Long-acting heparin anticoagulant coating and preparation method thereof

Abstract

The invention belongs to the technical field of heparin anticoagulant coatings, and particularly relates to a long-acting heparin anticoagulant coating and a preparation method thereof. The long-acting heparin anticoagulation coating is formed by curing a long-acting heparin anticoagulation coating, and the long-acting heparin anticoagulation coating comprises a component A and a component B; the raw materials of the component A comprise at least one of a monomer, an initiator, a polymer, poly-L-lysine hydrobromide, streptavidin, sodium hyaluronate and crotonaldehyde; wherein the monomer comprises at least one of MPC, PEGMA and SBMA, and the polymer comprises an amino substrate; the raw materials of the component B comprise at least one of a reducing agent and heparin. The preparation method comprises the following steps: circulating the long-acting heparin anticoagulant coating in an ECMO system, and curing to obtain the long-acting heparin anticoagulant coating. The long-acting heparin anticoagulant coating constructed by the invention can realize a lasting and stable anticoagulant effect in an ECMO system, and can overcome the defects in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of heparin anticoagulant coatings, and particularly relates to a long-acting heparin anticoagulant coating and a preparation method thereof. Background Art

[0002] Extracorporeal membrane oxygenation (ECMO) is used in intensive care to treat patients with severe respiratory and cardiac failure. ECMO puts the blood of critically ill patients in contact with a non-endothelialized circuit, which may put the patient at risk of both clotting and bleeding. Therefore, continuous anticoagulation management is required during ECMO, and the extracorporeal circuit also needs to be coated with an anticoagulant coating. The membrane oxygenator is an important component of the extracorporeal circuit and is prone to large thrombi due to its large surface area and the presence of low flow, turbulent, and stagnant flow areas.

[0003] The existing heparin anticoagulant coating fixes heparin on the surface of the extracorporeal circuit material by physical adsorption, layer-by-layer electrostatic adhesion, chemical bonding and other methods. However, the existing methods have the following limitations: 1. The stability problem of heparin coating. The physical adsorption and electrostatic adhesion stability of heparin are poor. 2. It is difficult for heparin molecules to maintain biological activity after the modification process. Although multiple covalent bonds can better stabilize heparin on the surface, non-specific fixation will affect the free movement of heparin molecules and limit the biological activity of the heparin layer. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a long-acting heparin anticoagulant coating and a preparation method thereof.

[0005] In order to achieve the above-mentioned object and other related objects, the present invention provides the following technical solutions: In the first aspect, the long-acting heparin anticoagulant coating is formed by curing the long-acting heparin anticoagulant coating, and the long-acting heparin anticoagulant coating includes component A and component B; the raw materials of component A include at least one of monomer, initiator, polymer, poly-L-lysine hydrobromide, streptavidin, sodium hyaluronate, and crotonaldehyde; the raw materials of component B include reducing agent and heparin. Among them, the monomer includes at least one of MPC, PEGMA, and SBMA; the polymer includes an amino substrate.

[0006] In one embodiment, the amino-based substrate is a star-shaped polymer with a primary amine ratio of ≥ 25%.

[0007] In one embodiment, the amino-based substrate includes at least one of polyamidoamine, polylysine, polyethyleneimine, and polypropyleneimine.

[0008] In one embodiment, the reducing agent includes at least one of sodium borohydride and sodium cyanoborohydride.

[0009] In one embodiment, the molecular weight of heparin is 3 kDa-10 kDa, and heparin includes at least one of low molecular weight heparin of 3-5 kDa, medium molecular weight heparin of 5-7 kDa, and high molecular weight heparin of 7-10 kDa.

[0010] In one embodiment, by weight, MPC is 30-40 parts, PEGMA is 10-20 parts, SBMA is 5-15 parts, the initiator is 0.5-1.5 parts, the polymer is 1.5-2.5 parts, poly-L-lysine hydrobromide is 0.8-1.2 parts, streptavidin is 0.3-0.7 parts, sodium hyaluronate is 0.1-0.3 parts, crotonaldehyde is 0.01-0.03 parts, and the reducing agent is 1-5 parts.

[0011] In a second aspect, the method for preparing the aforementioned long-acting heparin anticoagulant coating comprises the following steps: stirring and mixing the raw materials of component A to obtain a component A solution; stirring and mixing the raw materials of component B to obtain a component B solution; The component A solution is circulated in the ECMO system and solidified after circulation. After circulation, the component B solution is circulated in the ECMO system again and dried to form a long-acting heparin anticoagulant coating in the ECMO system.

[0012] More specifically, a portion of the component A solution is first circulated in the ECMO system and solidified after circulation, and then the remaining component A solution is circulated in the ECMO system. After circulation, the component B solution is circulated in the ECMO system and dried to form a long-acting heparin anticoagulant coating in the ECMO system.

[0013] It should be noted that when the component A solution is divided into two parts and introduced into the ECMO system, the two parts of the component A solution can be prepared into different component A solutions according to the raw materials of component A.

[0014] In one embodiment, the ECMO system includes at least one of an oxygenator, a power pump, and an arteriovenous line.

[0015] In one embodiment, the cycle conditions include 20-80°C.

[0016] In one embodiment, the cycling conditions include 100-1500 LPM.

[0017] The beneficial effects of the present invention are: 1. Long-term anticoagulant effect: The long-term heparin anticoagulant coating provided in this application can effectively prolong the anticoagulant effect time of heparin, reducing the need for frequent replacement or replenishment of heparin during the use of the coating. This long-term effect enables the coating to continuously maintain a good anticoagulant effect in the ECMO system, significantly reducing the risk of thrombosis.

[0018] 2. Improve biocompatibility: The amino-based substrate in the coating has good biocompatibility, which can reduce direct reactions with blood components and ensure the safety and stability of the device.

[0019] 3. Stable heparin binding ability: By selecting appropriate polymer substrates and reducing agents, this application ensures that heparin can be firmly bound to the surface of the ECMO system, avoiding rapid loss or dissociation of heparin, thereby maintaining the long-term anticoagulant ability of the coating.

[0020] 4. Coating uniformity and strong adhesion: Due to the combination of initiator, monomer and amino substrate, the coating of the present application can form a uniform and highly adhesive coating, ensuring that heparin can effectively cover the surface of the ECMO system and exert a stable anticoagulant effect for a long time.

[0021] 5. The heparin molecules constructed in the present application can present a directional "array" distribution. Such construction also solves the problems existing in the prior art, avoids excessive restrictions caused by multiple covalent bonds, maintains the conformational freedom of the heparin molecules, and achieves a balance between directional fixation and activity maintenance.

[0022] In general, the long-acting heparin anticoagulant coating constructed in the present application can achieve a long-lasting and stable anticoagulant effect in the ECMO system and can solve the defects of the existing technology.

[0023] The remaining detailed mechanisms are described in the examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0025] In the attached picture: Figure 1 It is a schematic diagram of the structure of the ECMO system of Example 1 of the present invention.

[0026] Figure 2 Schematic diagram of the circuit of oxygenator 1 according to Example 2 of the present invention. It should be noted that the tee is omitted in the figure.

[0027] Figure 3 It is the standard curve for determining the content of heparin sodium of the present invention.

[0028] Figure 4 It is a schematic diagram of the results of the stability of the heparin coating of the present invention.

[0029] Figure 5 It is the heparin sodium activity test standard curve of the present invention.

[0030] Figure 6It is a schematic diagram of the results of the activity of the heparin coating of the present invention.

[0031] Figure 7 It is a schematic diagram of the effect of the coating of the present invention on the gas flux.

[0032] The markings in the figure are: 1. oxygenator; 2. power pump; 3. arteriovenous line; 4. patient; 5. inlet port one; 6. outlet port one; 7. inlet port two; 8. outlet port two; 9. circulation pump.

[0033] It should be noted that Figure 1-Figure 2 This is to schematically illustrate the positional relationship of each component / equipment. The specific structure of each component / equipment of the ECMO system is well known and is not a key factor affecting the technical effect of the present application, so it will not be elaborated on. DETAILED DESCRIPTION

[0034] The applicant will describe embodiments of the present invention in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, if not otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized with reference to existing literature or known methods, and for reactions or test conditions not listed, they are also conventional techniques that are easily available to those skilled in the art. The terminology used in the present invention is general in the art, and those skilled in the art can clearly understand its implication and will not repeat them one by one.

[0035] Example 1 The ECMO system includes an oxygenator 1 and a power pump 2. Each device in the ECMO system is connected by a pipeline. Specifically: refer to Figure 1 The oxygenator 1 has a blood channel for blood flow inside, and the two ends of the blood channel are respectively an inlet end 5 and an outlet end 6. The power pump 2 also has a blood channel for blood flow, and the two ends of the blood channel are respectively an inlet end 7 and an outlet end 8.

[0036] The ECMO system also includes a plurality of arteriovenous lines 3. The inlet end 1 5 is connected to one end of an arteriovenous line 3, and the other end of the arteriovenous line 3 is connected to the outlet end 2 8.

[0037] The inlet port 2 7 is connected to one end of another arteriovenous line 3, and the other end of the arteriovenous line 3 is connected to the patient 4. The patient 4 is also connected to the outlet port 1 6 through the third arteriovenous line 3.

[0038] The working process includes: the ECMO system cooperates with the patient 4 to form a loop. The power pump 2 extracts unoxygenated venous blood from the patient 4 and delivers it to the inlet end 5 (i.e., the inlet) of the oxygenator 1. The blood enters the oxygenator 1 for oxygenation, and then the oxygenated blood is delivered back to the patient 4 from the outlet end 6 (i.e., the outlet) of the oxygenator 1. The basic structure and principle of the ECMO system and the rest of the working methods are well known, so they are not described in detail.

[0039] Example 2 A long-acting heparin anticoagulant coating is prepared. The long-acting heparin anticoagulant coating comprises component A and component B.

[0040] By weight, unless otherwise specified, select 99% purity, medical grade, available from Sigma-Aldrich: 1. Component A, component A is the bottom layer, component A is divided into component A1 and component A2: Component A1: (1) Monomer: MPC (2-methacryloyloxyethyl phosphorylcholine): 30-40 parts; PEGMA (polyethylene glycol dimethacrylate): 10-20 parts, MW 2000; SBMA (sulfobetaine methacrylate): 5-15 parts; (2) Initiator: AIBN (azobisisobutyronitrile): 0.5-1.5 parts; Component A2: (1) Polymer: The polymer includes an amino-based substrate, which is a star-shaped polymer with a primary amine ratio of ≥25%, and the amino-based substrate includes at least one of polyamide-amine, polylysine, polyethyleneimine, and polypropyleneimine.

[0041] Wherein, polymer: 1.5-2.5 parts, polyethyleneimine: MW 25000; (2) Additives: Poly-L-lysine hydrobromide: 0.8-1.2 parts, Sigma-Aldrich, model P7890; Streptavidin: 0.3-0.7 parts, Thermo Fisher; Sodium hyaluronate: 0.1-0.3 parts; Crotonaldehyde: 0.01-0.03 parts.

[0042] 2. Component B: Component B is the functional layer: (1) The reducing agent includes at least one of sodium borohydride and sodium cyanoborohydride, 1-5 parts.

[0043] (2) Heparin: molecular weight 3kDa-10kDa, concentration range 0.1-5%.

[0044] Low molecular weight heparin (3-5kDa): 1.0-2.0 copies; Medium molecular weight heparin (5-7 kDa): 0.8-1.2 copies; High molecular weight heparin (7-10kDa): 0.3-0.7 parts.

[0045] It should be noted that there are technical problems in the prior art: it is difficult for heparin molecules to maintain biological activity after the modification process. Although multiple covalent bonds can better stabilize heparin on the surface, non-specific fixation will affect the free movement of heparin molecules and limit the biological activity of the heparin layer.

[0046] This application constructs a multi-layer structure (number of layers ≥ 1 layer), the first layer uses component A to construct the bottom layer, and the second layer uses component B to construct the functional layer: In the bottom layer: Component A1: 1) MPC is used to form a phosphatidylcholine-like structure to simulate the cell membrane surface, and a regular brush-like structure is formed through self-assembly to increase the surface hydrophobicity, which can synergize with PEGMA to form an amphiphilic interface. 2) PEGMA with MW2000 is used to provide a moderate chain length, which ensures flexibility without affecting subsequent modifications, and forms an interpenetrating network structure with MPC to enhance mechanical stability. The PEG segment provides a steric hindrance effect to reduce nonspecific adsorption. 3) SBMA is used to introduce sulfonic acid groups to provide negative charge distribution, which can synergize with MPC to enhance the ability to resist protein adsorption, adjust the surface hydrophilicity, and optimize the interface properties.

[0047] Component A2: 1) Star-shaped amino substrates are used, and their high primary amine ratio (>25%) can provide more active sites. The star-shaped structure can increase spatial availability, form chemical bonds with the substrate, and improve stability. 2) Poly-L-lysine forms a directional bridging structure with streptavidin, and hyaluronic acid provides a three-dimensional network scaffold to achieve precise directional arrangement of heparin molecules.

[0048] In the functional layer: 1) Construct a multi-level molecular weight heparin system: low molecular weight heparin (3-5kDa) is used for biotin labeling to provide recognition sites; medium molecular weight heparin (5-7kDa) is used for directional modification to maintain the active conformation; high molecular weight heparin (7-10kDa) is used for sustained release through degradable bonds. This can not only ensure the activity of the heparin molecule, but also achieve directional movement. 2) Reducing agent: selectively reduce the aldehyde group at the end of the heparin molecule to form a primary alcohol group. It can undergo a reductive amination reaction with the amino substrate to form a stable covalent bond. It can also control the reaction rate to avoid conformational changes caused by too fast cross-linking.

[0049] In this embodiment, the bottom layer and the functional layer form a double-layer structure with a "gradient transition", the brush-like structure of component A1 and the star-like structure of component A2 in the bottom layer penetrate each other, and the heparin molecules in the functional layer present a directional "array" distribution.

[0050] Such a construction also solves the problems existing in the prior art, avoids excessive restrictions caused by multiple covalent bonds, maintains the conformational freedom of the heparin molecules, and achieves a balance between directional fixation and activity maintenance.

[0051] The ECMO system is managed for anticoagulation. Different long-acting heparin anticoagulant coatings are prepared and used for different devices to form a long-acting heparin anticoagulant coating, as follows: Example 3 refer to Figure 2 , which is different from Example 1, the patient 4 is not added to the circuit, the power pump 2 is replaced by a circulation pump 9, and the oxygenator 1 and the circulation pump 9 are connected by an arteriovenous line 3 in the same manner as in Example 1.

[0052] The long-acting heparin anticoagulant coating is circulated between the blood channel of the oxygenator 1 and the arteriovenous pipeline 3 through the circulation pump 9. A tee can be connected between the circulation pump 9 and the arteriovenous pipeline 3. The tee pipeline is connected to the external long-acting heparin anticoagulant coating, which facilitates the introduction of the external long-acting heparin anticoagulant coating into the circulation loop.

[0053] Referring to Example 2, the specific method of introducing the long-acting heparin anticoagulant coating in this example is as follows: 1. Prepare component A solution: Prepare component A1 solution: 35 parts of MPC, 15 parts of PEGMA, 10 parts of SBMA, 0.8 parts of AIBN and 300 parts of deionized water are stirred and mixed at 300rpm at 35°C to obtain component A1 solution. Prepare component A2 solution: 2 parts of polyethyleneimine, 1 part of poly-L-lysine hydrobromide, 0.5 parts of streptavidin, 0.2 parts of sodium hyaluronate, 0.01 parts of crotonaldehyde and 100 parts of deionized water are stirred and mixed at 300rpm to obtain component A2 solution. Circulate component A1 solution at 900LPM at 25°C for 30min. After circulation, pass 60°C hot air to dry. Circulate component A2 solution at 800LPM at 25°C for 10min.

[0054] 2. Prepare component B solution: 1 part sodium borohydride, 1.5 parts low molecular weight heparin, 1 part medium molecular weight heparin, 0.5 parts high molecular weight heparin and 100 parts deionized water are stirred and mixed at 300rpm to obtain component B solution. Circulate the component B solution at 800 LPM at 50°C for 12 hours. After circulation, clean the oxygenator 1 with pure water, and then blow dry the oxygenator 1 with dry clean air.

[0055] Through the aforementioned steps, the long-acting heparin anticoagulant coating forms a long-acting heparin anticoagulant coating in the oxygenator 1 .

[0056] Example 4 Different from Example 1, the patient 4 and the oxygenator 1 are not added to the circuit, and the arteriovenous lines 3 at both ends of the power pump 2 are connected, that is, the two ends of the blood channel of the power pump 2 are connected to form a circulation loop.

[0057] The circulation pump 9 and the tee can also be introduced with reference to Example 3. It is only necessary to pass the external long-acting heparin anticoagulant coating into the circulation loop. This is not a key factor affecting the technical effect of the present application and can be accomplished using conventional means, so it will not be described in detail.

[0058] Referring to Example 2, the specific method of introducing the long-acting heparin anticoagulant coating in this example is as follows: 1. Prepare component A solution: Prepare component A1 solution: 35 parts of MPC, 15 parts of PEGMA, 10 parts of SBMA, 0.8 parts of AIBN and 300 parts of deionized water are stirred and mixed at 300rpm at 35°C to obtain component A1 solution. Prepare component A2 solution: 2 parts of polyethyleneimine, 1 part of poly-L-lysine hydrobromide, 0.5 parts of streptavidin, 0.2 parts of sodium hyaluronate, 0.01 parts of crotonaldehyde and 100 parts of deionized water are stirred and mixed at 300rpm to obtain component A2 solution. Circulate component A1 solution at 30°C at 500LPM for 60min. After circulation, pass 60°C hot air to dry. Circulate component A2 solution at 45°C at 100LPM for 60min.

[0059] 2. Prepare component B solution: 1 part sodium cyanoborohydride, 1.5 parts low molecular weight heparin, 1 part medium molecular weight heparin, 0.5 parts high molecular weight heparin and 100 parts deionized water are stirred and mixed at 300rpm to obtain component B solution. Circulate the component B solution at 100 LPM at 25°C for 24 hours. After circulation, clean the blood channel of power pump 2 with pure water, and then dry the pump head in an oven at 60°C for 4 hours.

[0060] Through the aforementioned steps, the long-acting heparin anticoagulant coating forms a long-acting heparin anticoagulant coating in the power pump 2 .

[0061] Example 5 Different from Example 1, the patient 4, oxygenator 1 and power pump 2 are not added to the circuit, and the arteriovenous line 3, circulation pump 9 and tee are connected in series to form a circulation circuit. It is only necessary to pass the external long-acting heparin anticoagulant coating into the circulation circuit. This is not a key factor affecting the technical effect of the present application and can be accomplished by conventional means, so it is not described in detail.

[0062] Referring to Example 2, the specific method of introducing the long-acting heparin anticoagulant coating in this example is as follows: 1. Prepare component A solution: Prepare component A1 solution: 35 parts of MPC, 15 parts of PEGMA, 10 parts of SBMA, 0.8 parts of AIBN and 300 parts of deionized water are stirred and mixed at 300 rpm at 35°C to obtain component A1 solution. Prepare component A2 solution: 2 parts of polyethyleneimine, 1 part of poly-L-lysine hydrobromide, 0.5 parts of streptavidin, 0.2 parts of sodium hyaluronate, 0.01 parts of crotonaldehyde and 100 parts of deionized water are stirred and mixed at 300 rpm to obtain component A2 solution. Circulate component A1 solution at 30°C at 500 LPM for 90 minutes. After circulation, pass 60°C hot air to dry. Then circulate component A2 solution at 65°C at 1500 LPM for 35 minutes.

[0063] 2. Prepare component B solution: 1 part sodium cyanoborohydride, 1.5 parts low molecular weight heparin, 1 part medium molecular weight heparin, 0.5 parts high molecular weight heparin and 100 parts deionized water are stirred and mixed at 300rpm to obtain component B solution. Circulate the component B solution at 1500 LPM at 65°C for 0.5h. After circulation, clean the inner surface of the arteriovenous line 3 with pure water, and then pass dry clean air to dry the venous line 3.

[0064] Through the aforementioned steps, the long-acting heparin anticoagulant coating forms a long-acting heparin anticoagulant coating in the venous line 3 .

[0065] Detection: (1) Determination of heparin content: Toluidine blue spectrophotometry is used. The specific steps are as follows: In phosphate buffered saline at pH 7.4, the determination is carried out using the principle of electrostatic interaction between toluidine blue and sodium heparin. The absorbance of unbound toluidine blue at 629 nm and the decrease in absorbance are linearly related to the sodium heparin concentration within a certain range.

[0066] Preparation of standard solution: Use purified water to prepare at least six sodium heparin standard solutions in the range of 20-100ug / mL, add sodium heparin standard solution and 0.0005% toluidine blue solution in a volume ratio of 1:1, and test the absorbance value of the reaction solution at 631nm. Use heparin concentration as the horizontal axis and absorbance as the vertical axis to make a standard curve, and use a linear equation for fitting, R 2 Must be above 0.995. Figure 3 .

[0067] Test sample test: Take samples of the same material with heparin coating and without coating of a specific surface area and place them in a test tube. Add 0.0005% toluidine blue solution of the same volume as the heparin sodium standard solution at a ratio of 1mL / cm² of the sample surface area to balance, and then refer to the standard curve test steps. Substitute the test absorbance value into the standard curve to calculate the heparin concentration C1 of the sample.

[0068] The heparin content of the sample that had been eluted (physiological saline, circulated and flushed at a flow rate of 7 L / min) for 8 days was measured, and then the heparin content per unit surface area of ​​the sample was calculated according to formula (1), thereby obtaining a dynamic change curve of the heparin content on the coating surface to evaluate the stability of the coating. The long-acting heparin anticoagulant coating in the comparative example 1 (selecting the existing pump head on the market: Maikewei BE-RF32) and the power pump 2 of Example 4 were measured respectively using the above method.

[0069] The calculation formula (1) is: H = (C1 × V1) / S1 (1) Where: H: Heparin content per unit surface area of ​​the sample (μg / cm²); C1 is the heparin concentration in the sample extract (μg / mL); V1 is the volume of the extract (mL); S1 is the sample surface area (cm²).

[0070] With time (number of days of simulated washout in vitro) as the horizontal axis and heparin content (heparin content per unit surface area H) as the vertical axis, a curve of heparin content changing with time was plotted. The results are as follows: Figure 4 shown.

[0071] Analysis: Compared with Comparative Example 1, the coating stability of Example 4 of the present application is better.

[0072] (2) Heparin activity test: Heparin forms a complex with antithrombin III (AT-III), inhibiting the activity of excess added factor Xa. The chromogenic substrate specifically binds to the remaining factor Xa and hydrolyzes to release p-nitroaniline (pNA). The absorbance at 405 nm is inversely proportional to the heparin concentration in the reaction system. Prepare standard heparin sodium solutions of different concentrations, add antithrombin solution, chromogenic substrate solution and factor Xa solution in sequence, and finally add acetic acid solution to terminate the reaction. Test the absorbance at 405 nm, draw a standard curve with the logarithm of the heparin sodium concentration as the horizontal axis and the absorbance as the vertical axis, and use a linear equation for fitting. R 2 Must be above 0.99. Figure 5 .

[0073] Take a sample of a certain surface area and place it in a test tube. Add the same volume of buffer as the standard solution to balance it. Refer to the standard curve test steps. Substitute the absorbance value of the sample into the standard curve to calculate the heparin concentration C2 of the sample. Calculate the total amount of heparin anti-Xa factor activity Q per unit area of ​​the coating surface of the sample according to formula (2): Q = (C2 × V2) / S2 (2) Where: Q: Total amount of heparin anti-factor Xa activity per unit area of ​​the coating sample, in IU / cm 2 ; C2: sample heparin concentration, in IU / mL; V2: solvent volume, in milliliters (mL), in this test: 0.25mL; S1 is the sample surface area (cm²), which is 1cm in this test. 2 .

[0074] The long-acting heparin anticoagulant coating in the oxygenator 1 of the comparative example 2 (the oxygenator currently available on the market: the Mycove HLS oxygenator) and the oxygenator 1 of the embodiment 3 were measured respectively by the aforementioned method.

[0075] A bar graph was drawn with Comparative Example 2 and Example 3 as the abscissa and the heparin coating activity (the total amount of heparin anti-Xa factor activity Q per unit area of ​​the coating surface of the sample) as the ordinate. The results are shown in FIG. Figure 6 shown.

[0076] Analysis: Compared with Comparative Example 2, the heparin activity of Example 3 of the present application is higher.

[0077] (3) Gas permeation test: Gas permeation (gas flux) refers to the volume of gas that passes through a sample per unit area and per unit time at a constant temperature and unit pressure difference when the permeation is stable. It is usually expressed as a volume value at standard temperature and 1 standard atmospheric pressure, with the unit of mL / (cm²×min×bar). When gas passes through a polymer dense membrane, the gas molecules first contact the membrane, then dissolve on the membrane surface, thereby generating a concentration gradient on both sides of the membrane surface, causing the gas molecules to diffuse forward in the membrane and reach the other side of the membrane and be decomposed from the surface.

[0078] The oxygenation membrane of the oxygenator is used to separate the permeation cavity of a constant volume into two independent spaces, and a test gas (oxygen) of a certain pressure is filled into one side (the high-pressure side) to form a pressure difference between the two cavities. The volume of the test gas that permeates from the high-pressure side through the sample into the low-pressure side is the test gas permeation of the oxygenator. Among them, the oxygenator contains an oxygenation membrane, so it is suitable for detection by this method, which is well known and will not be elaborated.

[0079] The above method was used to measure the oxygenator 1 of Comparative Example 2 (selecting the oxygenator currently available on the market: Mycove HLS oxygenator) and Example 3, and Comparative Example 3, respectively, where Comparative Example 3 is the oxygenator 1 of Example 1 that is not coated with the long-acting heparin anticoagulant coating. The control membrane area is 10 cm 2 , time is 30s, pressure difference is 1bar.

[0080] A bar graph is drawn with Comparative Example 2 and Example 3 and Comparative Example 3 as the abscissa and the gas flux as the ordinate. The results are as follows: Figure 7 shown.

[0081] Analysis: The gas flux reflects the gas transmission speed of different oxygenators. Comparative Example 3 has a higher gas transmission speed because the coating will weaken this performance of the oxygenator. However, compared with Comparative Example 2, the gas flux of Example 3 of the present application is higher, indicating that the long-acting anticoagulation coating prepared by the method of the present application has less effect on the gas flux of oxygenator 1.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A long-acting heparin anticoagulant coating, wherein the long-acting heparin anticoagulant coating is formed by curing the long-acting heparin anticoagulant coating, and is characterized in that: The long-acting heparin anticoagulant coating includes component A and component B; the raw materials of component A include at least one of monomer, initiator, polymer, poly-L-lysine hydrobromide, streptavidin, sodium hyaluronate, and crotonaldehyde, and the raw materials of component B include at least one of a reducing agent and heparin; wherein the monomer includes at least one of MPC, PEGMA, and SBMA, and the polymer includes an amino substrate.

2. The long-acting heparin anticoagulant coating according to claim 1, characterized in that: The amino-based substrate is a star-shaped polymer with a primary amine ratio of ≥25%.

3. The long-acting heparin anticoagulant coating according to claim 1, characterized in that: The amino-based substrate includes at least one of polyamidoamine, polylysine, polyethyleneimine, and polypropyleneimine.

4. The long-acting heparin anticoagulant coating according to claim 1, characterized in that: The reducing agent includes at least one of sodium borohydride and sodium cyanoborohydride.

5. The long-acting heparin anticoagulant coating according to claim 1, characterized in that: The molecular weight of heparin is 3 kDa-10 kDa, and heparin includes at least one of low molecular weight heparin of 3-5 kDa, medium molecular weight heparin of 5-7 kDa, and high molecular weight heparin of 7-10 kDa.

6. The long-acting heparin anticoagulant coating according to claim 1, characterized in that: In parts by weight, MPC is 30-40 parts, PEGMA is 10-20 parts, SBMA is 5-15 parts, initiator is 0.5-1.5 parts, polymer is 1.5-2.5 parts, poly-L-lysine hydrobromide is 0.8-1.2 parts, streptavidin is 0.3-0.7 parts, sodium hyaluronate is 0.1-0.3 parts, crotonaldehyde is 0.01-0.03 parts, and reducing agent is 1-5 parts.

7. The method for preparing the long-acting heparin anticoagulant coating according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: stirring and mixing the raw materials of component A to obtain a solution of component A; stirring and mixing the raw materials of component B to obtain a solution of component B; The component A solution is circulated in the ECMO system and solidified after circulation. After circulation, the component B solution is circulated in the ECMO system again and dried to form a long-acting heparin anticoagulant coating in the ECMO system.

8. The method for preparing the long-acting heparin anticoagulant coating according to claim 7, characterized in that: The ECMO system includes at least one of an oxygenator, a power pump, and an arteriovenous line.

9. The method for preparing the long-acting heparin anticoagulant coating according to claim 7, characterized in that: The cycling conditions included 20-80°C.

10. The method for preparing the long-acting heparin anticoagulant coating according to claim 7, characterized in that: Cycling conditions included 100-1500 LPM.

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