CN113304332A - Anticoagulation coating and preparation method thereof - Google Patents

Abstract

Translated fromChinese

本发明公开了一种抗凝血涂层，自下而上依次包括基材、聚多巴胺涂层、多氨基化合物连接层、肝素‑蛋白功能层，各层之间通过共价键连接。本发明抗凝血涂层，通过蛋白质修饰肝素分子，克服了现有的共价键合法肝素涂层抗凝效果差的问题；通过使用连接层连接底层与功能层，解决了现有涂层血液稳定性差的问题；通过溶液流动法涂覆聚多巴胺底涂，解决了现有浸涂法涂覆不均匀的问题。同时，本发明还公开一种抗凝血涂层的制备方法。本发明抗凝血涂层的制备过程操作简单，全部涂覆时间可以控制在8小时以内，具有很好的应用潜力。The invention discloses an anticoagulation coating, which comprises a base material, a polydopamine coating, a polyamino compound connecting layer, and a heparin-protein functional layer in sequence from bottom to top, and the layers are connected by covalent bonds. The anticoagulant coating of the present invention overcomes the problem of poor anticoagulation effect of the existing covalently bonded heparin coating by modifying the heparin molecules with proteins; The problem of poor stability; the polydopamine primer is coated by the solution flow method, which solves the problem of uneven coating by the existing dip coating method. At the same time, the invention also discloses a preparation method of the anticoagulant coating. The preparation process of the anticoagulant coating of the present invention is simple to operate, and the entire coating time can be controlled within 8 hours, which has good application potential.

Description

Anticoagulation coating and preparation method thereof

Technical Field

The invention relates to the field of biomedical materials, in particular to an anticoagulant coating with strong substrate adaptability and a preparation method thereof.

Background

With the progress of science and technology, medical instruments are more and more widely applied to medical behaviors, and especially have important application in aspects of improving human health, preventing diseases and the like. The materials for preparing medical instruments are various and include non-metals, metal materials, composite materials and the like; for the medical apparatus and instruments which are in direct contact with the human body, the biocompatibility requirement of the material is high. For example, blood contact materials and intravascular implantable medical devices are directly contacted with blood, and the blood components are complex and various, and are easily interacted with the materials to cause a series of side effects and clinical complications such as hemolysis and blood coagulation. Therefore, the preparation of biological materials with good blood compatibility or the blood compatibility modification of the materials is a development hotspot in the field of medical devices.

The modification modes of the biomedical material mainly comprise two modes, wherein one mode is modification of a material body; the other is material surface modification; the body modification is to carry out anticoagulation modification on the material and then to carry out reprocessing and molding, and the method has the disadvantages of complex operation, high cost and difficult practical application. On the contrary, the material surface modification is a technology which is simple to operate, relatively low in cost and already in practical application. At present, the foreign commercialized anticoagulant coating has been developed to the third generation, but no domestic product appears in the domestic market for a while, so the price of the related medical appliance product is always high and monopolized by foreign manufacturers.

At present, the preparation of the anticoagulant coating mainly has the following difficulties: 1. the biological material needing the surface treatment of the anticoagulation coating relates to various materials such as metal, nonmetal and the like, and the current commercialized anticoagulation coating has the defect that the anticoagulation coating cannot be coated on various materials; 2. the traditional covalent heparin anticoagulant coating has the problem that the anticoagulant effect is greatly reduced due to the fact that the movement of acting groups on the surface of the material is limited; 3. the traditional anticoagulant coating has poor blood stability, and anticoagulant drug molecules are easy to fall off.

Disclosure of Invention

In view of this, the object of the present invention is to overcome the above-mentioned disadvantages of the prior art and to provide an anticoagulant coating with a strong substrate adaptability.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

an anticoagulant coating comprises a base material, a polydopamine coating, a polyamino compound connecting layer and a heparin-protein functional layer from bottom to top in sequence, wherein the layers are connected through covalent bonds.

Preferably, the polyamino compound-linked layer is a polylysine coating.

Meanwhile, the invention also provides a preparation method of the anticoagulant coating, which comprises the following steps:

s1, coating a polydopamine primer on the surface of the base material, and circularly flowing a dopamine hydrochloride solution through a peristaltic pump to uniformly flow and coat the solution on the surface of the base material to be coated to obtain a polydopamine coating;

s2, circularly flowing the polyamino compound solution through a peristaltic pump to enable the solution to be uniformly coated on the surface of the polydopamine coating in a flowing mode to obtain a polyamino compound connecting layer;

s3, circularly flowing the heparin-protein solution through a peristaltic pump to enable the solution to be uniformly coated on the surface of the polyamino compound connecting layer in a flowing mode, and obtaining the heparin-protein functional layer.

Preferably, in step S3, the heparin-protein solution is prepared as follows:

(1) preparing aldehyde heparin: dissolving heparin sodium in deionized water, adding sodium periodate while stirring, and after the reaction is finished, precipitating and purifying the reaction solution by an organic solvent;

(2) preparation of heparin-protein: dissolving the aldehyde heparin prepared in the step (1) in water, adding protein, quickly stirring for reaction, after the reaction is finished, carrying out suction filtration on the reaction solution, and carrying out precipitation purification through an organic solvent.

Preferably, in step S3, the heparin-protein is prepared by coupling reaction between heparin and amino group via a coupling agent; the coupling agent is at least one of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, N' -carbonyldiimidazole and N-hydroxysuccinimide.

Preferably, the polyamino compounds include macromolecular compounds and small molecule compounds; the macromolecular compound is at least one of polylysine, sodium polyaspartate, starch, polyethyleneimine, carboxymethyl chitosan and macromolecular polyether amine; the micromolecule compound is at least one of micromolecule polyether amine, ethylenediamine and amine-terminated polyether.

Preferably, in step S1, the concentration of the dopamine hydrochloride solution is 0.1-10mg/mL, and the pH value is 7-10; the dopamine hydrochloride solution contains sodium periodate with the mass percentage of 0.1-10 per mill;

when coating the polydopamine priming coat, the flow rate of a peristaltic pump is 5-300mL/min, the temperature of the hydrochloric acid dopamine solution is 20-80 ℃, and the coating time is 0.5-5 hours;

in step S2, the concentration of the polyamino compound solution is 0.1-20mg/mL, and the pH value is 7-9;

when the polyamino compound connecting layer is coated, the flow rate of a peristaltic pump is 5-300mL/min, the temperature of the polyamino compound solution is 20-80 ℃, and the coating time is 0.5-5 hours.

More preferably, in step S1, the concentration of the dopamine hydrochloride solution is 0.5-5mg/mL, and the pH value is 8-9; the dopamine hydrochloride solution contains sodium periodate with the mass percentage of 0.1-5 per mill;

when coating the polydopamine priming coat, the flow rate of a peristaltic pump is 50-200mL/min, the temperature of the hydrochloric acid dopamine solution is 35-70 ℃, and the coating time is 1-4 hours;

in step S2, the concentration of the polyamino compound solution is 1-10mg/mL, and the pH value is 8-9;

when the polyamino compound connecting layer is coated, the flow rate of a peristaltic pump is 50-200mL/min, the temperature of the polyamino compound solution is 35-70 ℃, and the coating time is 1-4 hours.

Most preferably, in step S1, the concentration of the dopamine hydrochloride solution is 1mg/mL, and the pH value is 8.5; the dopamine hydrochloride solution contains 1 per mill of sodium periodate by mass percent;

when coating the polydopamine base coat, the flow rate of a peristaltic pump is 100mL/min, the temperature of the hydrochloric acid dopamine solution is 55 ℃, and the coating time is 2 hours;

in step S2, the polyamino compound solution has a concentration of 1mg/mL and a pH of 9;

in coating the polyamino compound-linked layer, the peristaltic pump flow rate was 150mL/min, the temperature of the polyamino compound solution was 60 ℃ and the coating time was 3 hours.

The application has the advantages that the sodium periodate is added into the dopamine hydrochloride solution, so that the coating rate can be well improved; meanwhile, sodium periodate is used for oxidizing ortho-dihydroxy on a heparin sodium molecule, so that aldehyde group functionalized heparin with low molecular weight can be obtained.

Preferably, in the step (1), the reaction temperature is 0-28 ℃, the reaction time is 2-24 hours, and the mass percentage of the heparin sodium solution is 1% -10%; the molar ratio of the heparin sodium to the sodium periodate is 1:1-1:5, and the volume ratio of the reaction liquid to the organic solvent is 1:2-1: 10.

More preferably, in the step (1), the reaction temperature is 0-20 ℃, the reaction time is 5-20 hours, and the mass percentage of the heparin sodium solution is 2% -8%; the molar ratio of the heparin sodium to the sodium periodate is 1:2-1:4, and the volume ratio of the reaction liquid to the organic solvent is 1:2-1: 8.

Most preferably, in the step (1), the reaction temperature is 0 ℃, the reaction time is 12 hours, and the mass percentage of the heparin sodium solution is 5%; the molar ratio of the heparin sodium to the sodium periodate is 1:3, and the volume ratio of the reaction liquid to the organic solvent is 1: 5.

Preferably, after the reaction in step (1) is finished, ethylene glycol with the molar ratio of 1:1-1:3 to sodium periodate is added, the mixture is continuously stirred for 1-2 hours, then the mixture is distilled under reduced pressure at room temperature until no bubbles are generated, finally aldehyde-group heparin is precipitated by adding an organic solvent, and the aldehyde-group heparin is obtained by filtering and drying.

More preferably, after the reaction in step (1) is finished, ethylene glycol with the molar ratio of 1:1-1:2 to sodium periodate is added, the mixture is stirred for 1-2 hours, then the mixture is distilled under reduced pressure at room temperature until no bubbles are generated, finally aldehyde-group heparin is precipitated by adding an organic solvent, and the aldehyde-group heparin is obtained by filtering and drying.

Most preferably, after the reaction in step (1) is finished, ethylene glycol with the molar ratio of 1:2 to sodium periodate is required to be added, the mixture is stirred for 2 hours, then the mixture is distilled under reduced pressure at room temperature until no bubbles are generated, finally, the formylated heparin is precipitated by using an organic solvent, and the obtained product is filtered and dried to obtain the formylated heparin.

Preferably, in the step (2), the molar ratio of heparin to protein is 1:1-1:10, and the volume ratio of the reaction solution to the organic solvent is 1:2-1: 10; in the step S3, the concentration of the heparin-protein solution is 1-10mg/mL, and the pH value is 7-10. In addition, the protein classes in step (2) of the present application include, but are not limited to, bovine serum albumin, human serum albumin, hirudin, lumbrokinase, etc.; the organic solvent in step (1) and step (2) of the present application includes, but is not limited to, one or more of absolute ethyl alcohol, absolute methyl alcohol, isopropyl alcohol, n-propyl alcohol, and acetone.

More preferably, in the step (2), the molar ratio of the heparin to the protein is 1:2-1:8, and the volume ratio of the reaction solution to the organic solvent is 1:3-1: 8; in the step S3, the concentration of the heparin-protein solution is 2-8mg/mL, and the pH value is 8-9. In addition, the protein classes in step (2) of the present application include, but are not limited to, bovine serum albumin, human serum albumin, hirudin, lumbrokinase, etc.; the organic solvent in step (1) and step (2) of the present application includes, but is not limited to, one or more of absolute ethyl alcohol, absolute methyl alcohol, isopropyl alcohol, n-propyl alcohol, and acetone.

Most preferably, in the step (2), the molar ratio of the heparin to the protein is 1:4, and the volume ratio of the reaction solution to the organic solvent is 1: 5; in step S3, the concentration of the heparin-protein solution is 4mg/mL, and the pH value is 9. In addition, the protein classes in step (2) of the present application include, but are not limited to, bovine serum albumin, human serum albumin, hirudin, lumbrokinase, etc.; the organic solvent in step (1) and step (2) of the present application includes, but is not limited to, one or more of absolute ethyl alcohol, absolute methyl alcohol, isopropyl alcohol, n-propyl alcohol, and acetone.

Preferably, in step S3, the heparin-protein solution is circulated by a peristaltic pump, the solution is added with a coupling agent, the molar ratio of the coupling agent to the heparin is 2:1-10:1, the flow rate of the peristaltic pump is 5-300mL/min, the solution temperature is 20-45 ℃, and the coating time is 0.5-5 hours.

More preferably, in step S3, the heparin-protein solution is circulated by a peristaltic pump, the coupling agent is added to the solution, the molar ratio of the coupling agent to the heparin is 4:1-8:1, the flow rate of the peristaltic pump is 50-200mL/min, the temperature of the solution is 25-40 ℃, and the coating time is 1-4 hours.

Most preferably, in step S3, the heparin-protein solution is circulated by a peristaltic pump, the coupling agent is added to the solution, the molar ratio of the coupling agent to the heparin is 5:1, the flow rate of the peristaltic pump is 100mL/min, the solution temperature is 37 ℃, and the coating time is 3 hours.

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

the existing heparin coating needs to react a large number of groups of heparin molecules, so that the activity of the anticoagulant groups of the heparin molecules in the coating is reduced, and the anticoagulant effect is poor; the polydopamine base coat is coated by a solution flowing method, so that the surface of an object to be coated is always in a state that the coating concentration is similar to that of the coating environment, and the problem of uneven coating of the existing dip coating method is solved;

the preparation process of the anticoagulant coating is simple to operate, the total coating time can be controlled within 8 hours, and the anticoagulant coating has good application potential.

Drawings

FIG. 1 is a schematic structural diagram of an anticoagulant coating according to the present invention;

FIG. 2 is a schematic diagram of a process for preparing the anticoagulant coating of the present invention;

wherein, 1, a base material; 2. a polydopamine coating; 3. a polyamino compound tie layer; 4. the heparin-protein functional layer.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to the accompanying drawings and specific embodiments.

Example 1

In an embodiment of the anticoagulant coating, the anticoagulant coating is a polydopamine-polylysine- (heparin-protein complex number 1) coating, the structure of the anticoagulant coating is shown in the attached drawing 1, the anticoagulant coating sequentially comprises abase material 1, apolydopamine coating 2, a polyamino compound connecting layer 3 and a heparin-proteinfunctional layer 4 from bottom to top, and the layers are connected through covalent bonds; the preparation process is shown in figure 2 and specifically comprises the following steps:

step one, weighing 500mg of dopamine hydrochloride, dissolving the dopamine hydrochloride in 500ml of deionized water, adjusting the pH value to 8.5, adding 500mg of sodium periodate, and dissolving to prepare acoating solution 1. Thecoating liquid 1 is sucked into a circulating coating system by using a peristaltic pump, a PVC pipe to be coated is used as a circulating channel pipeline, and a part to be coated made of other materials to be coated is placed in a liquid accumulation bottle. The whole circulation system is maintained at 55 ℃, the solution flow rate parameter is set to be 300ml/min, and the flow coating is carried out for 2 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step two, weighing 500mg of polylysine, dissolving in 500mL of deionized water, adjusting the pH value to 9, and preparingcoating liquid 2. And (3) sucking thecoating liquid 2 into a circulating coating system by using a peristaltic pump, wherein a PVC pipe coated with polydopamine in the first step is used as a circulating channel pipeline, and a polydopamine-coated part in the first step is placed in a liquid accumulation bottle. The whole circulation system is maintained at 60 ℃, the solution flow rate parameter is set to be 150ml/min, and the flow coating is carried out for 1.5 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step three, weighing 5g of heparin sodium, dissolving the heparin sodium in 100mL of deionized water, placing the solution in a low-temperature reaction tank at 4 ℃, adding 5g of sodium periodate after the temperature is stable, continuing to stir for reaction for 8 hours, then adding 4g of ethylene glycol, and continuing to stir for 2 hours. After the reaction is finished, carrying out rotary evaporation at normal temperature and reduced pressure until no bubbles are generated, adding 400mL of absolute ethyl alcohol into the solution after rotary evaporation while stirring, and separating out a solid product. And finally, carrying out suction filtration and drying to obtain the aldehyde-group heparin. And weighing 1g of aldehyde-based heparin and 4g of bovine serum albumin, dissolving in 20mL of deionized water, adjusting the pH value to 8, stirring for reaction for 10 hours, filtering after the reaction is finished, reserving filtrate, and freeze-drying to obtain a powdery heparin-bovine serum albumin compound No. 1.

Step four, weighing 1.0g of No. 1 heparin-bovine serum albumin compound, dissolving the compound in 500mL of deionized water, adding 0.8g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 0.6g N-hydroxysuccinimide, adjusting the pH value to 8.5 to prepare coating liquid 3, sucking the coating liquid 3 into a circulating coating system by using a peristaltic pump, sucking a circulating channel pipeline into a PVC pipe coated with polylysine in the step two, and putting the polylysine-coated part in the step two into a liquid accumulation bottle. The whole circulation system is maintained at 37 ℃, the solution flow rate parameter is set to be 40ml/min, and the flow coating is carried out for 2 hours. And (3) after the coating is finished, washing the coated pipelines and parts for 5 minutes by using deionized water, drying at 45 ℃ to obtain the pipelines and parts with the surfaces coated with the anticoagulant coatings, and placing the pipelines and parts in a vacuum drier for storage and standby.

Example 2

In an embodiment of the anticoagulant coating, the anticoagulant coating is a polydopamine-polyethyleneimine- (heparin-protein 1 complex) coating, the structure of the anticoagulant coating is shown in the attached drawing 1, the anticoagulant coating sequentially comprises abase material 1, apolydopamine coating 2, a polyamino compound connecting layer 3 and a heparin-proteinfunctional layer 4 from bottom to top, and the layers are connected through covalent bonds; the preparation process is shown in figure 2 and specifically comprises the following steps:

step one, weighing 50mg of dopamine hydrochloride, dissolving the dopamine hydrochloride in 500ml of deionized water, adjusting the pH value to 7, adding 50mg of sodium periodate, dissolving, and preparingcoating liquid 1. Thecoating liquid 1 is sucked into a circulating coating system by using a peristaltic pump, a PVC pipe to be coated is used as a circulating channel pipeline, and a part to be coated made of other materials to be coated is placed in a liquid accumulation bottle. The whole circulation system is maintained at 80 ℃, the solution flow rate parameter is set to be 150ml/min, and the flow coating is carried out for 0.5 hour. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step two, weighing 50mg of polyethyleneimine, dissolving in 500mL of deionized water, adjusting the pH value to 8, and preparingcoating liquid 2. And (3) sucking thecoating liquid 2 into a circulating coating system by using a peristaltic pump, wherein a PVC pipe coated with polydopamine in the first step is used as a circulating channel pipeline, and a polydopamine-coated part in the first step is placed in a liquid accumulation bottle. The whole circulation system is maintained at 80 ℃, the flow rate parameter of the solution is set to be 5ml/min, and the flow coating is carried out for 5 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step three, weighing 2g of heparin sodium, dissolving the heparin sodium in 20mL of deionized water, placing the mixture in a low-temperature reaction tank at 0 ℃, adding 10g of sodium periodate after the temperature is stable, continuing to stir for reaction for 24 hours, then adding 4g of ethylene glycol, and continuing to stir for 2 hours. After the reaction is finished, performing rotary evaporation at normal temperature and reduced pressure until no bubbles are generated, adding 500mL of absolute ethyl alcohol into the solution after the rotary evaporation while stirring, and separating out a solid product. And finally, carrying out suction filtration and drying to obtain the aldehyde-group heparin. And weighing 1g of aldehyde-based heparin and 4g of bovine serum albumin, dissolving in 20mL of deionized water, adjusting the pH value to 7, stirring for reaction for 10 hours, filtering after the reaction is finished, reserving filtrate, and freeze-drying to obtain a powdery heparin-bovine serum albumin compound No. 1.

Step four, weighing 5.0g of No. 1 heparin-bovine serum albumin compound, dissolving the compound in 500mL of deionized water, adding 1g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 1g N-hydroxysuccinimide, adjusting the pH value to 7 to prepare coating liquid 3, sucking the coating liquid 3 into a circulating coating system by using a peristaltic pump, using a PVC pipe coated with the polyethyleneimine in the step two for a circulating channel pipeline, and putting the part coated with the polyethyleneimine in the step two into a liquid accumulation bottle. The whole circulation system is kept at 45 ℃, the flow rate parameter of the solution is set to be 300ml/min, and the flow coating is carried out for 0.5 hour. And (3) after the coating is finished, washing the coated pipelines and parts for 5 minutes by using deionized water, drying at 45 ℃ to obtain the pipelines and parts with the surfaces coated with the anticoagulant coatings, and placing the pipelines and parts in a vacuum drier for storage and standby.

Example 3

In an embodiment of the anticoagulant coating, the anticoagulant coating is a polydopamine-polyethyleneimine- (heparin 2-protein complex), the structure of the anticoagulant coating is shown in fig. 1, the anticoagulant coating sequentially comprises abase material 1, apolydopamine coating 2, a polyamino compound connecting layer 3 and a heparin-proteinfunctional layer 4 from bottom to top, and the layers are connected through covalent bonds; the preparation process is shown in figure 2 and specifically comprises the following steps:

weighing 5000mg of dopamine hydrochloride, dissolving the dopamine hydrochloride in 500ml of deionized water, adjusting the pH value to 10, adding 5000mg of sodium periodate, dissolving, and preparingcoating liquid 1. Thecoating liquid 1 is sucked into a circulating coating system by using a peristaltic pump, a PVC pipe to be coated is used as a circulating channel pipeline, and a part to be coated made of other materials to be coated is placed in a liquid accumulation bottle. The whole circulation system is maintained at 20 ℃, the solution flow rate parameter is set to be 5ml/min, and the flow coating is carried out for 5 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step two, weighing 1g of polyethyleneimine, dissolving in 100mL of deionized water, adjusting the pH value to 9, and preparingcoating liquid 2. And (3) sucking thecoating liquid 2 into a circulating coating system by using a peristaltic pump, wherein a PVC pipe coated with polydopamine in the first step is used as a circulating channel pipeline, and a polydopamine-coated part in the first step is placed in a liquid accumulation bottle. The whole circulation system is maintained at 20 ℃, the solution flow rate parameter is set to be 100ml/min, and the flow coating is carried out for 5 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step three, weighing 1g of heparin sodium, dissolving the heparin sodium in 20mL of deionized water, adding 0.76g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 0.58g N-hydroxysuccinimide, adjusting the pH value to 10, stirring for 0.5h, adding 10g of bovine serum albumin, continuously stirring at constant temperature of 25 ℃ for reaction for 24 hours, filtering after the reaction is finished, reserving filtrate, and freeze-drying to obtain the powdery heparin-bovine serum albumin compound No. 2.

Step four, weighing 1.0g of heparin-bovine serum albumin compound, dissolving the compound in 1000mL of deionized water, adding 6g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 4g N-hydroxysuccinimide, adjusting the pH value to 10 to prepare coating liquid 3, sucking the coating liquid 3 into a circulating coating system by using a peristaltic pump, sucking a circulating channel pipeline by using a PVC pipe coated with the polyethyleneimine in the step two, and putting the part coated with the polyethyleneimine in the step two into a liquid accumulation bottle. The whole circulation system is maintained at 20 ℃, the solution flow rate parameter is set to be 150ml/min, and the flow coating is carried out for 5 hours. And (3) after the coating is finished, washing the coated pipelines and parts for 5 minutes by using deionized water, drying at 45 ℃ to obtain the pipelines and parts with the surfaces coated with the anticoagulant coatings, and placing the pipelines and parts in a vacuum drier for storage and standby.

Example 4

In an embodiment of the anticoagulant coating, the anticoagulant coating is a polydopamine-polylysine- (heparin 2-protein complex) coating, the structure of the anticoagulant coating is shown in the attached drawing 1, the anticoagulant coating sequentially comprises abase material 1, apolydopamine coating 2, a polyamino compound connecting layer 3 and a heparin-proteinfunctional layer 4 from bottom to top, and the layers are connected through covalent bonds; the preparation process is shown in figure 2 and specifically comprises the following steps:

step one, weighing 500mg of dopamine hydrochloride, dissolving the dopamine hydrochloride in 500ml of deionized water, adjusting the pH value to 8.5, adding 500mg of sodium periodate, and dissolving to prepare acoating solution 1. Thecoating liquid 1 is sucked into a circulating coating system by using a peristaltic pump, a PVC pipe to be coated is used as a circulating channel pipeline, and a part to be coated made of other materials to be coated is placed in a liquid accumulation bottle. The whole circulation system is kept at 45 ℃, the flow rate parameter of the solution is set to be 100ml/min, and the flow coating is carried out for 2 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step two, weighing 500mg of polyethyleneimine, dissolving in 500mL of deionized water, adjusting the pH value to 9, and preparingcoating liquid 2. And (3) sucking thecoating liquid 2 into a circulating coating system by using a peristaltic pump, wherein a PVC pipe coated with polydopamine in the first step is used as a circulating channel pipeline, and a polydopamine-coated part in the first step is placed in a liquid accumulation bottle. The whole circulation system is maintained at 60 ℃, the solution flow rate parameter is set to be 150ml/min, and the flow coating is carried out for 1.5 hours. After the coating was complete, the coated tubing and parts were rinsed with deionized water for 5 minutes and ready for use.

Step three, weighing 1g of heparin sodium, dissolving the heparin sodium in 20mL of deionized water, adding 0.76g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 0.58g N-hydroxysuccinimide, adjusting the pH value to 7.5, stirring for 0.5h, adding 2g of bovine serum albumin, continuously stirring at constant temperature of 25 ℃ for reaction for 24 hours, filtering after the reaction is finished, reserving filtrate, and freeze-drying to obtain powdery heparin-bovine serum albumin compound No. 2.

Step four, weighing 1.0g of heparin-bovine serum albumin compound, dissolving the compound in 500mL of deionized water, adding 0.8g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and 0.6g N-hydroxysuccinimide, adjusting the pH value to 8.5 to prepare coating liquid 3, sucking the coating liquid 3 into a circulating coating system by using a peristaltic pump, using a PVC pipe coated with the polyethyleneimine in the step two for a circulating channel pipeline, and placing the part coated with the polyethyleneimine in the step two into a liquid accumulation bottle. The whole circulation system is maintained at 35 ℃, the solution flow rate parameter is set to be 5ml/min, and the flow coating is carried out for 3 hours. And (3) after the coating is finished, washing the coated pipelines and parts for 5 minutes by using deionized water, drying at 45 ℃ to obtain the pipelines and parts with the surfaces coated with the anticoagulant coatings, and placing the pipelines and parts in a vacuum drier for storage and standby.

Coating stability test

Fresh pig blood is injected into the PVC pipe coated with the anticoagulation coating obtained in the embodiment 1-4 of the invention, the PVC pipe circularly flows for 72 hours in an environment at 37 ℃, then the blood is poured out, a section of the PVC pipe is cut, the PVC pipe is dyed with toluidine blue for 10 minutes, and the contrast shows that the color of the dyed pipe without blood washing is not changed, which indicates that the coating has good stability.

Blood coagulation test

Static blood coagulation test: fresh pig blood was injected into the PVC tube coated with the coating of examples 1 to 4 of the present invention, left to stand at 37 ℃ for 168 hours, and then the blood was poured off to observe that no thrombus was attached to the tube wall.

Dynamic coagulation test: fresh pig blood was injected into the PVC tube coated with the coating of examples 1 to 4 of the present invention, circulated at 37 ℃ for 72 hours, and then the blood was poured off without adhesion of thrombus to the tube wall.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. The anticoagulant coating is characterized by sequentially comprising a base material, a polydopamine coating, a polyamino compound connecting layer and a heparin-protein functional layer from bottom to top, wherein the layers are connected through covalent bonds.

2. The anticoagulant coating of claim 1, wherein the polyamino compound linked layer is a polylysine coating.

3. A process for the preparation of an anticoagulant coating according to claim 1 or 2, comprising the steps of:

s1, coating a polydopamine primer on the surface of the base material, and circularly flowing a dopamine hydrochloride solution through a peristaltic pump to uniformly flow and coat the solution on the surface of the base material to be coated to obtain a polydopamine coating;

s2, circularly flowing the polyamino compound solution through a peristaltic pump to enable the solution to be uniformly coated on the surface of the polydopamine coating in a flowing mode to obtain a polyamino compound connecting layer;

s3, circularly flowing the heparin-protein solution through a peristaltic pump to enable the solution to be uniformly coated on the surface of the polyamino compound connecting layer in a flowing mode, and obtaining the heparin-protein functional layer.

4. The method of claim 3, wherein the heparin-protein solution is prepared as follows in step S3:

(1) preparing aldehyde heparin: dissolving heparin sodium in deionized water, adding sodium periodate while stirring, and after the reaction is finished, precipitating and purifying the reaction solution by an organic solvent;

(2) preparation of heparin-protein: dissolving the aldehyde heparin prepared in the step (1) in water, adding protein, quickly stirring for reaction, after the reaction is finished, carrying out suction filtration on the reaction solution, and carrying out precipitation purification through an organic solvent.

5. The method of claim 3, wherein in step S3, the heparin-protein is prepared by coupling heparin and amino group with a coupling agent; the coupling agent is at least one of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, N' -carbonyldiimidazole and N-hydroxysuccinimide.

6. The method of preparing an anticoagulant coating according to claim 3, wherein the polyamino compound comprises a macromolecular compound and a small molecular compound; the macromolecular compound is at least one of polylysine, sodium polyaspartate, starch, polyethyleneimine, carboxymethyl chitosan and macromolecular polyether amine; the micromolecule compound is at least one of micromolecule polyether amine, ethylenediamine and amine-terminated polyether.

7. The method for preparing an anticoagulant coating according to claim 3, wherein in step S1, the concentration of the dopamine hydrochloride solution is 0.1-10mg/mL, and the pH value is 7-10; the dopamine hydrochloride solution contains sodium periodate with the mass percentage of 0.1-10 per mill;

when coating the polydopamine priming coat, the flow rate of a peristaltic pump is 5-300mL/min, the temperature of the hydrochloric acid dopamine solution is 20-80 ℃, and the coating time is 0.5-5 hours;

in step S2, the concentration of the polyamino compound solution is 0.1-20mg/mL, and the pH value is 7-9;

when the polyamino compound connecting layer is coated, the flow rate of a peristaltic pump is 5-300mL/min, the temperature of the polyamino compound solution is 20-80 ℃, and the coating time is 0.5-5 hours.

8. The method for preparing an anticoagulant coating according to claim 4, wherein in the step (1), the reaction temperature is 0-28 ℃, the reaction time is 2-24 hours, and the mass percentage of the heparin sodium solution is 1% -10%; the molar ratio of the heparin sodium to the sodium periodate is 1:1-1:5, and the volume ratio of the reaction liquid to the organic solvent is 1:2-1: 10.

9. The method for preparing an anticoagulant coating according to claim 4, wherein in the step (2), the molar ratio of heparin to protein is 1:1-1:10, and the volume ratio of the reaction solution to the organic solvent is 1:2-1: 10; in the step S3, the concentration of the heparin-protein solution is 1-10mg/mL, and the pH value is 7-10.

10. The method of claim 3, wherein in step S3, the heparin-protein solution is circulated by a peristaltic pump, the coupling agent is added to the solution, the molar ratio of the coupling agent to the heparin is 2:1-10:1, the flow rate of the peristaltic pump is 5-300mL/min, the temperature of the solution is 20-45 ℃, and the coating time is 0.5-5 hours.

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