An anticoagulant material based on enzyme-like catalytic reaction

Abstract

The application discloses an anticoagulant material, which is based on enzyme-like catalytic reaction to produce nitric oxide, dinitrogen trioxide, nitrous acid and / or other similar substances with anticoagulant function, so as to improve the anticoagulant effect of a blood-contacting medical device or medical material surface. The application also discloses related medical devices or medical materials, and preparation methods and uses thereof. The anticoagulant coating of the blood-contacting medical device surface provided by the application based on enzyme-like catalytic reaction to produce nitric oxide or similar substances has excellent service effect, and can solve the problems of poor biocompatibility, easy blood coagulation on the surface, and the need to cooperate with anticoagulant drugs with large side effects of the blood-contacting medical device for a long time.

Description

Technical Field

[0001] This invention relates to biomedical engineering functional materials, particularly to the field of medical materials with anticoagulant effects, and specifically to an anticoagulant material based on an enzyme-like catalytic reaction. Background Technology

[0002] With the development of science and technology, the temporary or permanent implantation of medical devices to treat various medical conditions has become widespread. In particular, medical implants applied to the vascular system, esophagus, trachea, colon, biliary tract, and urinary tract (such as cardiovascular stents, heart valves, artificial blood vessels, prostate stents, biliary stents, and intra-body drug delivery catheters) have greatly alleviated the suffering of humans and animals, improving survival rates and quality of life. When implanting medical devices in humans or animals, support devices are needed, such as balloon catheters and cannulas; for external detoxification, filtration or purification devices are required, such as blood filters and blood purification devices. These medical devices generally achieve their intended purpose and treat diseases effectively.

[0003] However, these medical devices still present some challenges in practical use. For example, when introduced and passed through a patient's vascular system, they may cause mechanical damage to the vessel walls. Damage can lead to platelet and fibrin aggregation and adhesion, resulting in blood clots. Clot formation or thrombosis can cause narrowing of the vessel at the site of damage. Furthermore, if medical devices (such as bare-metal stents) remain in the patient's body for an extended period, smooth muscle cells often migrate to their surface, leading to neointimal hyperplasia and restenosis. This ultimately increases the risk of various complications such as heart attacks, pulmonary embolisms, and strokes. To mitigate these adverse effects, biocompatible coatings can be used to coat medical devices. These coatings can incorporate bioactive materials. When the disease is confined to a specific site (e.g., but not limited to blood vessels), such surface-modified medical devices can be used to directly apply bioactive materials to the specific site of the body for treatment. Theoretically, this local administration is more effective than systemic administration. However, in practice, it has been found that the drug release rate and duration of action significantly influence treatment efficacy. Therefore, improving the biocompatibility of these medical devices is a highly challenging and urgent problem to be solved, and the development of surface modification / coating technologies for medical devices with excellent anticoagulant function is imminent.

[0004] Common methods for forming surface coatings on medical devices include spraying, spin coating, immersion coating, static evaporation, vapor deposition, and electrospinning, each with its own characteristics. In recent years, the development of 3D printing technology has also driven the development of new medical devices, allowing for the direct acquisition of desired surfaces.

[0005] Currently, many commonly used medical devices are made of metallic materials. For example, nickel-titanium alloys are widely used due to their excellent shape memory properties; however, their positively charged surface and high free energy can induce thrombus formation. While heparinization of the alloy surface can improve its biocompatibility, it also introduces other problems, such as rapid inactivation of heparin in the physiological environment and reduced anticoagulant function due to covalent bonding. Therefore, recent research on surface modification of metallic medical devices has mainly focused on constructing surface coatings, aiming to improve the biocompatibility of metallic devices by designing surface coatings with excellent anticoagulant properties.

[0006] Surface coatings are mainly constructed in two categories: loaded coatings and catalytic coatings. Loaded coatings rely on direct chemical and / or physical modifications to the surface or the loading of exogenous anticoagulants, with drug-eluting coatings being the most promising. Drug-eluting surface coatings load exogenous anticoagulants onto a polymer layer of a certain thickness grown on the metal surface. After the intervention of the metal device, the anticoagulant in the surface coating is gradually released, exerting an anticoagulant function, thereby reducing thrombus formation, inhibiting neointimal hyperplasia, and lowering the incidence of restenosis. However, drug-eluting coatings still have some drawbacks. For example, the loading capacity of exogenous anticoagulants in coatings is very limited, and the release rate cannot be effectively controlled, making it difficult to meet the requirements of some medical devices that need long-term service. Many polymer coatings release monomer products during degradation, which can easily cause excessive local acidity, leading to local inflammation and subacute thrombosis. Released anticoagulants can inhibit endothelial cell migration and proliferation, delaying the vascular reendothelial repair process. After implantation of drug-eluting coated devices such as vascular stents, patients still need to take antiplatelet drugs such as aspirin and thienopyridines for a long period. Therefore, loaded coatings still cannot fully meet actual clinical requirements. Catalytic coatings, as an emerging type of medical device surface coating, do not rely on exogenous anticoagulants and have excellent long-term service performance, showing great application potential and attracting widespread attention from researchers. Currently, surface-constructed catalytic coatings mainly achieve the anticoagulant function of stent coatings by catalyzing the production of NO from endogenous nitric oxide (NO) prodrugs. Nitric oxide synthase (eNOS) in human vascular endothelial cells can catalyze the oxidation of endogenous arginine to produce NO. NO released onto the inner surface of blood vessels has a strong antiplatelet effect, thereby inhibiting coagulation and ensuring smooth blood flow. Inspired by this, researchers have designed a series of catalytic coatings that can catalyze the production of NO from endogenous prodrugs, applying them to the surface modification of vascular stents to improve the anticoagulant effect and long-term service performance of metallic vascular stents. For example, Yang et al. reported a functionalized coating modified with 3,3'-diselenodipropionic acid (SeDPA) (Zhilu Yang et al., Nitric oxide producing coating mimicking endothelium function for multifunctional vascular stents. Biomaterials. 2015; 63:80-92.). SeDPA has catalytic activity similar to glutathione peroxidase, catalyzing the decomposition of nitrosothiols (RSNO) to produce NO in the presence of glutathione. The released NO can inhibit platelet activation and aggregation, promote endothelial cell proliferation, inhibit smooth muscle cell proliferation, and promote vasodilation, exhibiting excellent anticoagulant function. However, all of the endogenous catalytic coatings reported so far have some problems that urgently need to be solved.For example, the catalysts supported on the surface of catalytic coatings are mostly unstable small-molecule compounds, whose catalytic activity is easily reduced or even deactivated due to structural changes; these catalysts are mostly selenium- or copper-containing compounds, which easily generate toxic free radicals; the content of RSNO in blood is low, and RSNO molecules are unstable and easily decomposed, resulting in insufficient RSNO supply and low NO production. Therefore, improving the stability of catalysts supported in catalytic coatings and selecting stable and sufficient endogenous or exogenous NO prodrugs are important challenges for the further development of catalytic anticoagulant coatings.

[0007] In recent years, biomimetic catalysis based on enzyme-like materials has attracted increasing attention. Enzyme-like materials possess catalytic activity similar to natural enzymes, while also exhibiting the unique physicochemical properties of artificial materials. They exhibit good stability, can undergo diverse surface functionalization modifications, can be mass-produced, and have low production costs. Therefore, enzyme-like materials are a good alternative to natural enzymes. If an enzyme-like material with natural eNOS catalytic function can be designed and loaded onto the surface of blood-contact medical devices or generated in situ during the molding process, utilizing sufficient and stable endogenous or exogenous substrates in blood to generate NO or similar compounds, then the current problems faced by surface coatings of catalytic blood-contact medical devices can be solved, potentially leading to their widespread clinical application. Summary of the Invention

[0008] The purpose of this invention is to provide an anticoagulant material with excellent anticoagulant function. To achieve this purpose, this invention provides an anticoagulant material loaded with and / or containing and / or growing enzyme-like materials. These enzyme-like materials can catalyze endogenous substrates and / or exogenously supplemented substrates in the blood to continuously generate nitric oxide or similar substances at specific local sites. The nitric oxide or similar substances released on the surface of blood-contact medical devices or medical materials can inhibit platelet adhesion and activation, thus achieving an anticoagulant effect.

[0009] In one embodiment, the anticoagulant material is loaded with and / or contains and / or has grown enzyme-like materials on the entirety, part or surface of a base material capable of being used for blood contact.

[0010] In one embodiment, the anticoagulant material is a coating or surface. Preferably, the surface is the surface of a medical device.

[0011] In one embodiment, the anticoagulant material is applied as a coating to the surface of the medical device.

[0012] In another embodiment, the anticoagulant material is used as one of the outer manufacturing materials of a medical device, and the surface of the resulting medical device contains the anticoagulant material.

[0013] In one embodiment, the effective anticoagulant molecule catalyzed by the enzyme-like material of the present invention is NO and / or its analogues. These small molecules can activate cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (GMP), upregulate the cyclization of adenosine and guanosine, and inhibit platelet adhesion and activation on blood-contact surfaces, thereby achieving an anticoagulant effect. Preferably, the anticoagulant material of the present invention achieves its anticoagulant function by catalyzing endogenous and / or exogenous substrates through loading and / or containing and / or growing enzyme-like materials to produce nitric oxide, nitrous oxide, nitrous acid, and / or other substances with anticoagulant functions; preferably, nitric oxide is produced.

[0014] In one embodiment, the substrate of the present invention is capable of producing NO and / or its analogues through a catalytic reaction, and can be an endogenous or exogenous substance. Endogenous substances are those already present in the human / animal body, including but not limited to nitrosothiols, arginine, nitrates, and nitrites. Exogenous substances are those supplemented into the human / animal body through injection, oral administration, or other means, including but not limited to guanidinoacetic acid, hydroxylamine, sodium nitroprusside, azides, metformin, hydroxyurea, nitroglycerin trinitrate, spermine, dioldiazepine, and nitrosamines. Preferably, the substrate of the present invention comprises one or more combinations of nitrosothiols, guanidinoacetic acid, hydroxylamine, sodium nitroprusside, arginine, azides, metformin, nitrates, nitrites, hydroxyurea, nitroglycerin trinitrate, spermine, dioldiazepine, and / or nitrosamines.

[0015] In one embodiment, the enzyme-like material is an enzyme-like material capable of mimicking peroxidase activity, oxidase-like activity, and / or nitrite reductase-like activity.

[0016] In one embodiment, the enzyme-like material is a carbon material (C) simultaneously doped with a metal element (M) and a nitrogen element (N) to have natural enzyme-like catalytic activity; the enzyme-like material is preferably MNC; preferably, M is a transition metal element; more preferably, M is selected from iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn), copper (Cu), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), iridium (Ir), titanium (Ti), vanadium (V), chromium (Cr), zinc (Zn), gold (Au), or a combination of one or more of the above elements.

[0017] In this invention, the catalytic reaction conditions for MNC mainly consider substrate concentration, pH, and temperature. The substrate concentration is 0-10 mmol / L, preferably the concentration under normal physiological conditions or the highest concentration allowed by pharmacokinetic analysis. The reaction pH is pH 0-pH 14, preferably pH 5-pH 8, and even more preferably pH 7.0-7.8.

[0018] In one embodiment, the base material comprises one or more of the following materials:

[0019] i) Metals; preferably stainless steel, tantalum, titanium, nickel-titanium alloys, gold, platinum, chromium-nickel-iron alloys, iridium, silver, tungsten and / or other biocompatible metals, and / or alloys of any of the above metals;

[0020] ii) Biocompatible polymers; preferably carbon fibers, cellulose acetate, cellulose nitrate, siloxanes, polyethylene terephthalate, polyurethane, polyamide, polyester, polyorthoester, polyanhydride, polyethersulfone, polycarbonate, polypropylene, high molecular weight polyethylene, polytetrafluoroethylene and / or other biocompatible polymers, and / or mixtures or copolymers thereof.

[0021] iii) Biodegradable polymers; preferably polylactic acid, polyglycolic acid, or copolymers of the above two materials, polyanhydride, polycaprolactone, polyhydroxybutyrate valerate, and / or other biodegradable polymers, and / or mixtures or copolymers thereof; and / or

[0022] iv) Biological agents; preferably proteins, extracellular matrix components, collagen, fibrin and / or other biological agents, and / or mixtures thereof.

[0023] In one embodiment, the coating or surface is a biodegradable polymer material coating or surface, a bio-inert polymer material coating or surface, a metal or alloy coating or surface, a carbon material coating or surface, a other non-metallic material coating or surface, or a coating or surface formed during the molding process.

[0024] In one embodiment, the material of the coating or surface comprises one or more of the following materials:

[0025] i) Polymers; preferably polycaprolactone (PCL), polylactic acid-glycolic acid copolymer (PLGA), polyvinylpyrrolidone (PVP), biodegradable polyurethane (PU), polyhydroxyalkanoate (PHA) and / or polylactic acid (PLA); and / or

[0026] ii) Biopolymers; preferably starch, cellulose, hyaluronic acid, collagen, albumin and / or gelatin.

[0027] In one embodiment, the anticoagulant material further comprises a bioactive material; the bioactive material is preferably a drug for adjunctive treatment or prevention of disease; preferably, the bioactive material comprises antitumor, anti-inflammatory, antiplatelet, anticoagulant, antithrombin, antibiotic, anti-allergic, and / or antioxidant substances; preferably, the antitumor substance comprises paclitaxel, methotrexate, and / or vincristine; preferably, the anti-inflammatory substance comprises aspirin and / or indomethacin; preferably, the antiplatelet substance comprises prostacyclin, clopidogrel, and / or prasugrel; preferably, the anticoagulant substance comprises dicumarol and / or warfarin; preferably, the antithrombin substance comprises heparin sodium and / or argatroban; preferably, the antibiotic comprises methicillin, cefazolin, roxithromycin, and / or azithromycin; preferably, the anti-allergic drug comprises diphenhydramine, promethazine, and / or chlorpheniramine; preferably, the antioxidant substance comprises vitamin C and / or vitamin E.

[0028] In one embodiment, the method for synthesizing the enzyme-like material is selected from at least one of the following methods: solvothermal method, high-temperature solid-phase method, co-precipitation method, and vapor deposition method.

[0029] In one embodiment, the enzyme-like material is loaded onto and / or contained in and / or grown in an anticoagulant material by at least one method selected from in situ growth, spraying, spin coating, impregnation, static evaporation, chemical bonding, electrospinning, and 3D printing.

[0030] Preferably, the method for synthesizing the enzyme-like material uses a solvent; the solvent is preferably compatible with the polymer and capable of dissolving the polymer liquid at the desired concentration; preferably, the solvent comprises at least one of dimethyl sulfoxide, chloroform, dichloroethane, acetone, water, xylene, methanol, ethanol, 1-propanol, tetrahydrofuran, dimethylformamide, dimethylacetamide, cyclohexanone, ethyl acetate, isopropanol and / or toluene.

[0031] The present invention also provides a medical device or medical material, wherein the medical device or medical material is loaded with and / or contains and / or has grown enzyme-like materials.

[0032] In one embodiment, the enzyme-like material is any of the enzyme-like materials described above in this invention.

[0033] In one embodiment, the medical device or medical material is loaded with and / or contains and / or has grown any of the anticoagulant materials described above in this invention.

[0034] In one embodiment, the enzyme-like material or the anticoagulant material constitutes the whole, part or surface of the medical device or medical material.

[0035] In one embodiment, the anticoagulant material is a coating or surface. Preferably, the surface is the surface of a medical device.

[0036] In one embodiment, the medical device or medical material is a cardiovascular stent, intravascular catheter, balloon catheter, pacing electrode, heart valve, artificial blood vessel, blood purification device, artificial joint, artificial organ, in vivo drug delivery catheter, urinary catheter, artificial arteriovenous catheter, ventricular assist device, heart or tissue repair material, prostate stent, biliary stent, or blood filter.

[0037] The present invention also provides a method for preparing a medical device or medical material, which involves loading an enzyme-like material onto and / or containing it in and / or growing it on the whole, part or surface of the medical device or medical material.

[0038] In one embodiment, the enzyme-like material is any of the enzyme-like materials described above in this invention.

[0039] In one embodiment, the preparation method includes the following steps: mixing the enzyme-like material with a material for forming a coating, and forming a film on the surface of a medical device or medical material; preferably, the material for forming the coating is a biocompatible material.

[0040] In one embodiment, the preparation method includes the following steps: mixing the enzyme-like material with a molding material, and directly molding the mixture using a molding technology to obtain the surface of a medical device or medical material; preferably, the molding technology is 3D printing, and the molding material is a 3D printing raw material.

[0041] In one embodiment, the preparation method includes the following steps: directly synthesizing the enzyme-like material on the surface of a medical device or medical material.

[0042] In one embodiment, the preparation method further includes the step of synthesizing the enzyme-like material; preferably, the enzyme-like material can be synthesized from a metal oxide and a carbon precursor; more preferably, the metal oxide is an iron oxide; even more preferably, the carbon precursor is guanine.

[0043] The present invention also provides a method for preparing an anticoagulant coating or surface on the surface of a medical device or medical material, which involves loading an enzyme-like material onto and / or containing it in and / or growing it on the surface of the medical device or medical material.

[0044] In one embodiment, the enzyme-like material is any of the enzyme-like materials described above in this invention.

[0045] In one embodiment, the method includes the following steps: mixing the enzyme-like material with a material for forming a coating, and forming a film on the surface of a medical device or medical material; preferably, the material for forming the coating is a biocompatible material.

[0046] In one embodiment, the method includes the following steps: mixing the enzyme-like material with a molding material, and directly molding the mixture using a molding technology to obtain the surface of a medical device or medical material; preferably, the molding technology is 3D printing, and the molding material is a 3D printing raw material.

[0047] In one embodiment, the method includes the step of directly synthesizing the enzyme-like material on the surface of a medical device or medical material.

[0048] In one embodiment, the method further includes the step of synthesizing the enzyme-like material; preferably, the enzyme-like material is synthesized from a metal oxide and a carbon precursor; more preferably, the metal oxide is an iron oxide; even more preferably, the carbon precursor is guanine.

[0049] The present invention also provides the use of enzyme-like materials in the preparation of anticoagulant materials, anticoagulant coatings or surfaces, or medical devices or medical materials.

[0050] In one embodiment, the enzyme-like material is any of the enzyme-like materials described above in this invention.

[0051] The present invention also provides the use of enzyme-like materials or anticoagulant coatings or surfaces containing enzyme-like materials or medical devices or medical materials containing enzyme-like materials in anticoagulation.

[0052] In one embodiment, the enzyme-like material is any of the enzyme-like materials described above in this invention.

[0053] The anticoagulant surface coating prepared by this invention can be a catalytic coating, which generates anticoagulant molecules through a chemical reaction catalyzed by a catalyst loaded on the coating, thereby achieving the anticoagulant function.

[0054] The beneficial effects of the present invention include the following aspects: (1) The endogenous or exogenous catalytic substrates involved are small molecules with stable structures, which avoids the side effects caused by spontaneous decomposition and improves the utilization rate of the substrates; (2) The catalytic reaction that generates nitric oxide (NO) and / or its analogues only occurs on the surface of the coating and has good selectivity; (3) The coating of the present invention can continuously catalyze the generation of nitric oxide (NO) and / or its analogues to exert an anticoagulant effect and ensure its excellent long-term service performance; (4) The surface coating prepared by the present invention has excellent anticoagulant function and is suitable for surface modification of various blood contact medical devices. It can improve the biocompatibility and blood compatibility of medical devices and reduce adverse reactions such as thrombosis caused by coagulation when medical devices come into contact with blood; (5) The anticoagulant material based on enzyme-like catalytic reaction to generate nitric oxide or its analogues provided by the present invention has excellent service performance and can solve the long-standing problems of poor biocompatibility of blood contact medical devices, easy coagulation on the surface, and the need to use anticoagulant drugs with large side effects. Attached Figure Description

[0055] Figure 1 Materials characterization of Fe-NC enzyme materials. A) Transmission electron microscope image of Fe-NC. B) Powder X-ray diffraction pattern of Fe-NC. C) X-ray photoelectron spectroscopy of Fe-NC. D) High-resolution X-ray photoelectron spectroscopy of the 2p orbital of Fe in Fe-NC.

[0056] Figure 2 Evaluation of the antiplatelet properties of Fe-NC-loaded coatings on blood-contact medical devices. A) Absorption spectrum of NO molecules produced by the oxidation of substrates catalyzed by the Fe-NC-loaded coating, detected with Griess reagent. B) Statistical analysis of the concentration of NO molecules produced by the oxidation of substrates catalyzed by the Fe-NC-loaded coating over time. C) Scanning electron microscope (SEM) image of the polycaprolactone (PCV) coating surface. D) SEM image of the PCV coating surface after incubation with platelet-rich plasma for 2 hours. E) SEM image of the Fe-NC-loaded coating surface. F) SEM image of the Fe-NC-loaded coating surface after incubation with platelet-rich plasma for 2 hours.

[0057] Figure 3 Absorption spectra of NO molecules generated by Fe-NC spray coatings of different concentrations were obtained using Griess reagent. Detailed Implementation

[0058] Unless otherwise specified, the terms used in this invention have their usual meanings in the art, and the reagents used are all commercially available reagents commonly used in the art.

[0059] In this invention, the term "enzyme-like material" refers to an artificial material that possesses catalytic activity similar to natural enzymes while also exhibiting its own unique physicochemical properties. MNCs are preferably preferred as enzyme-like materials.

[0060] In this invention, the term "MNC" refers to a class of carbon materials (C) simultaneously doped with a metal element (M) and a nitrogen element (N) and exhibiting natural enzyme-like catalytic activity. The metal element M can be a transition metal; M includes, but is not limited to, iron (Fe), cobalt (Co), nickel (Ni), manganese (Mn), copper (Cu), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), iridium (Ir), titanium (Ti), vanadium (V), chromium (Cr), zinc (Zn), gold (Au), and combinations of one or more of the above elements. The simulated natural enzyme catalytic activity includes, but is not limited to, peroxidase-like activity, oxidase-like activity, and nitrite reductase-like activity.

[0061] In this invention, the term "carbon precursor" refers to a raw material that can form carbon materials after high-temperature treatment. Guanine is a preferred carbon precursor.

[0062] In this invention, the term "medical device" refers to instruments, equipment, appliances, in vitro diagnostic reagents and calibrators, materials, and other similar or related articles that are used directly or indirectly on humans or animals. Preferably, the medical device is a cardiovascular stent, intravascular catheter, balloon catheter, pacing electrode, heart valve, artificial blood vessel, blood purification device, artificial joint, artificial organ, in vivo drug delivery catheter, urinary catheter, artificial arteriovenous catheter, ventricular assist device, heart or tissue repair material, prostate stent, biliary stent, or blood filter.

[0063] The technical content of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the present invention.

[0064] Example 1

[0065] A two-step method was used to construct a coating on the surface of a medical device loaded with Fe-NC. The first step was to synthesize the enzyme-like material Fe-NC. The second step was to uniformly mix Fe-NC with a biocompatible material that can form a coating and then form a film on the surface of the medical device.

[0066] The synthesis of Fe-NC proceeds as follows: Equal amounts of iron oxide particles and the carbon precursor guanine are ground and mixed thoroughly in an agate mortar. The resulting mixture is then placed in a high-temperature tube furnace and subjected to high-temperature carbonization under an inert gas atmosphere. The temperature is 900℃, and the high-temperature treatment time is 3 hours. The carbonized product is removed and immersed in an acid solution to remove the template and other impurities. The remaining solid product is obtained by high-speed centrifugation and washed several times with ultrapure water until the washing solution is neutral and free of free metallic iron ions. The washed product is then dried in a 60℃ drying oven to obtain Fe-NC.

[0067] The obtained Fe-NC enzyme materials were characterized, and the results are as follows: Figure 1 As shown. Figure 1 Transmission electron microscopy images of A show that the final material obtained has a thin-shell structure. Figure 1 Powder X-ray diffraction results of B confirmed that the material contains only pure carbon and no other crystalline phases. Figure 1 X-ray photoelectron spectroscopy analysis of C indicates that the material obtained in the example mainly contains four elements: C, N, O, and Fe. Further analysis of the 2p orbitals of Fe reveals that the Fe element in the material primarily exists in the form of divalent Fe ions. Figure 1 D).

[0068] Based on the synthesized Fe-NC material, a Fe-NC-loaded coating for medical devices was constructed via a solvent evaporation method. The process is as follows: Polycaprolactone (Polycaprolactone) with a molecular weight of 150,000 and Fe-NC were dispersed in tetrahydrofuran solvent and mixed thoroughly. The final concentration of Polycaprolactone was 40 mg / ml, and the final concentration of Fe-NC was 2 mg / ml. A medical-grade 316L stainless steel sheet was immersed in this mixed solution, and a Fe-NC-loaded polymer coating was deposited on its surface through solvent evaporation.

[0069] The anticoagulant function of the prepared Fe-NC-loaded medical device surface coating was evaluated. First, to verify the coating's ability to catalyze the production of nitric oxide, a 1 cm × 1 cm section of the coating was immersed in PBS buffer solution at pH 7.4, and 1 mmol / L of arginine substrate was added. The NO concentration in the solution was measured every ten minutes using Griess' reagent. The results are as follows: Figure 2 A and Figure 2 As shown in B. Figure 2As can be seen from A, in the presence of arginine, the product NO catalyzed by the coating for arginine oxidation can be detected by Griess reagent; as the reaction time increases, the detection signal of the absorption peak of Griess reagent at 550 nm also gradually increases (Note: The absorption peak at 0 minutes in the figure is the background signal of the detection system itself. When NO is not present, the mixture of solution A and solution B in Griess reagent can also spontaneously produce a weak reaction, i.e., the background signal). Figure 3 There are similar cases as well. Figure 2 B further demonstrates that the coating catalyzes rapidly, producing more than 1 micromole per liter of NO molecules within half an hour, which is sufficient to achieve a good antiplatelet effect.

[0070] Next, the antiplatelet effect of the coating was further verified and evaluated. Fresh blood was drawn from the ear vein of New Zealand white rabbits and placed in a blood collection tube containing 3.8% sodium citrate. The blood was centrifuged at 1500 rpm for 15 minutes, and the supernatant obtained was platelet-rich plasma, which was then used. 60 μL of platelet-rich plasma containing the catalytic substrate was applied to the coating surface and incubated at 37°C for 2 hours. After incubation, the coating was washed with physiological saline, then incubated with 60 μL of 2.5% glutaraldehyde for 1 hour, and then washed with physiological saline. Finally, it was dehydrated sequentially with four types of alcohol: 50%, 75%, 90%, and 100%. After drying, the coating surface was sputter-coated with gold for characterization analysis using scanning electron microscopy. The above treatment and characterization were performed on the prepared Fe-NC-loaded medical device surface coating and the simple polycaprolactone coating as a control, and the results are as follows. Figure 2 C to Figure 2 As shown in F.

[0071] The scanning electron microscopy characterization results show that the polycaprolactone coating alone does not have anticoagulant function; platelets are adsorbed and activated in large quantities on the coating surface. Figure 2 C, 2D). However, for Fe-NC-loaded coatings, because the coating can catalyze the production of NO, which has an anti-platelet effect, there is almost no platelet adsorption and aggregation on the coating surface. Figure 2 E, 2F) showed good anticoagulant effects.

[0072] Example 2

[0073] A two-step method was used to construct the surface coating of medical devices loaded with Fe-NC. In the first step, the enzyme-like material Fe-NC was synthesized using the same method as in Example 1. In the second step, the surface coating of cardiac stents loaded with Fe-NC was constructed by spraying.

[0074] The coating construction process is as follows:

[0075] Polylactic acid-glycolic acid copolymer (PLA) with a molecular weight of 150,000 and Fe-NC were dispersed in dichloromethane solvent. The final concentration of PLA was 10 mg / mL, and the final concentration of Fe-NC was 0, 0.25, 0.5, or 1.0 mg / mL. The Fe-NC material and PLA-glycolic acid copolymer solution in dichloromethane were mixed uniformly by magnetic stirring for 12 hours. The mixture was then sprayed onto the surface of a cardiac stent using an ultrasonic sprayer, and the solvent evaporated at room temperature to form a surface coating.

[0076] Next, the effect of Fe-NC coated modified cardiac stents on catalytic NO production was investigated. Four types of coated modified cardiac stents were immersed in 200 μL of reaction solution and incubated at 37°C in the dark for 30 minutes. The reaction solution was a phosphate buffer solution at pH 7.4, and the added substrate was hydroxyurea at a concentration of 1 mmol / L. Figure 3 The Griess test results showed that all three Fe-NC coated modified cardiac stents could catalyze the oxidation of the substrate hydroxyurea to produce NO. Among them, the Fe-NC coated modified cardiac stent prepared at a final Fe-NC concentration of 1.0 mg / mL showed the best catalytic effect in producing NO. This indicates that increasing the Fe-NC loading can improve the anticoagulant effect of the coating.

[0077] Example 3

[0078] Besides constructing the Fe-NC-loaded medical device surface coating using the methods of Examples 1 and 2, other methods capable of loading and / or containing and / or growing enzyme-like materials on or within the surface of a medical device can also be used to prepare the medical device of the present invention. The following examples are exemplarily listed (but not exhaustively described) in this embodiment:

[0079] (1) Fe-NC-containing medical device surfaces are constructed using molding technology. Specifically, Fe-NC-containing polymer cardiac scaffolds can be directly constructed using 3D printing technology. Fe-NC is added to the polymer used for 3D printing to create a high-performance functional composite material. The specific process is as follows:

[0080] Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) were used to perform target anatomical assessments at a cardiac catheterization workstation to identify atypical vascular geometries. Stents were designed based on the vascular shapes obtained from the imaging modal. Polycaprolactone was melted and added to Fe-NC synthesized according to the method in Example 1. After thorough mixing, the designed stent and its surface were obtained using fused deposition modeling (FDM) combined with 3-axis 3D printing technology.

[0081] The 3D printing technology used in this embodiment allows for personalized design, with the scaffold parameters determined based on the patient's specific condition. The scaffold model used in this experiment is a scaffold with closed rhomboid cells, and the following parameters were determined according to the patient's condition: scaffold inner diameter 4 mm, scaffold wall thickness 0.2 mm, 8 circumferential holes, hinge width 0.8 mm, and total length 20 mm. During printing, the nozzle temperature was controlled at 220°C, the bed temperature at 25°C, and the printing speed at 300 mm / min. After printing, the scaffold was sterilized in 70% ethanol solution for 12 hours, rinsed twice with phosphate-buffered saline (PBS), and then sterilized under ultraviolet light for 30 minutes.

[0082] (2) A one-step method was used to construct a Fe-NC-loaded medical device surface coating. The synthesis of the material was directly set to occur on the desired surface, resulting in a Fe-NC-covered medical device surface coating in one step. The specific process is as follows:

[0083] Medical-grade 316L stainless steel and guanine, a carbon precursor, were uniformly mixed and placed in an alumina crucible. The mixture was then transferred to a high-temperature tube furnace and carbonized at 700°C for 3 hours under an inert gas atmosphere. After cooling to room temperature, the instrument was removed and immersed in an acid solution to remove impurities. After impurity removal, the instrument was removed and washed repeatedly with ultrapure water until the washing solution was neutral and free of metal ion residue. The washed instrument was then dried in a 60°C vacuum drying oven to obtain an in-situ grown Fe-NC metal medical device surface.

[0084] Several approaches can be used to successfully construct surface coatings for blood-contact medical devices with excellent anticoagulant properties.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anticoagulant medical material, characterized in that, The anticoagulant medical material contains an enzyme-like material, which is a carbon material doped with both a transition metal element and a nitrogen element, exhibiting catalytic activity similar to natural enzymes; the transition metal element is iron. The enzyme-like material is an enzyme-like material capable of mimicking peroxidase activity, oxidase-like activity, and / or nitrite reductase-like activity.

2. The method for preparing the anticoagulant medical material according to claim 1, characterized in that, Enzyme-like materials are incorporated into the whole, part or surface of medical materials.

3. The preparation method according to claim 2, characterized in that, The preparation method includes the following steps: a) Mixing the enzyme-like material with a coating material to form a film on the surface of the medical material; or b) Mix the enzyme-like material with a molding material, and directly mold it using molding technology to obtain the surface of the medical material; or c) The enzyme-like material is synthesized directly on the surface of a medical material.

4. The preparation method according to claim 3, characterized in that, The material used to form the coating is a biocompatible material.

5. The preparation method according to claim 3, characterized in that, The molding technology is 3D printing, and the material used for molding is 3D printing raw material.

6. A method for preparing an anticoagulant coating or surface on the surface of a medical material, characterized in that, An enzyme-like material is incorporated into the surface of the medical material. This enzyme-like material is a carbon material doped with both a transition metal element and a nitrogen element, exhibiting catalytic activity similar to that of natural enzymes. The transition metal element is iron. The enzyme-like material is an enzyme-like material capable of mimicking peroxidase activity, oxidase-like activity, and / or nitrite reductase-like activity.

7. The use of enzyme-like materials in the preparation of anticoagulant materials, characterized in that, This type of enzyme material is a carbon material simultaneously doped with a transition metal element and a nitrogen element, exhibiting catalytic activity similar to that of natural enzymes; the transition metal element is iron. The enzyme-like material is an enzyme-like material capable of mimicking peroxidase activity, oxidase-like activity, and / or nitrite reductase-like activity.

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