A vascular stent and a method of manufacturing the same

Abstract

This invention provides a vascular stent and its preparation method, belonging to the field of medical device technology. The vascular stent includes a first stent unit and a second stent unit arranged alternately along the axial direction. The first stent unit is made of a metallic material, and the second stent unit is made of a non-metallic material. Connecting components include a connector and a receiver. The connector and receiver form a preliminary mechanical connection through an interference fit. Pressure and / or heat treatment are applied to the receiver, causing it to soften, melt, or undergo thermoplastic deformation, and after cooling and solidification, it adheres tightly to the connector. This vascular stent combines the advantages of both DES and BRS, providing reliable radial support and imaging positioning capabilities in the early stages of implantation, and restoring the vessel's own elasticity through the gradual degradation of the non-metallic material in the later stages. Simultaneously, the interference fit combined with pressure and / or heat treatment achieves a reliable fixed connection between stent units of different materials, effectively preventing loosening or detachment in the later stages.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a vascular stent and its preparation method. Background Technology

[0002] As an important interventional device for treating coronary artery stenosis, peripheral vascular disease, and other diseases, the structural design and material selection of vascular stents directly affect the mechanical support effect, biocompatibility, and long-term safety after implantation.

[0003] In recent years, drug-eluting stents (DES) and bioresorbable stents (BRS) have been widely used and have achieved significant technological advancements. DES possesses excellent radial support and radiopaque properties, providing stable support to blood vessels in the initial implantation stage. However, the bulk material of DES is non-degradable, remaining permanently within the vessel and causing long-term irritation, affecting normal vascular remodeling and contraction, and potentially leading to tissue inflammation, late in-stent restenosis, and late thrombosis. BRS, made from biodegradable polymer materials, gradually degrades after fulfilling its initial support function, helping the vessel regain its elastic contractile function. However, existing BRS generally suffer from insufficient radial support, requiring metal markers for radiopaque placement, affecting accurate assessment and increasing the difficulty and time of surgical procedures. Furthermore, current BRS are relatively short, failing to meet the needs of overlapping or laparoscopic applications for long lesions.

[0004] Each of the single DES or BRS has its own advantages and disadvantages in clinical applications. Therefore, how to combine the advantages of both and combine stents of different materials has become an important technical challenge in the current development of vascular stent technology. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a vascular stent to solve the problems of drug-eluting stents causing long-term irritation due to permanent retention in blood vessels, and bioresorbable stents having insufficient radial support, poor imaging performance, and limited length. At the same time, this invention also provides a method for preparing the vascular stent.

[0006] To achieve the above and other related objectives, the present invention provides the following technical solutions: In a first aspect, the present invention provides a vascular stent comprising a first stent unit and a second stent unit arranged alternately along an axial direction, wherein the first stent unit is made of a metallic material and the second stent unit is made of a non-metallic material; adjacent first stent units and second stent units are connected by a connecting member. The connecting component includes: a connecting arm fixedly disposed at the end of the first support unit, the end of the connecting arm having a plug-in component; and a receiving component fixedly disposed at the end of the second support unit, the receiving component being made of a non-metallic material; The connector and the receiver form a preliminary mechanical connection through an interference fit. After the preliminary connection, the receiver is subjected to pressure and / or heat treatment, causing it to soften, melt, or undergo thermoplastic deformation. After cooling and solidification, the receiver adheres tightly to the connector, forming an integrated and fixed connecting component.

[0007] Furthermore, the metal material is a bio-absorbable metal material or a non-bio-absorbable metal material, wherein the bio-absorbable metal material is selected from one or more of absorbable magnesium alloys, absorbable iron-based alloys, and absorbable zinc alloys; and the non-bio-absorbable metal material is selected from one or more of stainless steel, cobalt-chromium alloys, nickel-titanium alloys, gold, and platinum.

[0008] Furthermore, the non-metallic material includes a bioabsorbable polyester material selected from one or more of poly-L-lactic acid (PLLA), polyracemic lactic acid (PDLLA), polylactic-co-glycolic acid copolymer (PGLA), and polycaprolactone (PCL). The non-metallic material receiving component softens, melts, or undergoes thermoplastic deformation under pressure and / or heat fusion, thereby tightly adhering to the metallic material connector, forming a robust integral structure between the different material scaffold units and preventing loosening or detachment after implantation.

[0009] Furthermore, the non-metallic material also includes absorbable reinforcing fillers selected from one or more of hydroxyapatite (HA) microparticles, tricalcium phosphate (TCP), β-tricalcium phosphate (β-TCP) microparticles, type I collagen microfibers, or chitosan grafted modified microparticles. HA microparticles and β-TCP microparticles can enhance the mechanical strength of the non-metallic material, reducing wall thickness while meeting support requirements, thereby reducing the volume of foreign bodies within blood vessels and lowering the risk of thrombosis. Type I collagen microfibers and chitosan grafted modified microparticles exhibit good biocompatibility, improving the mechanical properties of the non-metallic material while also providing antibacterial properties and reducing inflammatory responses.

[0010] Furthermore, the amount of absorbable reinforcing filler added is 2%-15% of the mass fraction of the substrate, preferably 5%-10%; the particle size or diameter meets the following requirements: the particle size of the microparticles is 0.1-5μm, and the diameter of the microfibers is 50-500nm and the length is 5-20μm.

[0011] In this invention, the first stent unit, made of metallic material, possesses both excellent mechanical support and X-ray radiolucency, while the second stent unit, made of non-metallic material, exhibits biodegradability and good biocompatibility. Through the continuous alternation of metallic and non-metallic stent units, the advantages of both DES and BRS are combined. When the non-metallic portion degrades, only a very small portion of the metallic stent unit remains, greatly restoring the original elastic contractile function of the blood vessel. This solves the problem of permanent DES residue irritating the blood vessel, while also compensating for the shortcomings of BRS, such as insufficient support, difficulty in positioning, and poor wall apposition, achieving full-cycle functional coverage of "temporary support - precise positioning - elastic recovery." Furthermore, this combination and connection of multiple stent units improves the overall flexibility of the stent and enhances delivery performance during surgery.

[0012] Furthermore, both the first stent unit and the second stent unit are annular support structures suitable for intravascular implantation, preferably circular annular structures.

[0013] Furthermore, the connecting arm is disposed at the annular edge of the first support unit and extends outward along the axial direction; similarly, the receiving member is placed at the annular edge of the second support unit and extends outward along the axial direction. Distributing the connecting components at the annular edge of each support unit avoids stress concentration in the main support area, thereby improving the overall mechanical stability and fatigue reliability of the support.

[0014] Furthermore, at the docking end of the first support unit and the second support unit, there are no less than two plug-in / receiver components in the circumferential direction, and the number of plug-in components and the position of the receiver components are the same and correspond to each other, thereby ensuring that a reliable connection is formed between adjacent first support units and second support units, and enhancing the load-bearing capacity and stability of the connecting components.

[0015] Furthermore, the connectors / receivers are evenly spaced along the circumference of the first support unit / second support unit.

[0016] Through the circumferential synergistic effect of multiple connecting components, the relative rotation, sway and axial misalignment between adjacent stent units can be effectively suppressed, while the local stress concentration at the connection site is dispersed, thereby improving the connection stability and fatigue reliability of the stent under vascular pulsation and repeated radial expansion conditions.

[0017] Furthermore, the connecting arm and the plug are integrally formed with the first support unit, and the receiving component is integrally formed with the second support unit.

[0018] Furthermore, the receiving component has slots, fitting grooves, or openings adapted to the connector. The connector and the receiving component achieve an interference fit through dimensional interference; that is, during assembly, at least one of the connector and / or the receiving component undergoes elastic or micro-plastic deformation, causing the connector to embed into the slot, fitting groove, or opening of the receiving component, forming a preliminary positioning connection. This preliminary mating structure can limit the relative axial displacement and circumferential rotation between adjacent support units before heat fusion or pressure treatment, providing a stable structural foundation for subsequent connection and curing processes.

[0019] Furthermore, the interference fit connection methods specifically include plug-in, snap-fit, interlocking, overlapping, socket, and tenon-and-mortise connection methods, which can be flexibly selected according to material characteristics and clinical needs.

[0020] In a preferred embodiment, the receiving component has a through slot, and the width of the connector is greater than the width of the slot. Utilizing the elastic deformation of the metal connector (and / or the deformation of the non-metallic receiving component), the connector is inserted into the slot of the receiving component, achieving initial docking through mechanical engagement of their dimensions. After initial docking, a heat conduction process melts the receiving component, causing it to adhere tightly to the connector.

[0021] Furthermore, the shape of the slot can be any shape or combination thereof, such as circular, rectangular, long strip, elliptical, "cross", U-shaped, V-shaped, "convex", or irregular, as long as its maximum width is less than the width of the connector to avoid separation after engagement.

[0022] Furthermore, the shape of the connector can be any shape or combination thereof, such as symmetrical or asymmetrical circle, rectangle, horizontal stripe, crescent, heart, umbrella, U, V, triangle, ring, irregular shape, etc.

[0023] Furthermore, the connector is provided with through holes, and the number of through holes can be one or more. The through holes can reduce the weight of the connector and increase its surface area. When the receiving component comes into contact with it after being heat-melted, the contact area between the two can be increased, making the combination between the two tighter and stronger.

[0024] Furthermore, the width of the connecting arm is denoted as J, and the width of the slot is denoted as J1, where J is greater than J1, thus achieving an interference fit between the connecting arm and the slot, further improving the connection stability of the connecting components. Both J and J1 are 0.01-0.6 mm.

[0025] Furthermore, the width of the connector is denoted as A, and the width of the receiving component near the second support unit is denoted as B. A is greater than J1, and A is greater than B. Both A and B are 0.01-0.9 mm.

[0026] Furthermore, the thickness of the connecting arm and the connector is consistent, denoted as H1, and H1 is 0.01-0.1mm; after connection, the thickness of the connector and the receiver when they are in close contact (i.e., the sum of the wall thicknesses of the connector and the receiver) is denoted as H, and H is controlled within 0.02-0.2mm to ensure the overall minimally invasive nature of the stent and avoid the risk of thrombosis caused by excessive thickness.

[0027] Furthermore, the edge of the connecting arm has at least one protrusion, which enables the connecting arm to form a tighter interference fit with the slot. After hot melting and cooling, it solidifies and forms a mold, significantly improving the connection strength between the connecting arm and the plug.

[0028] Furthermore, the slot has a groove that matches the protrusion, which can position the connecting arm and achieve initial positioning of the connector and the slot, ensuring the consistency of each connecting component after connection.

[0029] Furthermore, at least a portion of the outer edge of the connector is wavy or serrated. The serrated or wavy outer edge can increase the surface area of ​​the connector. After the receiving component is heat-melted and solidified, the contact area between the connector and the receiving component is larger, and the connection between the two is more firm, tight, and difficult to separate.

[0030] In a preferred embodiment, the receiving component has a through or non-through fitting groove, the shape of which matches the shape of the connector, and the width of the connector is greater than or equal to the width of the fitting groove. After the connector is inserted into the fitting groove of the receiving component, a preliminary connection is formed through mechanical interlocking of their dimensions. After the preliminary connection, the receiving component is heated and melted through a heat conduction process, causing it to adhere tightly to the connector.

[0031] The shape of the connector can be any shape or combination thereof, such as a symmetrical or asymmetrical circle, rectangle, horizontal stripe, crescent, heart, umbrella, U, V, triangle, ring, or irregular shape. The shape of the fitting groove is adapted to the shape of the connector so that the connector can be embedded in the fitting groove.

[0032] Furthermore, the connector is provided with through holes, and the number of through holes can be one or more. The through holes can reduce the weight of the connector and increase its surface area. When the receiving component comes into contact with it after being heat-melted, the contact area between the two can be increased, making the combination between the two tighter and stronger.

[0033] In a preferred embodiment, the receiving component has multiple slots spaced apart along its length; the connector has at least two inserts extending away from the connecting arm; the inserts are alternately inserted into the slots, forming a preliminary positioning connection through their cross-winding, preventing relative sliding between the inserts and the receiving component. After preliminary docking, the receiving component is heated and melted through a heat conduction process, causing it to adhere tightly to the inserts, resulting in a very strong connection.

[0034] Furthermore, the ends of the two inserts away from the connecting arm can be connected together to form a ring.

[0035] Furthermore, the receiving component is fishbone shaped, meaning that multiple opening slots are provided at intervals on both sides of the receiving component.

[0036] Furthermore, both ends of the vascular stent are provided with first stent units made of metal material, so that the vascular stent is arranged in the form of "first stent unit-second stent unit-first stent unit" or "first stent unit-second stent unit-first stent unit-......-second stent unit-first stent unit". This form can utilize the rigidity of the metal stent units at both ends to improve the wall adhesion and positioning accuracy.

[0037] Furthermore, the surface of the first stent unit and / or the second stent unit is coated with a therapeutic agent, which is an anti-inflammatory and / or anti-proliferative drug. The therapeutic agent is selected from one or more of rapamycin, paclitaxel, arsenic trioxide or their drug derivatives, which can effectively inhibit inflammatory response of vascular tissue and smooth muscle cell proliferation, and reduce the risk of restenosis and thrombosis.

[0038] A second aspect of the present invention provides a method for preparing the above-mentioned vascular stent, comprising the following steps: S1. A first support unit made of metal and a second support unit made of non-metal are respectively manufactured. The first support unit has at least two connecting arms on its circumferential side at the end, and the end of the connecting arm has a plug-in. The second support unit has a receiving part on its circumferential side at the end that is adapted to the plug-in. S2. Alternately connect the first support unit and the second support unit so that the connector of the first support unit forms a preliminary mechanical connection with the receiving part of the adjacent second support unit; S3. The receiver is locally softened, melted or thermoplastically deformed by pressure and / or heat treatment. After it cools and solidifies, the receiver and the connector are tightly attached together, thereby obtaining a vascular stent with alternating connections of the first stent unit and the second stent unit.

[0039] In step S3, the heat treatment is preferably carried out by local heat conduction. The heat source can be a heating head, hot air, infrared or laser. The heating area is limited to the connection part where the receiving element is located, so as to avoid unnecessary deformation in other areas of the second support unit.

[0040] When the main material of the receiving component is PLLA, PDLLA or PGLA, the heat treatment temperature is preferably controlled within the range of 10-40°C above its glass transition temperature Tg, so that the receiving component material undergoes controllable softening and covers the connector under pressure. When the main material of the receiving component is PCL, the heat treatment temperature is preferably controlled near its melting point Tm, so that the receiving component material undergoes local melting and forms a mechanically locked structure after cooling.

[0041] In step S3, the pressure is preferably radial pressure or local clamping force, with a pressure of 5-30 N applied to a single connection point and a holding time of 1-10 s. After cooling and solidification, an irreversible mechanical locking and material bonding structure is formed between the connector and the receiver.

[0042] As described above, the vascular stent and its preparation method of the present invention have the following beneficial effects: (1) By alternating the combination of the first stent unit of metallic material and the second stent unit of non-metallic material, the advantages of both DES and BRS are combined. In the early stage of implantation, reliable radial support and imaging positioning ability are provided. In the later stage, the blood vessel’s own elasticity is restored through the gradual degradation of non-metallic material, reducing the long-term stimulation of blood vessels by permanent metal residue.

[0043] (2) By using an interference fit combined with pressure and / or heat treatment, a reliable fixed connection between stent units of different materials can be achieved, effectively preventing loosening or detachment under the action of vascular pulsation load after implantation.

[0044] (3) By using a circumferential multi-connection point structural design, the torsion resistance and fatigue resistance of the connection parts are improved. At the same time, by alternating combinations of multiple stent units, the overall flexibility and delivery performance of the stent are improved, thereby enhancing the safety and stability of clinical operations.

[0045] (4) By adding absorbable reinforcing fillers to non-metallic materials, the mechanical strength of non-metallic materials can be improved. Under the premise of meeting the support requirements, the wall thickness can be reduced, thereby reducing the volume of foreign bodies in blood vessels and reducing the risk of thrombosis. At the same time, some biocompatible absorbable reinforcing fillers can also be antibacterial and reduce inflammatory response. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the vascular stent structure disclosed in Embodiment 1 of the present invention.

[0047] Figure 2 This is a structural schematic diagram of the disconnected state of the connecting components disclosed in Embodiment 1 of the present invention.

[0048] Figure 3 This is a schematic diagram of the structure after the connecting components disclosed in Embodiment 1 of the present invention are connected.

[0049] Figure 4 This is a schematic diagram of the structure of the connecting component after hot pressing in the thickness direction as disclosed in Embodiment 1 of the present invention.

[0050] Figure 5 This is a schematic diagram of the structure of the connecting component in the separated state as disclosed in Embodiment 2 of the present invention.

[0051] Figure 6 This is a schematic diagram of the vascular stent structure disclosed in Embodiment 3 of the present invention.

[0052] Figure 7 This is a schematic diagram of the structure of the connecting component in the separated state as disclosed in Embodiment 3 of the present invention.

[0053] Figure 8 This is a schematic diagram of the structure after the connecting components are connected in Embodiment 3 of the present invention.

[0054] Figure 9 This is a structural schematic diagram of the disconnected state of the connecting component disclosed in Embodiment 4 of the present invention.

[0055] Figure 10 This is a schematic diagram of the structure after the connecting components are connected, as disclosed in Embodiment 4 of the present invention.

[0056] Figure 11 This is a schematic diagram of the structure of the connecting component in the separated state as disclosed in Embodiment 5 of the present invention.

[0057] Figure 12 This is a schematic diagram of the structure after the connecting components are connected, as disclosed in Embodiment 5 of the present invention.

[0058] Figure 13 This is a schematic diagram of the vascular stent structure disclosed in Embodiment 6 of the present invention.

[0059] Figure 14 This is a schematic diagram of the structure of the first support unit and the second support unit disclosed in Embodiment 6 of the present invention.

[0060] Figure 15 This is a structural schematic diagram of the disconnected state of the connecting component disclosed in Embodiment 6 of the present invention.

[0061] Figure 16 This is a schematic diagram of the structure after the connecting components are connected, as disclosed in Embodiment 6 of the present invention.

[0062] Figure 17 This is a schematic diagram of the vascular stent structure disclosed in Embodiment 7 of the present invention.

[0063] Figure 18 This is a structural schematic diagram of the disconnected state of the connecting component disclosed in Embodiment 7 of the present invention.

[0064] Figure 19 This is a schematic diagram of the structure along the thickness direction of the connecting components after initial docking as disclosed in Embodiment 7 of the present invention.

[0065] Figure 20 This is a schematic diagram of the structure of the connecting components after hot pressing connection as disclosed in Embodiment 7 of the present invention.

[0066] Figure 21 This is a structural schematic diagram of the disconnected state of the connecting component disclosed in Embodiment 8 of the present invention.

[0067] Figure 22 This is a schematic diagram of the structure after the connecting components are connected, as disclosed in Embodiment 8 of the present invention.

[0068] Component designation explanation 1. First support unit; 2. Second support unit; 3. Connecting component; 4. Connecting arm; 41. Protrusion; 5. Connector; 51. Through hole; 52. Insert; 6. Receiving component; 61. Slot; 62. Fitting groove; 63. Opening groove; 64. Groove. Detailed Implementation

[0069] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0070] The present invention will be further illustrated by the following specific embodiments. This description is only for illustrative purposes and is not intended to limit the scope of the present invention in any way. Any modifications and changes that can be easily made by those skilled in the art are included within the scope of the disclosure in this specification and the appended claims.

[0071] Example 1 Please see Figure 1-4 This embodiment provides a vascular stent, including a first stent unit 1 and a second stent unit 2 arranged alternately along the axial direction.

[0072] The first support unit 1 is made of metallic material, and the second support unit 2 is made of non-metallic material. The metallic material can be a bio-absorbable metallic material or a non-bio-absorbable metallic material. The bio-absorbable metallic material is selected from one or more of absorbable magnesium alloy, absorbable iron-based alloy, and absorbable zinc alloy. The non-bio-absorbable metallic material is selected from one or more of stainless steel, cobalt-chromium alloy, nickel-titanium alloy, gold, and platinum. The non-metallic material includes bio-absorbable polyester material, which is selected from one or more of poly-L-lactic acid (PLLA), polyracemic lactic acid (PDLLA), polylactic acid-glycolic acid copolymer (PGLA), and polycaprolactone (PCL).

[0073] The adjacent first support unit 1 and second support unit 2 are connected by a connecting component 3. The connecting component 3 includes: a connecting arm 4 fixedly disposed at the end of the first support unit 1, the end of the connecting arm 4 having a plug 5 formed thereon, the connecting arm 4 and the plug 5 being integrally formed with the first support unit 1; and a receiving component 6 fixedly disposed at the end of the second support unit 2, the receiving component 6 being integrally formed with the second support unit 2.

[0074] Connector 5 and receiver 6 form a preliminary mechanical connection through an interference fit, specifically: The receiver 6 has a through slot 61, and the width of the connector 5 is greater than the width of the slot 61. Utilizing the elastic deformation of the metal connector 5, it is inserted into the slot 61 of the receiver 6, and initial docking is achieved through mechanical engagement of the two. After initial docking, a hot-pressing process is used to melt the receiver 6 and bond it tightly to the connector 5.

[0075] The slot can be designed in any shape or combination thereof, such as circular, rectangular, elongated, oval, cross-shaped, U-shaped, V-shaped, convex, or irregular, as long as its maximum width is less than the width of the connector to ensure they do not separate after engagement. The connector can be symmetrical or asymmetrical in shape, such as circular, rectangular, horizontal stripe, crescent, heart, umbrella, U-shaped, V-shaped, triangular, ring, or irregular, or a combination thereof. This diverse shape design provides flexible options for different application scenarios.

[0076] In this embodiment, as Figure 2As shown, the slot 61 is elongated, and the connector 5 is symmetrically crescent-shaped, with a cross-shaped through hole 51 on it. The connecting arm 4 has at least one protrusion 41 on each side edge, which allows for a tighter interference fit between the connecting arm 4 and the slot 61. After heat melting and cooling, the connection strength between the connecting arm 4 and the connector 5 is significantly improved. The outer edge of the connector 5 is wavy, which increases its surface area. After the receiving component 6 is heat-melted and cured, the contact area between the connector 5 and the receiving component 6 is larger, resulting in a stronger, tighter, and more difficult-to-separate connection.

[0077] like Figure 3 As shown, the width of the connecting arm 4 is denoted as J, and the width of the slot 61 is denoted as J1. J is greater than J1, thus achieving an interference fit between the connecting arm 4 and the slot 61, further improving the connection stability of the connecting component 3. Both J and J1 are 0.01-0.6 mm. The width of the plug 5 is denoted as A, and the width of the receiving component 6 near the end of the second support unit 2 is denoted as B. A is greater than J1, and A is greater than B. Both A and B are 0.01-0.9 mm.

[0078] like Figure 4 As shown, the thickness of connecting arm 4 and connector 5 is the same, denoted as H1, where H1 is 0.01-0.1mm; the thickness of receiver 6 is denoted as H2, also 0.01-0.1mm. After connection, the thickness of connector 5 and receiver 6 when they are in close contact (i.e., the total thickness of connecting component 3) is denoted as H. H is controlled within 0.02-0.2mm to ensure the overall minimally invasive nature of the stent and avoid the risk of thrombosis due to excessive thickness.

[0079] Furthermore, such as Figure 1 As shown, both the first stent unit 1 and the second stent unit 2 are annular structures suitable for intravascular implantation. The connecting arm 4 is disposed on the annular edge of the first stent unit 1 and extends outward along the axial direction; similarly, the receiving member 6 is placed on the annular edge of the second stent unit 2 and extends outward along the axial direction.

[0080] Furthermore, the first stent unit 1 and the second stent unit 2 are provided with no less than two sets of connecting components 3 in the circumferential direction at their docking ends, and each connecting component 3 is evenly distributed in the circumferential direction. In this embodiment, each docking end is provided with 4 sets of evenly distributed connecting components 3, which can effectively suppress the relative rotation, sway and axial misalignment between adjacent stent units, while dispersing the local stress concentration at the connection site, and improving the connection stability and fatigue reliability of the stent under vascular pulsation and repeated radial expansion conditions.

[0081] Furthermore, the surface of the first stent unit 1 and / or the second stent unit 2 is coated with a therapeutic agent, which is an anti-inflammatory and / or anti-proliferative drug. The therapeutic agent is selected from one or more of rapamycin, paclitaxel, arsenic trioxide or its drug derivatives, and can effectively inhibit the inflammatory reaction of vascular tissue and the proliferation of smooth muscle cells, reducing the risk of restenosis and thrombosis.

[0082] Example 2 Please refer to Figure 5 , this example provides a vascular stent, including the first stent unit 1 and the second stent unit 2 arranged alternately along the axis. Compared with Example 1, the only difference lies in the structural shape of the slot 61.

[0083] In this example, as Figure 5 shown, the shape of the slot 61 is elongated, and grooves 64 matching the connecting arm protrusions 41 are provided on both sides of the slot 61. The cooperation between the grooves 64 and the protrusions 41 can position the position of the connecting arm 4, achieving the preliminary positioning of the plug-in member 5 and the slot 61.

[0084] Preferably, the size of the protrusion 41 is slightly larger than the size of the groove 64. When the protrusion 41 is embedded in the groove 64, it can make the connecting arm 4 and the slot 61 form a tighter interference fit. After hot melting and cooling, it is solidified. The connection strength between the connecting arm 4 and the plug-in member 5 is significantly improved.

[0085] Example 3 Please refer to Figure 6-8 , this example provides a vascular stent, including the first stent unit 1 and the second stent unit 2 arranged alternately along the axis. Compared with Example 1, the only difference lies in the structural shape of the connecting component 3.

[0086] In this example, as Figure 7-8 shown, the shape of the slot 61 is "convex" shaped, the shape of the plug-in member 5 is a triangle with a missing corner, and a part of the outer edge of the plug-in member 5 presents a serrated shape. The serrated shape can increase the surface area of the plug-in member 5. After the receiving member 6 is hot-melted and solidified, the contact area between the plug-in member 5 and the receiving member 6 is larger, and the connection between the two is more firm, tight and difficult to separate.

[0087] Example 4 Please refer to Figure 9-10 , this example provides a vascular stent, including the first stent unit 1 and the second stent unit 2 arranged alternately along the axis. Compared with Example 1, the only difference lies in the structural shape of the connecting component 3.

[0088] In this example, as Figure 9-10 shown, the shape of the slot 61 is elongated, and the shape of the plug-in member 5 is a symmetrical heart shape.

[0089] Furthermore, the connecting arm 4 has at least one protrusion 41 on each side edge, and the elongated slot 61 has grooves 64 on both sides that fit the protrusions 41, which can position the connecting arm 4 and achieve initial positioning of the connector 5 and the slot 61. At the same time, the protrusions 41 enable the connecting arm 4 and the slot 61 to form a tighter interference fit. After heat melting and cooling, the connection strength between the connecting arm 4 and the connector 5 is significantly improved.

[0090] Furthermore, at least a portion of the outer edge of the heart-shaped connector 5 is wavy. The wavy edge can increase the surface area of ​​the connector 5. After the receiver 6 is heat-melted and cured, the contact area between the connector 5 and the receiver 6 is larger, and the connection between the two is stronger, tighter, and harder to separate.

[0091] Example 5 Please see Figure 11-12 This embodiment provides a vascular stent, including a first stent unit 1 and a second stent unit 2 arranged alternately along the axial direction. Compared with Embodiment 1, the only difference is the structural shape of the connecting component 3.

[0092] In this embodiment, as Figure 11-12 As shown, the slot 61 is elongated, and the connector 5 is symmetrically umbrella-shaped.

[0093] Furthermore, a portion of the outer edge of the umbrella-shaped connector 5 is wavy, while another portion is serrated. The wavy and serrated edges can increase the surface area of ​​the connector 5. After the receiving component 6 is heat-melted and cured, the contact area between the connector 5 and the receiving component 6 is larger, and the connection between the two is stronger, tighter, and harder to separate.

[0094] Example 6 Please see Figure 13-16 This embodiment provides a vascular stent, including a first stent unit 1 and a second stent unit 2 arranged alternately along the axial direction.

[0095] The first support unit 1 is made of metallic material, and the second support unit 2 is made of non-metallic material. The metallic material can be a bio-absorbable metallic material or a non-bio-absorbable metallic material. The bio-absorbable metallic material is selected from one or more of absorbable magnesium alloy, absorbable iron-based alloy, and absorbable zinc alloy. The non-bio-absorbable metallic material is selected from one or more of stainless steel, cobalt-chromium alloy, nickel-titanium alloy, gold, and platinum. The non-metallic material includes bio-absorbable polyester material, which is selected from one or more of poly-L-lactic acid (PLLA), polyracemic lactic acid (PDLLA), polylactic acid-glycolic acid copolymer (PGLA), and polycaprolactone (PCL).

[0096] The adjacent first support unit 1 and second support unit 2 are connected by a connecting component 3. The connecting component 3 includes: a connecting arm 4 fixedly disposed at the end of the first support unit 1, the end of the connecting arm 4 having a plug 5 formed thereon, the connecting arm 4 and the plug 5 being integrally formed with the first support unit 1; and a receiving component 6 fixedly disposed at the end of the second support unit 2, the receiving component 6 being integrally formed with the second support unit 2.

[0097] Connector 5 and receiver 6 form a preliminary mechanical connection through an interference fit, specifically: The connector 5 is U-shaped, and the receiving component 6 has a through-hole fitting groove 62. The shape of the fitting groove 62 is also U-shaped and matches the shape of the connector 5, with the width of the connector 5 slightly larger than the width of the fitting groove 62. After the connector 5 is inserted into the fitting groove 62 of the receiving component 6, a preliminary connection is formed through mechanical interlocking of their dimensions. After the preliminary connection, the receiving component 6 is heated and melted through a heat conduction process, so that it is tightly attached to the connector 5.

[0098] Furthermore, such as Figure 13 and 14 As shown, both the first stent unit 1 and the second stent unit 2 are annular structures suitable for intravascular implantation. The connecting arm 4 is disposed on the annular edge of the first stent unit 1 and extends outward along the axial direction; similarly, the receiving member 6 is placed on the annular edge of the second stent unit 2 and extends outward along the axial direction.

[0099] Furthermore, the first stent unit 1 and the second stent unit 2 are provided with no less than two sets of connecting components 3 in the circumferential direction at their docking ends, and each connecting component 3 is evenly distributed in the circumferential direction. In this embodiment, each docking end is provided with three sets of evenly distributed connecting components 3, which can effectively suppress the relative rotation, sway and axial misalignment between adjacent stent units, while dispersing the local stress concentration at the connection site, and improving the connection stability and fatigue reliability of the stent under vascular pulsation and repeated radial expansion conditions.

[0100] Example 7 Please see Figure 17-20 This embodiment provides a vascular stent, including a first stent unit 1 and a second stent unit 2 arranged alternately along the axial direction.

[0101] The first support unit 1 is made of metallic material, and the second support unit 2 is made of non-metallic material. The metallic material can be a bio-absorbable metallic material or a non-bio-absorbable metallic material. The bio-absorbable metallic material is selected from one or more of absorbable magnesium alloy, absorbable iron-based alloy, and absorbable zinc alloy. The non-bio-absorbable metallic material is selected from one or more of stainless steel, cobalt-chromium alloy, nickel-titanium alloy, gold, and platinum. The non-metallic material includes bio-absorbable polyester material, which is selected from one or more of poly-L-lactic acid (PLLA), polyracemic lactic acid (PDLLA), polylactic acid-glycolic acid copolymer (PGLA), and polycaprolactone (PCL).

[0102] The adjacent first support unit 1 and second support unit 2 are connected by a connecting component 3. The connecting component 3 includes: a connecting arm 4 fixedly disposed at the end of the first support unit 1, the end of the connecting arm 4 having a plug 5 formed thereon, the connecting arm 4 and the plug 5 being integrally formed with the first support unit 1; and a receiving component 6 fixedly disposed at the end of the second support unit 2, the receiving component 6 being integrally formed with the second support unit 2.

[0103] Connector 5 and receiver 6 form a preliminary mechanical connection through an interference fit, specifically: refer to Figure 18 The receiving component 6 has multiple opening slots 63 spaced apart on both sides along its length, forming a fishbone shape; the plug-in component 5 has two inserts 52 extending away from the connecting arm 4.

[0104] refer to Figure 19 Two inserts 52 are alternately inserted into the opening slot 63, so that the inserts are wrapped around the fishbone-shaped receiver in an "S" shape. The two are intertwined to form a preliminary positioning connection, which prevents the inserts 52 from sliding relative to the receiver 6.

[0105] refer to Figure 20 After initial docking, the receiving part 6 is heated and melted through heat conduction process and then tightly attached to the insert 52. This connection method has strong axial load-bearing capacity, is not easy to loosen under axial tension, and has very high connection strength.

[0106] Example 8 Please see Figure 21-22 This embodiment provides a vascular stent, including a first stent unit 1 and a second stent unit 2 arranged alternately along the axial direction. Compared with embodiment 6, the only difference is the shape of the insert 52: the ends of the two inserts 52 away from the connecting arm 4 are connected together, so that the connector 5 forms a closed ring.

[0107] Example 9 This embodiment provides a vascular stent, including a first stent unit 1 and a second stent unit 2 arranged alternately along the axial direction. Compared with embodiments 1-8, the only difference is the material composition of the second stent unit 2.

[0108] The second support unit is made of non-metallic materials, including bio-absorbable polyester material and bio-absorbable reinforcing filler.

[0109] Since the first stent unit is made of metal, the ductility of metal allows for a very thin wall thickness (between 0.008-0.08 mm). To ensure that the second stent unit has the same wall thickness as the first stent unit, this invention adds a small amount of bioabsorbable reinforcing filler to the bioabsorbable polyester material to improve the mechanical strength of the non-metallic stent. While meeting the support requirements, the wall thickness is reduced from the existing 0.01-0.1 mm to 0.008-0.08 mm, thereby making the overall stent wall thinner, ensuring the overall minimally invasive nature of the stent, reducing the volume of foreign bodies in the blood vessel, and lowering the risk of thrombosis.

[0110] The bio-absorbable reinforcing filler is selected from one or more of the following: hydroxyapatite (HA) microparticles, tricalcium phosphate (TCP), β-tricalcium phosphate (β-TCP) microparticles, type I collagen microfibers, or chitosan grafted modified microparticles.

[0111] When HA microparticles are added, with a particle size of 0.1-2 μm and an addition amount of 3%-8% (mass fraction), the microparticles, which are consistent with the main components of human bone tissue, exhibit excellent biocompatibility. They can increase tensile strength by 20%-35% and elastic modulus by 30%-45%, while also enhancing cell adhesion without significant inflammatory response. This makes them suitable for vascular stents near hard tissues requiring long-term support (such as the proximal end of coronary arteries), utilizing the osteoconductive properties of HA microparticles to promote biofusion between the vessel wall and the stent.

[0112] When TCP microparticles with a particle size of 0.5-1 μm are added, the addition amount is 5%-10% (mass fraction); when β-TCP microparticles with a particle size of 0.5-3 μm are added, the addition amount is 5%-10%, and the crystallinity is ≥90%. The addition of TCP microparticles or β-TCP microparticles increases the tensile strength of the material by 40%-50%. During the degradation process, calcium and phosphorus ions are released, which can promote vascular endothelialization and avoid long-term residues caused by slow TCP degradation.

[0113] When type I collagen microfibers are added, with a fiber diameter of 100-500 nm and an addition amount of 3%-6%, the tensile strength of the material is increased by 10%-20%, the adhesion of vascular endothelial cells is significantly enhanced (adhesion rate increased by more than 30%), the degradation cycle is 3-6 months (rapid degradation without residue), and the inflammatory response is reduced (IL-6 factor expression level decreases by 40%).

[0114] When chitosan-grafted modified microparticles with a particle size of 0.5-2μm, an addition amount of 2%-5%, and a degree of deacetylation ≥90% are added, the compatibility with bioabsorbable polyester is improved through polylactic acid grafting modification. When added to bioabsorbable polyester materials, the tensile strength of the material increases by 15%-25%, while also possessing antibacterial properties (≥80% inhibition rate against Staphylococcus aureus). During degradation, it releases glucosamine, promoting vascular repair, with a degradation cycle of 6-9 months.

[0115] Furthermore, the absorbable reinforcing filler may be a blend of at least two selected from hydroxyapatite (HA) microparticles, tricalcium phosphate (TCP), β-tricalcium phosphate (β-TCP) microparticles, type I collagen microfibers, or chitosan grafted modified microparticles. When blended, the total amount of absorbable reinforcing filler added is 2%-15% of the mass fraction of the base material.

[0116] Example 10 This embodiment provides a method for preparing vascular stents in the above embodiments, including the following steps: S1. A first support unit made of metal and a second support unit made of non-metal are respectively manufactured; wherein, the first support unit has at least two connecting arms on the circumferential direction at its end, and the end of the connecting arm has a plug-in, the plug-in and the connecting arm are integrally formed with the first support unit; the second support unit has a receiving part on the circumferential direction at its end that corresponds to and matches the plug-in, and the receiving part is integrally formed with the second support unit. S2. Alternately connect the first support unit and the second support unit so that the plug of the first support unit and the receiving part of the adjacent second support unit form a preliminary mechanical connection through interference fit. S3. The receiver is locally softened, melted or thermoplastically deformed by pressure and / or heat treatment. After it cools and solidifies, the receiver and the connector are tightly attached together, thereby obtaining a vascular stent with alternating connections of the first stent unit and the second stent unit.

[0117] In step S3, the heat treatment is preferably carried out by local heat conduction. The heat source can be a heating head, hot air, infrared or laser. The heating area is limited to the connection part where the receiving element is located, so as to avoid unnecessary deformation in other areas of the second support unit.

[0118] When the main material of the receiver is PLLA, PDLLA or PGLA, the heat treatment temperature is preferably controlled within the range of 10-40°C above its glass transition temperature Tg, so that the receiver material undergoes controllable softening and covers the connector under pressure; when the main material of the receiver is PCL, the heat treatment temperature is preferably controlled near its melting point Tm, so that the receiver material undergoes local melting and forms a mechanical locking structure after cooling.

[0119] In step S3, the pressure is preferably radial pressure or local clamping force, with a pressure of 5-30 N applied to a single connection point and a holding time of 1-10 s. After cooling and solidification, an irreversible mechanical locking and material bonding structure is formed between the connector and the receiver.

[0120] In summary, the vascular stent of this invention combines the advantages of both DES and BRS, providing reliable radial support and imaging positioning capabilities in the early stages of implantation, and restoring the vessel's own elasticity through the gradual degradation of non-metallic materials in the later stages, reducing the long-term irritation of the vessel by permanent metal residues; simultaneously, through interference fit combined with pressure and / or heat treatment connection methods, reliable fixed connection between stent units of different materials is achieved, effectively preventing loosening or dislodgement under vascular pulsation loads after implantation. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0121] The terms used in this specification, such as "upper," "lower," "left," "right," "front," "back," "middle," and "one," are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of the invention.

[0122] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A vascular stent, characterized in that, It includes a first support unit and a second support unit arranged alternately along the axial direction. The first support unit is made of metal material, and the second support unit is made of non-metal material. Adjacent first support units and second support units are connected by connecting components. The connecting component includes: a connecting arm fixedly disposed at the end of the first support unit, the end of the connecting arm having a plug-in component; and a receiving component fixedly disposed at the end of the second support unit, the receiving component being made of a non-metallic material; The connector and the receiver form a preliminary mechanical connection through an interference fit. After the preliminary connection, the receiver is subjected to pressure and / or heat treatment, causing it to soften, melt, or undergo thermoplastic deformation. After cooling and solidification, the receiver adheres tightly to the connector.

2. The vascular stent according to claim 1, characterized in that, The metal material is either a bio-absorbable metal material or a non-bio-absorbable metal material; the bio-absorbable metal material is selected from one or more of absorbable magnesium alloys, absorbable iron-based alloys, and absorbable zinc alloys; the non-bio-absorbable metal material is selected from one or more of stainless steel, cobalt-chromium alloys, nickel-titanium alloys, gold, and platinum.

3. The vascular stent according to claim 1, characterized in that, The non-metallic material includes a bioabsorbable polyester material, which is selected from one or more of PLLA, PDLLA, PGLA, and PCL.

4. The vascular stent according to claim 1, characterized in that, The connecting arm and the plug are integrally formed with the first support unit; the receiving component is integrally formed with the second support unit.

5. The vascular stent according to claim 1, characterized in that, The receiving component has a slot, fitting groove or opening groove adapted to the plug-in component. The plug-in component and the receiving component achieve an interference fit through dimensional interference. That is, during the assembly process, at least one of the plug-in component and / or the receiving component undergoes elastic deformation or micro-plastic deformation, so that the plug-in component is embedded in the slot, fitting groove or opening groove of the receiving component to form a preliminary mechanical connection.

6. The vascular stent according to claim 5, characterized in that, The receiving component has a through slot, and the width of the connector is greater than the width of the slot. Utilizing the elastic deformation of the connector and / or the receiving component, the connector is inserted into the slot of the receiving component, achieving initial docking through mechanical engagement of their dimensions; or... The receiving component has a through or non-through fitting groove, the shape of which matches the shape of the connector, and the width of the connector is greater than or equal to the width of the fitting groove. After the connector is inserted into the fitting groove of the receiving component, a preliminary connection is formed through the mechanical interlocking of their dimensions; or... The receiving component has multiple opening slots spaced apart along its length, and the plug has at least two inserts extending away from the connecting arm; the inserts are alternately inserted into the opening slots, and a preliminary positioning connection is formed by the cross-winding of the inserts and the receiving component.

7. The vascular stent according to claim 6, characterized in that, At least a portion of the outer edge of the connector is wavy or serrated.

8. The vascular stent according to claim 1, characterized in that, Both the first support unit and the second support unit are annular structures; the connecting arm is disposed on the annular edge of the first support unit and extends outward along the axial direction; the receiving member is placed on the annular edge of the second support unit and extends outward along the axial direction.

9. The vascular stent according to claim 1, characterized in that, The first support unit and the second support unit are provided with no less than two connecting parts in the circumferential direction at their docking ends, and each connecting part is evenly distributed in the circumferential direction.

10. A method for preparing a vascular stent as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. A first support unit made of metal and a second support unit made of non-metal are respectively manufactured. The first support unit has at least two connecting arms on its circumferential side at the end, and the end of the connecting arm has a plug-in. The second support unit has a receiving part on its circumferential side at the end that is adapted to the plug-in. S2. Alternately connect the first support unit and the second support unit so that the connector of the first support unit forms a preliminary mechanical connection with the receiving part of the adjacent second support unit; S3. The receiver is locally softened, melted or thermoplastically deformed by pressure and / or heat treatment. After it cools and solidifies, the receiver and the connector are tightly attached together, thereby obtaining a vascular stent with alternating connections of the first stent unit and the second stent unit.

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