A method for preparing an artificial blood vessel with anti-coagulation and rapid endothelialization functions

Abstract

The scheme provides a preparation method of an artificial blood vessel with anticoagulant and rapid endothelialization functions, comprising the following steps: dissolving a cross-linking agent and a catalyst in an aqueous hydrochloric acid solution to obtain a first reaction solution; dissolving sulfonated starch and a catalyst in an aqueous hydrochloric acid solution to obtain a second reaction solution; wrapping the outer surface of an expanded polytetrafluoroethylene artificial blood vessel with aluminum foil paper, injecting the first reaction solution into the expanded polytetrafluoroethylene artificial blood vessel after plasma activation of the expanded polytetrafluoroethylene, sealing the two ends of the expanded polytetrafluoroethylene artificial blood vessel, and then placing the expanded polytetrafluoroethylene artificial blood vessel in an air shaker for reaction; taking out and washing the expanded polytetrafluoroethylene artificial blood vessel, then injecting the second reaction solution into the expanded polytetrafluoroethylene artificial blood vessel, sealing the two ends of the expanded polytetrafluoroethylene artificial blood vessel, and then placing the expanded polytetrafluoroethylene artificial blood vessel in an air shaker for reaction; taking out and washing the expanded polytetrafluoroethylene artificial blood vessel, and drying the washed expanded polytetrafluoroethylene artificial blood vessel to obtain an artificial blood vessel with anticoagulant and rapid endothelialization functions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of artificial blood vessel coating, in particular to a preparation method of an artificial blood vessel with anticoagulant and rapid endothelialization functions. BACKGROUND

[0002] In current clinical applications, large-diameter artificial blood vessels (inner diameter ≥ 6 mm) have been relatively mature, and mainstream products are mostly made of polyethylene terephthalate, expanded polytetrafluoroethylene (ePTFE) and other high molecular materials, which can basically meet the clinical needs. However, these materials have an essential defect--lack of biological activity, which cannot induce vascular endothelial cells and smooth muscle cells to regenerate on their surface, resulting in long-term coagulation risk after implantation and difficulty in achieving physiological fusion with the body's own blood vessels.

[0003] Compared with large-diameter artificial blood vessels, small-diameter artificial blood vessels (inner diameter < 6 mm) face more severe challenges. Such blood vessels are the urgent demand products for key surgeries such as heart coronary bypass and peripheral blood vessel replacement, but their small diameter makes them more prone to thrombosis due to changes in blood flow state and insufficient material surface biocompatibility. The postoperative restenosis rate is high, which has become the core bottleneck restricting the breakthrough of small-diameter artificial blood vessel technology.

[0004] In-depth analysis of the pathophysiological mechanism after artificial blood vessel implantation shows that the occurrence of thrombosis and lumen restenosis mainly comes from two key problems: first, after the implantation of artificial blood vessels in the body, the contact of blood with the surface of foreign materials will instantly trigger the coagulation cascade reaction, leading to platelet activation and aggregation, fibrin deposition, and ultimately thrombosis. At the same time, the change of material surface hemodynamic characteristics (such as low wall shear stress at the anastomosis site) will further exacerbate the risk of thrombosis. Second, vascular smooth muscle cells will undergo abnormal proliferation and migration under the stimulation of materials, leading to excessive neointimal hyperplasia, and ultimately causing artificial blood vessel lumen stenosis and loss of blood flow function. The fundamental solution to these problems depends on the breakthrough of two key technologies: one is to give the material surface high-efficiency anticoagulant function; the other is to achieve rapid endothelialization to form an active endothelial barrier with physiological function in the lumen of the artificial blood vessel.

[0005] Currently, there are related patents trying to solve the problems of anticoagulation and endothelialization, but there are still obvious limitations: for example, patent CN114808469A uses an ultraviolet light curing method to fix heparin anticoagulant coating on the surface of polyester fabric artificial blood vessels, which can continuously and stably release natural anticoagulant molecules for a period of time, achieving good local anticoagulant effect, but heparin depends on highly sulfated structure (sulfonic acid group, carboxylic acid group) to activate antithrombin III (ATIII), inhibit coagulation factors IIa and Xa, but it is easy to cause bleeding risk due to dose out of control, at the same time, research has found that heparin not only affects endothelial cell adhesion and growth, but also has animal origin and batch difference problems. For another example, patent CN106729998A reports a kind of mussel adhesive protein modified artificial blood vessel inner wall coating and its preparation method, which uses mussel adhesive protein to modify biological artificial blood vessels for the first time, and constructs a kind of biological artificial blood vessel with antithrombosis, which has no obvious effect on endothelialization, and the extraction of mussel adhesive protein is difficult, which is difficult to be applied on a large scale.

[0006] In summary, the existing technical solutions cannot simultaneously consider excellent anticoagulant performance and efficient endothelialization induction ability, and there are defects in safety, production feasibility and other aspects, and it is urgent to develop an artificial blood vessel coating technology with excellent anticoagulant performance and rapid endothelialization. SUMMARY

[0007] The purpose of the present application is to provide a preparation method of artificial blood vessels with anticoagulant and rapid endothelialization functions, using citric acid / butanetetracarboxylic acid as a crosslinking agent, potassium dihydrogen phosphate / sodium dihydrogen phosphate as a catalyst, grafting sulfonated starch on the inner surface of artificial blood vessels to endow the artificial blood vessels with anticoagulant and pro-endothelialization properties.

[0008] To achieve the above purpose, the technical solution provides a preparation method of artificial blood vessels with anticoagulant and rapid endothelialization functions, comprising the following steps:

[0009] (1) Dissolve the crosslinking agent and the catalyst in hydrochloric acid aqueous solution to obtain a first reaction solution;

[0010] (2) Dissolve the sulfonated starch and the catalyst in hydrochloric acid aqueous solution to obtain a second reaction solution;

[0011] (3) Wrap the outer surface of the expanded polytetrafluoroethylene artificial blood vessel with aluminum foil, and activate the inner surface of the expanded polytetrafluoroethylene artificial blood vessel using plasma to obtain an activated expanded polytetrafluoroethylene artificial blood vessel;

[0012] (4) Inject the first reaction solution into the activated expanded polytetrafluoroethylene artificial blood vessel, seal the two ends of the activated expanded polytetrafluoroethylene artificial blood vessel, and then place it in an air shaker for reaction;

[0013] (5) taking out and washing the expanded polytetrafluoroethylene artificial blood vessel, injecting the second reaction solution into the washed expanded polytetrafluoroethylene artificial blood vessel, sealing the two ends of the expanded polytetrafluoroethylene artificial blood vessel into which the second reaction solution is injected, and then placing the expanded polytetrafluoroethylene artificial blood vessel into an air shaker for reaction;

[0014] (6) taking out and washing the expanded polytetrafluoroethylene artificial blood vessel, drying the washed expanded polytetrafluoroethylene artificial blood vessel to obtain an artificial blood vessel with anticoagulant and rapid endothelialization functions.

[0015] It should be noted that the present scheme grafts sulfonated starch on the inner surface of the polytetrafluoroethylene artificial blood vessel to endow the artificial blood vessel with anticoagulant and pro-endothelialization properties. The polyhydroxy skeleton of sulfonated starch can flexibly control the sulfonation site density, simulate the high sulfation structure of heparin, inhibit blood coagulation factors IIa and Xa by activating antithrombin III, achieve high-efficiency anticoagulation (significantly prolong APTT), and at the same time, due to the stronger controllability of molecular weight, it can avoid the risk of bleeding caused by overdose due to excessive anticoagulant activity, and the linear structure of sulfonated starch can optimize the inhibition of blood coagulation factors, solving the problem of balance between anticoagulation and bleeding existing in heparin coating. In addition, the polysaccharide skeleton in sulfonated starch has immunomodulatory function, and the sulfonic acid group and glucose unit in the polysaccharide skeleton can synergistically promote the adhesion and proliferation of human umbilical vein endothelial cells (HUVEC), while the immunomodulatory function of the polysaccharide skeleton can guide macrophages to polarize to the anti-inflammatory type, reduce the damage of inflammation to endothelial cells, and assist endothelialization, in addition, the degradation product glucose can be directly used by endothelial cells for energy supply, avoiding cytotoxicity, and accelerating the construction and physiological fusion of blood vessel network. Sulfonated starch also has the advantages of simple preparation, cheap raw materials and high flexibility of structure modification, and can precisely optimize the anticoagulant activity by adjusting the sulfonation degree, molecular weight and the introduction of carboxyl groups, etc., avoiding the problems of animal origin and batch difference of heparin.

[0016] The preparation method of the artificial blood vessel with anticoagulant and rapid endothelialization functions proposed in the present scheme first activates the inner surface of the artificial blood vessel by oxygen plasma or air plasma, so that a large number of hydroxyl groups are endowed on the inner surface, then grafts sulfonated starch on the activated inner surface of the artificial blood vessel under the catalysis of dihydrogen phosphate, using citric acid / butanetetraalkane carboxylic acid as a crosslinking agent, endowing the artificial blood vessel with anticoagulant and rapid endothelialization properties, and the specific reaction schematic diagram is shown in Figure 1 .

[0017] Specifically, in step (1), the crosslinking agent is one or more of citric acid, butane tetra carboxylic acid, and the catalyst is one or more of potassium dihydrogen phosphate and sodium dihydrogen phosphate.

[0018] The present scheme adopts citric acid and / or butane tetracarboxylic acid as a crosslinking agent, which is used to construct a connecting bridge of the expanded polytetrafluoroethylene artificial blood vessel and sulfonated starch. The interior of the expanded polytetrafluoroethylene artificial blood vessel generates a large number of hydroxyl groups (-OH) after being activated by plasma, but the hydroxyl groups themselves have weak reactivity and cannot be directly and stably combined with sulfonated starch. The citric acid and / or butane tetracarboxylic acid contains multiple carboxyl groups (-COOH), which can react with the hydroxyl groups on the surface of the activated artificial blood vessel to form stable covalent bonds, and can also crosslink with the hydroxyl groups (polymer backbone) in the sulfonated starch molecules. Through the chain connection of "blood vessel surface-crosslinking agent-sulfonated starch", the sulfonated starch is firmly grafted on the inner surface of the blood vessel, avoiding the coating from falling off under the scouring of blood, ensuring the long-term use stability, and the crosslinking agent will leave some unreacted carboxyl groups on the surface of the blood vessel after the reaction. The carboxyl groups, as negative charge groups, can synergistically enhance the surface negative charge with the sulfonic acid groups of the sulfonated starch to repel negatively charged platelets (reduce activated aggregation), and at the same time promote the adsorption of endothelial cell adhesion proteins such as fibronectin, thereby assisting to improve the anticoagulation and endothelialization effects.

[0019] The present scheme adopts potassium dihydrogen phosphate and / or sodium dihydrogen phosphate as a catalyst, which is used to reduce the activation energy of the reaction to accelerate the crosslinking reaction process. As described above, the esterification and crosslinking reaction of the crosslinking agent with the hydroxyl groups have a very slow reaction rate at room temperature and the reaction is incomplete. However, the potassium dihydrogen phosphate / sodium dihydrogen phosphate can adjust the pH of the reaction system by proton transfer, thereby reducing the activation energy required for the reaction, allowing the crosslinking reaction to proceed efficiently under mild conditions, shortening the reaction time, and improving the reaction conversion rate, thereby ensuring the uniformity and compactness of the sulfonated starch coating.

[0020] In step (1), the mass concentration of the crosslinking agent is 0.1-0.5 g / L, the mass concentration of the catalyst is 0.05-0.25 g / L, and the molar concentration of the hydrochloric acid aqueous solution is 0.1 mol / L.

[0021] It should be noted that the selection of the mass concentration of the crosslinking agent can ensure that the crosslinking agent molecules can be uniformly dispersed in the first reaction solution, which can not only fully cover the activated surface of the blood vessel to form a complete crosslinking network and firmly graft the sulfonated starch, but also avoid excessive reaction to ensure the smoothness of the inner surface of the blood vessel.

[0022] In step (2), the sulfonated starch is prepared by the chlorosulfonic acid-pyridine method, and the degree of substitution is 0.8-1.2 and the sulfur content is >12%. Generally, the higher the degree of substitution of the sulfonated starch, the higher the sulfonation degree, and the better the anticoagulation performance of the final artificial blood vessel. The present scheme particularly selects the sulfonated starch prepared by the chlorosulfonic acid-pyridine method to obtain sulfonated starch with high degree of substitution.

[0023] In step (2), the catalyst is one or more of potassium dihydrogen phosphate and sodium dihydrogen phosphate.

[0024] In step (2), the mass concentration of the sulfonated starch is 1-5 g / L, and the sulfonated starch can be uniformly grafted under the action of the crosslinking agent to form a coating with a suitable thickness and a reasonable sulfonic acid group density, which can not only resist condensation through high-efficiency sulfonic acid groups, but also promote endothelialization by relying on the polysaccharide skeleton and glucose units, while avoiding problems such as agglomeration and swelling.

[0025] In step (2), the mass concentration of the catalyst is 0.05-0.25 g / L, and the molar concentration of the hydrochloric acid aqueous solution is 0.1 mol / L.

[0026] In step (3), the inner surface of the expanded polytetrafluoroethylene artificial blood vessel needs to be in direct contact with blood, and the bio-compatibility needs to be improved for grafting sulfonated starch through activation, while the outer surface needs to be in contact with human tissues, and the original structural stability and tissue compatibility need to be retained to avoid surface roughness or chemical property changes after activation, which may cause tissue inflammation or adhesion. Therefore, in this scheme, the outer surface of the expanded polytetrafluoroethylene artificial blood vessel is wrapped with aluminum foil, and only the inner surface of the expanded polytetrafluoroethylene artificial blood vessel is subjected to plasma activation.

[0027] In step (3), the plasma is one or more of oxygen plasma and air plasma. Specifically, the expanded polytetrafluoroethylene artificial blood vessel with the wrapped outer surface is fixed on the support in the plasma reaction chamber to ensure that the openings at both ends of the expanded polytetrafluoroethylene artificial blood vessel are directed towards the gas inlet and the gas outlet, so that the reaction gas of the plasma can uniformly pass through the inner cavity of the blood vessel. Oxygen in the reaction gas will be decomposed into oxygen radicals under the action of the plasma, which will combine with the exposed C atoms after bombardment to generate a large number of active groups such as hydroxyl and carboxyl groups on the inner surface of the expanded polytetrafluoroethylene artificial blood vessel. These groups can act as reaction sites and undergo esterification with the crosslinking agent in the subsequent step S1 to provide anchor points for the grafting of sulfonated starch.

[0028] In some embodiments, the air flow rate of the plasma is controlled at 10-20 seem to ensure a stable gas flow in the inner cavity of the blood vessel and avoid uneven local activation.

[0029] In steps (4) and (5), the reaction temperature of the air shaker is 50-80 ℃, the reaction time is 2-6 h, and the rotation speed of the air shaker is 110-130 rpm.

[0030] Preferably, the rotation speed of the air shaker is 120 rpm.

[0031] In steps (5) and (6), deionized water and anhydrous ethanol are used to wash the artificial blood vessel.

[0032] In step (6), the drying temperature is 55-65 ℃. Preferably, the drying temperature is 60 ℃.

[0033] The second aspect provides an artificial blood vessel with anti-coagulation and rapid endothelialization functions, which is an expanded polytetrafluoroethylene artificial blood vessel with sulfonic acid groups, hydroxyl groups and carboxyl groups attached to the inner surface.

[0034] The third aspect provides an artificial blood vessel with anti-coagulation and rapid endothelialization functions for use in the field of vascular implantation and cardiovascular disease treatment.

[0035] Compared with the prior art, the technical scheme has the following characteristics and beneficial effects:

[0036] 1) The polysaccharide skeleton in the sulfonated starch has immunomodulatory function, and the sulfonic acid groups and glucose units can synergistically promote the proliferation of endothelial cells (HUVEC) and regulate the polarization of macrophages to promote endothelial proliferation. The degradation product of the starch-based material is glucose, which is more easily utilized by endothelial cells and can accelerate the construction of vascular networks.

[0037] 2) The anti-coagulation of the sulfonic acid groups on the surface of the blood vessel can reduce the coverage of thrombus and provide an adhesion interface for endothelial cells, and the high sulfonation degree surface can inhibit the excessive proliferation of smooth muscle cells, promote the growth of endothelial cells and prevent vascular restenosis.

[0038] 3) The negatively charged surface is more easily adsorbed with fibronectin (Fibronectin) and other EC adhesion proteins, and the micro-nano structure of the sulfonated starch coating can simulate the basement membrane of blood vessels to guide the directional arrangement of endothelial cells. The negatively charged sulfonic acid groups combine with VEGF, FGF-2 and other pro-angiogenic factors to form a local concentration gradient, recruiting endothelial cells to migrate. At the same time, by regulating the polarization of macrophages to M2 type, it stimulates the secretion of endogenous VEGF, indirectly promoting the proliferation of endothelial cells. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a schematic diagram of the chemical reaction of the present application;

[0040] Figure 2 It is a sample inner surface morphology graph in Example 2 of the present application;

[0041] Figure 3 It is a sample inner surface morphology graph in Comparative Example 1 of the present application;

[0042] Figure 4 It is a sample section graph after 1 month of replacement of the dog carotid artery in Example 2 of the present application;

[0043] Figure 5 It is a sample section graph after 1 month of replacement of the dog carotid artery in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0044] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present application.

[0045] Embodiment 1

[0046] 1) Dissolve citric acid and potassium dihydrogen phosphate together in 0.1 mol / L hydrochloric acid aqueous solution to prepare reaction liquid A, wherein the mass concentration of citric acid is 0.1 g / L and the mass concentration of potassium dihydrogen phosphate is 0.05 g / L;

[0047] 2) Dissolve sulfonated starch and potassium dihydrogen phosphate together in 0.1 mol / L hydrochloric acid aqueous solution to prepare reaction liquid B, wherein the mass concentration of sulfonated starch is 1 g / L and the mass concentration of potassium dihydrogen phosphate is 0.05 g / L;

[0048] 3) Wrap the outer surface of the PTFE tube membrane with aluminum foil paper completely, and activate the inside using oxygen plasma;

[0049] 4) Inject reaction liquid A into the activated PTFE tube membrane, seal both ends, and then place it in an air shaker with a temperature of 50°C and a rotation speed of 120 rpm for 6 hours;

[0050] 5) Take out and wash the PTFE tube membrane with deionized water, then inject reaction liquid B, seal both ends, and then place it in an air shaker with a temperature of 80°C and a rotation speed of 120 rpm for 2 hours;

[0051] 6) Take out the PTFE artificial blood vessel and wash it with deionized water and anhydrous ethanol in sequence to obtain a PTFE artificial blood vessel with anticoagulant and rapid endothelialization functions.

[0052] Embodiment 2

[0053] 1) Dissolve citric acid and potassium dihydrogen phosphate together in 0.1 mol / L hydrochloric acid aqueous solution to prepare reaction liquid A, wherein the mass concentration of citric acid is 0.3 g / L and the mass concentration of potassium dihydrogen phosphate is 0.15 g / L;

[0054] 2) Dissolve sulfonated starch and potassium dihydrogen phosphate together in 0.1 mol / L hydrochloric acid aqueous solution to prepare reaction liquid B, wherein the mass concentration of sulfonated starch is 3 g / L and the mass concentration of potassium dihydrogen phosphate is 0.15 g / L;

[0055] 3) Wrap the outer surface of the PTFE tube membrane with aluminum foil paper completely, and activate the inside using oxygen plasma;

[0056] 4) The reaction solution A is injected into the activated PTFE tube membrane, both ends are sealed and placed in an air shaker with a temperature of 70°C and a rotation speed of 120 rpm for 3 hours;

[0057] 5) The PTFE tube membrane is taken out and washed with deionized water, then the reaction solution B is injected, both ends are sealed and placed in an air shaker with a temperature of 70°C and a rotation speed of 120 rpm for 3 hours;

[0058] 6) The PTFE artificial blood vessel is taken out and washed with deionized water and anhydrous ethanol in turn to obtain a PTFE artificial blood vessel with anticoagulant and rapid endothelialization functions.

[0059] Example 3:

[0060] 1) Citric acid and potassium dihydrogen phosphate are dissolved together in a 0.1 mol / L hydrochloric acid aqueous solution to prepare reaction solution A, wherein the mass concentration of citric acid is 0.5 g / L and the mass concentration of potassium dihydrogen phosphate is 0.25 g / L;

[0061] 2) Sulfonated starch and potassium dihydrogen phosphate are dissolved together in a 0.1 mol / L hydrochloric acid aqueous solution to prepare reaction solution B, wherein the mass concentration of sulfonated starch is 5 g / L and the mass concentration of potassium dihydrogen phosphate is 0.25 g / L;

[0062] 3) The outer surface of the PTFE tube membrane is completely wrapped with aluminum foil paper, and the inside is activated using oxygen plasma;

[0063] 4) The reaction solution A is injected into the activated PTFE tube membrane, both ends are sealed and placed in an air shaker with a temperature of 80°C and a rotation speed of 120 rpm for 2 hours;

[0064] 5) The PTFE tube membrane is taken out and washed with deionized water, then the reaction solution B is injected, both ends are sealed and placed in an air shaker with a temperature of 50°C and a rotation speed of 120 rpm for 6 hours;

[0065] 6) The PTFE artificial blood vessel is taken out and washed with deionized water and anhydrous ethanol in turn to obtain a PTFE artificial blood vessel with anticoagulant and rapid endothelialization functions.

[0066] Comparative Example 1:

[0067] The PTFE tube membrane is not treated.

[0068] Comparative Example 2:

[0069] The outer surface of the PTFE tube membrane is completely wrapped with aluminum foil paper, and the inside is activated using oxygen plasma.

[0070] Comparative Example 3:

[0071] 1) Citric acid and potassium dihydrogen phosphate were dissolved together in 0.1 mol / L hydrochloric acid aqueous solution to prepare a reaction solution, wherein the mass concentration of citric acid was 0.3 g / L and the mass concentration of potassium dihydrogen phosphate was 0.15 g / L;

[0072] 2) The outer surface of the PTFE tube membrane was completely wrapped with aluminum foil paper, and the inside was activated using oxygen plasma;

[0073] 3) The reaction solution was injected into the activated PTFE tube membrane, and after sealing at both ends, it was placed in an air shaker with a temperature of 70°C and a rotation speed of 120 rpm for 3 hours;

[0074] 4) The PTFE artificial blood vessel was taken out and washed with deionized water and anhydrous ethanol in sequence, and dried.

[0075] Anticoagulant performance test:

[0076] Activated partial thromboplastin time (APTT) and thrombin time (TT) were used as two important indicators in clinical practice. The coagulation analyzer (PUN-2048A) was used to measure the anticoagulant performance. In the APTT test, 0.1 mL of plasma was first placed in a test cup, then the membrane (1.0 cm x 1.0 cm) was folded to the appropriate size and inserted into the bottom of the solution. After that, the same volume of APTT reagent was sprayed into the mixture with a pipette. After incubation at 37°C for 5 minutes, 0.1 mL of CaCl2 (0.025 mol / mL 1 ) was quickly added to the mixture. Then, the APTT value was determined when the first coagulation occurred. Clotting time The final value was obtained from the average of three measurements. In the TT test, 0.2 mL of plasma was first injected into a test cup, then the sample (1.0 cm x 1.0 cm) was immersed in the plasma. After incubation at 37°C for 5 minutes in the coagulation analyzer, an equal amount of TT reagent was added to the test cup. The TT value was determined by the coagulation time of the PPP, and the coagulation time was also demonstrated by the average of 3 checks.

[0077] Animal experiment test:

[0078] A carotid artery replacement experiment was performed on a Labrador dog, and the samples of Example 2 and Comparative Example 1 were simultaneously replaced in the left and right carotid arteries of the same dog. After one month of implantation, whether thrombosis and endothelialization were formed was investigated, and three groups of experiments were balanced.

[0079] Table 1 Performance of different samples

[0080]

[0081] As shown in Table 1, the artificial blood obtained by the method has good anticoagulant property, and the APTT and TT time in the coagulation test are greatly prolonged. The artificial blood obtained by the method has no thrombosis in the early stage after implantation.

[0082] Figure 1 The figure is a schematic diagram of the chemical reaction of the anticoagulant coating of the application. After the chemical reaction, a large number of carboxyl groups, sulfonic acid groups and other groups with anticoagulant function are generated on the surface of the membrane. Figure 2 The figure is the inner surface morphology of the sample in Example 2 of the application, Figure 3 The figure is the inner surface morphology of the sample in Comparative Example 1 of the application. As can be seen from the comparison, the inner wall of the modified membrane has a layer of coating, and the surface is relatively smooth.

[0083] Figure 4 The figure is a section of the dog carotid artery after 1 month of replacement in Example 2 of the application. The vascular structure is clear and complete, the outside of the artificial blood vessel is wrapped by connective tissue layer, a small amount of fibrocytes infiltrate into the artificial blood vessel wall, the intimal cells grow densely and do not completely cover the artificial blood vessel, and no smooth muscle cell stratification and inflammatory infiltration is observed. Figure 5 The figure is a section of the dog carotid artery after 1 month of replacement in Comparative Example 1 of the application. The vascular structure is basically complete, the outside of the artificial blood vessel is wrapped by connective tissue layer, fibrocytes infiltrate into the artificial blood vessel wall, and thrombus exists in the lumen. No neointima is formed in the vascular lumen. Figure 4 And Figure 5 As can be seen from the comparison, the preparation method of the application can effectively anticoagulate and promote endothelialization.

[0084] Those skilled in the art should understand that the technical features of the above examples can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above examples are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the description.

[0085] The above examples only express several embodiments of the application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are all within the protection scope of the application. Therefore, the protection scope of the application should be subject to the appended claims.

Claims

1. A method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions, characterized in that, Includes the following steps: (1) The crosslinking agent and catalyst were dissolved in an aqueous hydrochloric acid solution to prepare the first reaction solution; (2) The second reaction solution was prepared by dissolving sulfonated starch and catalyst in hydrochloric acid aqueous solution; (3) Wrap the outer surface of the expanded polytetrafluoroethylene artificial blood vessel with aluminum foil, and activate the inner surface of the expanded polytetrafluoroethylene artificial blood vessel with plasma to obtain the activated expanded polytetrafluoroethylene artificial blood vessel. (4) Inject the first reaction solution into the activated expanded polytetrafluoroethylene artificial blood vessel, seal both ends of the activated expanded polytetrafluoroethylene artificial blood vessel and place it in an air shaker for reaction; (5) Take out and wash the expanded polytetrafluoroethylene artificial blood vessel, inject the second reaction solution into the washed expanded polytetrafluoroethylene artificial blood vessel, seal both ends of the expanded polytetrafluoroethylene artificial blood vessel injected with the second reaction solution and put it into an air shaker for reaction. (6) Remove and wash the expanded polytetrafluoroethylene artificial blood vessel, and dry the washed expanded polytetrafluoroethylene artificial blood vessel to obtain an artificial blood vessel with anticoagulation and rapid endothelialization functions.

2. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, In step (1), the crosslinking agent is one or more of citric acid and butanetetracarboxylic acid.

3. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, In steps (1) and (2), the catalyst is one or more of potassium dihydrogen phosphate and sodium dihydrogen phosphate.

4. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, In step (1), the mass concentration of the crosslinking agent is 0.1-0.5 g / L, the mass concentration of the catalyst is 0.05-0.25 g / L, and the molar concentration of the hydrochloric acid aqueous solution is 0.1 mol / L.

5. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, Sulfonated starch is prepared by the chlorosulfonic acid-pyridine method, with a degree of substitution of 0.8-1.2 and a sulfur content of >12%.

6. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, In step (2), the mass concentration of the catalyst is 0.05-0.25 g / L, and the molar concentration of the hydrochloric acid aqueous solution is 0.1 mol / L.

7. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, The plasma can be one or more of oxygen plasma and air plasma.

8. The method for preparing an artificial blood vessel with anticoagulant and rapid endothelialization functions according to claim 1, characterized in that, The reaction temperature of the air shaker is 50-80 ℃, the reaction time is 2-6 h, and the air shaker speed is 110-130 rpm.

9. An artificial blood vessel with anticoagulant and rapid endothelialization functions, characterized in that, The artificial blood vessel with anticoagulant and rapid endothelialization functions, prepared according to any one of claims 1 to 8, is an expanded polytetrafluoroethylene artificial blood vessel with sulfonic acid groups, hydroxyl groups, and carboxyl groups attached to its inner surface.

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