Intravascular stent and preparation method thereof

Abstract

The invention discloses an intravascular stent and a preparation method thereof, and relates to the technical field of medical instruments.The intravascular stent comprises a stent body and an anti-thrombus coating arranged on the surface of the stent body, and preparation raw materials of the anti-thrombus coating comprise 2-methacryloyloxyethyl phosphorylcholine; the intravascular stent provided by the invention can effectively inhibit aggregation of platelets and proteins on the surface of the intravascular stent, so that formation of thrombus on the surface of the intravascular stent is effectively reduced, formation of acute-stage and advanced-stage thrombus in an intravascular stent implantation operation is effectively avoided, dependence of a patient on an antithrombotic drug after the intravascular stent is implanted is reduced, and the intravascular stent has a good application prospect. And the probability of postoperative restenosis and hemorrhagic diseases is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a vascular stent and a preparation method thereof. Background Art

[0002] Atherosclerosis is the most important pathological feature of panvascular disease. Currently, vascular stents can be used to treat atherosclerotic lesions. Among them, the formation of thrombosis within the stent is the primary factor for the occurrence of in-stent restenosis. In particular, acute thrombosis has a certain incidence rate during intracranial stent implantation surgery. The appearance of acute thrombosis often hinders the normal blood circulation in the cerebral arteries, seriously endangering the patient's brain tissue, causing complications such as hemiplegia, blindness, aphasia, cognitive impairment, sensory impairment, movement disorders, and rapid death.

[0003] The current clinical pathway for antithrombotic treatment should comprehensively consider factors such as the site of vascular lesions, ischemia and bleeding risk, and choose single antiplatelet therapy (SAPT) or enhanced antithrombotic regimen. However, the use of antithrombotic drugs brings great hidden dangers and risks to stent interventional treatment, increasing the treatment cost and burden of patients. Summary of the invention

[0004] The main purpose of the present invention is to provide a vascular stent and a preparation method thereof, so as to solve the technical problems of thrombosis after stent implantation and harm to patients caused by taking antithrombotic drugs after surgery.

[0005] To achieve the above object, the present invention provides a vascular stent, which includes a stent body and an anti-thrombotic coating provided on the surface of the stent body, wherein the raw material for preparing the anti-thrombotic coating includes 2-methacryloyloxyethyl phosphorylcholine.

[0006] Optionally, the raw materials for preparing the anti-thrombotic coating further include an initiator, a conductive salt and a solvent.

[0007] Optionally, the initiator includes at least one of p-nitrobenzene diazonium tetrafluoroborate and 4-bromobenzene diazonium tetrafluoroborate; and / or,

[0008] The conductive agent is at least one of sodium nitrate, sodium nitrite and tetraethylammonium perchlorate; and / or,

[0009] The solvent is at least one of acetonitrile and tetrahydrofuran.

[0010] Optionally, the raw materials for preparing the anti-thrombotic coating include: 2-methacryloyloxyethyl phosphorylcholine, 0.5-2 g; initiator, 0.1-0.5 g; conductive salt, 0.1-0.4 g; solvent, 150-200 mL.

[0011] Optionally, the raw materials for preparing the anti-thrombotic coating further include additives, and the additives include at least one of n-butyl methacrylate, methacrylic acid, ethyl acrylate, and 4-vinylpyridine; the volume of the additives is 0.1 to 100 mL.

[0012] Optionally, the anti-thrombotic coating has a thickness of 30 to 200 nm.

[0013] The present invention also provides a method for preparing a vascular stent, the method comprising the following steps:

[0014] Weigh 2-methacryloyloxyethyl phosphorylcholine, an initiator, a conductive salt and a solvent according to a ratio, stir and mix to obtain an anti-thrombotic coating slurry;

[0015] The anti-thrombotic coating slurry is coated on the surface of the stent body by an electrochemical grafting method, and a vascular stent is obtained after drying.

[0016] Optionally, the step of applying the anti-thrombotic coating slurry on the surface of the stent body by an electrochemical grafting method and obtaining the vascular stent after drying comprises:

[0017] The starting potential of electrochemical grafting is -0.5 to -1.5 V, the ending potential is -2.5 to -3.5 V, the number of scanning circles is 10 to 50 circles, and the scanning frequency is 0.02 to 0.05 V / s.

[0018] Optionally, the step of applying the anti-thrombotic coating slurry on the surface of the stent body by an electrochemical grafting method and obtaining the vascular stent after drying comprises:

[0019] The drying temperature is 40-50°C and the drying time is 4-8 hours.

[0020] Optionally, the anti-thrombotic coating slurry also includes 0.1 to 100 mL of n-butyl methacrylate.

[0021] The vascular stent provided by the present invention comprises a stent body and an anti-thrombotic coating arranged on the surface of the stent body, and the raw materials for preparing the anti-thrombotic coating include 2-methacryloyloxyethyl phosphorylcholine. Thus, after the vascular stent is implanted, the aggregation of platelets and proteins on the surface of the vascular stent can be effectively inhibited, thereby effectively reducing the formation of thrombi on the surface of the vascular stent, effectively avoiding the formation of acute and late thrombi during the vascular stent implantation surgery, reducing the patient's dependence on anti-thrombotic drugs after the vascular stent is implanted, and reducing the probability of postoperative restenosis and hemorrhagic complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 This is the CV curve of grafting the MMA-MPC composite on the surface of the nickel-titanium alloy stent body in Example 1 of the present invention;

[0024] Figure 2 Schematic diagram of SEM morphology and EDS mapping results of the surface coating of the vascular stent obtained in Example 1 of the present invention;

[0025] Figure 3 This is the C1s element spectrum of the surface coating of the vascular stent obtained in Example 1 of the present invention;

[0026] Figure 4 Schematic diagram of the water drop contact angle between the surface of the vascular stent obtained in Example 1 and the surface of the stent without coating;

[0027] Figure 5 Schematic diagram of OCT results of an uncoated stent in a rabbit carotid artery and a vascular stent obtained in Example 1 of the present invention.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In view of the harm to patients caused by thrombosis after stent implantation and taking antithrombotic drugs after surgery, the present invention provides a vascular stent.

[0031] In one embodiment of the present invention, the vascular stent includes a stent body and an anti-thrombotic coating disposed on the surface of the stent body, and the raw material for preparing the anti-thrombotic coating includes 2-methacryloyloxyethyl phosphorylcholine.

[0032] The molecular structure of 2-methacryloyloxyethyl phosphorylcholine (MPC) is as follows:

[0033]

[0034] The above molecular structure originates from the characteristics of the biological functional group "phosphorylcholine group (PC group)". The polymer containing MPC monomer can imitate the function of natural cell membrane structure. Its strongly hydrophilic heads gather together to adsorb a layer of water molecules, which can then act as a non-specific impedance to components such as bacteria, platelets, proteins and cells. This substance has good blood compatibility, inhibition of protein adsorption, protein stabilization, surface hydrophilization and other properties.

[0035] The present invention innovatively arranges an anti-thrombotic coating on the surface of the stent body, which can effectively inhibit the aggregation of platelets and proteins on the surface of the vascular stent after the vascular stent is implanted, thereby effectively reducing the formation of thrombi on the surface of the vascular stent, effectively avoiding the formation of acute and late thrombi during the vascular stent implantation operation, reducing the patient's dependence on anti-thrombotic drugs after vascular stent implantation, and reducing the chance of postoperative restenosis and hemorrhagic complications.

[0036] It should be noted that the stent body is a metal stent, such as a nickel-titanium alloy stent, and MPC undergoes a grafting reaction with the metal surface to form a stable anti-thrombotic coating.

[0037] In some embodiments, the raw materials for preparing the anti-thrombotic coating further include an initiator, a conductive salt and a solvent.

[0038] As an initiator of the grafting reaction between MPC and the metal surface, the initiator can effectively promote a more complete grafting reaction between MPC and the metal surface, thereby forming an anti-thrombotic coating with better stability.

[0039] In some optional embodiments, the initiator includes at least one of p-nitrobenzene diazonium tetrafluoroborate and 4-bromobenzene diazonium tetrafluoroborate.

[0040] Conductive salt has good electrical conductivity, which can ensure that the vascular stent with the anti-thrombotic coating has good electrical conductivity.

[0041] In some optional embodiments, the conductive agent is at least one of sodium nitrate, sodium nitrite, and tetraethylammonium perchlorate.

[0042] In some optional embodiments, the solvent is at least one of acetonitrile and tetrahydrofuran.

[0043] In some embodiments, the raw materials for preparing the anti-thrombotic coating include: 2-methacryloyloxyethyl phosphorylcholine, 0.5-2g (for example, 0.5g, 1g, 1.5g, 2g and any interval between the two end points); initiator, 0.1-0.5g (for example, 0.1g, 0.2g, 0.3g, 0.4g, 0.5g and any interval between the two end points); conductive salt, 0.1-0.4g (for example, 0.1g, 0.2g, 0.3g, 0.4g and any interval between the two end points); solvent, 150-200mL (for example, 150mL, 160mL, 170mL, 180mL, 190mL, 200mL and any interval between the two end points).

[0044] The present invention can obtain an anti-thrombotic coating which is relatively uniform, has good stability and good anti-thrombotic performance by reasonably adjusting the ratio between the raw materials.

[0045] The raw materials for preparing the anti-thrombotic coating also include additives, which include at least one of n-butyl methacrylate, methacrylic acid, ethyl acrylate, and 4-vinyl pyridine. The above additives all contain vinyl functional groups and are soluble in DMF or acetonitrile. At the same time, the above additives can undergo copolymerization with MPC and be grafted on the surface of the stent body. The stability and uniformity of the anti-thrombotic coating formed in this way are further improved.

[0046] As an example, the additive is n-butyl methacrylate. n-butyl methacrylate (BMA) can copolymerize with MPC and be grafted onto the surface of the stent body. The stability and uniformity of the anti-thrombotic coating formed in this way are further improved.

[0047] Optionally, the volume of the additive (such as n-butyl methacrylate) is 0.1 to 100 mL (such as 0.1 mL, 10 mL, 30 mL, 50 mL, 80 mL, 100 mL and intervals between any two end points).

[0048] In some embodiments, the thickness of the anti-thrombotic coating is 30-200 nm (eg, 30 nm, 50 nm, 100 nm, 150 nm, 200 nm, and any interval between the two end points).

[0049] The present invention also provides a method for preparing the above-mentioned vascular stent, the preparation method comprising the following steps:

[0050] Weigh 2-methacryloyloxyethyl phosphorylcholine, an initiator, a conductive salt and a solvent according to a ratio, stir and mix to obtain an anti-thrombotic coating slurry;

[0051] The anti-thrombotic coating slurry is coated on the surface of the stent body by an electrochemical grafting method, and a vascular stent is obtained after drying.

[0052] The present invention adopts an electrochemical grafting method to graft an anti-thrombotic coating on the surface of the stent body. After the vascular stent is implanted, the aggregation of platelets and proteins on the surface of the vascular stent can be effectively inhibited, thereby effectively reducing the formation of thrombi on the surface of the vascular stent, effectively avoiding the formation of acute and late thrombi during vascular stent implantation surgery, reducing the patient's dependence on anti-thrombotic drugs after vascular stent implantation, and reducing the chances of postoperative restenosis and hemorrhagic complications.

[0053] The raw materials, dosage and thickness of the anti-thrombotic coating can refer to the above embodiments and will not be described in detail here.

[0054] In some embodiments, the step of applying the anti-thrombotic coating slurry on the surface of the stent body by an electrochemical grafting method and obtaining the vascular stent after drying comprises:

[0055] An anti-thrombotic coating is prepared on the surface of the stent body using the CV mode under an electrochemical workstation, the starting potential of the electrochemical grafting is -0.5 to -1.5 V (such as -0.5 V, -0.8 V, -1 V, -1.2 V, -1.5 V and any interval between the two end points), the ending potential is -2.5 to -3.5 V (such as -2.5 V, -2.8 V, -3 V, -3.2 V, -3.5 V and any interval between the two end points), the number of scanning circles is 10 to 50 circles (such as 10 circles, 20 circles, 30 circles, 40 circles, 50 circles and any interval between the two end points); the scanning frequency is 0.02 to 0.05 V / s (such as 0.02 V / s, 0.03 V / s, 0.04 V / s, 0.05 V / s and any interval between the two end points).

[0056] The above electrochemical grafting conditions can be used to obtain an anti-thrombotic coating that is more uniform, has better stability and better anti-thrombotic performance.

[0057] In some embodiments, the step of applying the anti-thrombotic coating slurry on the surface of the stent body by an electrochemical grafting method and obtaining the vascular stent after drying comprises:

[0058] The drying temperature is 40-50°C (such as 40°C, 42°C, 45°C, 48°C, 50°C and any interval between the two end points), and the drying time is 4-8h (such as 4h, 5h, 6h, 7h, 8h and any interval between the two end points).

[0059] In some embodiments, the anti-thrombotic coating slurry further includes 0.1-100 mL of n-butyl methacrylate.

[0060] The vascular stent and the preparation method thereof of the present invention are described in detail below through specific embodiments.

[0061] Example 1

[0062] The vascular stent provided in this embodiment is prepared by the following steps:

[0063] (1) Preparation of anti-thrombotic coating slurry: weigh 0.5 g MPC, 0.1 g p-nitrobenzene diazonium tetrafluoroborate, 0.2 g sodium nitrate, 10 mL BMA and 150 mL acetonitrile, and stir to obtain a uniform slurry.

[0064] (2) Preparation of vascular stents: The electrochemical grafting method was used to prepare a BMA-MPC polymer coating on the surface of the nickel-titanium alloy stent in the CV mode under an electrochemical workstation, i.e., an anti-thrombotic coating, and the vascular stent was obtained after drying. The starting potential of the electrochemical grafting was -0.5 V, the ending potential was -2.5 V, the number of scanning circles was 50, the scanning frequency was 0.02 V / s, the drying temperature was 45°C, and the drying time was 6; the thickness of the anti-thrombotic coating was 30 nm.

[0065] The CV curves during the electrochemical grafting process in this example are as follows: Figure 1 As shown, from Figure 1 An obvious reduction peak can be seen in the figure, indicating that the grafting reaction occurs effectively and the anti-thrombotic coating is generated on the stent surface.

[0066] The surface of the vascular stent obtained in this example was analyzed by SEM+EDSmapping, and the results are as follows: Figure 2 As shown, the surface of the vascular stent is covered with a granular structure. From the element distribution results, it can be seen that the unique elements C, N, O, and P of the BMA-MPC composite in the viewing area are evenly covered on the coating surface, indicating that the coating has been formed on the surface of the alloy stent.

[0067] Further, the C element on the surface of the vascular stent obtained in this embodiment was analyzed by XPS, and its C1s element spectrum is as follows: Figure 3 As shown by Figure 3 From the element distribution results, it can be seen that the C element peaks on the stent surface mainly exist in the form of -CC-, -CC=O, and -COC-, and -C=C- is not detected. The C=C in BMA and MPC has been polymerized during the grafting reaction, and the anti-thrombotic coating forms a covalent bond structure with the stent surface, which has better coating firmness.

[0068] Furthermore, the vascular stent obtained in this embodiment was tested for a water drop contact angle, and the results are as follows: Figure 4As shown in the figure, by comparison, it can be seen that the water drop contact angle of 23.61° on the surface of the vascular stent after the anti-thrombotic coating is prepared is much smaller than the water drop contact angle of 89.52° on the uncoated vascular stent. The excellent hydrophilicity can make a layer of water molecules adsorbed on the surface of the material, which can then play a non-specific impedance to components such as bacteria, platelets, proteins and cells. In particular, it inhibits the adsorption of proteins and stabilizes them. Therefore, the coating with excellent hydrophilicity can effectively inhibit the formation of thrombus.

[0069] like Figure 5 As shown in the figure, the results of the OCT experiment of implanting uncoated vascular stents and coated vascular stents in the rabbit carotid artery show that: 30 days after implantation of both stents, the vascular endothelium formed a neointimal structure on the surface of the vascular stent, no thrombotic morphology was observed on the inner wall of the vascular stent, and no verification and rejection reactions were observed. The animals had normal vital signs during the 30-day implantation period, and no deaths occurred in all animal samples. During the 30-day implantation experiment, the animals did not take dual-antibody drugs. The experimental results showed that the vascular stent with anti-thrombotic coating had good biocompatibility, and no thrombus was formed on the surface of the coated stent without taking dual-antibody drugs after surgery.

[0070] Example 2

[0071] The vascular stent provided in this embodiment is prepared by the following steps:

[0072] (1) Preparation of anti-thrombotic coating slurry: Weigh 1 g of MPC, 0.2 g of p-nitrobenzene tetrafluoroborate diazonium salt, 0.3 g of sodium nitrate, 40 mL of BMA and 160 mL of acetonitrile, and stir to obtain a uniform slurry.

[0073] (2) Preparation of vascular stents: The electrochemical grafting method was used to prepare a BMA-MPC polymer coating on the surface of the nickel-titanium alloy stent in the CV mode under an electrochemical workstation, i.e., an anti-thrombotic coating. After drying, a vascular stent was obtained. The starting potential of the electrochemical grafting was -1 V, the ending potential was -3 V, the number of scanning circles was 50, the scanning frequency was 0.03 V / s, the drying temperature was 40°C, and the drying time was 8 h. The thickness of the anti-thrombotic coating was 50 nm.

[0074] The vascular stent obtained in this embodiment refers to the detection method of Example 1, and BMA-MPC is also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet is measured to be 22.44°, which is lower than that of Example 1. The anti-thrombotic coating has good hydrophilicity and can play a non-specific impedance to components such as bacteria, platelets, proteins and cells, especially inhibiting the adsorption of proteins and stabilizing proteins, which can effectively inhibit the formation of thrombi.

[0075] Example 3

[0076] The vascular stent provided in this embodiment is prepared by the following steps:

[0077] (1) Preparation of anti-thrombotic coating slurry: 1.5 g MPC, 0.3 g 4-bromoboric acid diazobenzene tetrafluoroborate, 0.3 g tetraethylammonium perchlorate, 50 mL BMA and 170 mL acetonitrile were weighed and stirred to obtain a uniform slurry.

[0078] (2) Preparation of vascular stents: The electrochemical grafting method was used to prepare a BMA-MPC polymer coating on the surface of the nickel-titanium alloy stent in the CV mode under an electrochemical workstation, i.e., an anti-thrombotic coating. After drying, a vascular stent was obtained. The starting potential of the electrochemical grafting was -1.1 V, the ending potential was -3.1 V, the number of scanning circles was 50 circles, the scanning frequency was 0.04 V / s, the drying temperature was 50°C, and the drying time was 4 hours. The thickness of the anti-thrombotic coating was 100 nm.

[0079] The vascular stent obtained in this embodiment refers to the detection method of Example 1, and BMA-MPC is also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet is measured to be 21.06°, which is lower than that of Example 1. The anti-thrombotic coating has good hydrophilicity and can play a non-specific impedance to components such as bacteria, platelets, proteins and cells, especially inhibiting the adsorption of proteins and stabilizing proteins, which can effectively inhibit the formation of thrombi.

[0080] Example 4

[0081] The vascular stent provided in this embodiment is prepared by the following steps:

[0082] (1) Preparation of anti-thrombotic coating slurry: 1.5 g MPC, 0.4 g 4-bromoboric acid diazobenzene tetrafluoroborate, 0.3 g tetraethylammonium perchlorate, 60 mL BMA and 180 mL acetonitrile were weighed and stirred to obtain a uniform slurry.

[0083] (2) Preparation of vascular stents: The electrochemical grafting method was used to prepare a BMA-MPC polymer coating on the surface of the nickel-titanium alloy stent in the CV mode under an electrochemical workstation, i.e., an anti-thrombotic coating. After drying, a vascular stent was obtained. The starting potential of the electrochemical grafting was -1.2 V, the ending potential was -3.2 V, the number of scanning circles was 50, the scanning frequency was 0.04 V / s, the drying temperature was 45°C, and the drying time was 7 hours. The thickness of the anti-thrombotic coating was 150 nm.

[0084] The vascular stent obtained in this embodiment refers to the detection method of Example 1, and BMA-MPC is also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet is measured to be 21.14°, which is lower than that of Example 1. The anti-thrombotic coating has good hydrophilicity and can play a non-specific impedance to components such as bacteria, platelets, proteins and cells, especially inhibiting the adsorption of proteins and stabilizing proteins, which can effectively inhibit the formation of thrombi.

[0085] Example 5

[0086] The vascular stent provided in this embodiment is prepared by the following steps:

[0087] (1) Preparation of anti-thrombotic coating slurry: 2 g MPC, 0.5 g 4-bromoboric acid diazobenzene tetrafluoroborate, 0.4 g tetraethylammonium perchlorate, 100 mL BMA and 200 mL acetonitrile were weighed and stirred to obtain a uniform slurry.

[0088] (2) Preparation of vascular stents: The electrochemical grafting method was used to prepare a BMA-MPC polymer coating on the surface of the nickel-titanium alloy stent in the CV mode under an electrochemical workstation, i.e., an anti-thrombotic coating. After drying, a vascular stent was obtained. The starting potential of the electrochemical grafting was -1.5 V, the ending potential was -3.5 V, the number of scanning circles was 50 circles, the scanning frequency was 0.05 V / s, the drying temperature was 50°C, and the drying time was 6 hours. The thickness of the anti-thrombotic coating was 200 nm.

[0089] The vascular stent obtained in this embodiment refers to the detection method of Example 1, and BMA-MPC is also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet is measured to be 20.03°, which is lower than that of Example 1. The anti-thrombotic coating has good hydrophilicity and can play a non-specific impedance to components such as bacteria, platelets, proteins and cells, especially inhibiting the adsorption of proteins and stabilizing proteins, which can effectively inhibit the formation of blood clots.

[0090] Comparative Example 1

[0091] The difference between this comparative example and Example 1 is that the amount of MPC used in step (1) is 0.2 g, and the rest is the same as Example 1.

[0092] The vascular stent obtained in this comparative example was detected by the detection method of Example 1, and BMA-MPC was also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet was measured to be 58.46°.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is that the amount of MPC used in step (1) is 3 g, and the rest is the same as Example 1.

[0095] The vascular stent obtained in this comparative example was detected by the detection method of Example 1, and BMA-MPC was also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet was measured to be 57.82°.

[0096] Comparative Example 3

[0097] The difference between this comparative example and Example 1 is that the amount of BMC used in step (1) is 120 mL, and the rest is the same as Example 1.

[0098] The vascular stent obtained in this comparative example was detected by the detection method of Example 1, and BMA-MPC was also detected to be grafted on the surface of the nickel-titanium alloy stent. The contact angle of the water droplet was measured to be 60.13°.

[0099] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A vascular stent, characterized in that: The vascular stent comprises a stent body and an anti-thrombotic coating arranged on the surface of the stent body. The raw materials for preparing the anti-thrombotic coating include 2-methacryloyloxyethyl phosphorylcholine.

2. The vascular stent according to claim 1, characterized in that: The raw materials for preparing the anti-thrombotic coating also include an initiator, a conductive salt and a solvent.

3. The vascular stent according to claim 2, characterized in that: The initiator comprises at least one of p-nitrobenzene diazonium tetrafluoroborate and 4-bromobenzene diazonium tetrafluoroborate; and / or, The conductive agent is at least one of sodium nitrate, sodium nitrite and tetraethylammonium perchlorate; and / or, The solvent is at least one of acetonitrile and tetrahydrofuran.

4. The vascular stent according to claim 2, characterized in that: The raw materials for preparing the anti-thrombotic coating include: 2-Methacryloyloxyethyl phosphorylcholine, 0.5-2 g; Initiator, 0.1-0.5 g; Conductive salt, 0.1-0.4 g; Solvent, 150-200mL.

5. The vascular stent according to claim 4, characterized in that: The raw materials for preparing the anti-thrombotic coating further include additives, and the additives include at least one of n-butyl methacrylate, methacrylic acid, ethyl acrylate, and 4-vinyl pyridine; The volume of the additive is 0.1 to 100 mL.

6. The vascular stent according to any one of claims 1 to 5, characterized in that: The thickness of the anti-thrombotic coating is 30-200 nm.

7. A method for preparing a vascular stent, characterized in that: The preparation method comprises the following steps: Weigh 2-methacryloyloxyethyl phosphorylcholine, an initiator, a conductive salt and a solvent according to a ratio, stir and mix to obtain an anti-thrombotic coating slurry; The anti-thrombotic coating slurry is coated on the surface of the stent body by an electrochemical grafting method, and a vascular stent is obtained after drying.

8. The method for preparing a vascular stent according to claim 6, characterized in that: The step of applying the anti-thrombotic coating slurry on the surface of the stent body by an electrochemical grafting method and obtaining the vascular stent after drying comprises: The starting potential of electrochemical grafting is -0.5 to -1.5 V, the ending potential is -2.5 to -3.5 V, the number of scanning circles is 10 to 50 circles, and the scanning frequency is 0.02 to 0.05 V / s.

9. The method for preparing a vascular stent according to claim 6, characterized in that: The step of applying the anti-thrombotic coating slurry on the surface of the stent body by an electrochemical grafting method and obtaining the vascular stent after drying comprises: The drying temperature is 40-50°C and the drying time is 4-8 hours.

10. The method for preparing a vascular stent according to any one of claims 7 to 9, characterized in that: The anti-thrombotic coating slurry also includes 0.1 to 100 mL of n-butyl methacrylate.

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