Magnesium alloy surface self-repairing endothelial cell affinity coating and preparation method thereof

Abstract

The invention provides a magnesium alloy surface self-repairing endothelial cell affinity coating and a preparation method thereof, and relates to the technical field of medical magnesium alloy surface coatings, the magnesium alloy surface self-repairing endothelial cell affinity coating comprises a base layer coating, the base layer coating is arranged on the magnesium alloy surface, the outer side of the base layer coating is dip-coated with a middle coating, and the outer side of the middle coating is dip-coated with an outer coating; the base layer coating comprises the following raw materials: a corrosion inhibition electrolytic solution, the middle coating comprises the following raw materials: a corrosion inhibitor, a metal organic framework powder material and a polyurethane solution, and the outer coating comprises the following raw materials: a polylactic acid solution and an anti-inflammatory agent; according to the method, the base layer coating, the middle coating and the outer coating are compounded for protection, the base layer coating and the middle coating have the self-repairing effect by introducing the corrosion inhibitor, and then protection is conducted through the outer coating, so that the corrosion resistance of the magnesium alloy can be effectively improved, and the service life of the magnesium alloy is prolonged. And the service life of the magnesium alloy is effectively prolonged through the self-repairing mode of the coating.

Description

Technical Field

[0001] The invention relates to the technical field of medical magnesium alloy surface coatings, and in particular to a magnesium alloy surface self-repairing endothelial cell affinity coating and a preparation method thereof. Background Art

[0002] Medical magnesium alloys are biodegradable medical materials and are known as the third generation of biomedical materials. Magnesium is an element with good biocompatibility for the human body, showing excellent absorbability, and in orthopedic implant applications, its density and elastic modulus are close to those of bone tissue. In addition, medical magnesium alloys also have controllable corrosion rates and show good application prospects in the fields of cardiovascular implants and bone repair. The magnesium alloys studied mainly include WE43, AZ31, Mg-Ca, MgZnCa, etc.

[0003] As one of the important means of surface protection and corrosion prevention of metal substrates, coating technology has been widely used in all aspects of human production and life, and plays a key role in many industrial and life fields. Coatings can not only improve the aesthetics of the surface of objects, but also significantly improve their corrosion resistance and give them specific functionality. More importantly, coatings can effectively isolate the metal substrate from direct contact with the corrosive medium, thereby significantly slowing down or preventing the occurrence of the corrosion process.

[0004] Since magnesium alloy is directly used as an implant to repair bone tissue, it may lose its mechanical properties before the bone tissue heals due to its rapid corrosion. Therefore, in order to slow down the degradation rate of magnesium alloy, a coating is usually provided on the surface of magnesium alloy for protection. However, the protective effect of the single-layer coating in the prior art is low, and when there is a problem with the single-layer coating, the protective effect of the magnesium alloy will be significantly reduced. Therefore, the present invention proposes a magnesium alloy surface self-repairing endothelial cell affinity coating and a preparation method thereof to solve the problems existing in the prior art. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to propose a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy and a preparation method thereof. The self-repairing endothelial cell affinity coating on the surface of a magnesium alloy and a preparation method thereof protect the surface of the magnesium alloy through a multi-layer composite manner, and also have a self-repair function, thereby solving the problems existing in the prior art.

[0006] To achieve the purpose of the present invention, the present invention provides the following technical solutions: a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy, comprising a three-layer coating structure, which is a base coating, an intermediate coating and an outer coating in sequence, wherein the base coating is arranged on the surface of the magnesium alloy, the intermediate coating is dipped on the outside of the base coating, and the outer coating is dipped on the outside of the intermediate coating, the base coating comprises the following raw materials in parts by weight: 1 to 10 parts of corrosion-inhibiting electrolytic solution; the intermediate coating comprises the following raw materials in parts by weight: 10 to 20 parts of corrosion inhibitor, 5 to 10 parts of metal organic framework powder material and 50 to 100 parts of polyurethane solution; the outer coating comprises the following raw materials in parts by weight: 50 to 100 parts of polylactic acid solution and 1 to 2 parts of anti-inflammatory agent.

[0007] A further improvement is that the corrosion-inhibiting electrolytic solution is a mixture of a silicate corrosion inhibitor and a silicate electrolyte, wherein the silicate corrosion inhibitor accounts for 30 to 55 wt % of the corrosion-inhibiting electrolytic solution.

[0008] A further improvement is that the corrosion inhibitor is a molybdate corrosion inhibitor.

[0009] A further improvement is that the anti-inflammatory agent is curcumin powder.

[0010] A method for preparing a self-repairing endothelial cell affinity coating on a magnesium alloy surface comprises the following steps:

[0011] Step 1: Material preparation and processing

[0012] A magnesium alloy sheet to be processed is prepared, and then pre-treated for subsequent use. Next, materials are prepared according to a coating formula, wherein the formula includes the following materials in parts by weight: 1 to 10 parts of corrosion-inhibiting electrolytic solution, 10 to 20 parts of corrosion inhibitor, 5 to 10 parts of metal organic framework powder material, 50 to 100 parts of polyurethane solution, 50 to 100 parts of polylactic acid solution, and 1 to 2 parts of anti-inflammatory agent;

[0013] Step 2: Prepare base coating

[0014] Adding the corrosion-inhibiting electrolytic solution into the micro-arc oxidation equipment, placing the magnesium alloy sheet pretreated in step 1 into the corrosion-inhibiting electrolytic solution, and then starting the micro-arc oxidation equipment to perform micro-arc oxidation processing, thereby forming a base coating;

[0015] Step 3: Preparation of intermediate coating

[0016] The corrosion inhibitor is added to a mixing container, and distilled water is added to mix, and then the metal organic framework powder material is added, and the agitator is turned on to stir to achieve adsorption. After the adsorption is completed, the metal organic framework powder material loaded with the corrosion inhibitor is filtered to obtain the metal organic framework powder material, and then the metal organic framework powder material loaded with the corrosion inhibitor is treated. After the treatment, the metal organic framework powder material loaded with the corrosion inhibitor is mixed with the polyurethane solution to obtain an intermediate coating, and then the intermediate coating is prepared on the magnesium alloy sheet in step 2 by dip coating;

[0017] Step 4: Prepare the outer coating

[0018] The anti-inflammatory agent is added to the polylactic acid solution and dispersed and mixed by ultrasonic dispersion to obtain an outer coating. Subsequently, the magnesium alloy sheet treated in step three is dip-coated to prepare an outer coating, and finally a self-repairing endothelial cell affinity coating is formed on the surface of the magnesium alloy.

[0019] A further improvement is that in step one, the specific steps of pretreatment are: grinding the surface of the magnesium alloy sheet with sandpaper, and then ultrasonically cleaning it in distilled water and alcohol in turn after grinding, each cleaning time is 15 to 25 minutes, the number of cleaning times is ≥2 times, and drying is carried out after cleaning.

[0020] A further improvement is that in step 2, the micro-arc oxidation time is 20 to 30 minutes.

[0021] A further improvement is that in step three, the specific treatment method is: washing the metal organic framework powder material separated by filtration with water, and then drying the washed powder material.

[0022] A further improvement is that in step three and step four, after each layer of coating is processed, it is cured by heat treatment.

[0023] The beneficial effects of the present invention are as follows: the self-repairing endothelial cell affinity coating on the surface of the magnesium alloy provided by the present invention adopts a composite method of a base coating, an intermediate coating and an external coating to protect the magnesium alloy, wherein the base coating and the intermediate coating introduce a corrosion inhibitor so that the base coating and the intermediate coating have a self-repairing effect, and then the external coating is used for protection, which can effectively improve the corrosion resistance of the magnesium alloy, and the self-repairing method of the coating effectively prolongs the service life of the magnesium alloy. In addition, the intermediate coating and the external coating adopt a polymer with good biocompatibility as the material, which is conducive to the crawling of endothelial cells and the regeneration of the endothelial layer. The overall preparation process is simple and easy to operate, so it can reduce the preparation cost to a certain extent, bringing significant economic benefits to the company. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1It is a schematic diagram of the preparation method steps of the present invention. DETAILED DESCRIPTION

[0025] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with the examples. It should be emphasized that the examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0026] The raw materials used in the following examples were all obtained through conventional commercial channels, wherein the magnesium alloy is a medical magnesium alloy, the metal organic framework powder material type is MOF-177, the type of silicate corrosion inhibitor is sodium silicate, the type of silicate electrolyte is sodium silicate (Na2SiO3) electrolyte, which is a common silicate electrolyte, and the type of molybdate corrosion inhibitor is sodium molybdate (Na2MoO4).

[0027] Embodiment 1

[0028] according to Figure 1 As shown, this embodiment proposes a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy, including a base coating, which is arranged on the surface of the magnesium alloy, and an intermediate coating is dipped on the outside of the base coating, and an outer coating is dipped on the outside of the intermediate coating. The base coating includes the following raw materials in parts by weight: 1 part of corrosion-inhibiting electrolytic solution, the intermediate coating includes the following raw materials in parts by weight: 10 parts of corrosion inhibitor, 5 parts of metal organic framework powder material and 50 parts of polyurethane solution, and the outer coating includes the following raw materials in parts by weight: 50 parts of polylactic acid solution and 1 part of anti-inflammatory agent, wherein the corrosion-inhibiting electrolytic solution is a mixture of a silicate corrosion inhibitor and a silicate electrolyte, the silicate corrosion inhibitor accounts for 30wt% of the corrosion-inhibiting electrolytic solution, the corrosion inhibitor is a molybdate corrosion inhibitor, and the anti-inflammatory agent is curcumin powder. In this embodiment, the concentration of the polyurethane solution is 18wt%, and the concentration of the polylactic acid solution is 15wt%.

[0029] A method for preparing a self-repairing endothelial cell affinity coating on a magnesium alloy surface comprises the following steps:

[0030] Step 1: Material preparation and processing

[0031] Prepare the magnesium alloy sheet to be processed, and then pre-treat it. The purpose of the pre-treatment is to remove impurities on the surface of the magnesium alloy and ensure good adhesion of the subsequent coating on the metal surface. The specific pre-treatment steps are: use sandpaper to polish the surface of the magnesium alloy sheet, and then perform ultrasonic cleaning in distilled water and alcohol in turn after polishing. Each cleaning lasts 20 minutes, and the number of cleanings is ≥ 2 times. In this embodiment, each cleaning includes cleaning once in distilled water and alcohol, and drying after cleaning for use. Next, prepare the materials according to the formula of the coating, and the formula includes the following materials by weight: 1 part of corrosion-inhibiting electrolytic solution, 10 parts of corrosion inhibitor, 5 parts of metal organic framework powder material, 50 parts of polyurethane solution, 50 parts of polylactic acid solution, and 1 part of anti-inflammatory agent;

[0032] Step 2: Prepare base coating

[0033] Inject the corrosion-inhibiting electrolytic solution into the micro-arc oxidation equipment, place the magnesium alloy sheet treated in step one in the corrosion-inhibiting electrolytic solution, start the micro-arc oxidation equipment for micro-arc oxidation processing, and form a base coating, wherein the corrosion-inhibiting electrolytic solution is a mixture of a silicate corrosion inhibitor and a silicate electrolyte, and the silicate corrosion inhibitor accounts for 30wt% of the corrosion-inhibiting electrolytic solution. Since the micro-arc oxidation process requires the use of an electrolyte, the corrosion inhibitor is then added to the electrolyte, and ultrasonic dispersion is performed to obtain a corrosion-inhibiting electrolytic solution. The micro-arc oxidation process can form a silicon-containing oxide layer on the metal surface, which improves corrosion resistance. Accordingly, the introduction of the corrosion inhibitor setting gives it a certain self-repairing function. The principle is that when the coating is damaged, the corrosion inhibitor is released under the influence of factors such as pH value, and acts on the damaged part for self-repair and corrosion protection. Subsequently, the magnesium alloy sheet treated in step 1 is placed in the corrosion-inhibiting electrolytic solution again for micro-arc oxidation processing, thereby forming an inner coating on the magnesium alloy sheet and giving it a self-repairing function. The specific micro-arc oxidation parameters are: frequency 550 Hz, duty cycle 25%, pulse number ratio 2:2, current density 110 A / dm 2 , the micro-arc oxidation time is 20min;

[0034] Step 3: Preparation of intermediate coating

[0035] Add the corrosion inhibitor into a mixing container, and add distilled water to mix evenly to obtain an aqueous solution containing the corrosion inhibitor, wherein the ratio of distilled water to the corrosion inhibitor is 3:1, and then add the metal organic framework powder material, and start stirring to achieve sufficient stirring and adsorption, wherein the corrosion inhibitor is a molybdate corrosion inhibitor. In this embodiment, the metal organic framework powder material is first used to adsorb the corrosion inhibitor. The metal organic framework material (MOFs) is a type of porous crystalline material formed by self-assembly of metal ions or metal clusters and organic ligands through coordination bonds. This material is used as a carrier to adsorb the slow-release agent. Correspondingly, during the adsorption process, stirring is performed, that is, the mixing container has a stirring function, and the stirring speed is relatively low, which is set at 60rpm / min in this embodiment. After the adsorption is completed, the metal organic framework powder material loaded with a sustained release agent is separated by filtration, and then treated. The specific steps of the treatment are: the metal organic framework powder material obtained by filtration and separation is washed with water to remove the residual solution, and then dried after washing, and a hot air drying method with a temperature set to 70°C is used, and then the material is mixed with a polyurethane solution. The mixing process uses ultrasonic dispersion technology to make the material uniformly dispersed in the polyurethane solution to obtain a coating matrix. Then, the coating matrix is ​​coated on the magnesium alloy sheet treated in step 2 by a dip coating method to form an intermediate coating. The intermediate coating provides protection for the base coating. The self-repair of the coating requires a certain amount of time. When there is a problem with the intermediate coating, the base coating provides further protection and gives the intermediate coating enough time to self-repair. Under this condition, the performance of the magnesium alloy can be effectively improved;

[0036] Step 4: Prepare the outer coating

[0037] The anti-inflammatory agent is added to the polylactic acid solvent, and the ultrasonic dispersion technology is used for dispersion and mixing, and the outer coating is obtained after dispersion and mixing. Subsequently, the outer coating is prepared for the magnesium alloy sheet in step three by dip coating to form a self-repairing endothelial cell affinity coating on the surface of the magnesium alloy. Correspondingly, in steps three and four, all coatings are cured by heat treatment after processing, and the main function of the outer coating is to provide protection. The heat treatment is carried out in an oven at 70°C to complete the drying process.

[0038] Embodiment 2

[0039] according to Figure 1As shown, this embodiment proposes a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy, including a base coating, which is arranged on the surface of the magnesium alloy, and an intermediate coating is dipped on the outside of the base coating, and an outer coating is dipped on the outside of the intermediate coating. The base coating includes the following raw materials in parts by weight: 10 parts of corrosion-inhibiting electrolytic solution, the intermediate coating includes the following raw materials in parts by weight: 20 parts of corrosion inhibitor, 10 parts of metal organic framework powder material and 100 parts of polyurethane solution, and the outer coating includes the following raw materials in parts by weight: 100 parts of polylactic acid solution and 2 parts of anti-inflammatory agent, wherein the corrosion-inhibiting electrolytic solution is a mixture of a silicate corrosion inhibitor and a silicate electrolyte, the silicate corrosion inhibitor accounts for 55% of the corrosion-inhibiting electrolytic solution, the corrosion inhibitor is a molybdate corrosion inhibitor, and the anti-inflammatory agent is curcumin powder.

[0040] A method for preparing a self-repairing endothelial cell affinity coating on a magnesium alloy surface comprises the following steps:

[0041] Step 1: Material preparation and processing

[0042] Prepare the magnesium alloy sheet to be processed, and pretreat it to remove impurities on the surface of the magnesium alloy to ensure that the subsequent coating can adhere well to the metal surface. The specific pretreatment steps are: first, use sandpaper to polish the surface of the magnesium alloy sheet, and then ultrasonically clean the polished magnesium alloy in distilled water and alcohol in turn, each cleaning time is 20 minutes, and the number of cleanings is ≥2 times. In this embodiment, each cleaning refers to cleaning once in distilled water and alcohol, drying after cleaning, and drying the sample for later use. Subsequently, prepare the materials according to the formula of the coating, and its formula is shown in a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy proposed in this embodiment;

[0043] Step 2: Prepare base coating

[0044] The corrosion-inhibiting electrolytic solution is added to the micro-arc oxidation equipment, the magnesium alloy sheet treated in step one is placed in the corrosion-inhibiting electrolytic solution, the micro-arc oxidation equipment is started for micro-arc oxidation processing, and a base coating is formed, wherein the corrosion-inhibiting electrolytic solution is a mixture of a silicate corrosion inhibitor and a silicate electrolyte, and the silicate corrosion inhibitor accounts for 30% of the corrosion-inhibiting electrolytic solution. Since the micro-arc oxidation process requires the use of an electrolyte, the corrosion inhibitor is then added to the electrolyte, ultrasonically dispersed, and a corrosion-inhibiting electrolytic solution is obtained. The micro-arc oxidation method can form an oxide layer containing silicon on the metal surface, which can improve corrosion resistance. Correspondingly, the corrosion inhibitor setting is introduced to give it a certain self-repairing effect. The principle is that when the coating is damaged, the corrosion inhibitor in the coating is released under the influence of factors such as pH value, and acts on the damaged part for self-repair and corrosion protection, and then the magnesium alloy sheet treated in step one is placed in the corrosion-inhibiting electrolytic solution for micro-arc oxidation processing. Thus, an inner layer coating is formed on the magnesium alloy sheet, which has the function of self-repair. The specific parameters of the micro-arc oxidation process are: frequency 600Hz, duty cycle 25%, pulse number ratio 2:2, current density 110A / dm 2 , the micro-arc oxidation time is 25min;

[0045] Step 3: Preparation of intermediate coating

[0046] Add the corrosion inhibitor into a mixing container, and add distilled water to mix to obtain an aqueous solution containing the corrosion inhibitor, wherein the addition ratio of distilled water to the corrosion inhibitor is 3:1, and start stirring to achieve sufficient stirring and adsorption, wherein the corrosion inhibitor is a molybdate corrosion inhibitor. In this embodiment, the corrosion inhibitor is first adsorbed using a metal organic framework powder material. The metal organic framework material (MOFs) is a type of porous crystalline material formed by self-assembly of metal ions or metal clusters and organic ligands through coordination bonds. This material is used as a carrier to adsorb the slow-release agent. Correspondingly, during the adsorption process, stirring is performed, that is, the mixing container has a stirring function, and the stirring speed is relatively low, which is set at 60rpm / min in this embodiment. After the adsorption is completed, the metal organic framework powder material loaded with a sustained release agent is separated by filtering, and then treated. The specific steps of the treatment are: the metal organic framework powder material obtained by filtration and separation is washed with water to remove the residual molybdate corrosion inhibitor solvent, and then dried after washing. The drying is performed by hot air drying at a temperature set to 50°C, and then the material is mixed with a polyurethane solution. Ultrasonic dispersion is used during mixing to make the material uniformly dispersed in the polyurethane solution to obtain a coating substrate. Then, the coating substrate is coated on the magnesium alloy sheet treated in step 2 by a dip coating method to form an intermediate coating. The intermediate coating provides a layer of protection for the base coating. The self-repair of the coating requires a certain amount of time. When there is a problem with the intermediate coating, the base coating provides further protection and gives the intermediate coating enough time to self-repair. Under this condition, the performance of the magnesium alloy can be effectively improved;

[0047] Step 4: Prepare the outer coating

[0048] Add the anti-inflammatory agent to the polylactic acid solvent and mix it evenly by ultrasonic dispersion to obtain an outer coating. Subsequently, the outer coating is prepared on the magnesium alloy sheet in step three by dip coating to obtain a self-repairing endothelial cell affinity coating on the surface of the magnesium alloy. Correspondingly, in steps three and four, after each layer of coating is processed, it is cured by heat treatment. The outer coating mainly plays a protective role. The heat treatment method is to dry it in an oven environment set at a temperature of 70°C to ensure the protective function of the outer coating.

[0049] In combination with Example 1, Example 2 provides a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy, and sets up a control group, wherein the control group is a hydroxyapatite coating formed on the surface of a medical magnesium alloy by magnetron sputtering. Through an immersion experiment, a comparative test of the long-term protective performance of a magnesium alloy was conducted in a simulated body fluid (SBF) at 37°C. The simulated body fluid was replaced every two days, and the corrosion of the sample was recorded. The test results are shown in the following table, where the time indicates the time when the sample began to corrode:

[0050] Test items Embodiment 1 Embodiment 2 Control group Time (h) 834 820 632

[0051] As shown in the table above, compared with the control group, the present embodiment 1 and embodiment 2 have good corrosion resistance. Therefore, the present invention adopts a composite method of a base coating, an intermediate coating and an outer coating to protect the magnesium alloy, wherein the base coating and the intermediate coating introduce a corrosion inhibitor so that the base coating and the intermediate coating have a self-repairing effect, and then the outer coating is used for protection, which can effectively improve the corrosion resistance of the magnesium alloy, and cooperate with the self-repairing effect of the upper coating, and the corrosion time is longer than that of the control group, so compared with the control group, the present invention has a delayed effect on the corrosion of the magnesium alloy. Correspondingly, the intermediate coating and the outer coating use polymers (polyurethane and polylactic acid) with good biocompatibility as coating materials, which are conducive to the climbing of endothelial cells and the regeneration of the endothelial layer. In addition, in the preparation process, the overall steps are simple and easy to operate, so the cost of preparation can be reduced to a certain extent, bringing significant economic benefits to the company.

[0052] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the framework and scope of application of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A self-repairing endothelial cell affinity coating on the surface of a magnesium alloy, characterized in that: The invention comprises a three-layer coating structure, which are a base coating, an intermediate coating and an outer coating in sequence, wherein the base coating is arranged on the surface of the magnesium alloy, the intermediate coating is dip-coated on the outer side of the base coating, and the outer coating is dip-coated on the outer side of the intermediate coating. The base coating comprises the following raw materials in parts by weight: 1 to 10 parts of corrosion-inhibiting electrolytic solution; the intermediate coating comprises the following raw materials in parts by weight: 10 to 20 parts of corrosion inhibitor, 5 to 10 parts of metal organic framework powder material and 50 to 100 parts of polyurethane solution; the outer coating comprises the following raw materials in parts by weight: 50 to 100 parts of polylactic acid solution and 1 to 2 parts of anti-inflammatory agent.

2. The self-repairing endothelial cell affinity coating on the surface of magnesium alloy according to claim 1, characterized in that: The corrosion-inhibiting electrolytic solution is a mixture of a silicate corrosion inhibitor and a silicate electrolyte, wherein the silicate corrosion inhibitor accounts for 30-55 wt % of the corrosion-inhibiting electrolytic solution.

3. The self-repairing endothelial cell affinity coating on the surface of magnesium alloy according to claim 1, characterized in that: The corrosion inhibitor is a molybdate corrosion inhibitor.

4. The self-repairing endothelial cell affinity coating on the surface of magnesium alloy according to claim 1, characterized in that: The anti-inflammatory agent is curcumin powder.

5. A method for preparing a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Material preparation and processing A magnesium alloy sheet to be processed is prepared, and then pre-treated for subsequent use. Next, materials are prepared according to a coating formula, wherein the formula includes the following materials in parts by weight: 1 to 10 parts of corrosion-inhibiting electrolytic solution, 10 to 20 parts of corrosion inhibitor, 5 to 10 parts of metal organic framework powder material, 50 to 100 parts of polyurethane solution, 50 to 100 parts of polylactic acid solution, and 1 to 2 parts of anti-inflammatory agent; Step 2: Prepare base coating Adding the corrosion-inhibiting electrolytic solution into the micro-arc oxidation equipment, placing the magnesium alloy sheet pretreated in step 1 into the corrosion-inhibiting electrolytic solution, and then starting the micro-arc oxidation equipment to perform micro-arc oxidation processing, thereby forming a base coating; Step 3: Preparation of intermediate coating The corrosion inhibitor is added to a mixing container, and distilled water is added to mix, and then the metal organic framework powder material is added, and the agitator is turned on to stir to achieve adsorption. After the adsorption is completed, the metal organic framework powder material loaded with the corrosion inhibitor is filtered to obtain the metal organic framework powder material, and then the metal organic framework powder material loaded with the corrosion inhibitor is treated. After the treatment, the metal organic framework powder material loaded with the corrosion inhibitor is mixed with the polyurethane solution to obtain an intermediate coating, and then the intermediate coating is prepared on the magnesium alloy sheet in step 2 by dip coating; Step 4: Prepare the outer coating The anti-inflammatory agent is added to the polylactic acid solution and dispersed and mixed by ultrasonic dispersion to obtain an outer coating. Subsequently, the magnesium alloy sheet treated in step three is dip-coated to prepare an outer coating, and finally a self-repairing endothelial cell affinity coating is formed on the surface of the magnesium alloy.

6. The method for preparing a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy according to claim 5, characterized in that: In the step 1, the specific steps of pretreatment are: grinding the surface of the magnesium alloy sheet with sandpaper, and then ultrasonically cleaning it in distilled water and alcohol in turn after grinding, each cleaning time is 15 to 25 minutes, the number of cleaning times is ≥2 times, and drying is carried out after cleaning.

7. The method for preparing a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy according to claim 5, characterized in that: In the step 2, the micro-arc oxidation time is 20 to 30 minutes.

8. The method for preparing a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy according to claim 5, characterized in that: In the step three, the specific processing method is: washing the metal organic framework powder material separated by filtration with water, and then drying the washed powder material.

9. The method for preparing a self-repairing endothelial cell affinity coating on the surface of a magnesium alloy according to claim 5, characterized in that: In the step 3 and the step 4, after each layer of coating is processed, it is cured by heat treatment.

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