Blood contact material and preparation method thereof

Abstract

The invention relates to a blood contact material and a preparation method thereof. The preparation method of the blood contact material comprises the following steps that the anticoagulant layer is covalently connected to the surface of the base material in an atom transfer radical polymerization mode, the tail end of a polymer in the anticoagulant layer is provided with an initiator group, and the anticoagulant layer comprises one or more of a hydrophilic anticoagulant layer and a heparin anticoagulant layer; and reacting the initiator group with the substance with the NO catalytic release function to prepare the blood contact material. According to the preparation method, the stability of the membrane layer can be improved while a relatively good antithrombotic effect is ensured.

Description

Technical Field

[0001] The present invention relates to the field of medical materials, and particularly to a blood contact material and a preparation method thereof. Background Art

[0002] Blood compatibility is a very important measurement index for blood contact materials, especially for the constituent materials of implantable devices. When the device is implanted into the human body, if the blood compatibility of the material is poor, it often leads to the occurrence of a coagulation reaction, and then the formation of thrombus.

[0003] Nitric oxide (NO) has the functions of inhibiting platelet adhesion, aggregation and activation, promoting endothelial cell proliferation, and inhibiting smooth muscle cell proliferation in the human body. A large amount of endogenous nitric oxide donor S-nitrosothiol (RSNO) is contained in the blood. Researchers add a substance with NO catalytic release function to the blood contact material, so that it can catalyze the release of NO from the endogenous nitric oxide donor S-nitrosothiol to play an antithrombotic role. However, simple NO release is often insufficient for antithrombosis. Therefore, combining an anticoagulant layer with a substance having NO catalytic release function to further improve the antithrombotic effect is a commonly used method at present. However, the traditional combination method has the risk of easy detachment of the membrane layer, which is not conducive to the exertion of the antithrombotic effect. Summary of the Invention

[0004] Based on this, some embodiments of the present invention provide a blood contact material and a preparation method thereof, which can improve the stability of the membrane layer while ensuring a good antithrombotic effect.

[0005] A preparation method of a blood contact material includes the following steps:

[0006] Covalently connect an anticoagulant layer on the surface of the substrate by atom transfer radical polymerization. The end of the polymer in the anticoagulant layer has an initiator group. The anticoagulant layer includes one or several of a hydrophilic anticoagulant layer and a heparin anticoagulant layer;

[0007] React the initiator group with a substance having NO catalytic release function to prepare a blood contact material.

[0008] In some embodiments, the initiator group includes a halogen group, and the substance having NO catalytic release function has an amino group. In the step of reacting the initiator group with the substance having NO catalytic release function, a substitution reaction is carried out between the halogen group and the amino group.

[0009] In some embodiments, the step of reacting the initiator group with a substance having NO catalytic release function satisfies one or more of the following conditions:

[0010] (1) The substance with the function of catalytic NO release includes one or both of cystamine and selenocystamine;

[0011] (2) The reaction is carried out in an alkaline solution with a pH of 10 to 12;

[0012] (3) The reaction temperature is 20°C to 40°C, and the time is 1 h to 12 h;

[0013] (4) The substance with the function of catalytic NO release reacts in the form of a solution, and in the solution, the mass percentage concentration of the substance with the function of catalytic NO release is 1% to 5%.

[0014] In some embodiments, the preparation steps of the anticoagulant layer include:

[0015] Grafting the initiator group on the surface of the substrate, and the initiator group includes a halogen group;

[0016] Treating the substrate grafted with the initiator group with a reaction solution containing an anticoagulant monomer, a catalyst and a complexing agent, so that the anticoagulant monomer undergoes atom transfer radical polymerization reaction on the surface of the substrate grafted with the initiator group under the action of the initiator group, the catalyst and the complexing agent to prepare the anticoagulant layer.

[0017] In some embodiments, the step of grafting the initiator group on the surface of the substrate includes:

[0018] Obtaining a substrate with a hydroxyl group on the surface;

[0019] Performing a silanization reaction between the silanizing reagent containing the initiator group and the hydroxyl group on the surface of the substrate to graft the initiator group on the surface of the substrate.

[0020] In some embodiments, the step of grafting the initiator group on the surface of the substrate satisfies one or several of the following conditions:

[0021] (1) The silanizing reagent containing the initiator group includes one or a combination of more than one of (3-bromopropyl)trimethoxysilane, (3-bromopropyl)triethoxysilane, (3-chloropropyl)trimethoxysilane, (3-bromopropyl)trichlorosilane, 1-bromo-4-(trimethoxysilyl)benzene and (3-chloropropyl)trichlorosilane;

[0022] (2) The silanizing reagent containing the initiator group reacts in the form of a solution, and in the solution, the mass percentage concentration of the silanizing reagent containing the initiator group is 5% to 30%;

[0023] (3) The temperature of the silanization reaction is 25°C to 60°C, and the time is 3 h to 24 h.

[0024] In some of these embodiments, the step of grafting initiator groups onto the surface of the substrate includes:

[0025] obtaining a substrate with an amino group on its surface;

[0026] performing an acylation reaction between an acyl halide reagent containing an initiator group and the amino group on the surface of the substrate.

[0027] In some of these embodiments, the step of grafting initiator groups onto the surface of the substrate satisfies one or more of the following conditions:

[0028] (1) The acyl halide reagent containing an initiator group includes one or a combination of two of chloroacetyl chloride and 2-bromo-2-methylpropionyl bromide;

[0029] (2) The acyl halide reagent containing an initiator group reacts in the form of a solution, and in the solution, the mass percentage concentration of the acyl halide reagent containing an initiator group is 5% to 30%;

[0030] (3) The temperature of the acylation reaction is 0°C to 25°C, and the time is 5 h to 48 h.

[0031] In some of these embodiments, the anticoagulant layer includes a hydrophilic anticoagulant layer, and the step of preparing the hydrophilic anticoagulant layer satisfies one or more of the following conditions:

[0032] (1) The anticoagulant monomers include one or a combination of more of acrylamide, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylamide, potassium 3-sulfopropyl methacrylate, N-vinylpyrrolidone, acrylate-capped oligomers, methacrylate-capped oligomers, and zwitterionic monomers;

[0033] (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomers is 1% to 50%;

[0034] (3) The molar ratio of the carbon-carbon double bond in the anticoagulant monomers, the catalyst, and the ligand is 1:(0.005 to 0.1):(0.005 to 0.5);

[0035] (4) The temperature of the atom transfer radical polymerization reaction is 25°C to 70°C, and the time is 2 h to 24 h.

[0036] In some of these embodiments, the step of preparing the hydrophilic anticoagulant layer satisfies one or more of the following conditions:

[0037] (1) The anticoagulant monomers include zwitterionic monomers, and the structural formula of the zwitterionic monomer is shown as the following formula (II): In formula (II), R 1 includes a zwitterionic group, R2 including -NH- or -O-, R 3 including -H or -CH 3 wherein the zwitterionic group includes one or more of phosphorylcholine, sulfobetaine, and carboxybetaine;

[0038] (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 5% - 30%;

[0039] (3) The molar ratio of the carbon - carbon double bond in the anticoagulant monomer, the catalyst, and the ligand is 1:(0.01 - 0.1):(0.01 - 0.3);

[0040] (4) The time of the atom transfer radical polymerization reaction is 5 h - 10 h.

[0041] In some embodiments, the anticoagulant layer includes a heparin anticoagulant layer, and the steps for preparing the heparin anticoagulant layer satisfy one or more of the following conditions:

[0042] (1) The anticoagulant monomer includes a heparin - like substance with carbon - carbon double bonds;

[0043] (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 5% - 30%;

[0044] (3) The mass ratio of the anticoagulant monomer to the catalyst is 1:(0.005 - 0.05), and the molar ratio of the catalyst to the ligand is 1:(1 - 5);

[0045] (4) The temperature of the atom transfer radical polymerization reaction is 25°C - 70°C, and the time is 2 h - 12 h.

[0046] In some embodiments, the steps for preparing the heparin anticoagulant layer satisfy one or more of the following conditions:

[0047] (1) The preparation steps of the anticoagulant monomer include: reacting a heparin - like substance with a modifier containing a carbon - carbon double bond and a reactive group, so that the heparin - like substance has a carbon - carbon double bond, and the reactive group includes one or more of a carboxylic acid group, an acid anhydride group, an epoxy group, and an amide group;

[0048] (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 5% - 10%;

[0049] (3) The mass ratio of the anticoagulant monomer to the catalyst is 1:(0.005 - 0.01), and the molar ratio of the catalyst to the ligand is 1:(1.5 - 2);

[0050] (4) The time of the atom transfer radical polymerization reaction is 2 h to 6 h.

[0051] In some of these embodiments, the reaction solution satisfies one or more of the following conditions:

[0052] (1) The catalyst includes one or more combinations of low-valent salts of copper, iron, molybdenum, chromium, rhenium, ruthenium, rhodium, and nickel; optionally, the catalyst includes one or more of CuCl, FeCl 2 and RuCl 2 ;

[0053] (2) The ligand includes one or more combinations of amine substances and phosphine substances. The amine substances include one or more combinations of N,N,N,N,N-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, tris[2-(dimethylamino)ethyl]amine, tris(2-pyridylmethyl)amine, 1,4,8,11-tetraazacyclotetradecane, 2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, and 4,4'-bis(trifluoromethyl)-2,2'-bipyridine. The phosphine substances include triphenylphosphine; optionally, the ligand includes one or more of N,N,N,N,N-pentamethyldiethylenetriamine, tris[2-(dimethylamino)ethyl]amine, and 4,4'-di-tert-butyl-2,2'-bipyridine;

[0054] (3) The reaction solution further contains a reducing agent. The reducing agent includes a high-valent salt corresponding to the metal used in the catalyst or a radical thermal initiator. The molar ratio of the reducing agent to the catalyst is (0.1 - 0.3):1.

[0055] In some of these embodiments, the anticoagulant layer includes a hydrophilic anticoagulant layer and a heparin anticoagulant layer. The preparation steps of the anticoagulant layer include:

[0056] Grafting an initiator group on the surface of the substrate. The initiator group includes a halogen group;

[0057] Treating the substrate grafted with the initiator group with a first reaction solution containing a first anticoagulant monomer, a first catalyst, and a first ligand, so that the first anticoagulant monomer undergoes an atom transfer radical polymerization reaction on the surface of the substrate grafted with the initiator group to prepare the hydrophilic anticoagulant layer;

[0058] Treating the substrate with the hydrophilic anticoagulant layer with a second reaction solution containing a second anticoagulant monomer, a second catalyst, and a second ligand, so that the second anticoagulant monomer undergoes an atom transfer radical polymerization reaction on the surface of the substrate with the hydrophilic anticoagulant layer to prepare the heparin anticoagulant layer.

[0059] In some of these embodiments, the preparation step of the anticoagulant layer further includes repeating the preparation steps of the hydrophilic anticoagulant layer and / or the heparin anticoagulant layer, so that the total number of layers of the anticoagulant layer is 3 to 8 layers, and in the anticoagulant layer, the hydrophilic anticoagulant layer and the heparin anticoagulant layer are alternately stacked.

[0060] A blood-contacting material includes a substrate, an anticoagulant layer disposed on the surface of the substrate, and an active catalytic layer disposed on the surface of the anticoagulant layer away from the substrate;

[0061] Wherein, the anticoagulant layer is covalently connected to the surface of the substrate by atom transfer radical polymerization, and the anticoagulant layer includes one or more of a hydrophilic anticoagulant layer and a heparin anticoagulant layer;

[0062] The active catalytic layer can catalytically release NO, and the active catalytic layer is covalently connected to the end of the polymer in the anticoagulant layer.

[0063] In some of these embodiments, the blood-contacting material satisfies one or more of the following conditions:

[0064] (1) The material of the active catalytic layer includes one or more of cystamine and selenocystamine;

[0065] (2) The active catalytic layer is connected to the anticoagulant layer by a C-N bond;

[0066] (3) The anticoagulant layer includes a hydrophilic anticoagulant layer, and the water contact angle of the surface of the substrate on the side where the anticoagulant layer and the active catalytic layer are provided is less than 50°;

[0067] (4) The anticoagulant layer includes a heparin anticoagulant layer, and the heparin density on the surface of the substrate on the side where the anticoagulant layer and the active catalytic layer are provided is not less than 0.5 μg / cm 2 ;

[0068] (5) The anticoagulant layer includes a hydrophilic anticoagulant layer and a heparin anticoagulant layer, and the total number of layers of the anticoagulant layer is 2 to 8 layers. In the anticoagulant layer, the hydrophilic anticoagulant layer and the heparin anticoagulant layer are alternately stacked.

[0069] The inventors found in experiments that although the traditional method discloses the combination of an anticoagulant material and a substance with NO catalytic release function, usually the anticoagulant material and the substance with NO catalytic release function are combined in an interpenetrating manner, which affects their respective activities, or the layer-by-layer grafting method is used. However, after grafting the anticoagulant layer, there are fewer active sites and less grafting amount of the substance with NO catalytic release function. On the one hand, it affects the NO catalytic release effect. On the other hand, the binding force between the substance with NO catalytic release function and the anticoagulant layer is weak, and the stability is poor, so it is easy to fall off. In the preparation method of the above blood contact material, the anticoagulant material is grafted on the substrate surface by atom transfer radical polymerization (ATRP). On the one hand, the anticoagulant layer is covalently bonded to the substrate, with good stability. On the other hand, compared with other polymerization methods, ATRP technology has controllability of polymer structure and molecular weight, making the molecular chain grow gradually. After the polymerization is completed, the initiator group remains at the end of the molecular chain, reducing the risk of the initiator group being embedded, ensuring the active sites for grafting the next layer. Thus, after preparing the anticoagulant layer, the initiator group at the end of the anticoagulant layer reacts with the substance with NO catalytic release function and is stably connected to the surface of the anticoagulant layer by covalent bond, and it is not easy to fall off under the blood flow scouring during use, with excellent long-term stability and achieving long-term antithrombotic effect. In addition, in the above preparation method, the anticoagulant layer and the substance with NO catalytic release function are formed layer by layer on the substrate surface, and their respective activities will not be affected due to interpenetration. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0071] Figure 1 It is a schematic structural diagram of a blood contact material in some embodiments of the present invention;

[0072] Figure 2 It is a process flow chart of a preparation method of a blood contact material in some embodiments of the present invention;

[0073] Figure 3 is Figure 2 a schematic diagram of the process flow chart shown;

[0074] Figure 4 It is a graph of the in vitro NO release detection results of the blood contact material prepared in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0075] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. Preferred embodiments of the present invention are given in the specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0077] Unless otherwise stated or there is a contradiction, the terms or phrases used in the present invention have the following meanings:

[0078] In the present invention, "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of the features.

[0079] In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0080] In the present invention, "one or several" refers to any one, any two or any two or more of the listed items. Among them, "several" refers to any two or any two or more.

[0081] In the present invention, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after adding the component.

[0082] The terms "preferably", "more preferably" and the like in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain cases. However, in the same or other cases, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0083] When a numerical range is disclosed in the present invention, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise indicated, all ranges disclosed in the present invention should be understood to include any and all subranges included therein.

[0084] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0085] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or components that are inherent to these processes, methods, products, or devices.

[0086] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present invention may be combined with other embodiments.

[0087] Nitric oxide (NO) has the effects of inhibiting platelet adhesion, aggregation and activation, promoting endothelial cell proliferation, and inhibiting smooth muscle cell hyperplasia in the human body. The peroxide decomposition enzyme glutathione peroxidase (GPx) in the human body can catalyze the endogenous nitric oxide donor S-nitrosothiol (RSNO) to release NO. However, relying solely on GPx to catalyze RSNO to release NO is far from achieving the anti-thrombotic effect. Studies have shown that the active center of GPx is selenocysteine. Therefore, organic selenium compounds such as selenocystamine, 3,3'-diselendipropionic acid, and organic sulfides such as cystamine and cysteine ​​all have the catalytic activity of GPx. Therefore, applying substances with NO catalytic release function to blood contact materials and combining them with anticoagulant materials is a common way to improve the anti-thrombotic effect. The inventor found in the experiment that the composite layer currently combined with NO release catalytic substances has the risk of falling off, especially substances with NO catalytic release function.

[0088] Based on this, a first aspect of the present invention provides a blood-contacting material, comprising a substrate, an anticoagulant layer provided on the surface of the substrate, and an active catalytic layer provided on the surface of the anticoagulant layer away from the substrate;

[0089] Among them, the anticoagulant layer is covalently connected to the surface of the substrate by surface-initiated atom transfer radical polymerization, and the anticoagulant layer includes one or more of a hydrophilic anticoagulant layer and a heparin anticoagulant layer;

[0090] The active catalytic layer can catalytically release NO, and the active catalytic layer is covalently connected to the end of the polymer in the anticoagulant layer.

[0091] The above blood-contacting material includes a substrate, an anticoagulant layer provided on the surface of the substrate, and an active catalytic layer. The anticoagulant layer is covalently connected to the surface of the substrate by surface-initiated atom transfer radical polymerization. On the one hand, the anticoagulant layer and the substrate are connected by a covalent bond, with good stability. On the other hand, compared with other polymerization methods, ATRP technology has controllability of polymer structure and molecular weight, enabling the molecular chain to gradually grow, and the initiator group remains at the end of the molecular chain, reducing the risk of the initiator group being embedded, ensuring the active sites for grafting the next layer. Thus, after preparing the anticoagulant layer, the initiator group at the end of the anticoagulant layer reacts with a substance having a NO catalytic release function, so that the active catalytic layer is stably connected to the end of the polymer in the anticoagulant layer by a covalent bond, and is not easily detached under the scouring of blood flow during use, having excellent long-term stability and capable of achieving a long-term antithrombotic effect.

[0092] In some embodiments, the material of the substrate includes a combination of one or more of metal-based biomaterials, silicon-based biomaterials, and polymer-based biomaterials. It can be understood that when the material of the substrate includes a combination of multiple metal-based biomaterials, silicon-based biomaterials, and polymer-based biomaterials, it can be a multi-layer obtained by laminating multiple materials or a single layer prepared by mixing multiple materials. Optionally, the metal-based biomaterial includes, but is not limited to, medical stainless steel materials. The polymer-based biomaterial includes, but is not limited to, a combination of one or more of polyethylene, polypropylene, polycarbonate, polyester, polymethylpentene, and polylactic acid.

[0093] In some embodiments, the material of the hydrophilic anticoagulant layer includes a combination of one or more of polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylamide (PAAm), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(hydroxyethyl acrylamide) (PHEAA), potassium 3-sulfopropyl methacrylate (PSMP), polyvinylpyrrolidone (PVP), and zwitterionic polymers.

[0094] Specifically, the structural formula of the zwitterionic polymer is as follows formula (I):

[0095]

[0096] In formula (I), R 1 comprises an amphoteric ion group, and R 2 comprises -NH- or -O-, and R 3 comprises -H or -CH 3 , and the amphoteric ion group includes one or more of phosphorylcholine (PC), sulfobetaine (SB), and carboxybetaine (CB).

[0097] Optionally, the material of the hydrophilic anticoagulant layer includes one or a combination of several of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), poly(2-hydroxyethyl methacrylate) (PHEMA), and amphoteric ion polymers.

[0098] Optionally, the material of the hydrophilic anticoagulant layer includes an amphoteric ion polymer. Using an amphoteric ion polymer as the material of the hydrophilic anticoagulant layer can form a hydration layer on the material surface, further effectively hindering the non-specific adsorption of biomolecules such as proteins, thereby further improving the anticoagulant effect.

[0099] In some embodiments, the anticoagulant layer includes a hydrophilic anticoagulant layer, and the water contact angle of one surface of the substrate provided with the anticoagulant layer and the active catalytic layer is less than 50°. For example, the water contact angle of one surface of the substrate provided with the anticoagulant layer and the active catalytic layer can be, but is not limited to, 48°, 46°, 44°, 42°, 40°, 38°, 36°, 34°, 32°, 30°, 28°, or the range formed by any two of these values.

[0100] In some embodiments, the material of the heparin anticoagulant layer includes a polymer formed by polymerization of one or more of heparin, heparin derivatives, and heparin-like substances.

[0101] Optionally, the molecular weight of heparin, heparin derivatives, and heparin-like substances is 1500 - 10000. For example, the molecular weight can be, but is not limited to, 1500, 2000, 4000, 5000, 6000, 8000, 10000, or the range formed by any two of these values.

[0102] In some embodiments, the anticoagulant layer includes a heparin anticoagulant layer, and the heparin density on one surface of the substrate provided with the anticoagulant layer and the active catalytic layer is not less than 0.5 μg / cm 2 . It can be understood that not less than 0.5 μg / cm 2 means ≥ 0.5 μg / cm 2 . For example, the heparin density on one surface of the substrate provided with the anticoagulant layer and the active catalytic layer can be, but is not limited to, 0.5 μg / cm 2 , 0.6 μg / cm 2 , 0.8 μg / cm2 、 1 μg / cm 2 、 1.2 μg / cm 2 、 1.4 μg / cm 2 、 1.6 μg / cm 2 、 1.8 μg / cm 2 、 2 μg / cm 2 or a range formed by any two of these values. Optionally, the heparin density on the surface of the substrate on the side provided with the anticoagulant layer and the active catalytic layer is not less than 1 μg / cm 2 . Further, the heparin density on the surface of the substrate on the side provided with the anticoagulant layer and the active catalytic layer is not less than 1.5 μg / cm 2 .

[0103] In some embodiments, the material of the active catalytic layer includes one or several of cystamine and selenocystamine. Cystamine and selenocystamine can catalyze the release of NO.

[0104] In some embodiments, the active catalytic layer and the anticoagulant layer are connected by C-N bonds.

[0105] In some embodiments, the anticoagulant layer is a hydrophilic anticoagulant layer. At this time, the blood-contacting material includes a substrate, a hydrophilic anticoagulant layer and an active catalytic layer sequentially provided on the surface of the substrate. Combining the hydrophilic anticoagulant layer and the active catalytic layer can give full play to the anti-protein adsorption function of the hydrophilic anticoagulant layer and the anticoagulant function of the active catalytic layer. The two work together to further improve the anti-thrombosis effect on the surface of the blood-contacting material.

[0106] In some other embodiments, the anticoagulant layer is a heparin anticoagulant layer. At this time, the blood-contacting material includes a substrate, a heparin anticoagulant layer and an active catalytic layer sequentially provided on the surface of the substrate. Combining the heparin anticoagulant layer and the active catalytic layer can give full play to the anticoagulant functions of the heparin anticoagulant layer and the active catalytic layer. The two work together to further improve the anti-thrombosis effect on the surface of the blood-contacting material.

[0107] By grafting the anticoagulant layer and the active catalytic layer on the surface of the substrate by the above method, the anticoagulant layer and the active catalytic layer work together to significantly improve the anti-thrombosis effect and can meet most anti-thrombosis requirements. Further, in application scenarios with higher anti-thrombosis requirements, the anticoagulant layer can be optimized, and another anticoagulant layer can be grafted after forming one anticoagulant layer.

[0108] In some embodiments, the anticoagulant layer includes a hydrophilic anticoagulant layer and a heparin anticoagulant layer, and the total number of layers of the anticoagulant layer is 2 to 8 layers. In the anticoagulant layer, the hydrophilic anticoagulant layer and the heparin anticoagulant layer are alternately stacked. Grafting the hydrophilic anticoagulant layer, the heparin anticoagulant layer and the active catalytic layer onto the substrate can respectively exert the anti-protein adsorption function of the hydrophilic anticoagulant layer, the anticoagulant functions of the heparin anticoagulant layer and the active catalytic layer. The three work together to further improve the anticoagulant performance of the surface of the device. At the same time, the active catalytic layer can catalyze the release of NO from RSNO in vivo, thereby promoting the proliferation of endothelial cells and effectively promoting the occurrence of endothelialization.

[0109] It can be understood that the layer covalently connected to the active catalytic layer can be either a hydrophilic anticoagulant layer or a heparin anticoagulant layer.

[0110] In some of these embodiments, the anticoagulant layer has two layers, and the blood-contacting material includes a substrate, a hydrophilic anticoagulant layer, a heparin anticoagulant layer and an active catalytic layer provided on the surface of the substrate; or, the blood-contacting material includes a substrate, a heparin anticoagulant layer, a hydrophilic anticoagulant layer and an active catalytic layer sequentially provided on the surface of the substrate.

[0111] In other embodiments, the anticoagulant layer has three layers, and the blood-contacting material includes a substrate, a first hydrophilic anticoagulant layer, a heparin anticoagulant layer, a second hydrophilic anticoagulant layer and an active catalytic layer provided on the surface of the substrate; or, the blood-contacting material includes a substrate, a first heparin anticoagulant layer, a hydrophilic anticoagulant layer, a second heparin anticoagulant layer and an active catalytic layer sequentially provided on the surface of the substrate.

[0112] In still other embodiments, the anticoagulant layer has four layers, and the blood-contacting material includes a substrate, a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, a second heparin anticoagulant layer and an active catalytic layer sequentially provided on the surface of the substrate; or, the blood-contacting material includes a substrate, a first heparin anticoagulant layer, a first hydrophilic anticoagulant layer, a second heparin anticoagulant layer, a second hydrophilic anticoagulant layer and an active catalytic layer sequentially provided on the surface of the substrate.

[0113] It can be understood that the cases where the anticoagulant layer has five, six, seven and eight layers can be obtained according to the foregoing solutions and will not be elaborated here.

[0114] Please refer to Figure 1 , in some embodiments, the blood-contacting material includes a substrate 110, a first hydrophilic anticoagulant layer 120, a first heparin anticoagulant layer 130, a second hydrophilic anticoagulant layer 140, a second heparin anticoagulant layer 150 and an active catalytic layer 160 sequentially provided on the surface of the substrate 110.

[0115] It can be understood that Figure 1Only a schematic structural diagram of a blood contact material is given, but it is not limited thereto.

[0116] The second aspect of the present invention provides a method for preparing a blood contact material, comprising the following steps:

[0117] Covalently connect an anticoagulant layer on the surface of the substrate by means of atom transfer radical polymerization. The polymer at the end of the anticoagulant layer has an initiator group. The anticoagulant layer includes one or more of a hydrophilic anticoagulant layer and a heparin anticoagulant layer;

[0118] React the initiator group with a substance having NO catalytic release function to prepare the blood contact material.

[0119] In the above method for preparing a blood contact material, the anticoagulant material is grafted on the surface of the substrate by surface-initiated atom transfer radical polymerization. On the one hand, the anticoagulant layer is covalently bonded to the substrate, with good stability. On the other hand, compared with other polymerization methods, ATRP technology has controllability of polymer structure and molecular weight, enabling the molecular chain to gradually grow, and the initiator group remains at the end of the molecular chain, reducing the risk of the initiator group being embedded, ensuring the active sites for grafting the next layer. Therefore, after the anticoagulant layer is prepared, it is stably connected to the surface of the anticoagulant layer by covalent bond through the reaction of the initiator group with a substance having NO catalytic release function, and is not easily detached under the scouring of blood flow during use, having excellent long-term stability and achieving long-term antithrombotic effect. In addition, in the above preparation method, the anticoagulant layer and the substance having NO catalytic release function are formed layer by layer on the surface of the substrate, and their respective activities will not be affected due to interpenetration.

[0120] In some embodiments, the preparation steps of the anticoagulant layer include:

[0121] Graft an initiator group on the surface of the substrate. The initiator group includes a halogen group;

[0122] Treat the substrate grafted with the initiator group with a reaction solution containing an anticoagulant monomer, a catalyst and a ligand, so that the anticoagulant monomer undergoes an atom transfer radical polymerization reaction on the surface of the substrate grafted with the initiator group under the action of the initiator group, the catalyst and the ligand to prepare the anticoagulant layer.

[0123] In some embodiments, the material of the substrate includes one or a combination of more than one of metal-based biomaterials, silicon-based biomaterials, and polymer-based biomaterials. It can be understood that when the material of the substrate includes a combination of multiple metal-based biomaterials, silicon-based biomaterials, and polymer-based biomaterials, it can be a multi-layer obtained by laminating multiple materials or a single layer prepared by mixing multiple materials. Optionally, the metal-based biomaterial includes but is not limited to medical stainless steel materials. The polymer-based biomaterial includes but is not limited to a combination of one or several of polyethylene, polypropylene, polycarbonate, polyester, polymethylpentene, and polylactic acid.

[0124] The above preparation method can be applied to the surfaces of various different materials and is connected by covalent bonds, ensuring the stability of the entire coating.

[0125] In some embodiments, the initiator group includes a combination of one or several of α-halophenyl compounds, α-halocarbonyl compounds, α-halocyanide compounds, polyhalogen compounds, and sulfonyl halides.

[0126] The following provides two methods for grafting an initiator group onto the surface of a substrate, but is not limited thereto:

[0127] Method 1. In some embodiments, the steps for grafting an initiator group onto the surface of a substrate include:

[0128] Obtain a substrate with hydroxyl groups on its surface;

[0129] Perform a silanization reaction between the silanization reagent containing the initiator group and the hydroxyl groups on the surface of the substrate to graft the initiator group onto the surface of the substrate.

[0130] In some of these embodiments, the preparation steps for a substrate with hydroxyl groups on its surface include: obtaining a substrate with hydroxyl groups on its surface by surface activation of the substrate. Specifically, the methods for surface activation of the substrate include one or a combination of plasma treatment, strong oxidant oxidation method, and ultraviolet light irradiation method. Among them, the strong oxidant oxidation method can include but is not limited to piranha solution treatment and persulfate oxidation method.

[0131] In some of these embodiments, the silanization reagent containing the initiator group includes a combination of one or more of (3-bromopropyl)trimethoxysilane, (3-bromopropyl)triethoxysilane, (3-chloropropyl)trimethoxysilane, (3-bromopropyl)trichlorosilane, 1-bromo-4-(trimethoxysilyl)benzene, and (3-chloropropyl)trichlorosilane.

[0132] In some of these embodiments, the silanization reagent containing an initiator group reacts in the form of a solution, in which the mass percentage concentration of the silanization reagent containing an initiator group is 5% to 30%. Optionally, in the solution, the mass percentage concentration of the silanization reagent containing an initiator group can be but is not limited to 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30% or the range formed by any two of these values. Optionally, in the solution, the mass percentage concentration of the silanization reagent containing an initiator group is 5% to 10%.

[0133] In some of these embodiments, in the solution of the silanization reagent containing an initiator group, the solvent includes one or a combination of more of water, methanol, ethanol, isopropanol, butanol, and cyclohexanol. In a specific example, the solvent includes a mixture of water and ethanol.

[0134] In some of these embodiments, the temperature of the silanization reaction is 25°C to 60°C, and the time is 3h to 24h. Optionally, the temperature of the silanization reaction can be but is not limited to 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C or the range formed by any two of these values. The time of the silanization reaction can be but is not limited to 3h, 6h, 9h, 12h, 15h, 18h, 21h, 24h or the range formed by any two of these values.

[0135] In some of these embodiments, the step of grafting an initiator group on the substrate surface includes: immersing the substrate with hydroxyl groups on its surface in a solution of the silanization reagent containing an initiator group, and carrying out a silanization reaction between the silanization reagent containing an initiator group and the hydroxyl groups on the substrate surface at 25°C to 60°C for 3h to 24h to graft an initiator group on the substrate surface. Among them, in the solution of the silanization reagent containing an initiator group, the mass percentage concentration of the silanization reagent containing an initiator group is 5% to 30%.

[0136] Method 2. In some other embodiments, the step of grafting an initiator group on the substrate surface includes:

[0137] Obtaining a substrate with amino groups on its surface;

[0138] Carrying out an acylation reaction between the acyl halide reagent containing an initiator group and the amino groups on the substrate surface.

[0139] In some of these embodiments, the substrate is surface-activated to prepare a substrate with amino groups on its surface. Specifically, the method for surface-activating the substrate includes one or a combination of two of plasma treatment and chemical grafting. In a specific example, the method for surface-activating the substrate includes ammonia plasma treatment. For example, the substrate is placed in ammonia plasma and treated for 20 min.

[0140] In some of these embodiments, the acyl halide reagent containing an initiator group includes one or a combination of two of chloroacetyl chloride and 2-bromo-2-methylpropionyl bromide (BiBB).

[0141] In some of these embodiments, the acyl halide reagent containing an initiator group reacts in the form of a solution. In the solution, the mass percentage concentration of the acyl halide reagent containing an initiator group is 5% - 30%. Optionally, in the solution, the mass percentage concentration of the acyl halide reagent containing an initiator group can be, but is not limited to, 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, or the range formed by any two of these values. Optionally, in the solution, the mass percentage concentration of the acyl halide reagent containing an initiator group is 5% - 10%.

[0142] In some of these embodiments, the acyl halide reagent containing an initiator group reacts in the form of a solution. In the solution, the solvent includes one or a combination of more of water, N,N-dimethylformamide (DMF), tetrahydrofuran (THF), and diethyl ether.

[0143] In some of these embodiments, a third catalyst can also be added in the step of acylation reaction. For example, the third catalyst includes triethylamine.

[0144] In some of these embodiments, the temperature of the acylation reaction is 0°C - 25°C, and the time is 5 h - 48 h. Optionally, the acylation reaction temperature can be, but is not limited to, 0°C, 2°C, 5°C, 8°C, 10°C, 12°C, 15°C, 18°C, 20°C, 22°C, 25°C, or the range formed by any two of these values. Optionally, the acylation reaction time can be, but is not limited to, 5 h, 10 h, 12 h, 15 h, 20 h, 24 h, 30 h, 36 h, 40 h, 48 h, or the range formed by any two of these values. Optionally, the time of the acylation reaction is 8 h - 24 h.

[0145] In some of these embodiments, the step of grafting an initiator group on the substrate surface includes: immersing the substrate with amino groups on its surface in a solution of the acyl halide reagent containing an initiator group, and carrying out an acylation reaction between the acyl halide group in the acyl halide reagent containing an initiator group and the amino group on the substrate surface at 0°C - 25°C for 5 h - 48 h. In the solution, the mass percentage concentration of the acyl halide reagent containing an initiator group is 5% - 30%.

[0146] The following separately describes the cases where the anticoagulant layer includes a hydrophilic anticoagulant layer and the anticoagulant layer includes a heparin anticoagulant layer:

[0147] In some embodiments, the anticoagulant layer includes a hydrophilic anticoagulant layer, and the anticoagulant monomers include one or a combination of acrylamide, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylamide, potassium 3-sulfopropyl methacrylate, N-vinylpyrrolidone, acrylate-capped oligomers, methacrylate-capped oligomers, and zwitterionic monomers.

[0148] Specifically, the acrylate- or methacrylate-capped oligomers include PEG, PHEMA, PHEAA, or PVP, with a molecular weight of 800 to 3000. It can be understood that in the acrylate- or methacrylate-capped oligomers, the acrylate or methacrylate can cap one end or both ends.

[0149] Specifically, the structural formula of the zwitterionic monomer is as follows:

[0150] In formula (II), R 1 includes a zwitterionic group, R 2 includes -NH- or -O-, R 3 includes -H or -CH 3 , and the zwitterionic group includes phosphorylcholine (PC), sulfobetaine (SB), or carboxybetaine (CB).

[0151] Optionally, the anticoagulant monomers include one or several of N-vinylpyrrolidone, 2-hydroxyethyl methacrylate, polyethylene glycol dimethacrylate with a molecular weight of 1000 capped at both ends with methacrylate, and zwitterionic monomers.

[0152] Optionally, the anticoagulant monomers include zwitterionic monomers.

[0153] In a specific example, the zwitterionic monomer includes, but is not limited to, 2-(methacryloyloxy)ethyl-2-(trimethylammonio)ethyl phosphate.

[0154] In some embodiments, in the reaction solution, the mass percentage concentration of the anticoagulant monomers is 1% to 50%. For example, the mass percentage concentration of the anticoagulant monomers can be, but is not limited to, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or the range composed of any two of these values. Preferably, in the reaction solution, the mass percentage concentration of the anticoagulant monomers is 5% to 30%.

[0155] In some embodiments, the molar ratio of the carbon-carbon double bond, the catalyst, and the ligand in the anticoagulant monomer is 1:(0.005 - 0.1):(0.005 - 0.5). For example, the molar ratio of the carbon-carbon double bond to the catalyst in the anticoagulant monomer is 1:0.005, 1:0.008, 1:0.01, 1:0.02, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, or a range formed by any two of these values. The molar ratio of the carbon-carbon double bond to the ligand in the anticoagulant monomer can be, but is not limited to, 1:0.005, 1:0.008, 1:0.01, 1:0.02, 1:0.04, 1:0.05, 1:0.06, 1:0.08, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, or a range formed by any two of these values.

[0156] Preferably, the molar ratio of the carbon-carbon double bond, the catalyst, and the ligand in the anticoagulant monomer is 1:(0.01 - 0.1):(0.01 - 0.3).

[0157] In some embodiments, the catalyst includes one or a combination of more of low-valent salts of copper, iron, molybdenum, chromium, rhenium, ruthenium, rhodium, and nickel. It can be understood that the low-valent salt of a metal refers to, for a metal with variable valences, a salt formed by the metal with a lower valence. For example, copper has two valence states of +1 and +2, and the low-valent salt of copper refers to the salt formed by +1-valent copper, such as CuCl. The same applies to the low-valent salts of other metals. Preferably, the first catalyst includes CuCl, FeCl 2 and RuCl 2 or several of them.

[0158] In some embodiments, the ligand includes one or a combination of more of amine substances and phosphine substances. Specifically, the amine substances include one or a combination of more of N,N,N,N,N-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, tris[2-(dimethylamino)ethyl]amine, tris(2-pyridylmethyl)amine, 1,4,8,11-tetraazacyclotetradecane, 2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, and 4,4'-bis(trifluoromethyl)-2,2'-bipyridine. The phosphine substances include triphenylphosphine. Preferably, the ligand includes one of N,N,N,N,N-pentamethyldiethylenetriamine, tris[2-(dimethylamino)ethyl]amine, and 4,4'-di-tert-butyl-2,2'-bipyridine.

[0159] In some embodiments, in the reaction solution, the solvent comprises one or a combination of more than one of benzene, toluene, ethyl acetate, acetonitrile, tetrahydrofuran, acetone, N,N'-dimethylformamide, ethanol, methanol, isopropanol, and water. In a specific example, in the reaction solution, the solvent comprises ethanol or a mixture of ethanol and water.

[0160] In some embodiments, a reducing agent is further contained in the reaction solution. Adding a reducing agent can further promote the progress of the ATRP reaction. The reducing agent comprises a high-valent salt corresponding to the metal used in the catalyst or a radical thermal initiator. Among them, the radical thermal initiator comprises one or a combination of more than one of azobisisobutyronitrile (AIBN), azobisisoheptonitrile (AIVN), benzoyl peroxide (BPO), di-tert-butyl peroxide (DTBP), tert-butyl perpivalate (BPP), bis(4-tert-butylcyclohexyl) peroxydicarbonate (TBCP), and diisobutyl peroxydicarbonate (IBP).

[0161] It can be understood that the reducing agent comprising a high-valent salt corresponding to the metal used in the catalyst means, for a metal with variable valence, a salt formed by the metal with a higher valence. For example, the catalyst comprises CuCl, and the reducing agent comprises CuCl 2 。

[0162] Specifically, the molar ratio of the reducing agent to the catalyst is (0.1 - 0.3):1. For example, the molar ratio of the reducing agent to the catalyst can be, but is not limited to, 0.1:1, 0.12:1, 0.15:1, 0.18:1, 0.2:1, 0.22:1, 0.25:1, 0.28:1, 0.3:1, or a range composed of any two of these values.

[0163] In some embodiments, in the step of preparing the hydrophilic anticoagulant layer, the temperature of the atom transfer radical polymerization reaction is 25°C to 70°C, and the time is 2 h to 24 h.

[0164] Optionally, the time of the ATRP reaction can be, but is not limited to, 2 h, 5 h, 10 h, 12 h, 15 h, 18 h, 20 h, 24 h, or a range composed of any two of these values. Further, the time of the ATRP polymerization reaction is 5 h to 10 h.

[0165] Optionally, the reaction temperature can be, but is not limited to, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or a range composed of any two of these values.

[0166] It can be understood that during the ATRP polymerization process, it can be protected by an inert gas or not. Preferably, it is protected by nitrogen or argon during the ATRP polymerization process.

[0167] In some embodiments, the preparation steps of the hydrophilic anticoagulant layer include:

[0168] Obtain a reaction solution including a hydrophilic anticoagulant monomer, a catalyst, and a ligand. In the reaction solution, the mass percentage concentration of the hydrophilic anticoagulant monomer is 1% to 50%, and the molar ratio of the carbon-carbon double bond, the catalyst, and the ligand in the hydrophilic anticoagulant monomer is 1:(0.005 to 0.1):(0.005 to 0.5);

[0169] Immerse the substrate grafted with an initiator group in the reaction solution, and carry out atom transfer radical polymerization reaction of the hydrophilic anticoagulant monomer on the surface of the substrate grafted with the initiator group for 2 h to 24 h under closed conditions at 25°C to 70°C to prepare the hydrophilic anticoagulant layer.

[0170] In some other embodiments, the anticoagulant layer includes a heparin anticoagulant layer, and the anticoagulant monomer includes a carbon-carbon double bond-containing heparin-like substance.

[0171] Specifically, the preparation steps of the carbon-carbon double bond-containing heparin-like substance include: reacting the heparin-like substance with a modifier containing a carbon-carbon double bond and a reactive group to make the heparin-like substance carry a carbon-carbon double bond, and the reactive group includes one or more of a carboxylic acid group, an acid anhydride group, an amino group, an epoxy group, and an amide group.

[0172] In some embodiments, the modifier containing a carbon-carbon double bond and a reactive group includes one or more of a carbon-carbon double bond-containing carboxylic acid, a carbon-carbon double bond-containing acid anhydride, a carbon-carbon double bond-containing amine, a carbon-carbon double bond-containing epoxy compound, and a carbon-carbon double bond-containing amide compound.

[0173] In some of these embodiments, the general formula of the carbon-carbon double bond-containing carboxylic acid is CHX=CY-(L) n -COOZ, where X is hydrogen or phenyl, Y is hydrogen, C 1～ C 6 alkyl or halogen-substituted C 1～ C 6 alkyl, L is a divalent linking group, n is 0 or 1, and Z is hydrogen or sodium. Further, Y is hydrogen, methyl, or halogen-substituted methyl. For example, the halogen-substituted methyl can be trifluoromethyl. Preferably, L is an alkylene group. The alkylene group can be straight-chain or branched-chain. For example, the alkylene group is methylene (-CH 2 -), 1,1-ethyl (-CH(CH 3 ))-), 1,2-ethyl (-CH 2 CH 2 -), 1,1-propyl (-CH(CH 2 CH 3 ))-), 1,2-propyl (-CH 2 CH(CH 3)-), 1,3-propylene (-CH 2 CH 2 CH 2 -), and 1,4-butylene (-CH 2 CH 2 CH 2 CH 2 -).

[0174] In some of these embodiments, the carboxylic acid containing a carbon-carbon double bond is CH 2 =CH-(L) n -COOH, CH 2 =CH-(L) n -COONa, CH 2 =C(CH 3 )-(L) n -COOH, CH 2 =C(CH 3 )-(L) n -COONa, CH 2 =C(CF 3 )-COOH or C 6 H 5 -CH=CH-COOH, n is 0 or 1, and L is an alkylene group. In a specific example, the carboxylic acid containing a carbon-carbon double bond can be acrylic acid, crotonic acid, pentenoic acid, undecenoic acid, oleic acid, methacrylic acid, methylcrotonic acid, sodium acrylate, sodium crotonate, sodium pentenoate, sodium undecenoate, sodium oleate, sodium methacrylate, sodium methylcrotonate, cinnamic acid, trifluoromethylacrylic acid, etc.

[0175] In some of these embodiments, the general formula of the acid anhydride containing a carbon-carbon double bond is R 4 -C(=O)O-C(=O)-R 5 , where at least one of R 4 and R 5 is an alkenyl group of C 2 ~C 6 , or R 4 and R 5 form a 5- to 7-membered monocyclic ring, and the 5- to 7-membered monocyclic ring contains a carbon-carbon double bond or has a substituent containing a carbon-carbon double bond. Further, the acid anhydride containing a carbon-carbon double bond is selected from at least one of acrylic anhydride, methacrylic anhydride, and maleic anhydride.

[0176] In some of these embodiments, in the step of modifying heparin-like substances with a carboxylic acid or an acid anhydride containing a carbon-carbon double bond, the heparin-like substances are reacted with the carboxylic acid or the acid anhydride containing a carbon-carbon double bond in an alkaline solution for 3 h to 8 h, and the mass ratio of the heparin-like substances to the carboxylic acid or the acid anhydride containing a carbon-carbon double bond is 1:(0.05 to 0.5).

[0177] It is understood that after the reaction is completed, steps of dialysis and drying are further included. The drying can be, for example, freeze-drying.

[0178] Optionally, the mass ratio of the heparin-like substance to the carboxylic acid containing a carbon-carbon double bond or the acid anhydride containing a carbon-carbon double bond is 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, or a range composed of any two of these values.

[0179] In some other embodiments, the amine containing a carbon-carbon double bond includes 2-aminoethyl methacrylate.

[0180] Furthermore, in the step of modifying the heparin-like substance with the amine containing a carbon-carbon double bond, the heparin-like substance and the amine containing a carbon-carbon double bond are reacted for 3 h to 24 h under the action of an amide catalyst. The mass ratio of the heparin-like substance to the amine containing a carbon-carbon double bond is 1:(0.05 - 0.5), and the molar ratio of the amine containing a carbon-carbon double bond to the amide catalyst is 1:(0.8 - 1). For example, the mass ratio of the heparin-like substance to the amine containing a carbon-carbon double bond is 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, or a range composed of any two of these values. The molar ratio of the amine containing a carbon-carbon double bond to the amide catalyst can be, but is not limited to, 1:0.8, 1:0.82, 1:0.85, 1:088, 1:0.9, 1:0.92, 1:0.95, 1:0.98, 1:1, or a range composed of any two of these values.

[0181] In some other embodiments, the epoxide containing a carbon-carbon double bond includes one or more of glycidyl methacrylate, allyl glycidyl ether, epoxybutene and its homologues, 1,2-epoxy-4-vinylcyclohexane, and 3,4-epoxy-1-cyclohexene.

[0182] Furthermore, in the step of modifying the heparin-like substance with the epoxide containing a carbon-carbon double bond, the heparin-like substance and the epoxide containing a carbon-carbon double bond are reacted in a solution with a pH of 7 - 8 for 3 days to 8 days. The mass ratio of the heparin-like substance to the epoxide containing a carbon-carbon double bond is 1:(0.3 - 1).

[0183] Optionally, the mass ratio of the heparin-like substance to the epoxide containing a carbon-carbon double bond is 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, or a range composed of any two of these values.

[0184] Optionally, the solution with a pH of 7 - 8 can be a phosphate buffer solution.

[0185] In some other embodiments, the amide compound containing a carbon-carbon double bond includes N-(3-aminopropyl)methacrylamide hydrochloride or N-(3-aminopropyl)methacrylamide.

[0186] Further, in the step of modifying the heparin-like substance with the amide compound containing a carbon-carbon double bond, the heparin-like substance and the amide compound containing a carbon-carbon double bond are stirred and reacted at 0 °C to 4 °C for 3 h to 8 h under the action of an activator and a condensing agent, and the mass ratio of the heparin-like substance, the amide compound containing a carbon-carbon double bond, the activator and the condensing agent is (1 to 1.2):(0.8 to 1):(0.8 to 1):(0.8 to 1.2).

[0187] Optionally, the mass ratio of the heparin-like substance, the amide compound containing a carbon-carbon double bond, the activator and the condensing agent is 1.2:1:1:1.

[0188] Optionally, the activator includes NHS (N-hydroxysulfosuccinimide), and the condensing agent includes EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride).

[0189] The above provides a variety of ways to modify the heparin-like substance by double bond formation, so that the double bond-containing heparin-like substance can directly undergo ATRP reaction and be fixed on the substrate surface through covalent bonds formed by free radical polymerization, realizing the grafting of the heparin anticoagulant layer, and at the same time providing the potential for multi-layer grafting, further improving the anticoagulant ability of the blood contact material. Compared with the traditional method of fixing heparin by amide bond, it has a more stable bonding ability. In addition, it is easier to control the double bond modification density during the modification process, thereby further adjusting the reaction sites, optimizing the binding firmness while ensuring the activity of the heparin-like substance.

[0190] In some embodiments, in the reaction solution, the mass percentage concentration of the carbon-carbon double bond-containing heparin-like substance is 2% to 30%, the mass ratio of the carbon-carbon double bond-containing heparin-like substance to the catalyst is 1:(0.005 to 0.05), and the molar ratio of the catalyst to the ligand is 1:(1 to 5).

[0191] Optionally, in the reaction solution, the mass percentage concentration of the carbon-carbon double bond-containing heparin-like substance can be but is not limited to 2%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30% or the range composed of any two of these values. Preferably, in the reaction solution, the mass percentage concentration of the carbon-carbon double bond-containing heparin-like substance is 5% to 10%.

[0192] Optionally, the mass ratio of the carbon-carbon double bond-containing heparin-like substance to the catalyst can be, but is not limited to, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.015, 1:0.02, 1:0.025, 1:0.03, 1:0.035, 1:0.04, 1:0.045, 1:0.05, or the range formed by any two of these values. Preferably, the mass ratio of the carbon-carbon double bond-containing heparin-like substance to the catalyst is 1:(0.005 - 0.01).

[0193] Optionally, the molar ratio of the catalyst to the ligand can be, but is not limited to, 1:1, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:3, 1:4, 1:5, or the range formed by any two of these values. Preferably, the molar ratio of the catalyst to the ligand is 1:(1.5 - 2).

[0194] Specifically, the catalyst includes one or more combinations of low-valent salts of copper, iron, molybdenum, chromium, rhenium, ruthenium, rhodium, or nickel. Preferably, the catalyst includes CuCl, FeCl 2 and RuCl 2 or one or several of them.

[0195] The ligand includes one or more combinations of amine substances and phosphine substances. Among them, the amine substances include one or more combinations of N,N,N,N,N-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, tris[2-(dimethylamino)ethyl]amine, tris(2-pyridylmethyl)amine, 1,4,8,11-tetraazacyclotetradecane, 2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, or 4,4'-bis(trifluoromethyl)-2,2'-bipyridine. The phosphine substance includes triphenylphosphine.

[0196] Preferably, the ligand includes one or several combinations of N,N,N,N,N-pentamethyldiethylenetriamine, tris[2-(dimethylamino)ethyl]amine, and 4,4'-di-tert-butyl-2,2'-bipyridine.

[0197] It can be understood that the catalyst used in the process of preparing the hydrophilic anticoagulant layer can be the same as or different from the catalyst used in the process of preparing the heparin anticoagulant layer. Similarly, the ligand used in the process of preparing the hydrophilic anticoagulant layer can be the same as or different from the ligand used in the process of preparing the heparin anticoagulant layer.

[0198] In some of these embodiments, in the step of preparing the heparin anticoagulant layer, the solvent in the reaction solution includes one or a combination of more than one of water, ethanol, methanol, acetone, tetrahydrofuran, or N,N'-dimethylformamide.

[0199] In some of these embodiments, in the step of preparing the heparin anticoagulant layer, the reaction solution further includes a reducing agent. By adding the reducing agent, the progress of the ATRP reaction is promoted. The reducing agent includes a high-valent salt corresponding to the metal used in the catalyst or a radical thermal initiator. Among them, the radical thermal initiator includes one or a combination of more than one of azobisisobutyronitrile (AIBN), azobis(isopentanenitrile) (AIVN), benzoyl peroxide (BPO), di-tert-butyl peroxide (DTBP), tert-butyl perpivalate (BPP), bis(4-tert-butylcyclohexyl) peroxydicarbonate (TBCP), and diisobutyl peroxydicarbonate (IBP).

[0200] It can be understood that the reducing agent including a high-valent salt corresponding to the metal used in the catalyst means, for a metal with variable valence, a salt formed by the metal with a higher valence. For example, the catalyst includes CuCl, and the reducing agent includes CuCl 2 。

[0201] Specifically, the molar ratio of the reducing agent to the catalyst is (0.1 - 0.3):1. For example, the molar ratio of the reducing agent to the catalyst can be but is not limited to 0.1:1, 0.12:1, 0.15:1, 0.18:1, 0.2:1, 0.22:1, 0.25:1, 0.28:1, 0.3:1, or a range composed of any two of these values. It can be understood that in the step of preparing the heparin anticoagulant layer, the reducing agent can be the same as or different from the reducing agent used in the step of preparing the hydrophilic anticoagulant layer.

[0202] In some embodiments, in the step of treating the substrate grafted with an initiator group with a reaction solution containing an anticoagulant monomer, a catalyst, and a ligand, the substrate grafted with an initiator group is immersed in the reaction solution.

[0203] In some embodiments, in the step of preparing the heparin anticoagulant layer, the temperature of the atom transfer radical polymerization reaction is 25°C to 70°C, and the time is 2 h to 12 h. Optionally, the reaction temperature can be but is not limited to 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, or a range composed of any two of these values. Optionally, the time of the ATRP reaction can be but is not limited to 2 h, 4 h, 5 h, 6 h, 8 h, 10 h, 12 h, or a range composed of any two of these values. Further, the time of the ATRP polymerization reaction is 2 h to 6 h.

[0204] In some embodiments, during the step of preparing the heparin anticoagulant layer, the ATRP polymerization process can be protected by an inert gas or without inert gas protection. Preferably, the ATRP polymerization process is protected by nitrogen or argon.

[0205] In some of these embodiments, the steps of preparing the heparin anticoagulant layer include:

[0206] Modifying heparin substances with carboxylic acids containing carbon-carbon double bonds, acid anhydrides containing carbon-carbon double bonds, amines containing carbon-carbon double bonds, epoxy compounds containing carbon-carbon double bonds or amide compounds containing carbon-carbon double bonds to make the heparin substances carry carbon-carbon double bonds, and preparing carbon-carbon double bond-containing heparin substances;

[0207] Obtaining a reaction solution including carbon-carbon double bond-containing heparin substances, a catalyst and a ligand. In the reaction solution, the mass percentage concentration of the carbon-carbon double bond-containing heparin substances is 2% - 30%, the mass ratio of the carbon-carbon double bond-containing heparin substances to the catalyst is 1:(0.005 - 0.05), and the molar ratio of the catalyst to the ligand is 1:(1 - 5);

[0208] Immersing the substrate grafted with an initiator group in the reaction solution, and carrying out atom transfer radical polymerization reaction of the carbon-carbon double bond-containing heparin substances on the surface of the substrate grafted with the initiator group for 2h - 12h under closed conditions at 25°C - 70°C to prepare the heparin anticoagulant layer.

[0209] In still other embodiments, the anticoagulant layer includes a hydrophilic anticoagulant layer and a heparin anticoagulant layer, and the preparation steps of the anticoagulant layer include:

[0210] Grafting an initiator group on the surface of the substrate, and the initiator group includes a halogen group;

[0211] Treating the substrate grafted with the initiator group with a first reaction solution containing a first anticoagulant monomer, a first catalyst and a first ligand, and carrying out atom transfer radical polymerization of the first anticoagulant monomer on the surface of the substrate grafted with the initiator group to prepare the hydrophilic anticoagulant layer;

[0212] Treating the substrate grafted with the initiator group with a second reaction solution containing a second anticoagulant monomer, a second catalyst and a second ligand, and carrying out atom transfer radical polymerization of the second anticoagulant monomer on the surface of the substrate with the hydrophilic anticoagulant layer to prepare the heparin anticoagulant layer.

[0213] In some of these embodiments, the preparation steps of the anticoagulant layer further include repeating the preparation steps of the hydrophilic anticoagulant layer and / or the heparin anticoagulant layer, so that the total number of layers of the anticoagulant layer is 3 to 8 layers, and in the anticoagulant layer, the hydrophilic anticoagulant layer and the heparin anticoagulant layer are alternately stacked. Optionally, the total number of layers of the anticoagulant layer is 3 layers, 4 layers, 5 layers, 6 layers, 7 layers, 8 layers or the range composed of any two of these values.

[0214] It can be understood that repeating the preparation steps of the hydrophilic anticoagulant layer and / or the heparin anticoagulant layer can be to only repeat the preparation steps of the hydrophilic anticoagulant layer or only repeat the preparation steps of the heparin anticoagulant layer, or, simultaneously repeat the preparation steps of the hydrophilic anticoagulant layer and the heparin anticoagulant layer, with the same number of repetitions for both, or simultaneously repeat the preparation steps of the hydrophilic anticoagulant layer and the heparin anticoagulant layer, with different numbers of repetitions for both, as long as it is ensured that in the prepared anticoagulant layer, the heparin anticoagulant layer and the hydrophilic anticoagulant layer are alternately stacked.

[0215] In some embodiments, the initiator group includes a halogen group, the substance with NO catalytic release function has an amino group, and in the step of reacting the initiator group at the end of the anticoagulant material with the substance with NO catalytic release function, a substitution reaction is carried out between the halogen group and the amino group. If directly reacting the carboxyl group contained in the heparin-like substance with the amino group in the substance with NO catalytic release function, the carboxyl group in the heparin-like substance will be consumed, and the heparin-like substance exerts its activity depending on its carboxyl group. Therefore, the activity of the heparin-like substance will be affected. Therefore, in this embodiment, a substitution reaction is carried out between the halogen group contained in the initiator and the amino group in the substance with NO catalytic release function.

[0216] In some embodiments, the substance with NO catalytic release function includes one or both of cystamine and selenocystamine.

[0217] In some embodiments, the substitution reaction is carried out in an alkaline solution with a pH of 10 to 12. Optionally, the pH can be but is not limited to 10, 10.5, 11, 11.5, 12 or the range composed of any two of these values. Optionally, the alkaline solution includes one or both of sodium hydroxide solution and potassium hydroxide solution.

[0218] In some embodiments, the temperature of the substitution reaction is 20°C to 40°C, and the time is 1 h to 12 h. Optionally, the reaction time can be but is not limited to 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 10 h, 11 h, 12 h or the range composed of any two of these values. Further, the reaction time of the substitution reaction is 3 h to 6 h. Optionally, the reaction temperature can be but is not limited to 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40°C or the range composed of any two of these values.

[0219] In some embodiments, during the substitution reaction, the substrate with the anticoagulant layer is immersed in a solution containing a substance with a NO catalytic release function.

[0220] Specifically, in the solution containing the substance with a NO catalytic release function, the mass percentage concentration of the substance with a NO catalytic release function is 1% - 5%. Optionally, in the solution containing the substance with a NO catalytic release function, the mass percentage concentration of the substance with a NO catalytic release function can be, but is not limited to, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or the range formed by any two of these values.

[0221] Atom transfer radical polymerization (ATRP) is a method of controlled radical polymerization, which has the characteristics of controllable polymer structure, narrow molecular weight distribution, mild reaction conditions, etc. After the polymerization, halogen atoms still remain at the polymer chain ends, which can further undergo chemical reactions. Thus, a multi-layer hydrophilic anticoagulant layer and a heparin anticoagulant layer can be directly prepared by ATRP, and then a substance that catalyzes the release of NO can be chemically grafted to the end of the anticoagulant layer through the terminal halogen atoms. Since both hydrophilic anticoagulant monomers and double-bonded heparin-like substances can be grafted by ATRP, and the ATRP reaction conditions are mild, the same ATRP reaction system, namely the same catalyst, ligand, solvent, etc., can be more conveniently used during the layer-by-layer grafting process, so as to reduce the cost of industrial production. On the one hand, a multi-layer grafted structure can be directly prepared, and on the other hand, it is beneficial for production applications. At the same time, the polymer structure and molecular weight prepared by ATRP technology are controllable, which can effectively regulate the thickness of the anticoagulant layer and reduce the influence of the anticoagulant layer on the performance of the material itself.

[0222] In addition, the above-mentioned substance with a NO catalytic release function is directly grafted to the end of the anticoagulant layer by using the halogen remaining at the end after the ATRP reaction through a one-step reaction, with mild reaction conditions and high speed. In addition, when introducing a substance with a NO catalytic release function by traditional methods, polyphenolic substances are often used, which will cause the surface color of the product to darken and affect the appearance of the product. However, polyphenolic substances are not used in the above preparation method, and the appearance of the blood contact material prepared is good.

[0223] In some embodiments, grafting the hydrophilic anticoagulant layer, the heparin anticoagulant layer, and the substance with a NO catalytic release function onto the substrate can respectively exert the anti-protein adsorption function of the hydrophilic anticoagulant layer, the anticoagulant functions of the heparin anticoagulant layer and the substance with a NO catalytic release function. The three work together to further improve the anticoagulant performance of the surface of the device. At the same time, the substance with a NO catalytic release function can catalyze the release of NO from RSNO in vivo, thereby promoting the proliferation of endothelial cells and effectively promoting the occurrence of endothelialization.

[0224] Please refer to Figure 2 , in some embodiments, the preparation method of the blood contact material comprises the following steps:

[0225] Step S210: graft initiator groups on the surface of the substrate, and the initiator groups include halogen groups.

[0226] Step S220: treat the substrate grafted with initiator groups with a first reaction solution containing a first anticoagulant monomer, a first catalyst and a first complexing agent, so that the first anticoagulant monomer undergoes atom transfer radical polymerization on the surface of the substrate grafted with initiator groups under the action of the initiator groups, the first catalyst and the first complexing agent, to prepare a first hydrophilic anticoagulant layer.

[0227] Step S230: treat the substrate grafted with the first hydrophilic anticoagulant layer with a second reaction solution containing a second anticoagulant monomer, a second catalyst and a second complexing agent, so that the second anticoagulant monomer undergoes atom transfer radical polymerization on the surface of the substrate grafted with the first hydrophilic anticoagulant layer under the action of the initiator groups, the second catalyst and the second complexing agent, to prepare a first heparin anticoagulant layer.

[0228] Step S240: sequentially prepare a second hydrophilic anticoagulant layer and a second heparin anticoagulant layer on the surface of the first heparin anticoagulant layer.

[0229] Step S250: react the initiator groups at the end of the second heparin anticoagulant layer with a substance having NO catalytic release function to prepare the blood contact material.

[0230] Each step can be obtained according to the foregoing content and will not be elaborated herein.

[0231] Please also refer to Figure 3 , Figure 3 gives Figure 2 a schematic diagram of the process flow chart shown in. In Figure 3 , the substrate 110 is treated by step S210, so that the surface of the substrate 110 is provided with initiator groups 101. The substrate 110 with initiator groups 101 is treated by step S220, and a first hydrophilic anticoagulant layer 120 is covalently connected to the surface of the substrate 110. Then, it is treated by step S230, and a first heparin anticoagulant layer 130 is covalently connected to the surface of the first hydrophilic anticoagulant layer 120. After being treated by step S240, a second hydrophilic anticoagulant layer 140 and a second heparin anticoagulant layer 150 are continuously grafted. Finally, after being treated by step S250, a substance with NO catalytic release function is covalently connected to the surface of the second heparin anticoagulant layer 150 to form an active catalytic layer 160, and the blood contact material is obtained.

[0232] In order to make the objectives and advantages of the present invention clearer, the following further elaborates on the blood contact material of the present invention and its effects in combination with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and shall not be used to limit the present invention. Unless otherwise specified in the following embodiments, other components are not included except for inevitable impurities. Drugs and instruments used in the embodiments are all conventional selections in the art unless otherwise specified. For experimental methods without specific conditions indicated in the embodiments, they are carried out under conventional conditions, such as the conditions described in literature, books, or the methods recommended by the manufacturers.

[0233] Comparative Example 1

[0234] Comparative Example 1 provides a blood contact material, including a substrate and a hydrophilic anticoagulant layer provided on the surface of the substrate. The preparation steps are as follows:

[0235] (1) Place the polyethylene film in ammonia plasma for 20 minutes to make the polyethylene film carry amino groups. Subsequently, react with a DMF solution of BiBB at 20 °C for 12 hours. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, rinse with DMF three times first, and then rinse with pure water three times to obtain a polyethylene film grafted with an ATRP initiator.

[0236] (2) Prepare an ethanol solution of NVP with a mass percentage concentration of 8%, and add a CuCl catalyst and a tris[2-(dimethylamino)ethyl]amine ligand thereto. Among them, the molar percentages of CuCl and tris[2-(dimethylamino)ethyl]amine in the molar amount of NVP are 2% and 5% respectively to obtain a first reaction solution. Subsequently, immerse the polyethylene film grafted with the ATRP initiator in the first reaction solution, seal it, purge with nitrogen for 5 minutes, and then place it in an oven at 30 °C for reaction for 6 hours to form a hydrophilic anticoagulant layer on the surface of the polyethylene film. After the reaction, take it out, rinse with ethanol three times first, then rinse with pure water three times, and dry it to obtain the blood contact material.

[0237] Comparative Example 2

[0238] Comparative Example 2 provides a blood contact material, including a substrate and a heparin anticoagulant layer provided on the surface of the substrate. The preparation steps are as follows:

[0239] (1) Place the polyethylene film in ammonia plasma for 20 minutes to make the polyethylene film carry amino groups. Subsequently, react with a DMF solution of BiBB at 20 °C for 12 hours. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, rinse with DMF three times first, and then rinse with pure water three times to obtain a polyethylene film grafted with an ATRP initiator.

[0240] (2) React 1 g of heparin with 0.1 g of methacrylic anhydride in an aqueous sodium hydroxide solution with a pH of 8 for 8 hours, then dialyze and freeze-dry to obtain double-bonded heparin.

[0241] (3) Prepare an aqueous solution of double-bonded heparin with a mass percentage concentration of 8%. Add a CuCl catalyst and a tris[2-(dimethylamino)ethyl]amine ligand to it. Among them, the mass of CuCl is 1% of the mass of double-bonded heparin, and the molar amount of the tris[2-(dimethylamino)ethyl]amine ligand is 120% of the molar amount of CuCl to obtain a second reaction solution. Subsequently, immerse the polyethylene film grafted with an ATRP initiator in the second reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form a heparin anticoagulant layer on the surface of the polyethylene film. After the reaction, take it out, rinse it 3 times with pure water, dry it, and obtain a blood contact material.

[0242] Comparative Example 3

[0243] Comparative Example 3 provides a blood contact material, including a substrate, a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, and a second heparin anticoagulant layer sequentially arranged on the surface of the substrate. The preparation steps are as follows:

[0244] (1) Place the polyethylene film in ammonia plasma for treatment for 20 min to make the polyethylene film carry amino groups. Subsequently, react with a DMF solution of BiBB at 20 °C for 12 h. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, first rinse it 3 times with DMF, and then rinse it 3 times with pure water to obtain a polyethylene film grafted with an ATRP initiator.

[0245] (2) Prepare an ethanol solution of NVP with a mass percentage concentration of 8%. Add a CuCl catalyst and a tris[2-(dimethylamino)ethyl]amine ligand to it. Among them, the percentages of the molar amounts of CuCl and tris[2-(dimethylamino)ethyl]amine in the molar amount of NVP are 2% and 5% respectively to obtain a first reaction solution. Immerse the polyethylene film grafted with an ATRP initiator in the first reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form a first hydrophilic anticoagulant layer on the surface of the polyethylene film. After the reaction, take it out, first rinse it 3 times with ethanol, and then rinse it 3 times with pure water, and dry it.

[0246] (3) Prepare a second reaction solution according to the steps of Comparative Example 2, and then immerse the polyethylene film obtained in (2) in the second reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form a first heparin anticoagulant layer on the surface of the first hydrophilic anticoagulant layer. After the reaction, take it out, rinse it 3 times with pure water, and dry it.

[0247] (4) Repeat the above steps (2) and (3) once to successively form a second anticoagulant layer and a second heparin anticoagulant layer, obtaining a blood contact material.

[0248] Example 1

[0249] This example provides a blood contact material, including a substrate, a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, a second heparin anticoagulant layer, and an active catalytic layer successively disposed on the surface of the substrate. The preparation steps are as follows:

[0250] (1)-(4) are the same as steps (1)-(4) of Comparative Example 3, obtaining a polyethylene film grafted with two layers of hydrophilic anticoagulant layers and two layers of heparin anticoagulant layers.

[0251] (5) Prepare an aqueous cysteamine solution with a mass percentage concentration of 2%, and adjust the pH to 11 with 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (4) in the cysteamine aqueous solution, react at 30 °C for 4 h to form an active catalytic layer. After the reaction, take it out, rinse it 3 times with purified water, and dry it to obtain a blood contact material.

[0252] Example 2

[0253] This example provides a blood contact material, including a substrate, a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, a second heparin anticoagulant layer, and an active catalytic layer successively disposed on the surface of the substrate. The preparation steps are as follows:

[0254] (1)-(4) are the same as steps (1)-(4) of Comparative Example 3, obtaining a polyethylene film grafted with two layers of hydrophilic anticoagulant layers and two layers of heparin anticoagulant layers.

[0255] (5) Prepare an aqueous selenocysteamine solution with a mass percentage concentration of 2%, and adjust the pH to 11 with 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (4) in the selenocysteamine solution, react at 30 °C for 4 h to form an active catalytic layer. After the reaction, take it out, rinse it 3 times with purified water, and dry it to obtain a blood contact material.

[0256] Example 3

[0257] This example provides a blood contact material, including a substrate, a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, a second heparin anticoagulant layer, and an active catalytic layer successively disposed on the surface of the substrate. The preparation steps are as follows:

[0258] (1) Place the polyethylene film in an aqueous solution of potassium persulfate with a mass percentage concentration of 20%, and irradiate it with ultraviolet light at 50 °C for 10 h to make the polyethylene film carry hydroxyl groups. Subsequently, react it with an ethanol / water (V:V = 8:2) solution of (3-bromopropyl)trimethoxysilane with a mass percentage concentration of 10% at 25 °C for 8 h. After the reaction, rinse it three times with pure water to obtain a polyethylene film grafted with an ATRP initiator.

[0259] (2) Prepare an ethanol solution of NVP with a mass percentage concentration of 8%, and add a CuCl catalyst and a tris[2-(dimethylamino)ethyl]amine ligand thereto. Among them, the molar percentages of CuCl and tris[2-(dimethylamino)ethyl]amine in the molar amount of NVP are 2% and 5% respectively to obtain a first reaction solution. Immerse the polyethylene film grafted with the ATRP initiator in the first reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for 6 h to form a first hydrophilic anticoagulant layer. After the reaction, take it out, rinse it three times with ethanol, then rinse it three times with pure water, and dry it.

[0260] (3) Prepare a second reaction solution according to the steps of Comparative Example 2, and then immerse the film obtained in (2) in the second reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for 6 h to form a first heparin anticoagulant layer. After the reaction, take it out, rinse it three times with pure water, and dry it.

[0261] (4) Repeat the above steps (2) and (3) once to successively form a second hydrophilic anticoagulant layer and a second heparin anticoagulant layer.

[0262] (5) Prepare an aqueous solution of cysteamine with a mass percentage concentration of 2 wt%, and adjust the pH to 11 with a 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (4) in the cysteamine aqueous solution and react at 30 °C for 4 h to form an active catalytic layer. After the reaction, take it out, rinse it three times with purified water, and dry it to obtain a blood contact material.

[0263] Examples 4 to 10

[0264] Examples 4 to 10 respectively provide a blood contact material, including a substrate, and a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, a second heparin anticoagulant layer, and an active catalytic layer sequentially arranged on the surface of the substrate. The preparation steps are as follows:

[0265] (1) Place the films of different materials shown in Table 1 below in ammonia plasma for 20 min to make the substrate carry amino groups. Subsequently, react with the DMF solution of BiBB at 20 °C for 12 h. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, rinse with DMF three times and then with pure water three times to obtain the film grafted with ATRP initiator.

[0266] (2) Prepare a solution of the hydrophilic anticoagulant monomer shown in Table 1 below, add the first catalyst, the first ligand and optionally the first reducing agent shown in Table 1 below to obtain the first reaction solution. Among them, the dosages of the first catalyst and the first ligand are both in mole percentage of the hydrophilic anticoagulant monomer, and the dosage of the first reducing agent is in mole percentage of the first catalyst. Subsequently, place the film grafted with ATRP initiator into the first reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form the first hydrophilic anticoagulant layer. After the reaction, take it out, rinse with ethanol three times and then with pure water three times, and dry it to obtain the film grafted with the hydrophilic anticoagulant layer.

[0267] (3) Prepare double-bonded heparin according to the steps of Comparative Example 2, prepare an aqueous solution of double-bonded heparin with a mass percentage concentration of 8%, add the second catalyst and the second ligand. Among them, the second catalyst is the same as the first catalyst used in step (2), and the second ligand is the same as the first ligand used in step (2). The mass of the second catalyst is 1% of the mass of double-bonded heparin, and the molar addition amount of the second ligand is 120% of the molar number of the second catalyst to obtain the second reaction solution. Subsequently, immerse the film grafted with the hydrophilic anticoagulant layer in the second reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form the first heparin anticoagulant layer. After the reaction, take it out, rinse with pure water three times, and dry it.

[0268] (4) Repeat steps (2) and (3) once to successively form the second hydrophilic anticoagulant layer and the second heparin anticoagulant layer.

[0269] (5) Prepare an aqueous solution of cysteamine with a mass percentage concentration of 2%, and adjust the pH to 11 with 4 mol / L NaOH solution. Then immerse the film obtained in (4) in the cysteamine aqueous solution and react at 30 °C for 4 h to form the active catalytic layer. After the reaction, take it out, rinse with purified water three times, and dry it to obtain the blood contact material.

[0270] Table 1 Process parameters of Examples 4 to 10

[0271]

[0272] Examples 11 to 13

[0273] Examples 11 to 13 respectively provide a blood contact material, and the preparation steps are as follows:

[0274] (1) Place the polyethylene film in ammonia plasma for 20 minutes to make the polyethylene film carry amino groups. Subsequently, react with a DMF solution of BiBB at 20 °C for 12 hours. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, rinse with DMF three times first, and then rinse with pure water three times to obtain a polyethylene film grafted with an ATRP initiator.

[0275] (2) Prepare the first reaction solution according to the steps of Comparative Example 1. Immerse the polyethylene film grafted with the ATRP initiator in the first reaction solution, seal it, purge with nitrogen for 5 minutes, and then place it in an oven at 30 °C for 6 hours to form a first hydrophilic anticoagulant layer. After the reaction, take it out, rinse with ethanol three times first, and then rinse with pure water three times, and dry.

[0276] (3) Prepare the second reaction solution according to the steps of Comparative Example 2. Then immerse the film obtained in (2) in the second reaction solution, seal it, purge with nitrogen for 5 minutes, and then place it in an oven at 30 °C for 6 hours to form a first heparin anticoagulant layer. After the reaction, take it out, rinse with pure water three times, and dry to obtain a polyethylene film grafted with a first hydrophilic anticoagulant layer and a first heparin anticoagulant layer.

[0277] (4) Repeat steps (2) to (3) once, twice, and three times respectively to obtain a polyethylene film grafted with two hydrophilic anticoagulant layers and two heparin anticoagulant layers, a polyethylene film grafted with three hydrophilic anticoagulant layers and three heparin anticoagulant layers, and a polyethylene film grafted with four hydrophilic anticoagulant layers and four heparin anticoagulant layers, corresponding to Example 11, Example 12, and Example 13 in sequence.

[0278] (5) Prepare an aqueous cysteamine solution with a mass percentage concentration of 2%, and adjust the pH to 11 with a 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (4) in the aqueous cysteamine solution and react at 30 °C for 4 hours to form a catalytic layer. After the reaction, take it out, rinse with purified water three times, and dry to obtain the blood contact material.

[0279] Examples 14 to 16

[0280] Examples 14 to 16 respectively provide a blood contact material, including a substrate, a first hydrophilic anticoagulant layer, a first heparin anticoagulant layer, a second hydrophilic anticoagulant layer, a second heparin anticoagulant layer, and an active catalytic layer that are sequentially stacked on the surface of the substrate. The preparation steps are as follows:

[0281] (1) Place the polyethylene film in ammonia plasma for 20 min to make the polyethylene film carry amino groups. Subsequently, react it with a DMF solution of BiBB at 20 °C for 12 h. In the DMF solution, the mass percentage concentration of BiBB is 10%. After the reaction, rinse it with DMF three times first, and then rinse it with pure water three times to obtain a polyethylene film grafted with an ATRP initiator.

[0282] (2) Prepare the first reaction solution according to the steps of Comparative Example 1. Immerse the polyethylene film grafted with an ATRP initiator in the first reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h. After the reaction, take it out, rinse it with ethanol three times, and then rinse it with pure water three times, and dry it. Prepare the second reaction solution according to the steps of Comparative Example 2, and then immerse the film in the second reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h. After the reaction, take it out, rinse it with pure water three times, and dry it.

[0283] (3) Then repeat step (2) once to obtain a polyethylene film grafted with two layers of hydrophilic anticoagulant layers and two layers of heparin anticoagulant layers layer by layer.

[0284] (4) Prepare a cystamine aqueous solution as shown in Table 2 below, and adjust the pH to that shown in Table 2 with a 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (3) above in the cystamine aqueous solution and react for a period of time at the reaction temperature shown in Table 2 below. After the reaction, take it out, rinse it with purified water three times, and dry it to obtain a blood contact material.

[0285] Table 2 Process parameters of Examples 14 to 16

[0286]

[0287] Example 17

[0288] This example provides a blood contact material, including a substrate, a hydrophilic anticoagulant layer and an active catalytic layer provided on the surface of the substrate. The preparation steps are as follows:

[0289] (1) Place the polyethylene film in ammonia plasma for 20 min to make the polyethylene film carry amino groups. Subsequently, react it with a DMF solution of BiBB at 20 °C for 12 h. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, rinse it with DMF three times first, and then rinse it with pure water three times to obtain a polyethylene film grafted with an ATRP initiator.

[0290] (2) Prepare an ethanol solution of NVP with a mass percentage concentration of 8%. Add a CuCl catalyst and a tris[2-(dimethylamino)ethyl]amine ligand to it. Among them, the percentages of the molar amounts of CuCl and tris[2-(dimethylamino)ethyl]amine in the molar amount of NVP are 2% and 5% respectively to obtain a first reaction solution. Immerse the polyethylene film grafted with an ATRP initiator in the first reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form a first hydrophilic anticoagulant layer on the surface of the polyethylene film. After the reaction, take it out, rinse it 3 times with ethanol first, and then rinse it 3 times with pure water and dry it.

[0291] (3) Prepare an aqueous cysteamine solution with a mass percentage concentration of 2%, and adjust the pH to 11 with a 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (4) in the cysteamine aqueous solution and react at 30 °C for 4 h to form an active catalytic layer. After the reaction, take it out, rinse it 3 times with purified water and dry it to obtain a blood contact material.

[0292] Example 18

[0293] This example provides a blood contact material, including a substrate, a heparin anticoagulant layer and an active catalytic layer provided on the surface of the substrate. The preparation steps are as follows:

[0294] (1) Place the polyethylene film in ammonia plasma for treatment for 20 min to make the polyethylene film carry amino groups. Subsequently, react with a DMF solution of BiBB at 20 °C for 12 h. In the DMF solution of BiBB, the mass percentage concentration of BiBB is 10%. After the reaction, rinse it 3 times with DMF first, and then rinse it 3 times with pure water to obtain a polyethylene film grafted with an ATRP initiator.

[0295] (2) React 1 g of heparin with 0.1 g of methacrylic anhydride in an aqueous sodium hydroxide solution with a pH value of 8 for 8 hours, and then dialyze and freeze-dry to obtain double-bonded heparin.

[0296] (3) Prepare an aqueous solution of double-bonded heparin with a mass percentage concentration of 8%. Add a CuCl catalyst and a tris[2-(dimethylamino)ethyl]amine ligand to it. Among them, the mass of CuCl is 1% of the mass of double-bonded heparin, and the molar amount of the tris[2-(dimethylamino)ethyl]amine ligand is 120% of the molar amount of CuCl to obtain a second reaction solution. Subsequently, immerse the polyethylene film grafted with an ATRP initiator in the second reaction solution, seal it, purge with nitrogen for 5 min, and then place it in an oven at 30 °C for reaction for 6 h to form a heparin anticoagulant layer on the surface of the polyethylene film. After the reaction, take it out, rinse it 3 times with pure water and dry it to obtain a blood contact material.

[0297] (4) Prepare a cysteamine aqueous solution with a mass percentage concentration of 2%, and adjust the pH to 11 with a 4 mol / L NaOH solution. Then immerse the polyethylene film obtained in (4) in the cysteamine aqueous solution and react at 30 °C for 4 h to form an active catalytic layer. After the reaction, take it out, rinse it 3 times with purified water, and dry it to obtain a blood contact material.

[0298] The following is the specific test part:

[0299] 1. In vitro NO release detection

[0300] Use a chemiluminescence NO analyzer (NOA) to detect the NO generated by the decomposition of RSNO in vitro of the blood contact material prepared in Example 1. First, dilute freshly prepared platelet-poor plasma (PPP) 30-fold with PBS buffer (phosphate buffer), and then add 500 μM EDTA, 10 μM S-nitroso-N-acetyl-dl-penicillamine (SNAP, an in vitro NO donor), and 10 μM l-glutathione (GSH) as the working solution. When the sample starts to catalytically decompose SNAP, GSH acts as a reducing agent and NO can be released. The amount of NO released in the solution is calculated through the calibration curve of NOA. The calibration curve is obtained by integrating the NOA signal (ppb·s) during calibration with the amount of NO introduced into the system, where the NO introduced into the system is from the reduction of nitrite in an acidified potassium iodide solution.

[0301] Figure 4 It is a graph of the in vitro NO release detection results of the blood contact material of Example 1. As Figure 4 shown, after the blood contact material of Example 1 is put into the system, the system starts to detect the signal of NO release and gradually strengthens, which indicates that cysteamine, as the material of the catalytic layer, is fixed on the film and effectively plays its role in catalyzing the decomposition of SNAP, thereby producing NO. When the sample is taken out, the NO signal gradually decreases and returns to zero, indicating that the binding of cysteamine on the film is stable and does not fall off into the solution.

[0302] 2. Platelet adhesion experiment

[0303] Test the platelet adhesion of uncoated polyethylene films (blank group), Comparative Examples 1-3, Examples 1-2, and Examples 14-18. First, prepare platelet-rich plasma (PRP) by centrifuging fresh human whole blood. Place the samples on a 24-well plate, add 1 mL of platelet-rich plasma to each well, and add NO donors (10 μM SNAP and 10 μM GSH) to some of the samples while not adding to the other part. Subsequently, incubate all samples at 37 °C for 1 h. After incubation, wash the films with PBS buffer to remove unadhered platelets, and indirectly quantify the number of platelets adhered to the material surface by detecting the LDH released by cells using an LDH cytotoxicity kit. After the reaction is completed, measure the absorbance at 490 nm using an enzyme-linked immunosorbent assay (ELISA) reader. Among them, the absorbance at 490 nm measured with pure PBS buffer is A 0 . The relative adhesion of platelets = (absorbance at 490 nm of the experimental group - A 0 ) / (absorbance at 490 nm of the blank group - A 0 ). The test results are shown in Table 3.

[0304] Table 3 Platelet adhesion test results of each example and comparative example

[0305]

[0306] As shown in Table 3, in Comparative Examples 1-3, due to the coating of a hydrophilic anticoagulant layer, a heparin anticoagulant layer, or a composite coating of a hydrophilic anticoagulant layer and a heparin anticoagulant layer, the platelet adhesion decreased significantly compared to the blank group. However, after adding NO donors, the platelet adhesion hardly changed. In Examples 17 and 18, there were only a hydrophilic anticoagulant layer or a heparin anticoagulant layer, and the relative platelet adhesion changed little. However, due to the chemical grafting of a NO catalytic layer, after adding NO donors, the relative platelet adhesion decreased significantly. The polyethylene films in Examples 1-2 had both a hydrophilic anticoagulant layer and a heparin anticoagulant layer, and a NO catalytic layer grafted with cystamine or selenocystamine through a chemical reaction. When NO donors were added to the PRP, the platelet adhesion further decreased, and the relative adhesion value was only 0.06-0.07. Therefore, the above experimental results show that when the hydrophilic anticoagulant layer, heparin anticoagulant layer, and NO catalytic layer are jointly fixed on the material surface, the anticoagulant effects of the three can be synergistically exerted to further improve the anticoagulant effect on the surface of the device. Examples 14-16 show that when the surface NO grafting amount is higher, it can better catalyze the production of NO and reduce platelet adhesion.

[0307] 3. Long-term stability

[0308] Immerse the samples of Example 1 in PBS buffer for 1 h, 24 h, and 7 days respectively, and then test their water contact angles, heparin densities, and platelet adhesions. The results are shown in Table 4.

[0309] Table 4 Results of the long-term stability experiment of Example 1

[0310]

[0311] As shown in Table 4, after the blood contact material of Example 1 was soaked for 7 days, neither the water contact angle nor the heparin density showed a significant decrease, indicating that neither the hydrophilic anticoagulant layer nor the heparin anticoagulant layer had obvious detachment. In addition, the results of platelet adhesion also showed that there was still an excellent anticoagulant effect after long-term soaking, and the ability to catalyze NO release did not weaken. Therefore, the blood base material prepared in the embodiment of the present invention has very excellent long-term stability because each layer is connected by covalent bonds and has many binding sites.

[0312] The above long-term stability test only takes Example 1 as an example. The connection methods of each layer in the blood contact materials of other examples are the same as those of Example 1 and have long-term stability equivalent to that of Example 1, so they will not be repeated here.

[0313] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0314] The above-described embodiments only represent several implementation manners of the present invention, which are convenient for understanding the technical solutions of the present invention specifically and in detail, but should not be construed as limiting the protection scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments based on the technical solutions provided by the present invention are all within the protection scope of the appended claims of the present invention. Therefore, the protection scope of the present invention patent should be subject to the content of the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A preparation method of a blood-contacting material, characterized in that, it comprises the following steps: Covalently connect an anticoagulant layer on the surface of a substrate by means of atom transfer radical polymerization, the polymer at the end of the anticoagulant layer has an initiator group, and the anticoagulant layer includes one or more of a hydrophilic anticoagulant layer and a heparin anticoagulant layer; React the initiator group with a substance having a NO catalytic release function to prepare the blood-contacting material.

2. The preparation method of the blood-contacting material according to claim 1, characterized in that, the initiator group includes a halogen group, the substance having a NO catalytic release function has an amino group, and in the step of reacting the initiator group with the substance having a NO catalytic release function, the halogen group and the amino group are subjected to a substitution reaction.

3. The preparation method of the blood-contacting material according to claim 2, characterized in that, the step of reacting the initiator group with the substance having a NO catalytic release function satisfies one or more of the following conditions: (1) The substance having a NO catalytic release function includes one or both of cystamine and selenocystamine; (2) The reaction is carried out in an alkaline solution with a pH of 10 to 12; (3) The reaction temperature is 20°C to 40°C and the time is 1h to 12h; (4) The substance having a NO catalytic release function reacts in the form of a solution, and in the solution, the mass percentage concentration of the substance having a NO catalytic release function is 1% to 5%.

4. The preparation method of the blood-contacting material according to claim 1, characterized in that, the preparation step of the anticoagulant layer includes: Graft the initiator group on the surface of the substrate, and the initiator group includes a halogen group; Treat the substrate grafted with the initiator group with a reaction solution containing an anticoagulant monomer, a catalyst and a ligand, and make the anticoagulant monomer carry out an atom transfer radical polymerization reaction on the surface of the substrate grafted with the initiator group under the action of the initiator group, the catalyst and the ligand to prepare the anticoagulant layer.

5. The preparation method of the blood-contacting material according to claim 4, characterized in that, the step of grafting the initiator group on the surface of the substrate satisfies one of the following conditions: (1) The step of grafting the initiator group on the surface of the substrate includes: obtaining a substrate with a hydroxyl group on the surface; Perform a silanization reaction on the hydroxyl group on the surface of the substrate with a silanizing reagent containing an initiator group to graft the initiator group on the surface of the substrate; Optionally, the silanizing reagent containing an initiator group includes one or more combinations of (3-bromopropyl)trimethoxysilane, (3-bromopropyl)triethoxysilane, (3-chloropropyl)trimethoxysilane, (3-bromopropyl)trichlorosilane, 1-bromo-4-(trimethoxysilyl)benzene and (3-chloropropyl)trichlorosilane; Optionally, the silanizing reagent containing an initiator group reacts in the form of a solution, and in the solution, the mass percentage concentration of the silanizing reagent containing an initiator group is 5% to 30%; Optionally, the temperature of the silylation reaction is 25°C to 60°C, and the time is 3 h to 24 h; (2) The step of grafting an initiator group on the surface of the substrate includes: obtaining a substrate with amino groups on its surface; performing an acylation reaction between an acyl halide reagent containing an initiator group and the amino groups on the surface of the substrate; Optionally, the acyl halide reagent containing an initiator group includes one or a combination of two of chloroacetyl chloride and 2-bromo-2-methylpropionyl bromide; Optionally, the acyl halide reagent containing an initiator group reacts in the form of a solution, and in the solution, the mass percentage concentration of the acyl halide reagent containing an initiator group is 5% to 30%; Optionally, the temperature of the acylation reaction is 0°C to 25°C, and the time is 5 h to 48 h.

6. The method for preparing a blood-contacting material according to claim 4, wherein, the anticoagulant layer includes a hydrophilic anticoagulant layer, and the steps for preparing the hydrophilic anticoagulant layer satisfy one or more of the following conditions: (1) The anticoagulant monomer includes one or a combination of acrylamide, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylamide, potassium 3-sulfopropyl methacrylate, N-vinylpyrrolidone, acrylate-capped oligomer, methacrylate-capped oligomer, and zwitterionic monomer; (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 1% to 50%; (3) The molar ratio of the carbon-carbon double bond in the anticoagulant monomer, the catalyst, and the ligand is 1:(0.005 to 0.1):(0.005 to 0.5); (4) The temperature of the atom transfer radical polymerization reaction is 25°C to 70°C, and the time is 2 h to 24 h.

7. The method for preparing a blood-contacting material according to claim 6, wherein, the steps for preparing the hydrophilic anticoagulant layer satisfy one or more of the following conditions: (1) The anticoagulant monomer includes zwitterionic monomers, and the structural formula of the zwitterionic monomer is as shown in the following formula (II): In formula (II), R 1 includes a zwitterionic group, and R 2 includes -NH- or -O-, and R 3 includes -H or -CH 3 , and the zwitterionic group includes one or more of phosphorylcholine, sulfobetaine, and carboxybetaine; (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 5% to 30%; (3) The molar ratio of the carbon-carbon double bond in the anticoagulant monomer, the catalyst, and the ligand is 1:(0.01 to 0.1):(0.01 to 0.3); (4) The time of the atom transfer radical polymerization reaction is 5 h to 10 h.

8. The method for preparing a blood-contacting material according to claim 4, wherein, the anticoagulant layer includes a heparin anticoagulant layer, and the steps for preparing the heparin anticoagulant layer satisfy one or more of the following conditions: (1) The anticoagulant monomer includes a heparin-like substance with carbon-carbon double bonds; (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 5% to 30%; (3) The mass ratio of the anticoagulant monomer to the catalyst is 1:(0.005 to 0.05), and the molar ratio of the catalyst to the ligand is 1:(1 to 5); (4) The temperature of the atom transfer radical polymerization reaction is 25°C to 70°C, and the time is 2 h to 12 h.

9. The method for preparing a blood-contacting material according to claim 8, wherein, the steps for preparing the heparin anticoagulant layer satisfy one or more of the following conditions: (1) The preparation steps of the anticoagulant monomer include: reacting a heparin-like substance with a modifier containing a carbon-carbon double bond and a reactive group, so that the heparin-like substance has a carbon-carbon double bond, and the reactive group includes one or more of a carboxylic acid group, an acid anhydride group, an epoxy group, an amino group, and an amide group; (2) In the reaction solution, the mass percentage concentration of the anticoagulant monomer is 5% to 10%; (3) The mass ratio of the anticoagulant monomer to the catalyst is 1:(0.005 to 0.01), and the molar ratio of the catalyst to the ligand is 1:(1.5 to 2); (4) The time of the atom transfer radical polymerization reaction is 2 h to 6 h.

10. According to the method for preparing a blood-contacting material described in claim 4, wherein, the reaction solution satisfies one or more of the following conditions: (1) The catalyst includes one or a combination of multiple low-valence salts of copper, iron, molybdenum, chromium, rhenium, ruthenium, rhodium, and nickel; optionally, the catalyst includes CuCl, FeCl 2 and RuCl 2 one or several of them; (2) The ligand includes a combination of one or more of an amine substance and a phosphine substance. The amine substance includes one or more of N,N,N,N,N-pentamethyldiethylenetriamine, 1,1,4,7,10,10-hexamethyltriethylenetetramine, tris[2-(dimethylamino)ethyl]amine, tris(2-pyridylmethyl)amine, 1,4,8,11-tetraazacyclotetradecane, 2,2'-bipyridine, 4,4'-di-tert-butyl-2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, and 4,4'-bis(trifluoromethyl)-2,2'-bipyridine. The phosphine substance includes triphenylphosphine. Optionally, the ligand includes one or more of N,N,N,N,N-pentamethyldiethylenetriamine, tris[2-(dimethylamino)ethyl]amine, and 4,4'-di-tert-butyl-2,2'-bipyridine; (3) The reaction solution further contains a reducing agent. The reducing agent includes a high-valent salt corresponding to the metal used in the catalyst or a radical thermal initiator, and the molar ratio of the reducing agent to the catalyst is (0.1 to 0.3):

1.

11. According to the method for preparing a blood-contacting material described in any one of claims 4 to 10, wherein, the anticoagulant layer includes a hydrophilic anticoagulant layer and a heparin anticoagulant layer. The preparation steps of the anticoagulant layer include: grafting an initiator group on the surface of the substrate, and the initiator group includes a halogen group; treating the substrate grafted with the initiator group with a first reaction solution containing a first anticoagulant monomer, a first catalyst, and a first ligand, so that the first anticoagulant monomer undergoes an atom transfer radical polymerization reaction on the surface of the substrate grafted with the initiator group to prepare the hydrophilic anticoagulant layer; treating the substrate with a hydrophilic anticoagulant layer with a second reaction solution containing a second anticoagulant monomer, a second catalyst, and a second ligand, so that the second anticoagulant monomer undergoes an atom transfer radical polymerization reaction on the surface of the substrate with a hydrophilic anticoagulant layer to prepare the heparin anticoagulant layer.

12. According to the method for preparing a blood-contacting material described in claim 11, wherein, The preparation steps of the anticoagulant layer further include repeating the preparation steps of the hydrophilic anticoagulant layer and / or the heparin anticoagulant layer so that the total number of layers of the anticoagulant layer is 3 to 8 layers, and in the anticoagulant layer, the hydrophilic anticoagulant layer and the heparin anticoagulant layer are alternately stacked.

13. A blood contacting material, characterized in that, it comprises a substrate, an anticoagulant layer disposed on the surface of the substrate, and an active catalytic layer disposed on the surface of the anticoagulant layer away from the substrate; wherein, the anticoagulant layer is covalently connected to the surface of the substrate by means of atom transfer radical polymerization, and the anticoagulant layer comprises one or more of a hydrophilic anticoagulant layer and a heparin anticoagulant layer; the active catalytic layer can catalytically release NO, and the active catalytic layer is covalently connected to the end of the polymer in the anticoagulant layer.

14. The blood contacting material according to claim 13, characterized in that, the blood contacting material satisfies one or more of the following conditions: (1) The material of the active catalytic layer comprises one or more of cystamine and selenocystamine; (2) The active catalytic layer and the anticoagulant layer are connected by a C-N bond; (3) The anticoagulant layer comprises a hydrophilic anticoagulant layer, and the water contact angle of the surface of the substrate provided with the anticoagulant layer and the active catalytic layer is less than 50°; (4) The anticoagulant layer includes a heparin anticoagulant layer, and the heparin density on one surface of the substrate provided with the anticoagulant layer and the active catalytic layer is not less than 0.5 μg / cm 2 ; (5) The anticoagulant layer comprises a hydrophilic anticoagulant layer and a heparin anticoagulant layer, and the total number of layers of the anticoagulant layer is 2 to 8 layers. In the anticoagulant layer, the hydrophilic anticoagulant layer and the heparin anticoagulant layer are alternately stacked.

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