阅读说明：本技术 一种医用镁合金表面释药功能涂层的制备方法 (Preparation method of medical magnesium alloy surface drug release functional coating ) 是由 陈民芳 王岩松 于 2019-09-17 设计创作，主要内容包括：一种医用镁合金表面释药功能涂层的制备方法,特别适用于生物医药材料的表面处理及表面改性领域。本方法通过化学聚合法在镁或镁合金的无机涂层上制备释药涂层,旨在降低镁或镁合金的降解速度,并起到释放药物的作用,从而保证镁或镁合金在实际应用中的力学性能并更好缓解生物体的排异反应。镁或镁合金表面通过微弧氧化制备得到无机涂层,之后无机涂层上制备载药层。无机涂层是由MgO、Mg<Sub>2</Sub>SiO<Sub>4</Sub>和Mg<Sub>3</Sub>(PO<Sub>4</Sub>)<Sub>2</Sub>所构成的具有极佳耐蚀性的陶瓷涂层,可以有效地降低镁或镁合金的体内降解速度。载药层由载药聚合物与治疗性药物构成,减少植入后炎症反应的发生率和对药物的依赖作用及其副作用,并进一步提高镁或镁合金的耐蚀性。(A method for preparing a medical magnesium alloy surface drug release functional coating, which is particularly suitable for the fields of surface treatment and surface modification of biomedical materials. The method prepares the drug release coating on the inorganic coating of the magnesium or the magnesium alloy by a chemical polymerization method, aims to reduce the degradation speed of the magnesium or the magnesium alloy and plays a role in releasing the drug, thereby ensuring the mechanical property of the magnesium or the magnesium alloy in practical application and better relieving the rejection reaction of organisms. The surface of the magnesium or magnesium alloy is oxidized by micro-arc to obtain an inorganic coating, and then a drug-loaded layer is prepared on the inorganic coating. The inorganic coating is made of MgO and Mg 2 SiO 4 And Mg 3 (PO 4 ) 2 The formed ceramic coating with excellent corrosion resistance can effectively reduce the in-vivo degradation speed of magnesium or magnesium alloy. The drug-loaded layer is composed of drug-loaded polymer and therapeutic drug, reduces incidence rate of inflammatory reaction after implantation, dependence effect on drug and side effect thereof, and further improves corrosion resistance of magnesium or magnesium alloy.)

1. A preparation method of a medical magnesium alloy surface drug release functional coating comprises the following steps:

A. using pure magnesium or magnesium alloy as anode, and carrying out micro-arc oxidation in electrolyte to obtain the product containing MgO and Mg₂SiO₄And Mg₃(PO₄)₂Micro-arc oxidation film layer; the electrolyte comprises 2-25 g/L of trisodium phosphate, 2-10 g/L of sodium silicate and 2-15 g/L of sodium hydroxide;

B. b, immersing the magnesium or magnesium alloy obtained in the step A into a silanization solution prepared by a silane coupling agent to form a silane layer on the surface of the magnesium or magnesium alloy;

C. preparing a polymer monomer, a drug and an organic solvent to form an organic solution, and preparing an oxidant to form a solution;

D. and C, immersing the magnesium or magnesium alloy containing the silane layer obtained in the step B into the organic solution obtained in the step C, taking out the magnesium or magnesium alloy, putting the magnesium or magnesium alloy into the oxidant solution obtained in the step C, and repeating the operation to form a coating with a drug release function on the surface of the magnesium or magnesium alloy.

2. The method for preparing the medical magnesium alloy surface drug release functional coating according to claim 1, wherein the step A further comprises the following steps before micro-arc oxidation: polishing the magnesium alloy, and carrying out ultrasonic cleaning and oil removal by using acetone and ethanol in sequence, wherein the pH value of the electrolyte is 8-12.

3. The method for preparing the medical magnesium alloy surface drug release functional coating according to claim 1, wherein the parameters of the micro-arc oxidation in the step A comprise: the current density is 0.5 to 300mA/cm²The positive voltage is 250-500V, the negative voltage is 5-30V, the current frequency is 200-2000 Hz, the positive-negative frequency ratio is 0.5-2, the positive duty ratio is 10-50%, the negative duty ratio is 10-25%, the reaction time is 5-40 min, and the reaction temperature is 20-50 ℃.

4. The method for preparing the medical magnesium alloy surface drug release functional coating according to claim 1, wherein the concentration of the polymer monomer in the organic solution in the step C is 0.1-1 mol/L, and the concentration of the drug is 1-10 mmol/L; the concentration of the oxidant is 0.1-3 mmol/L, and the organic solvent is one of ethanol, ethylene glycol, propanol, isopropanol or butanol.

5. The method for preparing the medical magnesium alloy surface drug release functional coating according to any one of claims 1 to 4, wherein the magnesium alloy in the step A is one of biomedical binary magnesium alloy, biomedical ternary magnesium alloy, biomedical quaternary magnesium alloy and biomedical quinary magnesium alloy.

6. The method for preparing the medical magnesium alloy surface drug release functional coating according to any one of claims 1 to 4, wherein the silane coupling agent in the step B is one of bis- (gamma-triethoxysilylpropane) tetrasulfide, aminopropyl triethyl silane, vinyltrioxysilane, vinyltrimethoxysilane or vinyltris (beta-methoxyethoxy) silane.

7. The method for preparing the medical magnesium alloy surface drug release functional coating according to any one of claims 1 to 4, wherein the polymer monomer in the step C is one of pyrrole, aniline, acetylene or thiophene.

8. The method for preparing the medical magnesium alloy surface drug release functional coating according to any one of claims 1 to 4, wherein the oxidizing agent in the step C is one of copper chloride, ferric chloride, ferrous chloride, silver chloride, ammonium persulfate, molybdenum chloride, or hydrogen peroxide.

9. The method for preparing a medical magnesium alloy surface drug release functional coating according to any one of claims 1 to 4, wherein the drug in step C is one of dexamethasone, rapamycin, penicillin, isoniazid, paclitaxel, fluvastatin, nifedipine or metformin hydrochloride.

10. The method for preparing the medical magnesium alloy surface drug release functional coating according to any one of claims 1 to 4, wherein the number of times of repeating the above operation in the step D is 1 to 5.

Technical Field

The invention relates to the technical field of biological materials, in particular to a method for preparing a coating with a drug release function on the surface of medical magnesium alloy.

Background

Since the 70's of the 19 th century, magnesium alloys having good biocompatibility and magnesium density of 1.74g/cm, as compared with conventional metals, have been used as biomedical materials for over a century³Is mixed with natural bone (1.8-2.1 g/cm)³) Close to each other, the mechanical property is compatible with human skeleton-no stress shielding effect exists, and Mg²⁺It has also been shown to promote the adsorption and growth of bone cells. Magnesium alloy is considered as a biodegradable material with great development potential, but has limited wide application due to its fast degradation rate in human body.

Research results show that appropriate surface treatment can effectively reduce the corrosion rate of the magnesium alloy, and the current methods for improving the corrosion resistance of the magnesium alloy mainly comprise surface treatment technologies such as electrochemical deposition, chemical conversion coating, biodegradable polymer coating, micro-arc oxidation and the like. With the development of the technology, researchers do not simply satisfy the improvement of the corrosion resistance, and aim to improve the functionality of the coating so that the coating can play a greater role in practical application. The research hotspots mainly include: promoting the growth of coatings on affected parts, antibacterial coatings and drug release coatings on patient parts, wherein the drug release coatings have gradually become the hot spots of research.

Many studies have been made on preparing drug-releasing coatings on the surface of magnesium alloy, mainly focusing on using polymer to load drugs, but the polymer coating coated on the surface of magnesium alloy lacks enough hardness and wear resistance, and there is a risk of coating failure in practical surgical application. The traditional drug release coating has many limitations, the phenomenon of rapid drug release in the initial stage is still a problem, and most of the current researches on polymer drug release coatings mainly focus on the surfaces of inert metals such as titanium and the like, which proves that drugs with different amounts can be released according to the magnitude of current, and the preparation of the degradable metal surface is relatively less.

Disclosure of Invention

The invention aims to solve the problem of preparing a drug release coating on the surface of degradable metal and provides a method for preparing a coating with a drug release function on the surface of medical magnesium alloy. The preparation method provided by the invention has simple and controllable process, and can realize the preparation of the coating with the function of releasing the medicine on the surface of the magnesium alloy. The functional coating for releasing the drugs prepared by the method has good bonding performance with the degradable magnesium alloy matrix, not only improves the corrosion resistance of the magnesium alloy, but also can control the release of the drugs through the transmission of biological signals at focus. In the practical application process, the on-demand administration of organisms is realized, so that the dependence on medicines and the side effect thereof can be reduced, and the recovery period of patients can be effectively shortened.

Technical scheme of the invention

A preparation method of a medical magnesium alloy surface drug release functional coating comprises the following steps:

A. using pure magnesium or magnesium alloy as anode, and carrying out micro-arc oxidation in electrolyte to obtain the product containing MgO and Mg₂SiO₄And Mg₃(PO₄)₂Micro-arc oxidation film layer; the electrolyte comprises 2-25 g/L of trisodium phosphate, 2-10 g/L of sodium silicate and 2-15 g/L of sodium hydroxide.

B. And B, immersing the magnesium or magnesium alloy obtained in the step A into a silanization solution prepared by a silane coupling agent, and forming a silane layer on the surface of the magnesium or magnesium alloy.

C. Preparing a polymer monomer, a drug and an organic solvent to form an organic solution, and preparing an oxidant to form a solution.

D. And C, immersing the magnesium or magnesium alloy containing the silane layer obtained in the step B into the organic solution obtained in the step C, taking out the magnesium or magnesium alloy, putting the magnesium or magnesium alloy into the oxidant solution obtained in the step C, and repeating the operation for a plurality of times to form a coating with a drug release function on the surface of the magnesium or magnesium alloy.

Wherein, before the micro-arc oxidation in the step A, the method further comprises the following steps: polishing the magnesium alloy, and carrying out ultrasonic cleaning and oil removal by using acetone and ethanol in sequence.

And the pH value of the electrolyte in the step A is 8-12. The parameters of the micro-arc oxidation comprise: the current density is 0.5 to 300mA/cm²Positive voltage of 250 &500V, 5-30V of negative voltage, 200-2000 Hz of current frequency, 0.5-2 of positive and negative frequency ratio, 10-50% of positive duty ratio, 10-25% of negative duty ratio, 5-40 min of reaction time and 20-50 ℃ of reaction temperature.

And C, in the step C, the concentration of the polymer monomer in the organic solution is 0.1-1 mol/L, the concentration of the medicine is 1-10 mmol/L, the concentration of the oxidant is 0.1-3 mmol/L, and the organic solvent is one of ethanol, ethylene glycol, propanol, isopropanol and butanol.

The magnesium alloy is one of multi-element alloys such as biomedical binary magnesium alloy, biomedical ternary magnesium alloy, biomedical quaternary magnesium alloy and biomedical quinary magnesium alloy.

And the silane coupling agent in the step B is one of bis- (gamma-triethoxysilylpropane) tetrasulfide, aminopropyl triethyl silane, vinyl trioxysilane, vinyl trimethoxy silane or vinyl tri (beta-methoxyethoxy) silane.

And the polymer monomer in the step C is one of pyrrole, aniline, acetylene or thiophene. The oxidant is one of copper chloride, ferric chloride, ferrous chloride, silver chloride, ammonium persulfate, molybdenum chloride or hydrogen peroxide. The drug is one of dexamethasone, rapamycin, penicillin, isoniazid, paclitaxel, fluvastatin, nifedipine or metformin hydrochloride.

And D, repeating the operation for 1-5 times.

The invention has the advantages and beneficial effects that:

1. the invention realizes the surface modification of magnesium or magnesium alloy, and the prepared drug-releasing coating can be firmly attached to the surface of magnesium or magnesium alloy and is loaded with drugs;

2. the invention provides a novel method for preparing a drug release layer on the surface of magnesium or magnesium alloy, which controls the drug release by controlling the redox property of a polymer through the change of bioelectric current, realizes the drug release at the diseased part and reduces the drug dependence and side effects caused by over-administration.

3. The preparation method can be used for coating magnesium alloy with any shape, can be used for surface modification of magnesium alloy with complex structure, can control the thickness and the drug loading of the coating by controlling different preparation processes, and can be widely applied to actual production.

Drawings

FIG. 1 is a schematic scanning electron microscope of the micro-arc oxidation coating on the surface of the magnesium alloy in step A of the preparation method.

FIG. 2 is a schematic scanning electron microscope of a surface silane layer formed on the surface of a magnesium alloy in step B of the preparation method of the present invention.

Fig. 3 is a schematic scanning electron microscope of the drug release coating formed on the surface of the magnesium alloy in step D of the preparation method of the present invention.

FIG. 4 is a representation of the drug release amount of the drug release coating of example 1, example 2 and example 4 with different drug addition amounts in the preparation method of the present invention.

Detailed Description

The invention is described in detail below with reference to the attached drawing figures: