Long-acting heparin anticoagulant coating and preparation method thereof

Abstract

The present invention belongs to the technical field of heparin anticoagulant coatings, and in particular to a long-acting heparin anticoagulant coating and a preparation method thereof. The long-acting heparin anticoagulant coating is formed by curing the long-acting heparin anticoagulant coating, which includes component A and component B; the raw materials of component A include at least one of a monomer, an initiator, a polymer, poly-L-lysine hydrobromide, streptavidin, sodium hyaluronate, and crotonaldehyde; wherein the monomer includes at least one of MPC, PEGMA, and SBMA, and the polymer includes an amino substrate; the raw materials of component B include at least one of a reducing agent and heparin. Preparation method: the long-acting heparin anticoagulant coating is circulated in the ECMO system and cured to obtain a long-acting heparin anticoagulant coating. 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 prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of heparin anticoagulant coatings, and in particular 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 exposes the blood of critically ill patients to a non-endothelialized circuit, which can put patients at risk of both clotting and bleeding. Therefore, continuous anticoagulation management is required during ECMO, and the extracorporeal circuit also requires anticoagulant coating. The membrane oxygenator, a critical component of the extracorporeal circuit, is prone to extensive thrombus formation due to its large surface area and the presence of areas of low flow, turbulence, and stagnant flow.

[0003] Currently available heparin anticoagulant coatings fix heparin to the surface of extracorporeal circuit materials through methods such as physical adsorption, layer-by-layer electrostatic adhesion, and chemical bonding. However, existing methods have the following limitations: 1. The stability of the heparin coating is problematic, as heparin exhibits poor physical adsorption and electrostatic adhesion stability. 2. It is difficult for heparin molecules to maintain bioactivity after the modification process. Although multiple covalent bonds can better stabilize heparin on the surface, nonspecific fixation can affect the free movement of heparin molecules and limit the bioactivity of the heparin layer. Summary of the Invention

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

[0005] To achieve the above-mentioned and other related purposes, the present invention provides the following technical solutions:

[0006] First, a long-acting heparin anticoagulant coating is formed by curing a long-acting heparin anticoagulant coating. The long-acting heparin anticoagulant coating comprises component A and component B. Component A comprises a monomer, an initiator, a polymer, at least one of poly-L-lysine hydrobromide, streptavidin, sodium hyaluronate, and crotonaldehyde; and component B comprises a reducing agent and heparin. The monomer comprises at least one of MPC, PEGMA, and SBMA; and the polymer comprises an amino-based substrate.

[0007] In one embodiment, the amino-based substrate is a star-shaped polymer with a primary amine ratio of ≥25%.

[0008] In one embodiment, the amino-based substrate includes at least one of polyamidoamine, polylysine, polyethyleneimine, and polypropyleneimine.

[0009] In one embodiment, the reducing agent includes at least one of sodium borohydride and sodium cyanoborohydride.

[0010] 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.

[0011] 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.

[0012] 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;

[0013] 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.

[0014] 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.

[0015] 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.

[0016] In one embodiment, the ECMO system includes at least one of an oxygenator, a power pump, and an arteriovenous line.

[0017] In one embodiment, the cycle conditions include 20-80°C.

[0018] In one embodiment, the cycling conditions include 100-1500 LPM.

[0019] The beneficial effects of the present invention are:

[0020] 1. Long-lasting anticoagulant effect: The long-lasting heparin anticoagulant coating provided herein can effectively prolong the anticoagulant effect of heparin, reducing the need for frequent replacement or replenishment of heparin during coating use. This long-lasting effect enables the coating to maintain a good anticoagulant effect in the ECMO system, significantly reducing the risk of thrombosis.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 5. The heparin molecules constructed in this application can be distributed in a directional "array." This construction also solves the problems existing in the prior art, avoiding the excessive restrictions caused by multiple covalent bonds, maintaining the conformational freedom of the heparin molecules, and achieving a balance between directional fixation and activity maintenance.

[0025] In general, the long-acting heparin anticoagulant coating constructed in this application can achieve a long-lasting and stable anticoagulant effect in the ECMO system and can solve the defects of the existing technology.

[0026] The remaining detailed mechanisms are described in the Examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] In the attached figure:

[0029] Figure 1 Schematic diagram of the ECMO system structure of Example 1 of the present invention.

[0030] Figure 2 Schematic diagram of the circuit of the oxygenator 1 according to Example 2 of the present invention. It should be noted that the tee is omitted in the figure.

[0031] Figure 3 This is the standard curve for determining the content of heparin sodium of the present invention.

[0032] Figure 4 It is a schematic diagram of the results of the stability of the heparin coating of the present invention.

[0033] Figure 5 This is the standard curve for the heparin sodium activity test of the present invention.

[0034] Figure 6It is a schematic diagram of the results of the heparin coating activity of the present invention.

[0035] Figure 7 It is a schematic diagram showing the effect of the coating of the present invention on gas flux.

[0036] The markings in the figure are: 1. Oxygenator; 2. Power pump; 3. Arteriovenous line; 4. Patient; 5. Inlet port 1; 6. Outlet port 1; 7. Inlet port 2; 8. Outlet port 2; 9. Circulation pump.

[0037] It should be noted that Figure 1-Figure 2 This is to schematically illustrate the positional relationship of each component / device. The specific structure of each component / device of the ECMO system is well known and is not a key factor affecting the technical effect of this application, so it will not be described in detail. DETAILED DESCRIPTION

[0038] 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 adopted in the following examples are commercially available or can be synthesized with reference to existing literature or known methods. For reactions or test conditions not listed, they are also the conventional techniques readily available to those skilled in the art. Terms used herein are general in this area, and those skilled in the art can clearly understand their implication and will not go into details one by one.

[0039] Example 1

[0040] The ECMO system includes an oxygenator 1 and a power pump 2. Each device in the ECMO system is connected by pipelines. Specifically:

[0041] refer to Figure 1 The oxygenator 1 has a blood channel for blood flow, with an inlet port 5 and an outlet port 6 at each end. The power pump 2 also has a blood channel for blood flow, with an inlet port 7 and an outlet port 8 at each end.

[0042] The ECMO system also includes multiple arteriovenous lines 3. Inlet port 1 5 is connected to one end of an arteriovenous line 3, and the other end of the arteriovenous line 3 is connected to outlet port 2 8.

[0043] 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 via a third arteriovenous line 3 .

[0044] The ECMO system operates as follows: The system forms a circuit with patient 4. The power pump 2 draws unoxygenated venous blood from patient 4 and delivers it to inlet port 5 (i.e., the inlet) of the oxygenator 1. The blood then enters the oxygenator 1 for oxygenation. The oxygenated blood is then delivered back to patient 4 from outlet port 6 (i.e., the outlet) of the oxygenator 1. The basic structure and principles of the ECMO system, as well as its remaining operating methods, are well known and will not be elaborated upon.

[0045] Example 2

[0046] A long-acting heparin anticoagulant coating is prepared. The long-acting heparin anticoagulant coating comprises component A and component B.

[0047] By weight, unless otherwise specified, select 99% purity, medical grade, available from Sigma-Aldrich:

[0048] 1. Component A, Component A is the bottom layer, and Component A is divided into Component A1 and Component A2:

[0049] Component A1:

[0050] (1) Monomer:

[0051] MPC (2-methacryloyloxyethyl phosphorylcholine): 30-40 parts;

[0052] PEGMA (polyethylene glycol dimethacrylate): 10-20 parts, MW 2000;

[0053] SBMA (sulfobetaine methacrylate): 5-15 parts;

[0054] (2) Initiator:

[0055] AIBN (azobisisobutyronitrile): 0.5-1.5 parts;

[0056] Component A2:

[0057] (1) Polymers:

[0058] 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.

[0059] Among them, polymer: 1.5-2.5 parts, polyethyleneimine: MW 25000;

[0060] (2) Additives:

[0061] Poly-L-lysine hydrobromide: 0.8-1.2 parts, Sigma-Aldrich, model P7890;

[0062] Streptavidin: 0.3-0.7 parts, Thermo Fisher;

[0063] Sodium hyaluronate: 0.1-0.3 parts;

[0064] Crotonaldehyde: 0.01-0.03 parts.

[0065] 2. Component B: Component B is the functional layer:

[0066] (1) The reducing agent includes at least one of sodium borohydride and sodium cyanoborohydride, 1-5 parts.

[0067] (2) Heparin: molecular weight 3kDa-10kDa, concentration range 0.1-5%.

[0068] Low molecular weight heparin (3-5kDa): 1.0-2.0 parts;

[0069] Medium molecular weight heparin (5-7 kDa): 0.8-1.2 parts;

[0070] High molecular weight heparin (7-10kDa): 0.3-0.7 parts.

[0071] It should be noted that existing technologies present a technical challenge: it is difficult for heparin molecules to maintain their biological activity after the modification process. Although multiple covalent bonds can better stabilize heparin on the surface, nonspecific fixation can affect the free movement of heparin molecules and limit the biological activity of the heparin layer.

[0072] 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:

[0073] In the bottom layer: Component A1: 1) MPC forms a phosphatidylcholine-like structure, mimicking the cell membrane surface. This self-assembles into a regular brush-like structure, increasing surface hydrophobicity and synergizing with PEGMA to form an amphiphilic interface. 2) PEGMA with a MW of 2000 provides an appropriate chain length, ensuring flexibility without compromising subsequent modification. This interpenetrating network with MPC enhances mechanical stability. The PEG segments provide steric hindrance, reducing nonspecific adsorption. 3) SBMA introduces sulfonic acid groups, providing a negative charge distribution that synergistically enhances resistance to protein adsorption, modulates surface hydrophilicity, and optimizes interfacial properties.

[0074] Component A2: 1) A star-shaped amino-based substrate with a high primary amine content (>25%) provides more active sites. The star-shaped structure increases spatial availability, forming chemical bonds with the substrate and improving stability. 2) Poly-L-lysine forms a directional bridge structure with streptavidin, while hyaluronic acid provides a three-dimensional network scaffold, achieving precise directional alignment of heparin molecules.

[0075] In the functional layer: 1) A multi-stage molecular weight heparin system is constructed: low molecular weight heparin (3-5 kDa) is used for biotin labeling and provides recognition sites; medium molecular weight heparin (5-7 kDa) is targeted for modification to maintain the active conformation; and high molecular weight heparin (7-10 kDa) is released via a biodegradable bond. This ensures both the activity of the heparin molecule and its directional movement. 2) Reducing agent: This selectively reduces the aldehyde groups at the ends of the heparin molecule to form primary alcohol groups. This can undergo reductive amination with amino substrates to form stable covalent bonds. The reaction rate can also be controlled to avoid conformational changes caused by excessive cross-linking.

[0076] 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 are distributed in a directional "array".

[0077] Such a construction also solves the problems existing in the existing technology, avoids excessive restrictions caused by multiple covalent bonds, maintains the conformational freedom of heparin molecules, and achieves a balance between directional fixation and activity maintenance.

[0078] The following is the anticoagulation management of the ECMO system. Different long-acting heparin anticoagulant coatings are prepared and used for different equipment to form a long-acting heparin anticoagulant coating, as follows:

[0079] Example 3

[0080] refer to Figure 2 , 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 tube 3 in the same manner as in Example 1.

[0081] 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.

[0082] Referring to Example 2, the specific method of introducing the long-acting heparin anticoagulant coating in this embodiment is as follows:

[0083] 1. Prepare Component A Solution: Prepare Component A1 solution: Mix 35 parts MPC, 15 parts PEGMA, 10 parts SBMA, 0.8 parts AIBN with 300 parts deionized water at 35°C and 300 rpm to obtain Component A1 solution. Prepare Component A2 solution: Mix 2 parts polyethyleneimine, 1 part poly-L-lysine hydrobromide, 0.5 parts streptavidin, 0.2 parts sodium hyaluronate, and 0.01 parts crotonaldehyde with 100 parts deionized water at 300 rpm to obtain Component A2 solution. Circulate Component A1 solution at 900 LPM at 25°C for 30 minutes. After circulation, dry with hot air at 60°C. Circulate Component A2 solution at 800 LPM at 25°C for 10 minutes.

[0084] 2. Prepare Component B solution: Mix 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 at 300 rpm to obtain Component B solution. Circulate Component B solution at 800 LPM for 12 hours at 50°C. After circulation, rinse oxygenator 1 with pure water and then dry it with clean, dry air.

[0085] Through the aforementioned steps, the long-acting heparin anticoagulant coating forms a long-acting heparin anticoagulant coating in the oxygenator 1 .

[0086] Example 4

[0087] Different from Example 1, the patient 4 and the oxygenator 1 are not added to the circuit, and the arteriovenous tubes 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.

[0088] The circulation pump 9 and the tee can also be introduced with reference to Example 3. It is only necessary to be able 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.

[0089] Referring to Example 2, the specific method of introducing the long-acting heparin anticoagulant coating in this embodiment is as follows:

[0090] 1. Prepare Component A Solution: Prepare Component A1 solution: Mix 35 parts MPC, 15 parts PEGMA, 10 parts SBMA, 0.8 parts AIBN with 300 parts deionized water at 35°C and 300 rpm to obtain Component A1 solution. Prepare Component A2 solution: Mix 2 parts polyethyleneimine, 1 part poly-L-lysine hydrobromide, 0.5 parts streptavidin, 0.2 parts sodium hyaluronate, and 0.01 parts crotonaldehyde with 100 parts deionized water at 300 rpm to obtain Component A2 solution. Circulate Component A1 solution at 30°C and 500 LPM for 60 minutes. After circulation, dry with hot air at 60°C. Circulate Component A2 solution at 45°C and 100 LPM for 60 minutes.

[0091] 2. Prepare Component B solution: Mix 1 part sodium cyanoborohydride, 1.5 parts low molecular weight heparin, 1 part medium molecular weight heparin, and 0.5 parts high molecular weight heparin with 100 parts deionized water at 300 rpm to obtain Component B solution. Circulate Component B solution at 100 LPM for 24 hours at 25°C. After circulation, rinse 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.

[0092] Through the above steps, the long-acting heparin anticoagulant coating forms a long-acting heparin anticoagulant coating in the power pump 2 .

[0093] Example 5

[0094] Unlike Example 1, the circuit does not include patient 4, oxygenator 1, and power pump 2. Instead, the arteriovenous line 3, circulation pump 9, and tee are connected in series to form a circulation loop. It is sufficient to be able to introduce an external long-acting heparin anticoagulant coating into the circulation loop. This is not a critical factor affecting the technical effects of this application and can be accomplished using conventional means, so it will not be described in detail.

[0095] Referring to Example 2, the specific method of introducing the long-acting heparin anticoagulant coating in this embodiment is as follows:

[0096] 1. Prepare Component A Solution: Prepare Component A1 solution: Mix 35 parts MPC, 15 parts PEGMA, 10 parts SBMA, 0.8 parts AIBN, and 300 parts deionized water at 35°C and 300 rpm to obtain Component A1 solution. Prepare Component A2 solution: Mix 2 parts polyethyleneimine, 1 part poly-L-lysine hydrobromide, 0.5 parts streptavidin, 0.2 parts sodium hyaluronate, and 0.01 parts crotonaldehyde with 100 parts deionized water at 300 rpm to obtain Component A2 solution. Circulate Component A1 solution at 30°C and 500 LPM for 90 minutes. After circulation, dry with hot air at 60°C. Circulate Component A2 solution at 65°C and 1500 LPM for 35 minutes.

[0097] 2. Prepare Component B solution: Mix 1 part sodium cyanoborohydride, 1.5 parts low molecular weight heparin, 1 part medium molecular weight heparin, and 0.5 parts high molecular weight heparin with 100 parts deionized water at 300 rpm to obtain Component B solution. Circulate Component B solution at 65°C and 1500 LPM for 0.5 h. After circulation, rinse the inner surface of arteriovenous line 3 with pure water and then blow dry the line with clean, dry air.

[0098] Through the above steps, the long-acting heparin anticoagulant coating forms a long-acting heparin anticoagulant coating in the venous line 3 .

[0099] Detection:

[0100] (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 performed based on the 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.

[0101] Preparation of standard solution: Prepare at least six sodium heparin standard solutions in the range of 20-100ug / mL with purified water. Add sodium heparin standard solution and 0.0005% toluidine blue solution in a volume ratio of 1:1. Test the absorbance of the reaction solution at 631nm. Create a standard curve with heparin concentration as the horizontal axis and absorbance as the vertical axis. Use a linear equation to fit the curve. R 2 Must be above 0.995. Figure 3 .

[0102] Test Sample Testing: Place heparin-coated and uncoated samples of the same material of a specified surface area in a test tube. Add the same volume of 0.0005% toluidine blue solution as the heparin sodium standard solution at a ratio of 1 mL / cm² of sample surface area to balance. Follow the standard curve test procedure. Substitute the absorbance value into the standard curve to calculate the heparin concentration, C1, of the sample.

[0103] The heparin content of samples eluted (with saline solution, circulated at a flow rate of 7 L / min) for 8 days was measured. The heparin content per unit surface area of ​​the sample was then calculated according to formula (1). This yielded a dynamic curve of the heparin content on the coating surface, which was used to evaluate the coating's stability. The aforementioned method was used to measure the long-acting heparin anticoagulant coating in Comparative Example 1 (using a commercially available pump head: Maikewei BE-RF32) and in the power pump 2 of Example 4.

[0104] The calculation formula (1) is:

[0105] H=(C1×V1) / S1(1)

[0106] Where:

[0107] H: Heparin content per unit surface area of ​​the sample (μg / cm²);

[0108] C1 is the heparin concentration in the sample extract (μg / mL);

[0109] V1 is the volume of the extract (mL);

[0110] S1 is the sample surface area (cm²).

[0111] 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 drawn. The results are as follows: Figure 4 shown.

[0112] Analysis: Compared with Comparative Example 1, the coating stability of Example 4 of the present application is better.

[0113] (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 and draw a standard curve with the logarithm of the heparin sodium concentration as the horizontal axis and the absorbance as the vertical axis. Fit it with a linear equation, R 2 Must be above 0.99. Figure 5 .

[0114] Place a sample of a certain surface area in a test tube and add a buffer solution of the same volume as the standard solution to balance it. Follow the standard curve test steps. Substitute the sample absorbance value 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 sample coating surface according to formula (2):

[0115] Q = (C2 × V2) / S2 (2)

[0116] Where:

[0117] Q: Total heparin anti-factor Xa activity per unit area of ​​the coating sample, in IU / cm 2 ;

[0118] C2: sample heparin concentration, in IU / mL;

[0119] V2: solvent volume, in milliliters (mL), which is 0.25 mL in this test;

[0120] S1 is the sample surface area (cm²), which is 1cm in this test. 2 .

[0121] The long-acting heparin anticoagulant coatings in the oxygenator 1 of Comparative Example 2 (selecting an oxygenator currently available on the market: Maikewei HLS oxygenator) and Example 3 were measured using the aforementioned method.

[0122] A bar graph was drawn with Comparative Example 2 and Example 3 as the horizontal axis 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 vertical axis. The results are shown in FIG. Figure 6 shown.

[0123] Analysis: Compared with Comparative Example 2, the heparin activity of Example 3 of the present application is higher.

[0124] (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, during stable permeation. It is usually expressed as a volume value at standard temperature and 1 standard atmospheric pressure, with the unit being mL / (cm²×min×bar). When gas passes through a dense polymer membrane, the gas molecules first come into contact with the membrane and then dissolve on the membrane surface, creating a concentration gradient on both sides of the membrane. This causes the gas molecules to diffuse forward within the membrane and then dissolve from the other side of the membrane.

[0125] The oxygenator's oxygenation membrane divides a permeation chamber of constant volume into two independent compartments. A test gas (oxygen) at a constant pressure is introduced into one side (the high-pressure side), creating a pressure differential between the two compartments. The volume of test gas that permeates from the high-pressure side through the specimen into the low-pressure side is the test gas permeation rate of the oxygenator. The oxygenator contains an oxygenation membrane, making this method suitable for testing. This is well known and will not be elaborated on.

[0126] The above method was used to measure the oxygenator 1 of Comparative Example 2 (selecting the oxygenator currently available on the market: Maikewei HLS oxygenator) and Example 3, and Comparative Example 3, where Comparative Example 3 is the oxygenator 1 of Example 1 without the long-acting heparin anticoagulant coating. The control membrane area is 10 cm 2 , time is 30s, and pressure difference is 1bar.

[0127] With Comparative Example 2 and Example 3 and Comparative Example 3 as the horizontal axis and the gas flux as the vertical axis, a bar graph is drawn. The results are as follows: Figure 7 shown.

[0128] 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-lasting anticoagulation coating prepared by the method of the present application has less impact on the gas flux of the oxygenator 1.

[0129] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. Long-acting heparin anticoagulant coating, which is formed by curing the long-acting heparin anticoagulant coating, characterized in that: The long-acting heparin anticoagulant coating comprises component A and component B; the raw materials of component A include monomers, initiators, polymers, poly-L-lysine hydrobromide, streptavidin, sodium hyaluronate, and crotonaldehyde; the raw materials of component B include a reducing agent and heparin; wherein the monomers are MPC, PEGMA, and SBMA; the polymer includes an amino substrate; the amino substrate is a star-shaped polymer with a primary amine ratio of ≥25%, and the amino substrate includes polyethyleneimine; the molecular weight of heparin is 3kDa-10kDa, and heparin includes low molecular weight heparin of 3-5kDa, medium molecular weight heparin of 5-7kDa, and high molecular weight heparin of 7-10kDa; The preparation of the 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.

2. 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.

3. 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.

4. The method for preparing the long-acting heparin anticoagulant coating according to any one of claims 1 to 3, characterized in that: The method 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.

5. The method for preparing the long-acting heparin anticoagulant coating according to claim 4, characterized in that: The ECMO system includes at least one of an oxygenator, a power pump, and an arteriovenous line.

6. The method for preparing the long-acting heparin anticoagulant coating according to claim 4, characterized in that: The cycling conditions included 20-80°C.

7. The method for preparing the long-acting heparin anticoagulant coating according to claim 4, characterized in that: Cycling conditions included 100-1500 LPM.

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