Vascular stent

Abstract

The application discloses a vascular stent and relates to the technical field of medical devices.The vascular stent comprises a stent body, and the stent body is made of a composite material of shape memory polyurethane and silk fibroin; the stent body comprises spiral main ribs and elastic connecting bridges, a plurality of spiral main ribs and a plurality of elastic connecting bridges are interwoven to form a spiral net-shaped tube body, and each of the adjacent two spiral main ribs is connected through a plurality of elastic connecting bridges, so that the stent body can periodically stretch and shrink along with the physiological pulsation of blood vessels.The vascular stent structure is improved, the physiological pulsation of blood vessels can be simulated, rigid restraint on the blood vessel wall is avoided, the restenosis rate in the stent is reduced, and the treatment effect is improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more particularly to a vascular stent. Background Technology

[0002] Peripheral artery disease and coronary atherosclerosis are common clinical conditions, and stent implantation is a primary treatment method. However, the incidence of intracoronary stent restenosis (ISR) remains a core issue limiting long-term efficacy. Existing research indicates that one of the main pathological mechanisms of ISR is that the rigid constriction of the vessel wall after stent implantation alters the normal vasomotor function, leading to an abnormal mechanical environment of the vessel wall. This, in turn, activates transcriptomic changes in smooth muscle cells through mechanical conduction mechanisms, causing smooth muscle cells to transform from "contractile" to "synthetic" types, ultimately resulting in intimal hyperplasia and restenosis.

[0003] Existing biocompatible stents employ a cobalt-chromium alloy helical structure, with helical units connected by a biodegradable polymer coating. Once the coating is absorbed, the stent "unlocks," restoring vascular pulsation. However, these stents are primarily made of metal, posing a potential risk of long-term metal retention. Furthermore, the "unlocking" process relies on coating degradation, and the degradation products may trigger adverse reactions. Summary of the Invention

[0004] The main objective of this invention is to provide a vascular stent that avoids the potential risks of long-term retention of the metal structure of the vascular stent in the body and avoids reliance on coating degradation to prevent adverse reactions that may be caused by degradation products.

[0005] To achieve the above objectives, the present invention proposes a vascular stent, comprising a stent body, wherein the stent body is made of a composite material of shape memory polyurethane and silk fibroin; the stent body includes helical main ribs and elastic connecting bridges, wherein multiple helical main ribs and multiple elastic connecting bridges are interwoven to form a helical mesh tube, and adjacent helical main ribs are connected by a number of elastic connecting bridges, so that the stent body can periodically expand and contract with the physiological pulsation of blood vessels.

[0006] Optionally, the elastic connecting bridge is in the shape of an arc or an S-curve.

[0007] Optionally, the mass ratio of shape memory polyurethane to silk fibroin in the composite material is 70:30 to 90:10.

[0008] Optionally, the helix angle of the helical main rib is 15-60°.

[0009] Optionally, in the axial direction of the support body, the helix angles of all the helical main ribs are equal; or, Along the axial direction of the support body, the helix angle of the helical main ribs located at both ends of the support body is smaller than the helix angle of the helical main rib located in the middle of the support body.

[0010] Optionally, the helical pitch of the helical main ribs is equal along the axial direction of the support body; or, Along the axial direction of the support body, the helical pitch of the helical main rib gradually increases or decreases from the proximal end to the distal end of the support body.

[0011] Optionally, in the axial direction of the support body, the helical pitch of the helical main rib gradually increases from 2.5 mm to 4.0 mm from the proximal end to the distal end of the support body.

[0012] Optionally, the vascular stent further includes a drug coating applied to the surface of the stent body.

[0013] Optionally, the drug coating is a biomimetic coating composed of elastin and cerium oxide nanoparticles; and / or, The thickness of the drug coating is 2-5 μm.

[0014] Optionally, the outer diameter of the support body is 3.0-5.0 mm; and / or, The length of the main body of the support is 13-38mm.

[0015] In the technical solution of this invention, the vascular stent includes a stent body, which is made of a composite material of shape memory polyurethane and silk fibroin. The stent body includes helical main ribs and elastic connecting bridges. Multiple helical main ribs and multiple elastic connecting bridges intertwine to form a helical mesh tube. Adjacent helical main ribs are connected by several elastic connecting bridges, so that the stent body can periodically expand and contract with the physiological pulsation of the blood vessel. It can be understood that this invention improves the structure of the vascular stent. By using a composite material of shape memory polyurethane and silk fibroin to make the stent body, the vascular stent does not have a metal structure, avoiding the potential risks of long-term metal retention in the body. The shape memory polyurethane and silk fibroin composite material achieves a unity of mechanical biomimicry and biological activity, matching the elastic modulus of the blood vessel wall and actively promoting endothelial repair.

[0016] In this invention, the vascular stent achieves its "breathing" function in response to vascular pulsation by setting elastic connecting bridges between adjacent spiral main ribs. This stent can pulsate with the blood vessel from the moment of implantation, mimicking physiological vascular pulsation without waiting for material degradation, achieving true immediate compliance. This avoids rigid constriction of the vascular wall, reduces the incidence of in-stent restenosis, and improves treatment efficacy. Furthermore, the vascular stent of this invention does not rely on coating degradation, effectively preventing adverse reactions that may be caused by degradation products and improving controllability.

[0017] In this invention, the surface of the scaffold body is coated with a drug coating. The antioxidant function of the cerium oxide nanoparticles in the drug coating works synergistically with the biomimetic mechanical structure. The mechanical structure can reduce the activation of inflammatory signaling pathways caused by mechanical stimulation, and the nanoparticles can remove the generated reactive oxygen species. The dual mechanism synergistically inhibits the proliferation of smooth muscle cells. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of the vascular stent of the present invention; Figure 2 This is a schematic diagram of the working state of the vascular stent in one embodiment of the present invention, showing the "breathing" of the vascular stent as it pulsates with the blood vessel (diagram of the vascular stent under pressure and deformation during vascular contraction). Figure 3 This is a schematic diagram of the "breathing" working state of the vascular stent as it pulsates with the blood vessel in one embodiment of the present invention (illustration of the elastic recovery state of the vascular stent during vasodilation). Figure 4 This is a partial unfolded schematic diagram of the main body of the biomimetic spiral mesh structure of the vascular stent in one embodiment of the present invention; Figure 5 This is a schematic diagram of a segmented variable stiffness helical structure as the main body of the vascular stent in one embodiment of the present invention; Figure 6 This is a schematic diagram of a vascular stent embodiment of the present invention, in which the stent body is a variable pitch helical structure; Figure 7 This is a schematic diagram of the structure of the stent body and drug coating in one embodiment of the vascular stent of the present invention.

[0020] Explanation of icon numbers: 100. Scaffold body; 110. Spiral main rib; 120. Elastic connecting bridge; 111. Proximal anchoring zone; 112. Mid-section conformation zone; 113. Distal anchoring zone; 1101. First segment; 1102. Second segment; 1103. Third segment; 200. Drug coating; 210. Elastin molecular layer; 220. Cerium oxide nanoparticle layer.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. In the description of this invention, the terms "proximal end" and "distal end" refer to near and far relative to the operator. When using this invention, the end closer to the operator is the "proximal end," that is, the end where the operator is located, and the end farther from the operator is the "distal end."

[0025] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. The word "and / or" throughout the text means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. The technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] Peripheral artery disease and coronary atherosclerosis are common clinical conditions, and stent implantation is a primary treatment method. However, the incidence of intracoronary stent restenosis (ISR) remains a core issue limiting long-term efficacy. Existing research indicates that one of the main pathological mechanisms of ISR is that the rigid constriction of the vessel wall after stent implantation alters the normal vasomotor function, leading to an abnormal mechanical environment of the vessel wall. This, in turn, activates transcriptomic changes in smooth muscle cells through mechanical conduction mechanisms, causing smooth muscle cells to transform from "contractile" to "synthetic" types, ultimately resulting in intimal hyperplasia and restenosis.

[0027] Existing biocompatible stents employ a cobalt-chromium alloy helical structure, with helical units connected by a biodegradable polymer coating. Once the coating is absorbed, the stent "unlocks," restoring vascular pulsation. However, these stents are primarily made of metal, posing a potential risk of long-term metal retention. Furthermore, the "unlocking" process relies on coating degradation, and the degradation products may trigger adverse reactions.

[0028] In response, this invention proposes a vascular stent to address the problems existing in the aforementioned technologies.

[0029] Reference Figures 1 to 4 In one embodiment of the present invention, the vascular stent includes a stent body 100, which is made of a composite material of shape memory polyurethane and silk fibroin. The stent body 100 includes a spiral main rib 110 and an elastic connecting bridge 120. Multiple spiral main ribs 110 and multiple elastic connecting bridges 120 are interwoven to form a spiral mesh tube. Adjacent spiral main ribs 110 are connected by a number of elastic connecting bridges 120 so that the stent body 100 can periodically expand and contract with the physiological pulsation of blood vessels.

[0030] It should be noted that shape memory polyurethane is a smart polymer material with a shape memory effect, capable of autonomously recovering from a temporarily compressed state to a preset expanded state under body temperature conditions. The hard segments in its molecular chains provide physical cross-linking points, giving the material good shape fixation and shape recovery rates; the soft segments, on the other hand, impart flexibility and elasticity. Compared to metallic materials, the elastic modulus of shape memory polyurethane (typically 10-100 MPa) is closer to the mechanical properties of natural blood vessel walls, effectively reducing compliance mismatch between vascular stents and blood vessel walls.

[0031] Silk fibroin is a natural structural protein with good biocompatibility, biodegradability, and endothelial cell adhesion and proliferation-promoting activity. Introducing silk fibroin into composite material systems can, on the one hand, adjust the mechanical properties of shape memory polyurethane to more closely approximate the elastic modulus range of the blood vessel wall; on the other hand, the arginine-glycine-aspartic acid (RGD) peptide sequence on the surface of silk fibroin can promote endothelial cell adhesion and proliferation, accelerating the endothelialization process after vascular stent implantation.

[0032] In this embodiment, the mass ratio of shape memory polyurethane to silk fibroin in the composite material is 70:30 to 90:10. Studies have shown that when the silk fibroin content is below 10%, the endothelialization-promoting effect is not significant; when the silk fibroin content is above 30%, the shape memory performance of the material decreases significantly, leading to insufficient scaffold expansion and affecting clinical efficacy.

[0033] Compared with existing technologies (such as simple polylactic acid stents, cobalt-chromium alloy stents, etc.), the shape memory polyurethane and silk fibroin composite material of the present invention achieves the unity of mechanical biomimicry and bioactivity. It can simulate the elastic characteristics of the blood vessel wall at the material level, while actively promoting endothelial cell repair, thereby fundamentally reducing the risk of restenosis.

[0034] Reference Figures 1 to 4 In this embodiment, the vascular stent is a biomimetic spiral mesh tubular structure. This structure is formed by multiple spiral main ribs 110 extending along the stent's axial direction and several elastic connecting bridges 120 distributed along the stent's circumference. Each elastic connecting bridge 120 can be arc-shaped, S-shaped, or similar, etc., and is not limited here.

[0035] Main reference Figure 2 and Figure 3Because the elastic connecting bridge 120 has elastic deformation capability, the vascular stent can elastically deform during vascular pulsation, converting the contractile pressure of the vessel wall into bending deformation of the elastic connecting bridge 120, rather than directly transmitting it to the vessel wall tissue. When the vessel dilates, the elastic restoring force of the elastic connecting bridge 120 drives the stent to return to its original shape. The vascular stent of the present invention has a "breathing" function. With the synergistic effect of the spiral main rib 110 and the elastic connecting bridge 120, the stent of the present invention can periodically expand and contract with the physiological pulsation of the blood vessel, making the stent pulsate with the blood vessel, as if the stent is "breathing".

[0036] It is understood that this invention improves the structure of vascular stents by using a composite material of shape memory polyurethane and silk fibroin to fabricate the stent body 100. The vascular stent does not have a metal structure, thus avoiding the potential risks of long-term metal retention in the body. The shape memory polyurethane and silk fibroin composite material achieves a unity of mechanical biomimicry and bioactivity, matching the elastic modulus of the blood vessel wall while actively promoting endothelial repair.

[0037] Compared to existing bioadaptive stents (such as the DynamX Bioadaptor), the "unlocking" mechanism of bioadaptive stents relies on the degradation of the polymer coating, and the stent still rigidly binds the blood vessel until the coating degrades. However, the vascular stent of this invention, by setting elastic connecting bridges 120 between adjacent helical main ribs 110, enables the vascular stent to "breathe" with the blood vessel's pulsation. This vascular stent can pulsate with the blood vessel from the moment of implantation, without waiting for material degradation, achieving a true immediate compliance effect. It can simulate the physiological pulsation of the blood vessel, avoid rigid binding to the blood vessel wall, reduce the incidence of in-stent restenosis, and improve treatment efficacy. The vascular stent of this invention does not rely on coating degradation, which can effectively prevent adverse reactions that may be caused by degradation products and improve the controllability of the vascular stent.

[0038] To meet the support requirements of blood vessels of different diameters and expand the applicability of the vascular stent, in one embodiment, the outer diameter of the stent body 100 in the supported state is 3.0-5.0 mm, and the length of the stent body 100 is 13-38 mm, which is not limited here.

[0039] Specifically, this embodiment provides a biomimetic wave-like intelligent respiratory vascular stent. The stent body 100 is made of a composite material of shape memory polyurethane (SMPU, Shore hardness 80A, glass transition temperature Tg of about 40-45℃) and silk fibroin (SF, molecular weight of about 100 kDa), with a mass ratio of SMPU to SF of 80:20.

[0040] Reference Figures 1 to 4The main body 100 of the support structure is a biomimetic spiral mesh structure, formed by six spiral main ribs 110 extending axially along the main body 100 and elastic connecting bridges 120 distributed circumferentially. The spiral main ribs 110 have a spiral angle of 30° and a spiral pitch p of 3.0 mm. The elastic connecting bridges 120 have an arc-shaped design with an arc height of 0.3 mm, connecting adjacent spiral main ribs 110. After the support is opened, its outer diameter is adjustable from 3.0 to 5.0 mm, its length is adjustable from 18 to 38 mm, and its wall thickness is 0.15 mm.

[0041] Wherein, the helix angle is the angle formed between the helix and the axis of the support body 100. (Refer to...) Figure 4 The two points where the two ends of the elastic connecting bridge 120 are connected to the two adjacent spiral main ribs 110 intersect the axis of the support body 100 and form an acute angle α. The spiral angle can be set to be equal to this acute angle α.

[0042] In this embodiment, after the vascular stent is implanted, the SMPU / SF composite material triggers a shape memory effect at body temperature (37°C), causing the stent to expand to a preset shape. During vascular pulsation (pulse pressure gradient of approximately 40 mmHg), the contractile force of the vessel wall causes the connecting bridges to elastically bend and deform, resulting in an overall diameter change of approximately 5%-8% with vascular pulsation, thus achieving a "breathing" function. Silk fibroin is exposed on the stent surface, promoting endothelial cell adhesion through the RGD peptide sequence.

[0043] To further improve the effect of simulating physiological vascular pulsation, further avoid rigid constriction of the vascular wall, and further reduce the incidence of in-stent restenosis, refer to Figure 1 and Figure 4 In some embodiments, the helix angle of the helical main rib 110 can be set to 15-60°. The smaller the helix angle, the higher the radial stiffness of the support body 100; the larger the helix angle, the stronger the compliance of the support body 100. By designing a suitable helix angle, the radial support force and flexibility of the support body 100 can be optimally balanced.

[0044] like Figure 1 As shown, in this embodiment, the helix angle of all the helical main ribs 110 can be designed to be equal, specifically 30°, along the axial direction of the support body 100.

[0045] As a deformable mode, such as Figure 5 As shown, in the axial direction of the support body 100, the helix angle of the helical main ribs 110 located at both ends of the support body 100 is smaller than the helix angle of the helical main ribs 110 located in the middle of the support body 100.

[0046] The helical structure of this vascular stent can be flexibly configured. The stent body 100 can be divided into regions of different stiffness along the axial direction. For example, dense helical regions with small helix angles (15°-30°) can be provided at both ends of the stent body 100 to provide stable anchoring; sparse helical regions with larger helix angles (40°-60°) can be provided in the middle section of the stent body 100 to enhance compliance.

[0047] Specifically, such as Figure 5 As shown, the stent body 100 of the vascular stent in this embodiment is divided into three axial regions, including a proximal anchoring region 111, a mid-section compliance region 112, and a distal anchoring region 113 connected sequentially from the proximal end to the distal end. The proximal anchoring region 111 is 5 mm long with a helix angle of 20°, and this section is used to provide stable anchoring; the mid-section compliance region 112 is 18 mm long with a helix angle of 45°, and this section is used to enhance compliance; the distal anchoring region 113 is 5 mm long with a helix angle of 20°, and this section is mainly used to provide stable anchoring. The regions are smoothly connected by a gradual transition section. This embodiment provides a segmented variable stiffness intelligent respiratory vascular stent. This segmented variable stiffness design enables the stent to have better adaptability in curved vascular segments, with stable anchoring at both ends and mid-section compliance with vascular pulsation and curvature.

[0048] To further improve the effect of simulating physiological vascular pulsation, further avoid rigid constriction of the vascular wall, and further reduce the incidence of in-stent restenosis, refer to Figure 1 In one embodiment, the spiral pitch p of the spiral main ribs 110 can be designed to be equal along the axial direction of the support body 100, specifically 3.0 mm.

[0049] As a deformable mode, it mainly refers to Figure 6 Along the axial direction of the stent body 100, the helical pitch p of the helical main rib 110 gradually increases or decreases from the proximal end to the distal end of the stent body 100. That is, the vascular stent of this embodiment adopts a variable pitch helical design. Within one helical cycle of the stent body 100, the helical pitch p gradually increases or decreases along the axial direction, so that the compliance of different parts of the stent exhibits a gradual change characteristic.

[0050] Specifically, it mainly refers to Figure 6In this embodiment, the vascular stent body 100 is divided into three axial regions, including a first segment 1101, a second segment 1102, and a third segment 1103 connected sequentially from the proximal end to the distal end. The helical pitch p of the first segment 1101 is smaller than that of the second segment 1102, and the helical pitch p of the second segment 1102 is smaller than that of the third segment 1103. Along the axial direction of the stent body 100, the helical pitch p of the main helical rib 110 gradually increases from 2.5 mm to 4.0 mm from the proximal end to the distal end. This embodiment provides a variable-pitch helical intelligent respiratory vascular stent. The stent body 100 of this embodiment adopts a variable-pitch helical design. In each helical cycle of the stent body 100, the helical pitch p gradually increases from the proximal end to the distal end, causing the radial stiffness of the stent body 100 to show a continuous gradual change along the axial direction, avoiding stress concentration problems caused by abrupt changes in stiffness.

[0051] Compared to existing closed-loop spiral lower limb arterial stents, although the prior art uses a spiral structure, its spiral design aims to improve radial support and wall apposition performance. However, the vascular stent of this invention connects adjacent spiral main ribs 110 via elastic connecting bridges 120, mainly to enable the vascular stent to "breathe" with the vascular pulsation, and the vascular stent itself has the ability to deform with pulsation.

[0052] In one embodiment, reference is made to Figure 7 The vascular stent may also include a drug coating 200, which is applied to the surface of the stent body 100.

[0053] In this embodiment, the drug coating 200 includes an elastin molecular layer 210 and a cerium oxide nanoparticle layer 220. The thickness of the drug coating 200 can be 2-5 μm, and is not limited here.

[0054] Elastin precursor is a soluble precursor of elastin that can self-assemble into a structure similar to natural elastic fibers, giving the coating good elasticity and bioactivity, and promoting the adhesion and proliferation of endothelial cells.

[0055] Cerium oxide nanoparticles (CeO2NPs) possess unique redox dual properties, with their surface Ce³... + / Ce 4+ The reversible conversion process endows it with superoxide dismutase and catalase-like activities, enabling it to efficiently remove reactive oxygen species (ROS) from the site of vascular injury. ROS are key signaling molecules that trigger inflammatory responses and abnormal proliferation of smooth muscle cells after stent implantation. By removing ROS, cerium oxide nanoparticles can inhibit the abnormal proliferation of smooth muscle cells, regulate the local inflammatory microenvironment, and synergize with the biomechanical properties of the material to further reduce the incidence of restenosis.

[0056] Specifically, this embodiment provides a smart respiratory stent with an antioxidant biomimetic coating. Based on the aforementioned embodiment, a biomimetic drug coating 200 is added to the surface of the stent body 100. The coating consists of elastin (Tropoelastin) and cerium oxide nanoparticles (CeO2NPs, particle size 5-15 nm, Ce³⁺). + Composed of approximately 22% ions. The drug coating 200 has a thickness of 2-5 μm. Elastin provides the coating with good elasticity, allowing it to expand and contract synchronously with the respiratory movements of the stent body 100 without detaching. Cerium oxide nanoparticles exert a ROS scavenging effect in the oxidative stress microenvironment at the site of vascular injury, inhibiting abnormal proliferation of smooth muscle cells.

[0057] Compared to existing pure iron vascular stents, which have cerium oxide films deposited on their surfaces, the coating of this invention employs an organic-inorganic composite system. Elastin provides bioactivity and elasticity matching, while cerium oxide nanoparticles provide antioxidant function, forming a synergistic effect of bioactivity and antioxidant properties, which differs from modification methods that simply involve the injection or deposition of inorganic elements.

[0058] In this invention, the surface of the scaffold body 100 is coated with a drug coating 200. The antioxidant function of the cerium oxide nanoparticles in the drug coating 200 works synergistically with the biomimetic mechanical structure. The mechanical structure can reduce the activation of inflammatory signaling pathways caused by mechanical stimulation, and the nanoparticles can remove the generated reactive oxygen species. The dual mechanism synergistically inhibits the proliferation of smooth muscle cells.

[0059] In summary, the vascular stent of this invention can simulate the physiological pulsation of blood vessels from the moment of implantation, achieving intelligent breathing and avoiding the rigid constraint of the vascular stent on the vessel wall, thus reducing the inducing factors of restenosis from the mechanical source. The stent body 100 of this invention uses a shape memory polyurethane and silk fibroin composite material, achieving a unity of mechanical biomimicry and bioactivity, matching the elastic modulus of the vessel wall and actively promoting endothelial repair. The vascular stent of this invention does not rely on coating degradation to unlock, avoiding adverse reactions that may be caused by degradation products. The stent body 100 of this invention is made entirely of non-metallic polymer materials, avoiding the potential risks of long-term retention of metal materials and achieving MRI compatibility. In this invention, the drug coating 200 on the surface of the stent body 100 uses cerium oxide nanoparticles, which have antioxidant functions and form a synergistic effect with the biomimetic mechanical structure. The mechanical structure reduces the activation of inflammatory signaling pathways caused by mechanical stimulation, while the nanoparticles clear the generated reactive oxygen species. This dual mechanism synergistically inhibits smooth muscle cell proliferation.

[0060] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A vascular stent, characterized in that, The stent body is made of a composite material of shape memory polyurethane and silk fibroin. The stent body includes helical main ribs and elastic connecting bridges. Multiple helical main ribs and multiple elastic connecting bridges are interwoven to form a helical mesh tube. Adjacent helical main ribs are connected by several elastic connecting bridges so that the stent body can periodically expand and contract with the physiological pulsation of blood vessels.

2. The vascular stent as described in claim 1, characterized in that, The elastic connecting bridge is in the shape of an arc or an S-shaped curve.

3. The vascular stent as described in claim 1, characterized in that, The mass ratio of shape memory polyurethane to silk fibroin in the composite material is 70:30 to 90:

10.

4. The vascular stent as described in claim 1, characterized in that, The helix angle of the main helical rib is 15-60°.

5. The vascular stent as described in claim 1 or 4, characterized in that, Along the axial direction of the support body, the helix angles of all the helical main ribs are equal; or, Along the axial direction of the support body, the helix angle of the helical main ribs located at both ends of the support body is smaller than the helix angle of the helical main rib located in the middle of the support body.

6. The vascular stent as described in claim 1 or 4, characterized in that, Along the axial direction of the support body, the helical pitch of the helical main ribs is equal; or, Along the axial direction of the support body, the helical pitch of the helical main rib gradually increases or decreases from the proximal end to the distal end of the support body.

7. The vascular stent as described in claim 6, characterized in that, Along the axial direction of the support body, the helical pitch of the helical main rib gradually increases from 2.5 mm to 4.0 mm from the proximal end to the distal end of the support body.

8. The vascular stent as described in claim 1, characterized in that, The vascular stent also includes a drug coating applied to the surface of the stent body.

9. The vascular stent as described in claim 8, characterized in that, The drug coating is a biomimetic coating composed of elastin and cerium oxide nanoparticles; and / or, The thickness of the drug coating is 2-5 μm.

10. The vascular stent as described in claim 1, characterized in that, The outer diameter of the main body of the support is 3.0-5.0 mm; and / or, The length of the main body of the support is 13-38mm.

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