阅读说明：本技术 一种基于双层异相结构的药物缓释涂层及其制备方法和应用 (Drug sustained-release coating based on double-layer heterogeneous structure and preparation method and application thereof ) 是由 计剑 任科峰 汪璟 于 2019-11-14 设计创作，主要内容包括：本发明公开了一种基于双层异相结构的药物缓释涂层的制备方法,包括：1)利用医用聚合物I和油溶性药物在基底上构建底层载药涂层；2)将医用聚合物II与水溶性聚合物溶于溶剂后喷涂于所述底层载药涂层上,再用水浸没后得到上层为多孔涂层的双层异相涂层；3)利用多孔涂层的毛细作用,将双层异相涂层通过浸没吸附的方式负载水溶性功能分子得到。本发明还公开了上述方法制得的药物缓释涂层及其在医疗领域中的应用。本发明方法简单高效,大大简化了制备步骤,制得的涂层能使生物因子能高度活性负载,从而实现了活性因子与药物的复合,进一步提高了药物的效果。(The invention discloses a preparation method of a drug sustained-release coating based on a double-layer heterogeneous structure, which comprises the following steps: 1) constructing a bottom drug-loaded coating on a substrate by using a medical polymer I and an oil-soluble drug; 2) dissolving a medical polymer II and a water-soluble polymer in a solvent, spraying the solution on the bottom drug-loaded coating, and immersing the solution in water to obtain a double-layer heterogeneous coating with a porous coating on the upper layer; 3) the double-layer heterogeneous coating is obtained by loading water-soluble functional molecules in a submerged adsorption mode by utilizing the capillary action of the porous coating. The invention also discloses a drug sustained-release coating prepared by the method and application thereof in the medical field. The method is simple and efficient, the preparation steps are greatly simplified, and the prepared coating can enable the biological factors to be loaded with high activity, so that the compounding of the active factors and the medicine is realized, and the effect of the medicine is further improved.)

1. A preparation method of a drug sustained-release coating based on a double-layer heterogeneous structure comprises the following steps:

(1) constructing a bottom drug-loaded coating on a substrate by using a medical polymer I and an oil-soluble drug;

(2) dissolving a medical polymer II and a water-soluble polymer in a solvent, spraying the solution on the bottom drug-loaded coating, and immersing the solution in water to obtain a double-layer heterogeneous coating with a porous coating on the upper layer;

(3) the double-layer heterogeneous coating is obtained by loading water-soluble functional molecules in a submerged adsorption mode by utilizing the capillary action of the porous coating.

2. The preparation method of the drug sustained-release coating based on the double-layer heterogeneous structure according to claim 1, wherein in the step (1), the bottom drug-loaded coating is obtained by dissolving an oil-soluble drug and a medical polymer I in a solvent and spraying the solution on a substrate.

3. The method for preparing a drug sustained-release coating based on a two-layer heterogeneous structure according to claim 1 or 2, wherein the oil-soluble drug comprises an antiproliferative drug or an antibacterial drug.

4. The method for preparing a drug sustained-release coating based on a bilayer heterogeneous structure according to claim 1, wherein in the step (2), the water-soluble polymer is polyethylene glycol or polyvinylpyrrolidone, and the number average molecular weight is 1 to 20 ten thousand.

5. The method for preparing a drug sustained-release coating based on a two-layer heterogeneous structure according to claim 1, wherein in the step (2), the water-soluble polymer accounts for 20-80% of the total polymer by mass.

6. A drug sustained-release coating based on a double-layer heterogeneous structure, which is characterized by being prepared by the preparation method of any one of claims 1 to 5.

7. Use of a drug sustained release coating based on a bilayer heterogeneous structure according to claim 6 in the medical field.

Technical Field

The invention relates to the field of biomedical materials, in particular to a drug sustained-release coating based on a double-layer heterogeneous structure, and a preparation method and application thereof.

Background

In the field of biomedical materials, a coating with a specific function is an important tool for providing multiple functions to materials and apparatuses, and the functional medical coating can improve the compatibility of the materials and living bodies, can provide new treatment functions to the materials and the apparatuses, and reduces the occurrence of complications. For example, the occurrence of a drug eluting stent and balloon system with antiproliferative capability greatly reduces the problem of restenosis after traditional bare stent and bare balloon surgery, and significantly improves the postoperative curative effect of patients; the medical catheter modified by the super-lubricating coating can obviously improve the safety and the efficacy of the traditional catheter. Therefore, the functional medical coating provides rich designability and diverse customized application prospects for the traditional medical materials and instruments based on mechanical support, and becomes one of the most important methods for Combination medical Products (Combination Products).

With the development of medical technology and medical materials, more and more researchers adsorb or fix macromolecules with high biological activity on the surface of a material from the bionic aspect in recent years, and further the research and development of the bionic functional medical coating are greatly expanded. However, to date, functional medical coatings with biological activity have found little clinical application. Antibody-modifying coatings, as represented by the Genous scaffold developed by orbus neich corporation, are currently a few bioactive coatings. However, in actual clinical comparative studies, the antibody anti-CD34 modified Genous stent did not exhibit the expected superior effect compared to the conventional drug eluting stent. In fact, bioactive medical coatings present numerous challenges in practical applications: on one hand, the indispensable processes of sterilization and storage in the preparation process can cause irreversible damage to the bioactive molecules, so that the bioactive molecules are partially or completely ineffective, and the action of the bioactive molecules is greatly weakened; on the other hand, conventional small molecule drugs are still indispensable in the treatment of many diseases. Therefore, how to construct a composite coating of bioactive molecules on the basis of the traditional medical drug sustained-release coating is a major challenge and opportunity for further expanding the medical coating technology and improving the safety and effectiveness of materials and apparatuses. Considering the problems of sterilization and storage, how to effectively ensure the activity of bioactive functional molecules is a key bottleneck problem.

Among the foreign advanced composite medical products, bioactive composite medical instruments represented by the medton force bone implant material Infuse are gaining wide attention. The adopted bone morphogenetic protein-2 (BMP-2) effectively guarantees the bioactivity of the BMP-2 by utilizing the strategy that the bone morphogenetic protein is adsorbed on the collagen sponge block after being dissolved in the operation. However, the coating design concept combining the mode with the traditional drug sustained-release coating is not reported so far, and whether the loading of the bioactive molecules in the operation in the drug sustained-release coating can be realized or not still needs to be solved.

Disclosure of Invention

The invention aims to provide a preparation method of a drug sustained-release coating based on a double-layer heterogeneous structure, which can realize the load of water-soluble functional molecules by utilizing capillary action by constructing a micron-sized porous coating which is mutually penetrated on the drug sustained-release coating, thereby realizing the compounding with oil-soluble drugs.

In order to realize the aim, the invention provides a preparation method of a drug sustained-release coating based on a double-layer heterogeneous structure, which comprises the following steps:

(1) constructing a bottom drug-loaded coating on a substrate by using a medical polymer I and an oil-soluble drug;

(2) dissolving a medical polymer II and a water-soluble polymer in a solvent, spraying the solution on the bottom drug-loaded coating, and immersing the solution in water to obtain a double-layer heterogeneous coating with a porous coating on the upper layer;

(3) the double-layer heterogeneous coating is obtained by loading water-soluble functional molecules in a submerged adsorption mode by utilizing the capillary action of the porous coating.

The design idea of the double-layer heterogeneous structure is as follows: the bottom layer of the coating is a compact medical polymer coating containing oil-soluble micromolecular drugs, so that the slow release of the micromolecular drugs is realized; the top layer of the coating is a micron-sized porous coating which penetrates through the coating, water-soluble functional molecules, particularly bioactive factors which have high bioactivity but are very fragile, are adsorbed by capillary adsorption, and therefore effective compounding of the water-soluble functional molecules and oil-soluble drug molecules is achieved.

The preparation method of the drug sustained-release coating based on the double-layer heterogeneous structure comprises the following three steps: the method comprises the steps of constructing a bottom drug-loaded coating, constructing an upper micron-sized penetrating porous coating and loading water-soluble functional molecules.

In the step (1), constructing a bottom drug-loaded coating:

the construction method of the bottom drug-loaded coating specifically comprises the following steps: the medical polymer I and the oil-soluble medicine are dissolved in a solvent and then sprayed on a substrate to obtain the medical polymer I.

The medical polymer I is one of medical grade poly-L-lactic acid (PLLA), poly-racemic-lactic acid (PDLLA), poly-lactic-co-glycolic acid (PLGA), Polycaprolactone (PCL), Polyurethane (PU) and polymethyl methacrylate (PMMA); the number average molecular weight is 1-30 ten thousand. The number average molecular weight is preferably 5 to 15 ten thousand in consideration of the processability of the coating spray.

The oil-soluble drug is selected according to the requirements of use environment and functions, and the invention emphasizes that the heterogeneous double-layer structure coating realizes the characteristic of compounding the oil-soluble drug and the water-soluble functional molecules, and the specific drug is not limited.

The oil-soluble drug includes, but is not limited to, antiproliferative drugs (such as paclitaxel and its derivatives, rapamycin and its derivatives, etc.), antibacterial drugs (such as triclosan, gentamicin, daptomycin or piperacillin, etc.). The dosage of the oil-soluble drug depends on the actual application, and the common usage range is 1-100 mug/cm²Preferably 5 to 50. mu.g/cm²。

The solvent comprises one or more of acetone, ethyl acetate, dichloromethane, chloroform and tetrahydrofuran, and preferably one or more of acetone, ethyl acetate and chloroform.

The thickness of the bottom drug-loaded coating is 3-50 μm, preferably 5-20 μm.

In the step (2), the upper porous coating is constructed:

the medical polymer II is one of medical grade poly-L-lactic acid (PLLA), poly-racemic-lactic acid (PDLLA), poly-lactic-co-glycolic acid (PLGA), Polycaprolactone (PCL) Polyurethane (PU) or polymethyl methacrylate (PMMA), and the number average molecular weight is 1-30 ten thousand. The number average molecular weight of the coating material is preferably 5 to 15 ten thousand in consideration of the spray processability.

It should be noted that compatibility matching between the medical polymer II in the upper porous coating and the medical polymer I in the bottom drug-loaded coating needs to be achieved, so that the phenomenon of falling off between the two coatings is avoided.

The water-soluble polymer contains polyethylene glycol or polyvinylpyrrolidone and has a number average molecular weight of 1 to 20 ten thousand. In view of the fact that the water solubility of the water-soluble polymer is closely related to the molecular weight, the number average molecular weight is preferably 1 to 8 ten thousand.

The solvent comprises one or more of acetone, ethyl acetate, dichloromethane, chloroform and tetrahydrofuran, and dichloromethane or chloroform is preferred in view of the common solubility of the two polymers.

In the mixed solution of the medical polymer II and the water-soluble polymer, the water-soluble polymer accounts for 20-80% of the total polymer by mass. The water-soluble polymer is used as a corrosion phase, and when the water-soluble proportion is too low, the uniformity of a porous structure obtained by phase separation is poor; when the water solubility ratio is too high, the stability of the porous coating layer may be affected; therefore, in consideration of uniformity of the porous structure and stability of the coating layer, it is preferable that the water-soluble polymer accounts for 40 to 60 mass% of the total polymer.

Preferably, the medical polymer II and the water-soluble polymer are dissolved in a solvent and then sprayed on the bottom drug-loaded coating in an ultrasonic atomization mode, and then the upper porous coating is obtained by immersion and corrosion with ultrapure water. The erosion time of the ultrapure water is 4-6 minutes/time, and the erosion times is 2-3 times.

The thickness of the upper porous coating layer is 2-50 μm, preferably 5-20 μm.

In the third step (3), water-soluble functional molecules are adsorbed by utilizing the capillary action:

the loading of the water-soluble functional molecules is realized by immersing the double-layer heterogeneous coating in the water solution of the water-soluble functional molecules. The immersion time is 1 to 60 minutes, preferably 1 to 20 minutes; after completion of the adsorption, the reaction mixture was washed with sterile ultrapure water.

The invention emphasizes the characteristic of realizing the loading of the water-soluble functional molecules based on the capillary action of the porous coating, wherein the type and the concentration of the water-soluble functional molecules are determined according to the actual application condition.

The invention also discloses the application of the drug sustained-release coating based on the double-layer heterogeneous structure in the medical field.

The applications in the medical field include applications in cardiovascular and cerebrovascular implant interventional products (such as cardiovascular stents, peripheral vascular stents, etc.), orthopedic implants (such as bone nails, bone plates, etc.), hernia patches and surgical cosmetic implants.

According to different practical applications, the selection of the high-activity biological factors is greatly different, the invention does not limit the variety of the biological factors, and only provides the construction method of the double-layer heterogeneous structure coating. The biological factors specifically comprise protein functional molecules, nucleic acid molecules with a therapeutic function, hydrophilic molecules with catalytic activity molecule release and the like.

The protein functional molecules comprise human Vascular Endothelial Growth Factor (VEGF), human Hepatocyte Growth Factor (HGF) or bone morphogenetic protein-2 (BMP-2). The nucleic acid molecule with therapeutic function comprises plasmid DNA, messenger RNA, short hairpin RNA or MicroRNA. The hydrophilic molecule with catalytically active molecular release comprises a nitric oxide donor SNAP or nitroglycerin.

Compared with the prior art, the invention has the following beneficial effects:

(1) aiming at the serious limitation that the application of high-activity biological functional molecules in a functional medical coating is limited by a plurality of processes such as coating preparation, sterilization, storage and the like, the load of a biological factor with high biological activity is realized by further constructing the mutually penetrated porous coating on the drug-loaded coating, thereby overcoming the difficulty that the activity of the water-soluble biological factor in the existing coating is difficult to store and realizing the effective combination of the biological factor and a small molecule drug.

(2) The method has high efficiency and simple preparation process, and can realize the industrial high-efficiency stable preparation of the drug sustained-release coating based on the double-layer heterogeneous structure.

Drawings

FIG. 1 is a micrograph of a drug sustained-release coating prepared in example 1 of the present invention.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.