An antibacterial, anticoagulant coating composition, an antibacterial, anticoagulant coating and a method for producing the same, a medical material

Abstract

The application provides an antibacterial and anticoagulant coating composition, an antibacterial and anticoagulant coating and a preparation method thereof and a medical material. The antibacterial and anticoagulant coating composition comprises a catechol compound, a polyamine compound, an anticoagulant substance and a metal salt. The preparation method of the antibacterial and anticoagulant coating based on the coating composition is simpler and more convenient. The preparation method comprises the following steps: firstly, constructing a phenylamine bottom coating through Schiff base reaction between the catechol compound and the polyamine compound; secondly, realizing the fixation of the anticoagulant substance through chemical reaction between the activated anticoagulant substance and the amino group of the phenylamine bottom coating; and finally, forming a complex coating of the anticoagulant substance and metal ions on the surface through coordination reaction between the anticoagulant substance and the metal ions. In the application, the complex coating of the anticoagulant substance and the metal ions can activate the anticoagulant capacity of the anticoagulant substance, improve the self-cleaning capacity and the photocatalytic antibacterial capacity of the coating surface.

Description

Technical Field

[0001] This invention belongs to the field of medical materials, specifically relating to an antibacterial and anticoagulant coating composition, an antibacterial and anticoagulant coating and its preparation method, and a medical material. Background Technology

[0002] Cardiovascular diseases pose a serious threat to human health. Currently, implanted blood-contact devices, such as catheters, heart valves, and artificial blood vessels, have become a common clinical treatment for cardiovascular diseases. Polyurethane, due to its good chemical stability and mechanical properties, is widely used in the manufacture of medical devices. However, polyurethane materials have poor blood compatibility and are prone to thrombus formation during use, limiting their application in blood-contact devices. Furthermore, blood-contact devices typically lack hydrophilic lubrication and sterilization capabilities, leading to bacterial and protein adhesion during use and increasing the risk of infection. Therefore, improving the anticoagulant and antibacterial effects of blood-contact devices is of great practical significance for their application.

[0003] Regarding anticoagulation, studies have shown that immobilizing anticoagulants on the surface of blood contact devices can improve their anticoagulant effect. Generally, the anticoagulant structures and mechanisms of anticoagulants vary considerably. For example, heparin, an indirect inhibitor of thrombin, has a special pentasaccharide sequence that can specifically bind to antithrombin III. Furthermore, due to the charge effect of heparin, it can further bind to thrombin to form a ternary complex that inhibits thrombin activity and plays an anticoagulant role. In addition, heparin also has the function of inhibiting smooth muscle cell proliferation and promoting endothelial cell proliferation, which can effectively reduce the occurrence of restenosis caused by common blood contact devices. At present, there are two strategies for surface modification of heparin: (1) forming a drug-releasing coating through physical adsorption methods such as electrostatic interaction, but due to the instability of physical adsorption, heparin is easily detached; (2) obtaining a heparin functionalized surface formed by covalent bonds through chemical reactions such as amide reaction. This method has stable binding and high safety, but although heparin can directly interact with coagulation factors, the loading capacity is limited. If the usage time is too long, the anticoagulant effect will decrease significantly.

[0004] For antibacterial purposes, blood contact devices typically form antibacterial surfaces by immobilizing antibacterial polymers or loading antibacterial agents. However, immobilizing antibacterial polymers usually weakens the surface's anticoagulant ability, while loading antibacterial agents can induce drug resistance problems.

[0005] It is evident that the anticoagulant and antibacterial effects of blood-contact medical devices still need further improvement. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide an antibacterial and anticoagulant coating composition, an antibacterial and anticoagulant coating and its preparation method, and a medical material. The aforementioned antibacterial and anticoagulant composite coating exhibits excellent antibacterial and anticoagulant effects.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an antibacterial and anticoagulant coating composition comprising catechol compounds, polyamine compounds, anticoagulant substances, and metal salts.

[0009] Preferably, the ratio of the catechin compound, polyamine compound, anticoagulant and metal salt is (35-45):(35-45):(5-12):(10-20).

[0010] Preferably, the catechin compounds include any one or more of catechins, catechinic acids, catechinic acid amines, or flavonoids.

[0011] Preferably, the polyamine compound includes any one or more of polyimide, polyamide, or polyurethane.

[0012] Preferably, the anticoagulant includes heparin and / or tissue plasminogen.

[0013] Preferably, the metal salt includes any one or more of titanium, zinc, or tin metal salts.

[0014] More preferably, the catechol compound is selected from any one or more of levodopa, norepinephrine, dopamine, dopamine hydrochloride, or phenylalanine.

[0015] More preferably, the polyamine compound is selected from polyethyleneimine and / or polyacrylamide.

[0016] More preferably, the titanium metal salt is selected from TiBALDH and / or tetrabutyl titanate, the zinc metal salt is selected from zinc acetate dihydrate and / or zinc nitrate, and the tin metal salt is selected from tin chloride dihydrate and / or tin acetate.

[0017] In a second aspect, the present invention provides an antibacterial and anticoating coating formed from the above-mentioned antibacterial and anticoating coating composition.

[0018] Thirdly, the present invention provides a method for preparing an antibacterial and anti-coating coating, comprising the following steps:

[0019] S1: Immerse the medical material in a solution containing catechol compounds and polyamine compounds. After the reaction, a medical material coated with a phenolamine undercoat is obtained.

[0020] S2: Medical materials coated with a phenolamine undercoat are soaked in an anticoagulant solution and reacted to obtain anticoagulant-modified medical materials.

[0021] S3: Medical materials modified with anticoagulant substances are soaked in a metal salt solution. After the reaction, medical materials with antibacterial and anticoagulant coatings are obtained.

[0022] Preferably, the soaking temperature in steps S1, S2, and S3 is 20–40°C and the soaking time is 0.1–30 h.

[0023] Preferably, the soaking in step S2 is carried out under conditions of pH 4 to 6.

[0024] Preferably, the anticoagulant in the anticoagulant solution in step S2 has undergone activation treatment.

[0025] Preferably, the soaking in step S3 is carried out under conditions of pH 8 to 10.

[0026] Fourthly, the present invention provides a medical material comprising a medical material matrix and a coating formed on the surface of the medical material matrix;

[0027] The coating is the aforementioned antibacterial and anticoating coating.

[0028] Preferably, the medical material matrix includes a blood contact material matrix.

[0029] Preferably, the material of the medical material matrix is ​​selected from metallic materials, inorganic non-metallic matrix materials, or polymer materials.

[0030] Preferably, the thickness of the antibacterial and anticoating coating is 10–25 μm.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] This invention provides an antibacterial and anticoagulant coating composition comprising catechol compounds, polyamine compounds, an anticoagulant substance, and a metal salt. Furthermore, based on this coating composition, this invention provides an antibacterial and anticoagulant coating, and its preparation method is simpler and more convenient. The preparation method first constructs a phenol-amine underlayer coating through a Schiff base reaction between the catechol compounds and the polyamine compounds; then, the activated anticoagulant substance reacts chemically with the amino groups of the phenol-amine underlayer coating to fix the anticoagulant substance; finally, a complex coating of the anticoagulant substance and metal ions is formed on the surface through a coordination reaction between the anticoagulant substance and metal ions. In this invention, the complex coating of the anticoagulant substance and metal ions can activate the anticoagulant substance's anticoagulant ability, improve the coating surface's self-cleaning ability and photocatalytic antibacterial ability. Attached Figure Description

[0033] Figure 1 This is a comparison chart of the hemolysis rates of the products obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4;

[0034] Figure 2 This is a comparison chart of the anti-protein adhesion levels of the products obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4.

[0035] Figure 3 Comparative electron micrographs of platelet adhesion of the products obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4;

[0036] Figure 4 Comparison chart of activated partial thromboplastin time (APTT) and thrombin time (TT) of the products obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4;

[0037] Figure 5 This is a comparison chart of the antibacterial rates of the products obtained in Example 1, Comparative Example 1, and Comparative Example 2;

[0038] Figure 6 This is a comparison diagram of the visible light absorption peaks of the products obtained in Example 1 and Comparative Example 4;

[0039] Figure 7 The image shows cell viability data of the products obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4. Detailed Implementation

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] The present invention provides an antibacterial and anticoagulant coating composition comprising catechol compounds, polyamine compounds, anticoagulant substances, and metal salts; wherein the mass ratio of the catechol compounds, polyamine compounds, anticoagulant substances, and metal salts is (35-45):(35-45):(5-12):(10-20), preferably (35-40):(40-45):(8-10):(10-15), and more preferably 38:42:8:12.

[0042] In this invention, the catechol compounds include any one or more of catechol, catecholic acid, catecholamine, or flavonoids; the polyamine compounds include any one or more of polyimide, polyamide, or polyurethane; the anticoagulant includes heparin and / or tissue plasminogen; and the metal salts include any one or more of titanium, zinc, or tin.

[0043] In some preferred embodiments of the present invention, the catechol compound is dopamine hydrochloride; and / or, the polyamine compound is polyethyleneimine; and / or, the anticoagulant is heparin; and / or, the metal salt solution is a titanate solution.

[0044] The present invention also provides an antibacterial and anticoating coating formed from the above-described antibacterial and anticoating coating composition.

[0045] The present invention also provides a method for preparing the above-mentioned antibacterial and anticoating coating, comprising the following steps:

[0046] S1: Immerse the medical material in a solution containing catechol compounds and polyamine compounds. After the reaction, a medical material coated with a phenolamine undercoat is obtained.

[0047] S2: Medical materials coated with a phenolamine undercoat are soaked in an anticoagulant solution and reacted to obtain anticoagulant-modified medical materials.

[0048] S3: Medical materials modified with anticoagulant substances are soaked in a metal salt solution. After the reaction, medical materials with antibacterial and anticoagulant coatings are obtained.

[0049] According to the present invention, the medical material is first immersed in a solution containing catechol compounds and polyamine compounds. After the reaction, the medical material coated with a phenolamine undercoat is obtained.

[0050] The medical material may include a blood-contact matrix; the material of the medical material is selected from metallic materials, inorganic non-metallic matrix materials, or polymer materials. In some embodiments of the present invention, the medical material is thermoplastic polyurethane, polypropylene, etc. The medical material is preferably pretreated before immersion, and the pretreatment generally involves: preparing the medical material into a substrate, cleaning, and drying it for later use. The steps of preparing the substrate, cleaning, and drying are not particularly limited and can be performed using methods well known to those skilled in the art.

[0051] In this invention, the catechol compounds include any one or more of catechols, catechol acids, catecholamines, or flavonoids, specifically selected from any one or more of levodopa, norepinephrine, dopamine, dopamine hydrochloride, or phenylalanine. In this invention, the concentration of the catechol compounds in the solution is 10–40 mg / mL, preferably 10–30 mg / mL, most preferably 15–25 mg / mL, and the solvent includes any one or more of water, acetone, or dimethyl sulfoxide.

[0052] In this invention, the polyamine compound includes any one or more of polyimide, polyamide, or polyurethane, specifically selected from polyethyleneimine (PEI) and / or polyacrylamide. In this invention, the concentration of the polyamine compound in the solution is 10–40 mg / mL, preferably 10–30 mg / mL, and most preferably 15–25 mg / mL, and the solvent includes any one or more of water, acetone, or ethanol.

[0053] In some embodiments of the present invention, step S1 is: preferably, the medical material is immersed in a solution containing catechol compounds and polyamine compounds at 20-40°C for 0.1-30 hours, preferably at 25-37°C for 10-24 hours, and a phenolamine undercoat is constructed by the Schiff base reaction between the catechol compounds and the polyamine compounds, thereby obtaining the medical material coated with the phenolamine undercoat.

[0054] In some preferred embodiments of the present invention, the underlayer coating is obtained by reacting dopamine with polyethyleneimine, and the preparation method of the underlayer coating includes the following steps:

[0055] Step 1: Ultrasonically wash the substrate material in an ethanol-water solution and dry it for later use;

[0056] Step 2: Place the cleaned medical materials into a dopamine / polyethyleneimine mixed solution and soak for 8-14 hours. Then remove and shake to wash for 5-12 hours to remove compounds that are physically adhering to the surface, and then dry.

[0057] In step 2, the concentration ratio of dopamine to polyethyleneimine is (0.5–2):1, preferably (0.75–1.5):1, and / or the solvent in the dopamine / polyethyleneimine mixed solution is at least one of water, ethanol, or methanol. Step 2, the method for preparing the undercoat solution, further includes placing the cleaned medical material in a dopamine solution for 10–15 hours, shaking and cleaning for 10–15 hours, drying it, then placing it in a polyethyleneimine solution for 10–15 hours, shaking and cleaning for 10–15 hours, and drying it for later use.

[0058] In this invention, the phenolamine deposition process utilizes non-covalent interactions between polyamine compounds and medical materials, such as hydrogen bonding or electrostatic interactions, to adorn the polyamine compounds onto the substrate surface, thus preserving the polymeric properties of the polyamine compounds. Furthermore, polyamine compounds possess strong hydrophilicity, and the numerous amino groups on the polyamine compounds can participate in the oxidative self-polymerization of catechol compounds, thereby promoting the reaction. Moreover, the good hydrophilicity of polyamine compounds can inhibit particle aggregation, improving the stability of the final anticoagulant and antibacterial coating.

[0059] After step S1 is completed, according to the present invention, the medical material coated with a phenolamine undercoat is immersed in an anticoagulant solution. After the reaction, a medical material with an anticoagulant coating and an undercoat is obtained. In the present invention, the anticoagulant includes heparin and / or tissue plasminogen lysate. The concentration of the anticoagulant solution is 1–3 mg / mL, preferably 1.5–2.5 mg / mL, and the solvent includes any one or more of water, dimethyl sulfoxide, and ethanol.

[0060] In some embodiments of the present invention, it is preferred to prepare a solution of an anticoagulant, and immerse the medical material obtained in step S1 in the solution of the anticoagulant at 20-40°C, preferably 25-37°C, adjust the pH to 4-6 to activate the anticoagulant, immerse for 0.1-30 hours, preferably 0.1-10 hours, and after washing, obtain the medical material modified with the anticoagulant.

[0061] In some preferred embodiments of the present invention, the anticoagulant in the anticoagulant solution is activated, thereby grafting the phenolamine undercoat with the activated anticoagulant, making the loading of the anticoagulant more stable and firm, and the grafting of the anticoagulant provides active sites for subsequent grafting.

[0062] For example, taking heparin as an example, in some embodiments of the present invention, the activation process of heparin includes the following steps;

[0063] Step (1): Dissolve sodium heparin in a solvent to obtain a sodium heparin solution;

[0064] Step (2): Dissolve 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) in a solvent to obtain a mixed solution of EDC and NHS;

[0065] Step (3): Add the mixed solution of EDC and NHS to the sodium heparin solution and react at room temperature for 10-60 minutes to fully activate the sodium heparin, so that it can be further grafted onto the medical material coated with the bottom layer coating.

[0066] Step (4): The medical material grafted with phenolamine undercoat is added to the activated heparin sodium solution for 0.1 to 30 hours, taken out and shaken for 10 to 15 hours and then dried.

[0067] In step (3) above, the mass ratio of EDC to NHS is (0.3-0.8):1; and / or, the mass ratio of heparin sodium to EDC is (0.3-0.8):1; and / or, the mass ratio of heparin sodium to NHS is (0.1-0.5):1; when the EDC / NHS mixed solution is mixed, the pH is adjusted to between 4 and 6.

[0068] The above-mentioned heparin activation process utilizes EDC and NHS to activate heparin, making the carboxyl groups on heparin reactive. This allows them to form covalent bonds with the phenolamine undercoat through an amide reaction, thus promoting the coating of heparin. The coating is firm and stable, and the reaction conditions are simple.

[0069] After step S2 is completed, according to the present invention, the medical material modified with anticoagulant is soaked in a metal salt solution. After the reaction, a medical material with an antibacterial and anticoagulant coating is obtained. The soaking temperature is 20–40°C, preferably 25–37°C; the soaking time is 0.1–30 h, preferably 0.1–10 h. In this step, the soaking is preferably carried out under conditions of pH 8–10 to promote the hydrolysis of the metal salt solution into metal oxides.

[0070] In this invention, the metal salt in the metal salt solution is any one or more of titanium, zinc, or tin. The titanium salt is selected from TiBALDH and / or tetrabutyl titanate, the zinc salt is selected from zinc acetate dihydrate and / or zinc nitrate, and the tin salt is selected from tin chloride dihydrate and / or tin acetate. The corresponding volume percentage of the metal salt solution is 2-6% (v / v), preferably 3-5% (v / v).

[0071] It should be noted that single metal compounds are difficult to dissolve in solvents during the coating process, posing a certain degree of difficulty in dispersion and often resulting in uneven dispersion and unstable bonding. Therefore, this invention uses a salt solution of the metal compound, which can promote its dispersion and make it easier to bind with anticoagulants, thereby achieving an antibacterial effect under photocatalysis. Moreover, the method is simple and can easily produce a uniform and stable coating.

[0072] Taking a titanate solution as an example, in some embodiments of the present invention, the reaction process of the metal salt solution includes the following steps:

[0073] Step 1: Dissolve titanium di(2-hydroxypropionic acid) diammonium hydroxide (TiBALDH) in ammonia water to form titanium dioxide sol gel;

[0074] Step 2: Add the anticoagulant-modified medical material to the titanium dioxide sol gel for 18-30 hours, remove it, shake and wash for 10-15 hours, and then dry it.

[0075] Wherein, the volume ratio of TiBALDH to ammonia is (0.02-0.06):1, (0.02-0.04):1, more preferably 0.02:1; and / or, the concentration of ammonia is 0.1-2 mol / L, preferably 0.1-1 mol / L, more preferably 0.1 mol / L; and / or, the mass concentration of TiBALDH is 20-60 wt% (w / v), preferably 50 wt% (w / v).

[0076] In other embodiments of the present invention, the reaction process of the metal salt solution includes the following steps:

[0077] Titanic acid was dissolved in hydrochloric acid solution to form a titanium dioxide gel. Then, anticoagulant-modified medical materials were added to the titanium dioxide sol-gel for 18–30 hours, removed, shaken and washed for 10–15 hours, and then dried.

[0078] The dissolution temperature is 50–100℃, preferably 80℃; the dissolution time is 0.5–2h, preferably 1h; and the hydrochloric acid concentration is 0.01–0.1mol / L, preferably 0.05–0.1mol / L, more preferably 1mol / L.

[0079] In the aforementioned titanium dioxide coating process, titanate (such as TiBALDH) is hydrolyzed into titanium dioxide sol-gel, which then forms metal-carboxyl coordination bonds with activated anticoagulant substances (such as heparin carboxyl groups), thus achieving titanium dioxide grafting. Simultaneously, the titanium dioxide coating can regulate the concentration of anticoagulant substances (such as heparin), thereby promoting endothelial cell proliferation, facilitating endothelialization of the coating material, improving biocompatibility, and meeting the surface modification requirements for blood contact materials.

[0080] It should be noted that when titanium dioxide is exposed to ultraviolet light, it can generate ROS, which has a significant killing effect on both Gram-negative and Gram-positive bacteria. In addition, titanium dioxide has good hydrophilic lubrication properties, which can effectively prevent bacterial adhesion.

[0081] In summary, in some embodiments of the present invention, the method for preparing an antibacterial and anti-coating coating includes the following steps:

[0082] Step 1: Prepare a solution containing catechol compounds and polyamine compounds, immerse the medical material in the solution containing catechol compounds and polyamine compounds to form a base layer coating, and obtain the medical material with the base layer coating after cleaning;

[0083] Step 2: Prepare an anticoagulant solution, immerse the medical material obtained in Step 1 in the anticoagulant solution, adjust the pH to 4-6, immerse for 0.1-10 hours, and then wash to obtain the anticoagulant-modified medical material.

[0084] Step 3: Immerse the medical material obtained in Step 2 in a metal salt solution, adjust the pH to 8-10, immerse for 0.1-10 hours, remove, clean and dry to obtain a medical material with an antibacterial and anticoagulant coating.

[0085] In some embodiments of the present invention, the catechol compound is dopamine hydrochloride; the polyamine compound is polyethyleneimine; the anticoagulant is heparin; and the metal salt solution is a titanate solution.

[0086] Based on this technical solution, compared with the prior art, the method for preparing a multifunctional coating with antibacterial and anticoagulant capabilities provided by this invention involves the substrate material (i.e., medical material) undergoing a Schiff base reaction with polyethyleneimine and dopamine under weakly alkaline conditions. This accelerates the co-deposition of dopamine and polyethyleneimine, forming a polyphenol-amine underlayer coating. Then, heparin with activated carboxyl groups undergoes amidation and charge interaction with the residual amino groups, thereby fixing the heparin. Finally, titanium dioxide is grafted onto the surface through the coordination of carboxyl groups with metal ions, resulting in a multifunctional coating composition. This simple and efficient reaction process produces a stable and robust coating composition, providing a new approach for the preparation of multifunctional coatings.

[0087] The present invention also provides a medical material comprising a medical material matrix and a coating formed on the surface of the medical material matrix, wherein the coating is the aforementioned antibacterial and anticoagulant coating.

[0088] In some embodiments of the present invention, the medical material matrix includes a blood contact material matrix; the material of the medical material matrix is ​​selected from metallic materials, inorganic non-metallic matrix materials, or polymer materials (such as thermoplastic polyurethane, polypropylene, etc.). The thickness of the antibacterial and anticoagulant coating is 20 μm.

[0089] To further illustrate the present invention, the following embodiments provide a detailed description. The thermoplastic polyurethane used in the following embodiments of the present invention was purchased from Covestro Bayer, 285A, and the polypropylene was purchased from Formosa Plastics Industrial (Ningbo) Co., Ltd., 5600XT.

[0090] Example 1

[0091] (1) Substrate preparation: The flat vulcanizing machine was preheated to 130°C for the upper plate and 140°C for the lower plate. 25g of thermoplastic polyurethane granules were weighed and placed into the mold. The mold was placed into the flat vulcanizing machine and compressed at 7MPa for 7min. Then the flat vulcanizing machine was adjusted to repeatedly squeeze the mold to remove air from the thermoplastic polyurethane. After compression at 10MPa for 5min, it was taken out and placed into the cold press. It was cooled and shaped at room temperature at 10MPa for 10min. The mold was taken out to obtain the thermoplastic polyurethane substrate.

[0092] (2) Substrate cleaning: Place the thermoplastic polyurethane substrate in a mixed solution of ethanol:water = 1:1 (volume ratio), ultrasonically clean for 5 minutes, remove and dry at room temperature for later use.

[0093] (3) Preparation of Tris buffer solution: Dissolve 6.057g of tris(hydroxymethyl)aminomethane in 1L of deionized water, and adjust the pH to 8.5 using 1mol / L hydrochloric acid solution and 1mol / L sodium hydroxide solution;

[0094] (4) Preparation of phenolic amine undercoat: 0.11 g PEI (Mw = 600) was dissolved in 50 mL Tris buffer. After the PEI was completely dissolved, 0.1 g DA was added to obtain a mixed deposition solution of DA and PEI. The thermoplastic polyurethane substrate was immersed in the mixed deposition solution and reacted at 37 °C for 12 h to complete co-deposition. After washing with shaking in ultrapure water for 12 h, it was dried in a vacuum oven at 25 °C to constant weight to obtain a thermoplastic polyurethane substrate coated with phenolic amine undercoat.

[0095] (5) Grafting of heparin: 0.1917g EDC and 0.2877g NHS were dissolved in 50mL of 0.1mol / L MES buffer solution, and then 0.05g sodium heparin was added. The reaction was carried out at room temperature for 0.5h to fully activate the carboxyl groups of heparin. Then, a thermoplastic polyurethane substrate coated with a phenolic amine undercoat was added and the reaction was carried out in a constant temperature shaker at 37℃ for 24h. The substrate was then removed and washed with ultrapure water for 12h. It was then dried in a vacuum oven at 25℃ to constant weight to obtain a heparinized thermoplastic polyurethane substrate.

[0096] (6) Grafting of titanium dioxide: 48 μL of TiBALDH was dissolved in 1 mL of 0.01 mol / L ammonia solution and added to a heparinized thermoplastic polyurethane substrate. The substrate was shaken at 37 °C for 24 h, then removed and placed in ultrapure water for shaking and washing for 12 h. The substrate was then dried in a vacuum oven at 25 °C to constant weight to obtain a thermoplastic polyurethane substrate with a dopamine / polyethyleneimine-heparin-titanium dioxide coating.

[0097] The dopamine / polyethyleneimine-heparin-titanium dioxide coating utilizes polyethyleneimine to participate in the oxidative self-polymerization of dopamine, thereby promoting the deposition of dopamine and constructing a phenolic amine underlayer coating. Then, through an amide reaction, heparin is covalently grafted, and finally, through carboxyl coordination of titanium dioxide, a multifunctional coating with antibacterial and anticoagulant properties is constructed on the surface of a thermoplastic polyurethane substrate, which can be applied to blood contact devices.

[0098] Compared to existing heparin coatings, this multifunctional coating exhibits a more significant anticoagulant effect due to the enhanced hydrophilicity of titanium dioxide. It significantly reduces platelet adhesion, activation, and aggregation, and lowers the risk of local thrombosis after use in the fabrication of blood-contact devices. Furthermore, because heparin is covalently bound to the phenolamine undercoat, it does not enter the body during use and therefore does not affect the patient's systemic coagulation function, resulting in high safety. Simultaneously, the titanium dioxide modification of the coating enables photocatalysis under ultraviolet light, generating ROS to destroy bacterial membranes and kill bacteria, demonstrating safety, efficiency, and potential for clinical application.

[0099] Example 2

[0100] (1) Substrate preparation: The flat vulcanizing machine is preheated to 130°C for the upper plate and 140°C for the lower plate. 25g of polypropylene granules are weighed and placed into the mold. The mold is placed into the flat vulcanizing machine and compressed at 7MPa for 7min. Then the flat vulcanizing machine is adjusted to repeatedly squeeze the mold to remove air from the thermoplastic polypropylene. After compression at 10MPa for 5min, it is taken out and placed in the cold press. It is then cooled and shaped at 25°C at 10MPa for 10min to obtain the polypropylene substrate.

[0101] (2) Substrate cleaning: Place the polypropylene substrate in acetone solution and ultrasonically clean for 5 minutes. After removing it, dry it at room temperature for later use.

[0102] (3) The preparation of the Tris buffer solution is the same as step (3) in Example 1;

[0103] (4) Preparation of phenolamine undercoat: 0.11 g PEI (Mw = 600) was dissolved in 50 mL Tris buffer. After the PEI was completely dissolved, 0.1 g norepinephrine was added to obtain a mixed deposition solution of norepinephrine and PEI. The polypropylene substrate was immersed in the mixed deposition solution and reacted at 37 °C for 12 h to complete the co-deposition. Then it was placed in ultrapure water and shaken for 12 h. Finally, it was dried in a vacuum oven at 25 °C to constant weight to obtain a polypropylene substrate coated with phenolamine undercoat.

[0104] (5) Grafting of heparin is the same as step (5) in Example 1;

[0105] (6) Grafting of zinc oxide: At room temperature, 0.5% low molecular weight polyethylene glycol (Mw = 300) was added to 20 mL of 0.025 mol / L NaOH, followed by dropwise addition of 15 mL of 1 mg / mL zinc acetate dihydrate solution. Heparinized thermoplastic polypropylene substrate was then added and stirred for 3 h. The substrate was then removed and washed with ultrapure water for 12 h, and dried to constant weight in a vacuum oven at 25 °C.

[0106] Example 3

[0107] (1) The substrate preparation is the same as step (1) in Example 1;

[0108] (2) The substrate cleaning is the same as step (2) in Example 1;

[0109] (3) The preparation of the Tris buffer solution is the same as step (3) in Example 1;

[0110] (4) Preparation of phenolamine undercoat: 0.11 g PEI (Mw = 600) was dissolved in 50 mL Tris buffer. After the PEI was completely dissolved, 0.1 g phenylalanine was added to obtain a mixed deposition solution of phenylalanine and PEI. The thermoplastic polyurethane substrate was immersed in the mixed deposition solution and reacted at 37 °C for 12 h to complete co-deposition. Then it was placed in ultrapure water and shaken for 12 h. Finally, it was dried in a vacuum oven at 25 °C to constant weight to obtain a thermoplastic polyurethane substrate coated with phenolamine undercoat.

[0111] (5) Grafting of heparin is the same as step (5) in Example 1;

[0112] (6) Grafting of tin dioxide: 0.407 g of tin chloride dihydrate was dissolved in 5 mL of 2 mol / L HCl solution to obtain a precursor sol. Then, heparinized thermoplastic polyurethane substrate was added, and the reaction was carried out at 75 °C with shaking for 18 h. After that, it was taken out and placed in ultrapure water for shaking and washing for 12 h, and then dried in a vacuum oven at 25 °C to constant weight.

[0113] Example 4

[0114] (1) The substrate preparation is the same as step (1) in Example 1;

[0115] (2) The substrate cleaning is the same as step (2) in Example 1;

[0116] (3) The preparation of the Tris buffer solution is the same as step (3) in Example 1;

[0117] (4) Preparation of phenolic amine undercoat: 0.11 g PEI (Mw = 600) was dissolved in 50 mL Tris buffer. After the PEI was completely dissolved, 0.1 g phenylalanine was added to obtain a mixed deposition solution of phenylalanine and PEI. The thermoplastic polyurethane substrate was immersed in the mixed deposition solution and reacted at 37 °C for 12 h to complete co-deposition. Then it was placed in ultrapure water and shaken for 12 h. Finally, it was dried in a vacuum oven at 25 °C to constant weight to obtain a thermoplastic polyurethane substrate coated with phenolic amine undercoat.

[0118] (5) Grafting of tissue plasminogen: 0.1917g EDC and 0.2877g NHS were dissolved in 50mL of 0.1mol / L MES buffer solution, and 0.05g of recombinant tissue plasminogen activator was added. The mixture was then reacted at room temperature for 0.5h to fully activate the carboxyl group of heparin. A thermoplastic polyurethane substrate coated with an amide undercoat was then added and the mixture was shaken in a constant temperature shaker at 37℃ for 24h. The mixture was then removed and washed with ultrapure water for 12h and dried in a vacuum oven at 25℃ to constant weight.

[0119] (6) The grafting of titanium dioxide is the same as step (6) in Example 1.

[0120] Example 5

[0121] In this embodiment, steps (1), (2), (3), (4), and (5) are the same as in embodiment 1, and step (6) is the same as in embodiment 2.

[0122] Example 6

[0123] In this embodiment, steps (1), (2), (3), (4), and (5) are the same as in embodiment 1, and step (6) is the same as in embodiment 3.

[0124] Example 7

[0125] In this embodiment, steps (1), (2), (3), (5), and (6) are the same as in embodiment 1, and step (4) is the same as in embodiment 2.

[0126] Example 8

[0127] In this embodiment, steps (1), (2), (3), (5), and (6) are the same as in embodiment 1, and step (4) is the same as in embodiment 3.

[0128] Comparative Example 1 (without heparin or titanium dioxide modification)

[0129] The difference between this comparative example and Example 1 is that heparin and titanium dioxide grafting is not performed, that is, steps (5) and (6) are not performed, and dopamine and polyethyleneimine are directly fixed on the surface of the thermoplastic polyurethane substrate by co-deposition.

[0130] Comparative Example 2 (without titanium dioxide modification)

[0131] The difference between this comparative example and Example 1 is that titanium dioxide grafting is not performed, that is, step (6) is not performed, which utilizes the amide reaction between the phenolic amine undercoat and heparin to graft heparin onto the surface of the thermoplastic polyurethane substrate.

[0132] Comparative Example 3 (without heparin modification)

[0133] The difference between this comparative example and Example 1 is that, instead of modifying with heparin, titanium dioxide is directly grafted onto the surface of the thermoplastic polyurethane substrate by coordinating dopamine catechol with titanium dioxide on the phenolamine undercoat.

[0134] Comparative Example 4

[0135] A thermoplastic polyurethane substrate obtained in step (1) of Embodiment 1 is provided.

[0136] Comparative Example 5 (using nano-titanium dioxide directly)

[0137] (1) The substrate preparation is the same as step (1) in Example 1;

[0138] (2) The substrate cleaning is the same as step (2) in Example 1;

[0139] (3) The preparation of the Tris buffer solution is the same as step (3) in Example 1;

[0140] (4) Preparation of phenolamine undercoat: 0.11 g of polyacrylamide was dissolved in 50 mL of Tris buffer. After complete dissolution, 0.1 g of dopamine was added to obtain a mixed deposition solution of dopamine and PEI. The polyurethane substrate was immersed in the mixed deposition solution and reacted at 37 °C for 12 h to complete co-deposition. Then it was placed in ultrapure water and shaken for 12 h. Finally, it was dried in a vacuum oven at 25 °C to constant weight to obtain a thermoplastic polyurethane substrate coated with phenolamine undercoat.

[0141] (5) Grafting of heparin is the same as step (5) in Example 1;

[0142] (6) Grafting of titanium dioxide: 0.5g of nano titanium dioxide was added to 10mL of deionized water and ultrasonically dispersed for 10min. Heparinized thermoplastic polyurethane substrate was added and the mixture was kept at 37℃ and shaken for 24h. Then it was taken out and placed in ultrapure water and shaken and washed for 12h. Finally, it was dried in a vacuum oven at 25℃ until constant weight.

[0143] Performance testing

[0144] (1) Hemolysis rate test

[0145] The testing method is as follows:

[0146] Fresh whole blood was centrifuged at 1500 rpm for 15 min at 4°C, the supernatant was discarded, and the lower layer was centrifuged in physiological saline at 1500 rpm for 3 min to wash red blood cells until the supernatant was clear. Red blood cells were diluted with physiological saline to a volume fraction of 4%. The samples (products obtained from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4) were cut into 1×1 cm pieces and incubated in 500 μL of red blood cell suspension and an equal volume of physiological saline at 37°C for 1 h. The incubated red blood cells were then collected and centrifuged at 2000 rpm for 3 min, the supernatant was extracted, and the absorbance was measured at 540 nm. A negative control group was prepared by adding 500 μL of red blood cell suspension and an equal volume of physiological saline, and a positive control group was prepared by adding 500 μL of red blood cell suspension and an equal volume of deionized water. No samples were added to either control group.

[0147] Finally, use the following formula to calculate:

[0148] Hemolysis rate (%) = (OD) 实验组 -OD 阴性对照组 ) / (OD 阳性对照组 -OD 阴性对照组 )×100%.

[0149] The comparison chart of hemolysis rates of the products obtained from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4 is shown below. Figure 1 As shown, Figure 1 In the middle, from left to right, the six tubes correspond to Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 4, Positive Control Group, and Negative Control Group, respectively.

[0150] (2) Resistance to protein adhesion

[0151] When blood-contacting materials come into contact with vascular endothelial cells, the coagulation cascade and complement system are often activated. In this process, the adhesion of various proteins is considered the first step in the coagulation cascade reaction. The ability to resist protein adhesion was assessed by measuring the levels of fibrinogen (Fib) and bovine serum albumin (BSA) adsorbed on the sample surface using the BCA method.

[0152] The test results are shown in Table 1 and Figure 2 (As shown in the comparison chart of the anti-protein adhesion amount of the products obtained from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4).

[0153] (3) Antiplatelet adhesion ability

[0154] Platelet adhesion, activation, and diffusion are the main causes of thrombus formation, and the platelet adhesion ability of blood-contact materials is an important indicator for evaluating their anticoagulant ability. In this invention, PRP (platelet-rich plasma) was incubated on samples (products obtained from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4) for 2 hours, then fixed with paraformaldehyde, followed by gradient dehydration with ethanol, and the amount of platelets adhering to the sample surface was observed using scanning electron microscopy.

[0155] Comparative electron micrographs of platelet adhesion of the products obtained in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4 are shown below. Figure 3 As shown.

[0156] Depend on Figure 3 It is evident that the product obtained in Example 1 exhibits excellent anti-platelet adhesion ability. In Example 1, the grafting of titanium dioxide enhances the hydrophilicity of the substrate material (i.e., the medical material) surface. Due to the high affinity of the surface for water, upon contact with water, the coating surface directly connects with water molecules through hydrogen bonds, thereby dispersing water molecules on the surface and forming a hydrated layer. When BSA and Fib come into contact with the coating surface, the presence of the hydrated layer prevents platelet adhesion, effectively inhibiting the further progression of the coagulation cascade and exerting an anticoagulant effect. Furthermore, heparin can participate in intrinsic coagulation, inhibiting coagulation factor Xa and thrombin, thereby inhibiting platelet activation and further enhancing anticoagulant capacity.

[0157] (4) Thrombin time test

[0158] The obtained products were subjected to activated partial thromboplastin time (APTT) and thrombin time (TT) tests, specifically using an APTT kit.

[0159] The test results are shown in Table 1 and Figure 4 (Comparison diagrams of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4 are shown).

[0160] (5) Antibacterial rate test

[0161] Infection is a major complication during the use of all implantable interventional materials. This invention conducted 12 control experiments using products obtained from Examples 1-9, Comparative Examples 1, 2, and 4, and included a blank group (i.e., containing only bacterial suspension). The antibacterial rate was obtained using the plate coating method, specifically:

[0162] 8×10 7 CFU / mL bacterial suspension (Staphylococcus aureus or Escherichia coli) was co-cultured with materials from different groups, and then incubated in agar medium at 37°C for 24 h. The number of colonies was observed, and the inhibition rate was calculated by using the difference in the number of colonies between the blank group and the experimental group.

[0163] The formula for calculating the inhibition rate is: (number of colonies in the blank group - number of colonies in the experimental group) / number of colonies in the blank group);

[0164] Test results are as follows Figure 5 As shown in the comparison chart of antibacterial rates of Example 1, Comparative Example 1, and Comparative Example 2, and Table 1, it can be seen that the antibacterial ability of the product obtained in Example 1 is better than that of the other control groups, and it has better application potential.

[0165] (6) Stability test

[0166] The products obtained from Examples 1-9, Comparative Examples 1, 2, and 4 were immersed in PBS for 7 days, and the elemental composition of the coating was analyzed to evaluate its stability.

[0167] The specific evaluation criteria are as follows: observe whether the element content decreases. For example, in a titanium dioxide coating, if the titanium content decreases, it indicates that the coating was damaged during the immersion process, proving that it is not stable enough. Conversely, if the content does not decrease, it indicates that the coating is stable.

[0168] The test results are shown in Table 1.

[0169] Depend on Figures 1-6 It can be seen that Example 1 has good absorption capacity in the ultraviolet light region, can absorb ultraviolet light and exhibit photocatalytic properties, and has less protein adhesion, higher antibacterial rate and longer coagulation time, demonstrating good antibacterial and anticoagulant ability.

[0170] (7) Visible light absorption peak test

[0171] Visible light absorption peak tests were performed on the products obtained in Example 1 and Comparative Example 4, and the results are as follows: Figure 6 As shown.

[0172] (8) Cytotoxicity

[0173] Natural endothelial cells are considered the ideal surface for blood-contact materials, and blood-contact devices with rapid endothelialization have immense potential in clinical applications. Human umbilical vein endothelial cells (HUVECs) were used to evaluate the rapid endothelialization ability of sample surfaces. After observing the growth status of HUVECs under a microscope, the culture medium in the culture dish was discarded, the cells were washed twice with PBS, and 1 mL of trypsin solution containing EDTA was added. The cells were then incubated for 3 min, and after removal, an appropriate amount of culture medium was added to terminate the digestion. The cells were centrifuged at 1000 rpm for 5 min, the supernatant was discarded, and culture medium was added and the cells were mixed by pipetting. The culture medium containing the cells was then added to 6-well plates, so that each well contained approximately 5 × 10⁶ cells. 3Cells were seeded and plated. Samples were cut into 1×1 cm pieces and placed in wells for 24h and 48h incubation. Cell viability was assessed using the CCK-8 assay.

[0174] Cell viability data of the products obtained from Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4 are shown in the figure below. Figure 7 As shown.

[0175] It can be seen that the cell viability of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 4 is greater than 100%, indicating that it is harmless to cells.

[0176] Table 1

[0177]

[0178]

[0179] As shown in Table 1, compared with Examples 5-7, Example 1 exhibits less protein adhesion and a longer thrombin time, demonstrating better anticoagulation ability. Although the antibacterial rate has decreased, it still shows a relatively good bactericidal effect overall. Compared with Example 9, all performance aspects have been enhanced. In summary, Example 1 has superior antibacterial and anticoagulant capabilities.

[0180] In Examples 3 and 6, the catechol compounds used were phenylalanine (L-DOPA), which, compared to dopamine hydrochloride, has an additional carboxyl group, resulting in greater steric hindrance and poorer self-polymerization efficiency. Consequently, the coating obtained under the same time (4h) exhibits poorer stability.

[0181] Comparative Example 4 is a blank thermoplastic polyurethane substrate without the modification of anticoagulant and antibacterial substances. It can be seen that without the modification of titanium dioxide and heparin, it exhibits poor performance.

[0182] Comparative Example 1, based on Comparative Example 4, has a phenolic amine intermediate layer. Due to its improved hydrophilicity and the charge carried by some of the polyethyleneimine, it has enhanced some of the resistance to protein adhesion and antibacterial ability, but it is still insufficient and does not have good anticoagulant ability (thrombin time). After further modification with heparin (Comparative Example 2), its anticoagulant ability is improved, but due to the charge balance with the charge carried by the phenolic amine intermediate layer, the antibacterial rate decreases.

[0183] Comparative Example 5 directly used nano-titanium dioxide powder instead of hydrolyzing it with a metal salt solution, resulting in insufficient uniform dispersion, poor coating effect, and a significant decrease in antibacterial rate.

[0184] In summary, the antibacterial and anticoagulant coating provided by this invention, wherein heparin provides excellent anticoagulant ability, titanium dioxide provides excellent bactericidal performance, and further enhances hydrophilicity, thus improving the overall antibacterial and anticoagulant ability. In contrast, Comparative Example 2 does not contain titanium dioxide and has insufficient bactericidal performance, Comparative Example 1 does not contain titanium dioxide and heparin and has insufficient antibacterial and anticoagulant abilities, and Comparative Example 4 does not have any modification and has insufficient hydrophilicity, antibacterial and anticoagulant abilities.

[0185] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An antibacterial and anti-condensation coating, characterized in that, Formed from an antibacterial and anti-coating coating composition; The antibacterial and anticoagulant coating composition comprises catechol compounds, polyamine compounds, anticoagulant substances, and metal salts; the mass ratio of the catechol compounds, polyamine compounds, anticoagulant substances, and metal salts is (35~45):(35~45):(5~12):(10~20); The catechol compounds are selected from one or more of norepinephrine, dopamine, or dopamine hydrochloride. The polyamine compound is selected from polyethyleneimine and / or polyacrylamide; The anticoagulant includes heparin and / or tissue plasminogen; The metal salt includes any one or more of titanium, zinc, or tin; the titanium metal salt is selected from TiBALDH and / or tetrabutyl titanate, the zinc metal salt is selected from zinc acetate dihydrate and / or zinc nitrate, and the tin metal salt is selected from tin chloride dihydrate and / or tin acetate. The method for preparing the antibacterial and anticoating coating includes the following steps: S1: Immerse the medical material in a solution containing catechol compounds and polyamine compounds. After the reaction, a medical material coated with a phenolamine undercoat is obtained. S2: Medical materials coated with a phenolamine undercoat are soaked in an anticoagulant solution and reacted to obtain anticoagulant-modified medical materials. S3: Medical materials modified with anticoagulant substances are soaked in metal salt solution. After the reaction, medical materials with antibacterial and anticoagulant coatings are obtained. The soaking described in step S2 is carried out under conditions of pH 4 to 6; In step S2, the anticoagulant in the anticoagulant solution undergoes activation treatment; The soaking described in step S3 is carried out under conditions of pH 8 to 10.

2. A method for preparing an antibacterial and anticoating coating as described in claim 1, characterized in that, Includes the following steps: S1: Immerse the medical material in a solution containing catechol compounds and polyamine compounds. After the reaction, a medical material coated with a phenolamine undercoat is obtained. S2: Medical materials coated with a phenolamine undercoat are soaked in an anticoagulant solution and reacted to obtain anticoagulant-modified medical materials. S3: Medical materials modified with anticoagulant substances are soaked in metal salt solution. After the reaction, medical materials with antibacterial and anticoagulant coatings are obtained. The soaking described in step S2 is carried out under conditions of pH 4 to 6; In step S2, the anticoagulant in the anticoagulant solution undergoes activation treatment; The soaking described in step S3 is carried out under conditions of pH 8 to 10.

3. The preparation method according to claim 2, characterized in that, The soaking temperature in steps S1, S2, and S3 is 20~40℃ and the soaking time is 0.1~30 h.

4. A medical material, characterized in that, Includes a medical material matrix and a coating formed on the surface of the medical material matrix; The coating is the antibacterial and anticoagulant coating as described in claim 1 or the antibacterial and anticoagulant coating obtained by the preparation method according to claim 2 or 3.

5. The medical material according to claim 4, characterized in that, The medical material matrix includes blood contact material matrices; The material of the medical material matrix is ​​selected from metallic materials, inorganic non-metallic matrix materials, or polymer materials.

6. The medical material according to claim 4 or 5, characterized in that, The thickness of the antibacterial and anticoating coating is 10~25 μm.

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