixture is dialyzed with a molecular cutoff of 8000 to 14000 Da and freeze-dried to obtain the hydrazide collagen grafted polyaniline copolymer; and / or, The preparation of the collagen-based conductive hydrogel comprises: The dialdehyde polysaccharide grafted aminophenylboronic acid copolymer and the hydrazide collagen grafted polyaniline copolymer are mixed to obtain the collagen-based conductive hydrogel, wherein the mass ratio of the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer to the hydrazide collagen grafted polyaniline copolymer is 1:(1-8).

3. The preparation method according to claim 2, characterized in that: in, The concentration of the phosphate buffer is 0.01 mol / L, and / or the concentration of the hydrochloric acid is 0.1 mol / L.

4. The preparation method according to any one of claims 1 to 3, characterized in that The polysaccharide is selected from one or more of hyaluronic acid, sodium hyaluronate, alginic acid, sodium alginate, carboxymethyl cellulose, sodium carboxymethyl cellulose, chondroitin sulfate, xanthan gum, guar gum, carrageenan, konjac glucomannan and starch.

5. The dual-responsive collagen-based conductive hydrogel prepared according to the preparation method of any one of claims 1-4.

6. A dual-responsive drug-releasing collagen-based conductive hydrogel drug, comprising a dual-responsive collagen-based conductive hydrogel prepared by the preparation method according to any one of claims 1 to 4 and a loaded drug, wherein the loaded drug is selected from antioxidant active substances and / or anti-inflammatory drugs.

7. The collagen-based conductive hydrogel drug with dual-responsive drug release according to claim 6, characterized in that: The loaded drugs include antioxidant active substances whose mass is 0.1-0.5% of the mass of the dual-responsive collagen-based conductive hydrogel and anti-inflammatory drugs whose mass is 0.1-0.5% of the mass of the dual-responsive collagen-based conductive hydrogel.

8. The collagen-based conductive hydrogel drug with dual-responsive drug release according to claim 6, characterized in that: The antioxidant active substance is selected from one or more of gallic acid, tannic acid, anthocyanidin, proanthocyanidin, luteolin, and epigallocatechin gallate; the anti-inflammatory drug is selected from one or more of aspirin, indomethacin, diclofenac, metformin hydrochloride, and gliquidone.

9. A method for preparing a collagen-based conductive hydrogel drug with dual-responsive drug release according to any one of claims 6 to 8, comprising: Obtaining the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer; Obtaining the hydrazide collagen grafted polyaniline copolymer; The loaded drug is added to the hydrazide collagen grafted polyaniline copolymer, and after being evenly mixed, the dialdehyde polysaccharide grafted aminophenylboronic acid copolymer is added to obtain the dual-responsive drug-releasing collagen-based conductive hydrogel drug.

10. Use of the collagen-based conductive hydrogel according to claim 5 or the dual-responsive drug-releasing collagen-based conductive hydrogel drug according to any one of claims 6 to 8 in the preparation of a medicament for treating diabetic wounds.

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