Electrochemical method for the preparation of a medical anticoagulant coating and product thereof

Abstract

The application discloses an electrochemical preparation method of a medical anticoagulant coating and a product thereof, and belongs to the technical field of anticoagulant material preparation. The method is as follows: a heparin-pyrrole coating is deposited on a base material by anodic electropolymerization in a two-electrode system, and the electrolyte of the two-electrode system is prepared by taking deionized water as a solvent and taking heparin sodium, pyrrole monomer and Na2SO4 as solutes. The method can not only maintain the advantages of ionic bond and the natural conformation of heparin, but also make up for the shortcomings of weak ordinary ionic bond and poor stability, so that the prepared coating has good stability and anticoagulant property.

Description

Technical Field

[0001] This invention relates to the field of anticoagulant material preparation technology, and in particular to an electrochemical preparation method for a medical anticoagulant coating and its product. Background Technology

[0002] Cardiovascular disease is one of the most serious threats to human health, accounting for a significant proportion of morbidity and mortality worldwide. Treatment methods for cardiovascular disease mainly include drug therapy, surgical treatment, and interventional therapy. Surgical and interventional therapies involve implanting expanded cardiovascular stents at the lesion site to restore stable blood supply to the blood vessel, offering advantages such as good treatment efficacy and low cost. However, contact between blood and the implant can trigger a blood defense response, known as the coagulation cascade, which can lead to various complications, including allergic reactions, lung and kidney dysfunction, and thrombosis. Therefore, cardiovascular medical materials need to possess good biocompatibility, and particularly require excellent anticoagulant properties on their surface. To achieve superior blood compatibility, surface modification of materials used in artificial heart valves and vascular stents, enhancing their anticoagulant properties without altering their intrinsic beneficial properties, has significant research and application value.

[0003] Heparin is currently the most widely used polysaccharide anticoagulant in clinical practice, possessing antithrombotic, anti-inflammatory, and lipid-regulating effects. It is primarily used in the treatment of cardiovascular and cerebrovascular diseases and hemodialysis. Heparin can be immobilized on material surfaces in various ways to obtain heparinized and functionalized anticoagulant surfaces, effectively reducing blood activation upon contact with artificial surfaces. As a natural indirect inhibitor, heparin acts as a catalyst in the reaction process, avoiding the problem of continuous consumption and rapid failure of direct inhibitors. Currently, the main methods for immobilizing heparin are ionic bonding and covalent bonding. However, ionic bonding results in weaker binding between heparin and the material, making it easy for heparin to detach under the complex environment and blood flow, thus failing to achieve a long-lasting anticoagulant effect. Covalent bonding may cause physical damage to the bulk material and alters the normal conformation of heparin, reducing its anticoagulant activity. Furthermore, both methods are relatively complex to implement. Therefore, the development of heparinization modification technology for material surfaces and the improvement of its performance stability will continue to be an important field and hot topic in the surface modification of artificial cardiovascular materials. Finding a simple method that produces surface heparinized materials with stable performance is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide an electrochemical preparation method and product of a medical anticoagulant coating, to solve the problems of complex preparation process and insufficient performance stability of surface heparinized materials in the prior art. This invention prepares a heparin-polypyrrole coating on a titanium substrate using electrochemical technology, improving the blood compatibility of the titanium substrate while enhancing its corrosion resistance and hydrophilicity. This preparation method is simple to operate and is a relatively inexpensive, green, and energy-saving approach.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] One of the technical solutions of the present invention is a method for preparing a medical anticoagulant coating, which uses a two-electrode system to deposit a heparin-polypyrrole coating on a substrate material by anodic electropolymerization.

[0007] The electrolyte of the two-electrode system uses deionized water as the solvent and heparin sodium, pyrrole monomer and Na2SO4 as solutes.

[0008] Furthermore, the concentration of heparin sodium in the electrolyte is 0.1–1 g / L, the concentration of pyrrole monomer is 1–8 g / L, and the concentration of Na2SO4 is 2–8 g / L.

[0009] Furthermore, the electrolyte should be stirred thoroughly during preparation.

[0010] Furthermore, the current density of the anodic electropolymerization is 1–5 mA / cm². 2 The deposition time is 600–1600 s, and the working temperature is -5–25℃.

[0011] Furthermore, the matrix material is pure titanium, and the titanium content of the pure titanium is ≥99.99%.

[0012] Furthermore, the matrix material serves as the working electrode of the two-electrode system, and the counter electrode of the two-electrode system is a platinum electrode.

[0013] Furthermore, a step of pretreating the substrate material is included before the anodic electropolymerization deposition.

[0014] Furthermore, the pretreatment includes polishing, degreasing, and cleaning.

[0015] Furthermore, after the anodic electropolymerization deposition is completed, the process also includes a step of drying the deposited coating.

[0016] The second technical solution of the present invention: a medical anticoagulant coating prepared according to the above preparation method.

[0017] The present invention discloses the following technical effects:

[0018] (1) This invention employs a two-electrode system and electrochemical copolymerization technology to directly prepare a heparin-polypyrrole composite coating on a titanium substrate. Under the influence of an electric field, heparin and polypyrrole, two long-chain macromolecules, form an interwoven network structure. This not only maintains the advantages of ionic bonding and preserves the natural conformation of heparin, but also overcomes the shortcomings of weak ionic bonding and poor stability in ordinary coatings, resulting in a coating with excellent stability and anticoagulant properties. This provides a new method for preparing anticoagulant coatings and expands their application in the treatment of cardiovascular diseases.

[0019] (2) The preparation method of the present invention is simple to operate, low in cost, green and energy-saving, easy to control, and easy to promote and apply on a large scale. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 An optical photograph of the heparin-polypyrrole coating prepared in Example 1 of this invention;

[0022] Figure 2 An optical photograph of the heparin-polypyrrole coating prepared in Comparative Example 1 of this invention;

[0023] Figure 3 An optical photograph of the polypyrrole coating prepared in Comparative Example 2 of this invention;

[0024] Figure 4 An optical photograph of the polypyrrole coating prepared in Comparative Example 3 of this invention;

[0025] Figure 5 An optical photograph of the polypyrrole coating prepared in Comparative Example 4 of this invention;

[0026] Figure 6 An optical photograph of the polypyrrole coating prepared in Comparative Example 5 of this invention;

[0027] Figure 7 An optical photograph of the titanium substrate after pretreatment, as shown in Comparative Example 5 of this invention.

[0028] Figure 8 A scanning electron microscope image of the heparin-polypyrrole coating prepared in Example 1 of this invention;

[0029] Figure 9 A scanning electron microscope image of the heparin-polypyrrole coating prepared in Example 2 of this invention;

[0030] Figure 10 A scanning electron microscope image of the heparin-polypyrrole coating prepared in Example 9 of this invention;

[0031] Figure 11 This is a scanning electron microscope image of the titanium sheet substrate after pretreatment in Example 1 of the present invention;

[0032] Figure 12 A scanning electron microscope image of the polypyrrole coating prepared in Comparative Example 3 of this invention;

[0033] Figure 13 The water contact angle diagram of the heparin-polypyrrole coating prepared in Example 1 of this invention;

[0034] Figure 14 Tafel polarization curves of the heparin-polypyrrole coating and the titanium substrate prepared in Examples 1 and 2 of this invention. Detailed Implementation

[0035] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0036] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0037] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe the methods and materials associated with those references. In the event of any conflict with any incorporated reference, the contents of this specification shall prevail.

[0038] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This application specification and embodiments are merely exemplary.

[0039] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0040] Example 1

[0041] (1) Electrode pretreatment

[0042] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0043] (2) Preparation of electrolyte

[0044] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.4 g / L heparin sodium, 5 g / L pyrrole monomer, and 5 g / L Na2SO4.

[0045] (3) Coating preparation

[0046] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 600 s, and the current density was 2 mA / cm². 2 The operating temperature is 0℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed clean with deionized water and then dried with nitrogen.

[0047] Example 2

[0048] (1) Electrode pretreatment

[0049] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0050] (2) Preparation of electrolyte

[0051] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.4 g / L heparin sodium, 5 g / L pyrrole monomer, and 5 g / L Na2SO4.

[0052] (3) Coating preparation

[0053] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 600 s, and the current density was 1 mA / cm². 2 The operating temperature is 5℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed off with deionized water and then dried with nitrogen.

[0054] Example 3

[0055] (1) Electrode pretreatment

[0056] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0057] (2) Preparation of electrolyte

[0058] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.4 g / L heparin sodium, 5 g / L pyrrole monomer, and 5 g / L Na2SO4.

[0059] (3) Coating preparation

[0060] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 1000 s, and the current density was 3 mA / cm². 2 The operating temperature is -5℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed off with deionized water and then dried with nitrogen.

[0061] Example 4

[0062] (1) Electrode pretreatment

[0063] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0064] (2) Preparation of electrolyte

[0065] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.2 g / L heparin sodium, 5 g / L pyrrole monomer, and 8 g / L Na2SO4.

[0066] (3) Coating preparation

[0067] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 800 s, and the current density was 2 mA / cm². 2 The operating temperature is 0℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed clean with deionized water and then dried with nitrogen.

[0068] Example 5

[0069] (1) Electrode pretreatment

[0070] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0071] (2) Preparation of electrolyte

[0072] The electrolyte uses deionized water as the solvent, and the solute composition is: 1 g / L heparin sodium, 5 g / L pyrrole monomer, and 5 g / L Na2SO4.

[0073] (3) Coating preparation

[0074] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 1200 s, and the current density was 4 mA / cm². 2 The operating temperature is -5℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed off with deionized water and then dried with nitrogen.

[0075] Example 6

[0076] (1) Electrode pretreatment

[0077] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0078] (2) Preparation of electrolyte

[0079] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.3 g / L heparin sodium, 8 g / L pyrrole monomer, and 5 g / L Na2SO4.

[0080] (3) Coating preparation

[0081] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 800 s, and the current density was 2 mA / cm². 2 The operating temperature is 10℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed clean with deionized water and then dried with nitrogen.

[0082] Example 7

[0083] (1) Electrode pretreatment

[0084] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0085] (2) Preparation of electrolyte

[0086] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.4 g / L heparin sodium, 6 g / L pyrrole monomer, and 2 g / L Na2SO4.

[0087] (3) Coating preparation

[0088] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 1600 s, and the current density was 3 mA / cm². 2The operating temperature is 20℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed off with deionized water and then dried with nitrogen.

[0089] Example 8

[0090] (1) Electrode pretreatment

[0091] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0092] (2) Preparation of electrolyte

[0093] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.4 g / L heparin sodium, 6 g / L pyrrole monomer, and 6 g / L Na2SO4.

[0094] (3) Coating preparation

[0095] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 600 s, and the current density was 3 mA / cm². 2 The operating temperature is 5℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed off with deionized water and then dried with nitrogen.

[0096] Example 9

[0097] (1) Electrode pretreatment

[0098] Titanium sheets (Ti≥99.99%, 10mm×10mm×0.2mm) were successively polished with 500, 800 and 1000 grit metallographic sandpaper until the surface scratches were uniform and in the same direction. The polished titanium sheets were ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 10 minutes respectively. After cleaning, the surface was dried with nitrogen gas and set aside for use.

[0099] (2) Preparation of electrolyte

[0100] The electrolyte uses deionized water as the solvent, and the solute composition is: 0.6 g / L heparin sodium, 5 g / L pyrrole monomer, and 5 g / L Na2SO4.

[0101] (3) Coating preparation

[0102] The working electrode was a treated pure titanium sheet, and the counter electrode was a platinum electrode (25mm × 25mm × 0.2mm). Both electrodes were fixed in an electrolytic cell, and electrolyte was added, ensuring the working surface of the working electrode was completely immersed in the electrolyte, while maintaining the relative position of the counter electrode to the working electrode. During the electrochemical preparation process, the preparation time was 600 s, and the current density was 2 mA / cm². 2 The operating temperature is 0℃. After the anodic electropolymerization deposition is completed, the heparin-polypyrrole coating deposited on the surface of the pure titanium sheet is rinsed clean with deionized water and then dried with nitrogen.

[0103] Comparative Example 1

[0104] Same as Example 1, except that the operating temperature is 35°C.

[0105] Comparative Example 2

[0106] Same as Example 1, except that the preparation time is 1800s.

[0107] Comparative Example 3

[0108] Same as Example 1, except that no sodium heparin was added to the electrolyte.

[0109] Comparative Example 4

[0110] Same as Example 1, except that the current density during preparation is 0.5 mA / cm². 2 .

[0111] Comparative Example 5

[0112] Same as Example 1, except that no pyrrole monomer was added to the electrolyte.

[0113] Effect verification

[0114] (1) Morphological structure

[0115] Optical photographs of the heparin-polypyrrole coating prepared in Example 1 are shown below. Figure 1 As shown, by Figure 1 As can be seen, the heparin-polypyrrole coating prepared in Example 1 is black and uniformly flat. The appearance of the heparin-polypyrrole coatings prepared in Examples 2-9 is similar to that of Example 1, all being black and uniformly flat. Optical photographs of these coatings will not be listed here. Optical photographs of the heparin-polypyrrole coatings prepared in Comparative Examples 1-5 are shown below. Figure 2-6 As shown, the preparation temperature of Comparative Example 1 was 35℃. The preparation temperature was too high, resulting in an uneven coating that could not completely cover the substrate (see...). Figure 2 Comparative Example 2 had a preparation time of 1800 s, which was too long, resulting in poor coating adhesion and large areas of coating peeling off during drying (see...). Figure 3In Comparative Example 3, no sodium heparin was added to the electrolyte, and the coating was grayish-black and uniformly flat (see...). Figure 4 The current density during preparation of Comparative Example 4 was 0.5 mA / cm². 2 If the current density is too low, the coating thickness will be very thin and a uniform composite coating cannot be obtained (see...). Figure 5 In Comparative Example 5, no pyrrole monomer was added to the electrolyte, and the resulting coating was slightly bluish (see...). Figure 6 The coating is very thin, and the scratches are clearly visible, compared to a photo of the pretreated titanium substrate (see...). Figure 7 The difference is very small.

[0116] Scanning electron microscope images of the heparin-polypyrrole coatings prepared in Examples 1, 2, and 9 are shown below. Figure 8-10 As shown, the coating surface is uniform and free of cracks and pores, exhibiting a dense microsphere structure, consistent with the scanning electron microscope image of the pretreated titanium substrate (see [image missing]). Figure 11 The comparison clearly shows that the coating has been uniformly adhered to the substrate surface. The surface structure of the heparin-polypyrrole coatings prepared in Examples 3-8 is similar to that in Examples 1, 2, and 9, all being uniform without cracks or pores, and possessing a dense microsphere structure, only differing in the size of the microspheres. Optical photographs of each microsphere are not listed here. A scanning electron microscope image of the polypyrrole coating prepared in Comparative Example 3 is shown below. Figure 12 Its surface has no cracks or holes, and the resulting microspheres vary greatly in size.

[0117] (2) Thickness, surface roughness and water contact angle

[0118] The coatings prepared in Examples 1-9 and Comparative Example 3 were tested for thickness, surface roughness and water contact angle. The pretreated pure titanium sheet substrate was used as a blank control group. Three different locations were selected for each coating for each item. The results were the average of the three sets of data, as shown in Table 1 (the thickness in Table 1 is the thickness of the coating alone, excluding the titanium sheet substrate).

[0119] Table 1

[0120] Thickness / μm Surface roughness / nm Water contact angle / ° Example 1 3.18 349 5.67 Example 2 2.45 178 15.50 Example 3 5.20 399 47.75 Example 4 3.55 356 24.52 Example 5 5.71 443 35.08 Example 6 3.39 365 23.75 Example 7 2.87 486 44.08 Example 8 5.23 365 44.75 Example 9 3.37 343 22.75 Comparative Example 3 6.83 233 64.50 Blank control group — 86.2 58.75

[0121] As shown in Table 1, compared with the pure titanium substrate, the coatings prepared in Examples 1-9 of this invention have increased surface roughness, decreased water contact angle, and improved hydrophilicity. In particular, the water contact angle of the coating prepared in Example 1 is only 5.67°, as shown in the water contact angle image below. Figure 13 As shown, it has reached a superhydrophilic state, and its hydrophilic surface easily adsorbs adhesion proteins, promotes cell adhesion, and has good biocompatibility.

[0122] (3) Tafel polarization curve

[0123] The coatings prepared in Examples 1-2 were subjected to Tafel polarization curve testing, with the pretreated titanium substrate serving as a control group. The Tafel polarization curves for each group are shown below. Figure 14 As shown, by Figure 14 It can be seen that the coatings prepared in Examples 1 and 2 show a significantly positive shift in corrosion potential and improved corrosion resistance compared to the substrate titanium sheet. The Tafel polarization curves of the coatings obtained in Examples 3-9 are similar to those in Examples 1-2.

[0124] (4) Activated partial thromboplastin time (APTT) test (used to detect the clotting time of biomolecules)

[0125] The activated partial thromboplastin time (APTT) of each fresh serum sample was first tested using a fully automated coagulation analyzer and recorded as the raw value. Then, the serum was incubated on the coatings prepared in each example and comparative example for 30 min, and the APTT was tested again. The pretreated pure titanium sheet substrate was used as a blank control group. The test results are shown in Table 2.

[0126] Table 2

[0127] APTT initial value / s APTT value after incubation / s Example 1 34.0 55.6 Example 2 32.8 37.8 Example 3 36.5 70.7 Example 4 31.2 48.1 Example 5 38.8 47.4 Example 6 34.8 55.1 Example 7 33.2 41.6 Example 8 39.1 50.3 Example 9 35.8 50.1 Comparative Example 3 39.8 38.4 Blank control group 39.8 38.9

[0128] As shown in Table 2, the APTT value of the coatings prepared in Examples 1-9 of the present invention was significantly prolonged after incubation with serum compared with the initial value, indicating that the coatings prepared in Examples 1-9 of the present invention have certain anticoagulant properties.

[0129] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a medical anticoagulant coating, characterized in that, A heparin-polypyrrole coating was deposited on a substrate material via anodic electropolymerization using a two-electrode system. The electrolyte of the two-electrode system uses deionized water as solvent and heparin sodium, pyrrole monomer and Na2SO4 as solute; The electrolyte contains 0.1–1 g / L sodium heparin, 1–8 g / L pyrrole monomer, and 2–8 g / L Na2SO4. The current density of the anodic electropolymerization is 1–5 mA / cm². 2 The deposition time is 600–1600 s, and the working temperature is -5–25℃.

2. The preparation method according to claim 1, characterized in that, The matrix material is pure titanium, and the titanium content of the pure titanium is ≥99.99%.

3. The preparation method according to claim 1, characterized in that, The matrix material serves as the working electrode of the two-electrode system, and the counter electrode of the two-electrode system is a platinum electrode.

4. The preparation method according to claim 1, characterized in that, The process also includes a pretreatment step of the substrate material prior to the anodic electropolymerization deposition.

5. The preparation method according to claim 4, characterized in that, The pretreatment includes grinding, degreasing, and cleaning.

6. The preparation method according to claim 1, characterized in that, The process of anodic electropolymerization deposition also includes a step of drying the deposited coating.

7. A medical anticoagulant coating prepared by the preparation method according to any one of claims 1-6.

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