Guide wire with intravascular stent

Abstract

The invention discloses a guide wire with an intravascular stent. The guide wire comprises a guide wire body and the intravascular stent arranged on the guide wire body in a sleeving mode, and a connecting wire is arranged between the guide wire body and the intravascular stent. The guide wire comprises an inner guide wire and an outer guide wire; the inner guide wire and the outer guide wire are both of tubular structures, the outer guide wire is arranged on the outer side of the inner guide wire in a sleeving mode, and the intravascular stent is located between the inner guide wire and the outer guide wire; the connecting wire is respectively connected with the outer guide wire and the intravascular stent; an easy-to-break point is arranged in the middle of the connecting wire; a stable supporting frame is provided through the double-tube structure of the inner guide wire and the outer guide wire, the inner guide wire serves as a main guide wire and provides hardness and rigidity, accurate positioning of the guide wires in a blood vessel is guaranteed, the outer guide wire plays a protection role, the intravascular stent is prevented from making direct contact with the blood vessel wall in the positioning process, potential damage to the blood vessel is reduced, and the intravascular stent has a good application prospect. The controllability of the guide wire can be effectively improved, so that a doctor can accurately adjust the placement position of the intravascular stent, and the stability and the optimal unfolding effect of the intravascular stent are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a guide wire with a vascular stent. Background Art

[0002] A stent is implanted in an area of ​​the carotid artery that is located above the 6th and 7th cervical vertebrae, usually in the higher part of the cervical spine near the base of the skull. This is usually done to treat or prevent cerebrovascular disease caused by carotid artery stenosis. Carotid artery stenosis may lead to insufficient blood flow to the brain and increase the risk of stroke. By implanting a stent, the narrowed blood vessels can be expanded and normal blood flow can be restored, thereby reducing the risk of stroke.

[0003] When implanting vascular stents in the area above C6C7 of the carotid artery, special design is required: the carotid artery in this area not only has a complex path, but also has a fast blood flow rate, which places extremely high demands on the operation of the guidewire and catheter. When passing through these narrow and curved blood vessels, traditional single-layer guidewires are prone to damage the blood vessel wall, and the vascular stent may not be fully deployed or adhere to the blood vessel wall after release, thus affecting the treatment effect.

[0004] Therefore, it is necessary to design a guide wire with a vascular stent to solve the above-mentioned problems. Summary of the invention

[0005] The invention overcomes the deficiencies of the prior art and provides a guide wire with a vascular stent.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a guide wire with a vascular stent, comprising: a guide wire, and a vascular stent sleeved with the guide wire, wherein a connecting wire is provided between the guide wire and the vascular stent; The guide wire comprises: an inner guide wire and an outer guide wire; both the inner guide wire and the outer guide wire are tubular structures, the outer guide wire is sleeved on the outside of the inner guide wire, a limiting wire fixed to the inner guide wire is provided in the cavity between the inner guide wire and the outer guide wire, and the vascular stent is located between the inner guide wire and the outer guide wire; The connecting wire is connected to the outer guide wire and the vascular stent respectively, and a breakable point is arranged in the middle of the connecting wire.

[0007] In a preferred embodiment of the present invention, the vascular stent is prepared by mixing polycaprolactone and polydioxanone, the inner diameter of the vascular stent is 3-4 mm, and the vascular stent is adhered to the inner wall of the blood vessel by expansion; The vascular stent is a multi-layer structure, each layer is composed of nanofiber membranes, and the fiber structures of the nanofiber membranes of two adjacent layers are perpendicular to each other.

[0008] In a preferred embodiment of the present invention, the outer guide wire is made of a nickel-titanium alloy by spiral winding, the inner guide wire is made of a cobalt-chromium alloy by spiral winding, and the thickness of the breaking point is 30%-50% of the wall thickness of the connecting wire, and the connecting wire is made of polycaprolactone.

[0009] In a preferred embodiment of the present invention, the method for preparing the vascular stent comprises the following steps: S1, mixing polycaprolactone and polydioxanone in a mass ratio of 7-10:3-6, and dissolving them in an acidic solution to prepare a mixed solution with a concentration of 10-15%; Step S2, modifying the magnesium-rare earth alloy nanoparticles, adding the modified magnesium-rare earth alloy nanoparticles into the mixed solution, and mixing them evenly to obtain a reinforcement solution; Step S3, preparing a plurality of oriented nanofiber membrane layers by electrospinning the reinforcement solution; Step S4, forming a vascular stent by pasting several layers of nanofiber membranes on a high-speed drum collector.

[0010] In a preferred embodiment of the present invention, in step S1, the molecular weight of polycaprolactone is 40,000-100,000, and the molecular weight of polydioxanone is 20,000-30,000.

[0011] In a preferred embodiment of the present invention, in step S1, the acidic solution is a trifluoroacetic acid solution with a concentration of 10%-20%.

[0012] In a preferred embodiment of the present invention, in step S2, the particle size of the magnesium-rare earth element alloy nanoparticles is 30nm-80nm, and the particles are modified by polyacrylic acid.

[0013] In a preferred embodiment of the present invention, in step S2, the mixed solution and the magnesium-rare earth alloy nanoparticles are mixed in a ratio of 20-25:1-5, and stirred at a temperature of 40-50° C. for 10-20 min.

[0014] In a preferred embodiment of the present invention, the method for modifying magnesium-rare earth alloy nanoparticles by polyacrylic acid comprises the following steps: Step S21, washing the magnesium-rare earth alloy nanoparticles with deionized water, and drying the washed nanoparticles; Step S22, dissolving polyacrylic acid with a molecular weight of 500000-1000000 in deionized water to obtain a polyacrylic acid solution with a concentration of 0.5%-5%; Step S23, adding the dried magnesium-rare earth alloy nanoparticles to hydrofluoric acid with a concentration of 10%-20% for activation treatment, and drying the activated magnesium-rare earth alloy nanoparticles; Step S24, mixing the magnesium-rare earth element alloy nanoparticles and the polyacrylic acid solution at a mass ratio of 1:5-10 to modify the magnesium-rare earth element alloy nanoparticles, and stirring for 30-60 minutes; Step S25, taking out the modified magnesium-rare earth alloy nanoparticles and washing them with deionized water, and placing the washed magnesium-rare earth alloy nanoparticles in an oven at 40-60° C. to dry for 10-15 minutes.

[0015] In a preferred embodiment of the present invention, in step S4, the inner diameter of the vascular stent is 3-4 mm, and the fiber structures in two adjacent layers of the nanofiber membranes in the vascular stent are perpendicular to each other.

[0016] The present invention solves the defects existing in the background technology and has the following beneficial effects: (1) The present invention provides a guidewire with a vascular stent. The vascular stent is arranged between an inner guidewire and an outer guidewire. The double-tube structure of the inner guidewire and the outer guidewire provides a stable support frame. The inner guidewire serves as the main guidewire, providing hardness and rigidity to ensure accurate positioning of the guidewire in the blood vessel. The outer guidewire plays a protective role to prevent the vascular stent from directly contacting the blood vessel wall during the positioning process, thereby reducing potential damage to the blood vessel. The guidewire can effectively improve the controllability of the guidewire, allowing the doctor to accurately adjust the placement position of the vascular stent, thereby ensuring the stability of the vascular stent and the best deployment effect.

[0017] (2) The present invention prepares a vascular stent by using polycaprolactone and polydioxanone. The vascular stent expands unevenly in the vascular wall, so that the vascular stent curls into a tubular structure in the vascular wall. The expansion and contraction ability of the vascular stent and the reaction force of the vascular wall are used to produce a mechanical locking effect with the vascular wall, thereby increasing the bonding force between the vascular stent and the vascular wall, so that the vascular stent can fit closely to the vascular wall, reduce gaps and irregular contacts, increase the contact area between the vascular stent and the vascular wall, and have higher mechanical stability. After self-curling, the multi-layer oriented nanofiber structure forms a stronger tubular structure, which can better resist the impact of blood flow and the mechanical stress of the vascular wall, thereby solving the problem that the blood flow velocity near the skull base is relatively fast and will not shift due to changes in blood flow velocity.

[0018] (3) The present invention adds modified magnesium-rare earth alloy nanoparticles to the preparation of the vascular stent, so that the surface of the nanoparticles forms a good bond with the polymer of the nanofiber membrane. The adhesion between the nanofiber membrane layers is enhanced, thereby ensuring the stability and integrity of the layers of the vascular stent during expansion and preventing the membrane layers from separating or falling off during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. Figure 1 It is a schematic diagram of the structural decomposition of a guide wire with a vascular stent according to the present invention; Figure 2 is a schematic diagram of the cross-sectional structure of a guide wire according to a preferred embodiment of the present invention; Figure 3 is a schematic diagram of the three-dimensional structure of a guide wire according to a preferred embodiment of the present invention; In the figure: 1. Vascular stent; 2. Connecting wire; 3. Inner guide wire; 4. Outer guide wire; 5. Limiting wire; 6. Breaking point. DETAILED DESCRIPTION

[0020] 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.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "multiple" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0024] like Figure 1 As shown, a guide wire with a vascular stent comprises: a guide wire, and a vascular stent 1 which is sheathed on the guide wire, and a connecting wire 2 between the guide wire and the vascular stent 1; like Figure 2 and Figure 3 As shown, the guide wire includes: an inner guide wire 3 and an outer guide wire 4; the inner guide wire 3 and the outer guide wire 4 are both tubular structures, the outer guide wire 4 is sleeved on the outside of the inner guide wire 3, a limiting wire 5 fixed to the inner guide wire 3 is provided in the cavity between the inner guide wire 3 and the outer guide wire 4, and the vascular stent 1 is located between the inner guide wire 3 and the outer guide wire 4; The connecting wire 2 is connected to the outer guide wire 4 and the vascular stent 1 respectively, and a breakable point 6 is arranged in the middle of the connecting wire 2 .

[0025] By arranging the vascular stent 1 between the inner guide wire 3 and the outer guide wire 4, the double-tube structure of the inner guide wire 3 and the outer guide wire 4 provides a stable support frame. The inner guide wire 3 serves as the main guide wire, providing hardness and rigidity to ensure accurate positioning of the guide wire in the blood vessel, and the outer guide wire 4 plays a protective role to prevent the vascular stent 1 from directly contacting the blood vessel wall during the positioning process. After the vascular stent 1 is delivered to the designated blood vessel position in the stenotic area through the guide wire, pressure is applied to the outer guide wire 4 to stretch the outer guide wire 4, thereby disconnecting the connecting wire 2 from the breakable point 6, exposing the vascular stent 1, and the vascular stent 1 expands until it fits tightly against the inner wall of the blood vessel, and then the inner guide wire 3 and the outer guide wire 4 are withdrawn, so that the vascular stent 1 supports the blood vessel in the stenotic area, dilates the stenotic blood vessel, and restores normal blood flow, thereby reducing the risk of stroke.

[0026] It should be noted that, by setting the connecting wire 2, the vascular stent 1 can be synchronously entered into the blood vessel with the guide wire. In order to allow the outer guide wire 4 and the vascular stent 1 to be separated, a breakable point 6 is set at the middle position of the connecting wire 2. The thickness of the breakable point 6 is 30%-50% of the wall thickness of the connecting wire 2. When the vascular stent 1 is pushed into the target blood vessel by the guide wire, the breakage of the breakable point 6 can effectively avoid excessive force acting on the inner wall of the blood vessel, and prevent blood vessel damage caused by excessive operation of the guide wire. The setting of the breakable point 6 can ensure that the vascular stent 1 is accurately deployed at the appropriate time, and the vascular stent 1 will not be improperly positioned or cause blood vessel damage due to the continued force of the guide wire, thereby speeding up the operation process, reducing the operation time, and improving the safety of the operation; A limiting wire 5 fixed to the inner guide wire 3 is provided between the inner guide wire 3 and the outer guide wire 4. When the outer guide wire 4 is stretched to separate it from the vascular stent 1, the limiting wire 5 supports and limits the vascular stent 1, thereby preventing the vascular stent 1 from moving synchronously with the outer guide wire 4, thereby separating the vascular stent 1 from the outer guide wire 4 and exposing the blood vessel in the narrow area.

[0027] In the present invention, the vascular stent 1 is prepared by mixing polycaprolactone and polydioxanone, and the inner diameter of the vascular stent 1 is 3-4 mm, and the vascular stent 1 is adhered to the inner wall of the blood vessel by expansion; Polydioxanone is a biodegradable polymer with relatively strong hydrophilicity. In aqueous solution, especially under physiological conditions, the molecular chain of polydioxanone can absorb water and swell. When exposed to body fluid or blood, it can swell, so that the vascular stent 1 gradually unfolds in the blood vessel and comes into close contact with the blood vessel wall, helping the vascular stent 1 to better fit the blood vessel wall. As a synthetic polymer with a long degradation cycle, polycaprolactone has excellent mechanical strength and stability. The glass transition temperature of polycaprolactone is as high as 60°C and remains relatively stable at 37°C. Therefore, it can provide the rigidity and structural support required by the vascular stent 1 to prevent excessive expansion. When the vascular stent 1 is exposed to the blood in the blood vessel, the expansibility of polydioxanone will cause the surface of the vascular stent 1 to expand, causing the material of the vascular stent 1 to gradually stretch and deform. Since the structure of polycaprolactone is relatively stable, the expansion difference of the vascular stent 1 causes the vascular stent 1 to form a self-curling structure in the blood vessel, so that the vascular stent 1 can fit closely to the blood vessel wall, reduce gaps and irregular contacts, increase the contact area between the vascular stent 1 and the blood vessel wall, and have higher mechanical stability. After self-curling, the multi-layer oriented nanofiber structure forms a more solid tubular structure, which can better resist blood flow impact and mechanical stress of the blood vessel wall, and solves the problem that the blood flow velocity near the skull base is faster and will not shift due to changes in blood flow velocity.

[0028] It should be noted that the stability and elasticity of the vascular stent 1 enable the blood vessel to be supported while maintaining softness and elasticity, thereby ensuring that the vascular stent 1 can maintain good contact with the blood vessel wall for a long time.

[0029] The vascular stent 1 is a multi-layer structure, each layer is composed of a nanofiber membrane, and the fiber structures of the nanofiber membranes of two adjacent layers are perpendicular to each other; The fiber structures of adjacent layers are perpendicular to each other, so that the fibers of each layer provide support in different directions, imitating the multi-layer structure of natural blood vessels, making the vascular stent 1 stronger and more stable, and able to withstand greater external impact or pressure without being easily deformed or collapsed; Different orientations of the fiber structure can increase the tensile and compressive resistance of the vascular stent 1. For example, vertically oriented fibers can enhance the longitudinal strength of the vascular stent 1, while horizontally oriented fibers help enhance its lateral stability. In this way, the bearing capacity of the vascular stent 1 in the blood vessel is balanced, thereby improving the overall stability.

[0030] In the present invention, the outer guide wire 4 is made of a spiral roll of nickel-titanium alloy, and has a soft gradient section at the front end, a rigid support section in the middle section, and an operating handle at the rear end; the length of the soft gradient section at the front end is 20-30 mm, which is used to reduce damage to the blood vessel wall; the rigid support section in the middle section is used to provide stability for the guide wire; the operating handle at the rear end facilitates the user to precisely control the guide wire; the inner guide wire 3 is made of a spiral roll of cobalt-chromium alloy, and the connecting wire 2 is made of polycaprolactone.

[0031] In the present invention, the preparation method of the vascular stent 1 comprises the following steps: Step S1, mixing polycaprolactone and polydioxanone in a mass ratio of 7-10:3-6, and dissolving them in an acidic solution to prepare a mixed solution with a concentration of 10-15%; Step S2, modifying the magnesium-rare earth alloy nanoparticles, adding the modified magnesium-rare earth alloy nanoparticles into the mixed solution, and mixing them evenly to obtain a reinforcement solution; Step S3, preparing a plurality of oriented nanofiber membrane layers by electrospinning the reinforcement solution; Step S4, forming a vascular stent 1 by pasting several layers of nanofiber membranes layer by layer on a high-speed drum collector.

[0032] In step S1, the molecular weight of polycaprolactone is 40,000-100,000, and the molecular weight of polydioxanone is 20,000-30,000.

[0033] The acidic solution is a trifluoroacetic acid solution with a concentration of 10%-20%. The polycaprolactone and polydioxanone are mixed and added into the trifluoroacetic acid solution, which can effectively dissolve the polycaprolactone and polydioxanone. It also has a strong depolarizing effect and can promote the dissolution process. In addition, the trifluoroacetic acid solvent has a good regulating effect on the solubility of the polymer and the performance of electrospinning, and can make the viscosity of the solution moderate, which is suitable for the subsequent electrospinning operation. By dissolving polycaprolactone and polydioxanone in an acidic solution, a basis is provided for subsequent spinning, ensuring that the nanofiber structure formed during the electrospinning process is uniform and the fiber surface is smooth.

[0034] In the present invention, in step S2, the particle size of the magnesium-rare earth element alloy nanoparticles is 30nm-80nm, and the nanoparticles are modified by polyacrylic acid.

[0035] In step S2, the mixed solution and magnesium-rare earth alloy nanoparticles are mixed in a ratio of 20-25:1-5, and stirred at a temperature of 40-50° C. for 10-20 minutes.

[0036] In the present invention, the method for modifying magnesium-rare earth alloy nanoparticles by polyacrylic acid comprises the following steps: Step S21, washing the magnesium-rare earth alloy nanoparticles with deionized water to remove impurities, pollutants and oxides that may exist on the surface of the particles to ensure that the surface is clean and can better react with polyacrylic acid. The washed magnesium-rare earth alloy nanoparticles need to be dried to remove moisture to ensure the effectiveness of the modification process; Step S22, dissolving polyacrylic acid with a molecular weight of 500000-1000000 in deionized water to obtain a polyacrylic acid solution with a concentration of 0.5%-5%; Step S23, adding the dried magnesium-rare earth alloy nanoparticles to hydrofluoric acid with a concentration of 10%-20% for activation treatment, removing the oxide layer on the surface of the magnesium-rare earth alloy nanoparticles and effectively exposing the metal surface, thereby improving the efficiency of the subsequent modification reaction, and drying the magnesium-rare earth alloy nanoparticles after the activation treatment to remove the hydrofluoric acid residue and prepare for modification; Step S24, mixing the magnesium-rare earth element alloy nanoparticles and the polyacrylic acid solution at a mass ratio of 1:5-10 to modify the magnesium-rare earth element alloy nanoparticles, and stirring for 30-60 minutes; Through the modification of polyacrylic acid, a strong hydrophilic layer can be formed on the surface of magnesium-rare earth alloy nanoparticles, thereby improving the compatibility and adhesion of magnesium-rare earth alloy nanoparticles with the mixed solution of polymer matrix polycaprolactone and polydioxanone. In addition, polyacrylic acid not only improves the dispersibility of the particles, but also improves the binding force between the particles and polycaprolactone and polydioxanone in the solution, promoting the stability of the reinforcement solution and the performance of the fiber in the subsequent electrospinning process. Step S25, taking out the modified magnesium-rare earth alloy nanoparticles and washing them with deionized water, and placing the washed magnesium-rare earth alloy nanoparticles in an oven at 40-60° C. to dry for 10-15 minutes.

[0037] In step S3 and step S4, the obtained reinforcement solution is loaded into a syringe, and the syringe needs to be connected to the nozzle 50-100nm of the electrospinning equipment (ET-3556H electrospinning machine, from Beijing Yongkang Leye Technology Development Co., Ltd.). The solution in the syringe is controlled by a pump to ensure a stable flow rate and solution supply. A high voltage of 10kV-30kV is applied between the syringe and the collector to generate a strong electric field. The polymer in the solution will be stretched under the action of the electric field to form slender fibers. At the other end of the electrospinning, the fibers are collected by the collector. The fibers will be stretched and deposited on its surface to form a nanofiber membrane. The movement trajectory of the collector is changed, so that the arrangement of each layer of the nanofiber membrane is different, so that the fiber structures of the two adjacent layers of the nanofiber membrane in the subsequently prepared vascular stent 1 are perpendicular to each other, and the fiber structures of the adjacent layers are perpendicular to each other; The inner diameter of the vascular stent 1 is 3-4 mm. The fiber structures in the two adjacent layers of the nanofiber membrane in the vascular stent 1 are perpendicular to each other. The fiber structures of the adjacent layers are perpendicular to each other, so that the fibers of each layer provide support in different directions, imitating the multi-layer structure of natural blood vessels, making the vascular stent 1 stronger and more stable, and able to withstand greater external force impact or pressure without being easily deformed or collapsed.

[0038] In summary, in order to verify that different ratios of polycaprolactone and polydioxanone will directly affect the expansibility, structural stability and adhesion effect of the vascular stent 1 with the vascular wall, the following experiments were conducted.

[0039] Experimental Example 1: 1. Purpose of the experiment To study the expansion, stability and adhesion effect of vascular stents with different ratios of polycaprolactone (PCL) and polydioxanone (PCDC) on the vascular wall. The material ratio is optimized by quantitatively analyzing the expandability, contact uniformity, pressure distribution and conformity with the blood vessel wall of the vascular stent.

[0040] 2. Experimental steps 1. Preparation of vascular stent samples Example 1: Select polycaprolactone with a molecular weight of 50,000 (from Shenzhen Guanghua Weiye Co., Ltd.) and polydioxanone with a molecular weight of 30,000 (from Wuhan Xinxin Jiali Biotechnology Co., Ltd.), mix polycaprolactone and polydioxanone in a mass ratio of 7:3, dissolve in a trifluoroacetic acid solution with a concentration of 15%, and obtain a mixed solution. The solution is loaded into a syringe. The syringe needs to be connected to an electrospinning device with a nozzle of 50 nm. The solution in the syringe is controlled by a pump. A high voltage of 10 kV is applied between the syringe and the collector to control the flow rate of the spinning solution to 0.45 ml / h to form long and thin fibers. At the other end of the electrospinning, the fibers are collected by a collector. The fibers will be stretched and deposited on its surface to form a nanofiber membrane. The movement trajectory of the collector is changed, so that the arrangement of each layer of the nanofiber membrane is different, so that the fiber structures of adjacent nanofiber membranes prepared subsequently are perpendicular to each other. The fiber structures of adjacent layers are perpendicular to each other to form a vascular stent with a diameter of 3 mm and a length of 10 mm.

[0041] Example 2: Select polycaprolactone with a molecular weight of 50,000 and polydioxanone with a molecular weight of 30,000, mix polycaprolactone and polydioxanone in a mass ratio of 7:4, dissolve in a trifluoroacetic acid solution with a concentration of 15%, and obtain a mixed solution. The solution is loaded into a syringe. The syringe needs to be connected to an electrospinning device with a nozzle of 50 nm. The solution in the syringe is controlled by a pump. A high voltage of 10 kV is applied between the syringe and the collector. The flow rate of the spinning solution is controlled to 0.45 ml / h to form long and thin fibers. At the other end of the electrospinning, the fibers are collected by a collector. The fibers will be stretched and deposited on its surface to form a nanofiber membrane. The movement trajectory of the collector is changed, so that the arrangement of each layer of the nanofiber membrane is different, so that the fiber structures of adjacent nanofiber membranes prepared subsequently are perpendicular to each other. The fiber structures of adjacent layers are perpendicular to each other to form a vascular stent with a diameter of 3 mm and a length of 10 mm.

[0042] Example 3: Select polycaprolactone with a molecular weight of 50,000 and polydioxanone with a molecular weight of 30,000, mix polycaprolactone and polydioxanone in a mass ratio of 7:5, dissolve them in a trifluoroacetic acid solution with a concentration of 15%, and obtain a mixed solution. The solution is loaded into a syringe. The syringe needs to be connected to an electrospinning device with a nozzle of 50 nm. The solution in the syringe is controlled by a pump. A high voltage of 10 kV is applied between the syringe and the collector. The flow rate of the spinning solution is controlled to 0.45 ml / h to form long and thin fibers. At the other end of the electrospinning, the fibers are collected by a collector. The fibers will be stretched and deposited on its surface to form a nanofiber membrane. The movement trajectory of the collector is changed, so that the arrangement of each layer of the nanofiber membrane is different, so that the fiber structures of adjacent nanofiber membranes prepared subsequently are perpendicular to each other. The fiber structures of adjacent layers are perpendicular to each other to form a vascular stent with a diameter of 3 mm and a length of 10 mm.

[0043] Example 4: Select polycaprolactone with a molecular weight of 50,000 and polydioxanone with a molecular weight of 30,000, mix polycaprolactone and polydioxanone in a mass ratio of 7:6, dissolve in a trifluoroacetic acid solution with a concentration of 15%, and obtain a mixed solution. The solution is loaded into a syringe. The syringe needs to be connected to an electrospinning device with a nozzle of 50 nm. The solution in the syringe is controlled by a pump. A high voltage of 10 kV is applied between the syringe and the collector. The flow rate of the spinning solution is controlled to 0.45 ml / h to form long and thin fibers. At the other end of the electrospinning, the fibers are collected by a collector. The fibers will be stretched and deposited on its surface to form a nanofiber membrane. The movement trajectory of the collector is changed, so that the arrangement of each layer of the nanofiber membrane is different, so that the fiber structures of adjacent nanofiber membranes prepared subsequently are perpendicular to each other. The fiber structures of adjacent layers are perpendicular to each other to form a vascular stent with a diameter of 3 mm and a length of 10 mm.

[0044] 2. Experiments on vascular stent samples 1. An artificial blood vessel model was made by 3D printing technology to simulate a blood vessel with a diameter of 6 mm. The vascular stents prepared in Examples 1 to 4 were respectively inserted into the artificial blood vessel model and placed in 37°C physiological saline. The expansion of the vascular stent in the simulated blood vessel was observed and recorded. The expansion rate was calculated by recording the change in the expansion diameter of the vascular stent after 24 hours. The expansion rate = after expansion - before expansion / before expansion 100%; 2. Observe the contact between the vascular stent and the vascular wall through CT scanning technology, and measure the contact area, contact uniformity, and contact pressure; Contact area: record the contact area between the vascular stent and the vascular wall to evaluate whether the vascular stent fits the entire vascular wall; Contact uniformity: Evaluate whether the contact between the stent surface and the vessel wall is uniform, whether there are gaps of uneven contact, and calculate the contact area between the stent and the vessel wall. If the contact area is ≥90%, it is excellent; if it is 90%>contact area ≥70%, it is good; if it is 70%>contact area ≥50%, it is fair; if it is <50%, it is poor; Contact pressure: Use a pressure sensor or strain gauge to measure the pressure distribution when the stent contacts the vessel wall to ensure that the pressure is evenly distributed to reduce damage to the vessel; 3. Simulate the dynamic environment in the blood vessel, such as blood flow and blood pressure fluctuations, and use the TABER friction and wear tester to measure the friction between the vascular stent and the simulated blood vessel wall. The specific steps are as follows: The vascular stent and the simulated vascular wall are placed in a TABER friction and wear tester, and a certain pressure is applied to simulate the pressure inside the vascular wall under the condition of 120 mmHg, and a relative movement speed of 5 mm / s is used to simulate the speed of blood flow, and the friction between the vascular stent and the vascular wall is measured, and the friction of the vascular stents obtained in Examples 1 to 4 under the same pressure and movement conditions is tested; Observe the long-term stability of the vascular stent in the blood vessel, and record whether the vascular stent can maintain its original shape and whether there is excessive expansion or collapse.

[0045] The following data are obtained, as shown in Table 1 Table 1

[0046] By comparing the data of Examples 1 to 4, it can be concluded that when the proportion of polydioxanone increases, the water absorption and expansion of polydioxanone, when the vascular stent contacts the vascular wall, the water and small molecules of the fluid components in the vascular wall can penetrate into the fibers of the vascular stent, resulting in increased chain fluidity, so that the vascular stent expands in the vascular wall until it contacts the vascular wall, while polycaprolactone is structurally stable at 37°C, and the vascular stent forms irregular expansion and is self-curling, and the contact area between the vascular stent and the blood vessel increases, and can fit closely to the vascular wall. The higher the expansion capacity of the vascular stent in the blood vessel, the larger the contact area between the vascular stent and the inner wall of the blood vessel, and the closer it fits to the inner wall of the blood vessel, the greater the friction and adhesion between the vascular wall and the stent, which helps the stent to maintain a stable state in the blood vessel for a longer time, and prevents the stent from shifting or falling off; However, as the proportion of polydioxanone is too large, the vascular stent expands irregularly and becomes self-curling, and the contact area between the vascular stent and the blood vessel increases accordingly. The flexibility and low stiffness of polydioxanone make the stent surface smoother. When this smooth surface contacts the blood vessel wall, the friction and adhesion are low. In addition, due to the high flexibility of polydioxanone, the vascular stent may cause a slight slip between the inner wall of the blood vessel and the stent when expanding. The slip will reduce the contact surface, thereby reducing the friction and adhesion. At the same time, the flexibility of polydioxanone makes it impossible to evenly distribute the force due to the uneven pressure distribution on the blood vessel wall in dynamic environments such as blood flow fluctuations, vascular contraction and expansion. Deformation within the blood vessel may cause pressure concentration or uneven distribution, affecting the contact stability between the stent and the blood vessel wall.

[0047] Experimental Example 2: 1. Purpose of the experiment The effect of different concentrations of magnesium-rare earth alloy nanoparticles on the adhesion enhancement between nanofiber membrane layers was compared.

[0048] 2. Experimental steps 1. Preparation steps Example 5: Select polycaprolactone with a molecular weight of 50,000 (from Shenzhen Guanghua Weiye Co., Ltd.) and polydioxanone with a molecular weight of 30,000 (from Wuhan Xinxin Jiali Biotechnology Co., Ltd.), mix polycaprolactone and polydioxanone in a mass ratio of 7:5, and dissolve them in a trifluoroacetic acid solution with a concentration of 15% to obtain a mixed solution; Dissolve polyacrylic acid with a molecular weight of 800,000 (from Shanghai Yuanye Biotechnology Co., Ltd.) in deionized water to obtain a polyacrylic acid solution with a concentration of 1.5%, add the dried magnesium-rare earth alloy nanoparticles to 10% hydrofluoric acid for activation treatment, mix the activated magnesium-rare earth alloy nanoparticles with the polyacrylic acid solution at a mass ratio of 1:8, modify the magnesium-rare earth alloy nanoparticles, and stir for 45 minutes, take out the modified magnesium-rare earth alloy nanoparticles, and wash them with deionized water, and place the washed magnesium-rare earth alloy nanoparticles in an oven at 40°C for 15 minutes; The dried magnesium-rare earth element alloy nanoparticles and the mixed solution are mixed in a ratio of 1:20, stirred at a temperature of 40°C for 20 minutes to obtain a reinforcement solution, and the solution is loaded into a syringe. The syringe needs to be connected to an electrospinning device with a nozzle of 50nm. The solution in the syringe is controlled by a pump, and a 10kV high voltage is applied between the syringe and the collector to control the spinning solution flow rate to 0.45ml / h to form long and thin fibers. At the other end of the electrospinning, the fibers are collected by a collector, and the fibers are stretched and deposited on their surface to form a nanofiber membrane, changing the movement trajectory of the collector so that the arrangement of each layer of the nanofiber membrane is different, so that the fiber structures of adjacent nanofiber membranes prepared subsequently are perpendicular to each other. The fiber structures of adjacent layers are perpendicular to each other to form a vascular stent with a diameter of 3mm and a length of 10mm, and the vascular stent is sheared and flattened to obtain a layered vascular stent.

[0049] Example 6: It is generally the same as Example 5, except that the dried magnesium-rare earth alloy nanoparticles and the mixed solution are mixed in a ratio of 2:20, and a vascular stent with a diameter of 3 mm and a length of 10 mm is prepared by an electrospinning device, and the vascular stent is sheared and flattened to obtain a layered vascular stent.

[0050] Example 7: It is generally the same as Example 5, except that the dried magnesium-rare earth alloy nanoparticles and the mixed solution are mixed in a ratio of 3:20, and a vascular stent with a diameter of 3 mm and a length of 10 mm is prepared by an electrospinning device, and the vascular stent is sheared and flattened to obtain a layered vascular stent.

[0051] Example 8: It is generally the same as Example 5, except that the dried magnesium-rare earth alloy nanoparticles and the mixed solution are mixed in a ratio of 4:20, and a vascular stent with a diameter of 3 mm and a length of 10 mm is prepared by an electrospinning device, and the vascular stent is sheared and flattened to obtain a layered vascular stent.

[0052] Example 9: It is generally the same as Example 5, except that the dried magnesium-rare earth alloy nanoparticles and the mixed solution are mixed in a ratio of 5:20, and a vascular stent with a diameter of 3 mm and a length of 10 mm is prepared by an electrospinning device, and the vascular stent is sheared and flattened to obtain a layered vascular stent.

[0053] 2. Experiments on vascular stent samples 1. Shear force test: Use the Wanli shear force tester to place the layered vascular stent in the test fixture, gradually apply shear force until the membrane layers separate, record the maximum shear force value, and measure the adhesion between each membrane layer; 2. Tensile force test: Use a tensile tester to measure the tensile adhesion between the layered vascular stent membrane layers. Stretch each layer of the membrane until the membrane layers separate and record the tensile strength; measure the tensile force of different membrane layer combinations.

[0054] The vascular stent obtained in Example 3 was sheared and flattened to obtain a vascular stent with a layered structure. The vascular stents with layered structures obtained in Example 3 and Example 5 to Example 9 were subjected to shear tensile tests, respectively, as shown in Table 2; Table 2

[0055] By comparing Example 3, Example 5 to Example 9, a vascular stent with a layered structure is obtained. The vascular stent with a layered structure obtained in Example 3 has relatively low shear force and tensile force between layers. With the addition of magnesium-rare earth element alloy nanoparticles, the shear force and tensile force between layers of the vascular stent with a layered structure are improved. This is mainly because the surface of the magnesium-rare earth element alloy nanoparticles is modified with polyacrylic acid to have carboxyl and amino chemical groups. The chemical groups can form hydrogen bonds with the hydroxyl and amino groups of polycaprolactone and polydioxanone. This weak interaction between molecules can stabilize the bonding between the membrane layers. Moreover, the magnesium-rare earth alloy nanoparticles have a large specific surface area and high surface energy, and play the role of "adhesive" between multiple membrane layers. When the magnesium-rare earth alloy nanoparticles are evenly distributed in the nanofiber membrane, the surface of the magnesium-rare earth alloy nanoparticles will contact the membrane layer, thereby enhancing the adhesion between the layers; specifically, the magnesium-rare earth alloy nanoparticles have high mechanical strength, and are embedded between different membrane layers to form a physical bond, making the contact between the membrane layers closer, and the magnesium-rare earth alloy nanoparticles exist as a "bridge", connecting the fiber structures of different layers, playing the role of bonding and stabilizing the membrane layers. Through this "bridging" mechanism, the bonding force between different membrane layers is enhanced, thereby ensuring the stability and integrity between the layers of the vascular stent during the expansion process, and preventing the membrane layers from separating or falling off during use; However, as the content of magnesium-rare earth alloy nanoparticles is too large, the shear force and tensile force between the layers of the vascular stent will decrease, because there is an interaction force between polycaprolactone, polydioxanone and magnesium-rare earth alloy nanoparticles. The content of magnesium-rare earth alloy nanoparticles is too high, and the interaction force between polycaprolactone, polydioxanone and magnesium-rare earth alloy nanoparticles may compete, resulting in the weakening of the force of the particles on the interface, affecting the adhesion between the film layers, and a large number of magnesium-rare earth alloy nanoparticles increase the space occupied at the interface, thereby weakening the bonding force between the particles and the matrix. In summary, Example 8 is the optimal solution of the present invention.

[0056] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A guide wire with a vascular stent, comprising: A guide wire, and a vascular stent mounted on the guide wire, wherein a connecting wire is provided between the guide wire and the vascular stent; characterized in that: The guide wire comprises: an inner guide wire and an outer guide wire; both the inner guide wire and the outer guide wire are tubular structures, the outer guide wire is sleeved on the outside of the inner guide wire, a limiting wire fixed to the inner guide wire is provided in the cavity between the inner guide wire and the outer guide wire, and the vascular stent is located between the inner guide wire and the outer guide wire; The connecting wire is connected to the outer guide wire and the vascular stent respectively, and a breakable point is arranged in the middle of the connecting wire.

2. A guidewire with a vascular stent according to claim 1, characterized in that: The vascular stent is prepared by mixing polycaprolactone and polydioxanone, the inner diameter of the vascular stent is 3-4 mm, and the vascular stent is adhered to the inner wall of the blood vessel by expansion; The vascular stent is a multi-layer structure, each layer is composed of nanofiber membranes, and the fiber structures of the nanofiber membranes of two adjacent layers are perpendicular to each other.

3. A guidewire with a vascular stent according to claim 1, characterized in that: The outer guide wire is made of a nickel-titanium alloy by spiral rolling, the inner guide wire is made of a cobalt-chromium alloy by spiral rolling, and the thickness of the easy-to-break point is 30%-50% of the wall thickness of the connecting wire. The connecting wire is made of polycaprolactone.

4. The guide wire with a vascular stent according to claim 1, characterized in that: The method for preparing the vascular stent comprises the following steps: Step S1, mixing polycaprolactone and polydioxanone in a mass ratio of 7-10:3-6, and dissolving them in an acidic solution to prepare a mixed solution with a concentration of 10-15%; Step S2, modifying the magnesium-rare earth alloy nanoparticles, adding the modified magnesium-rare earth alloy nanoparticles into the mixed solution, and mixing them evenly to obtain a reinforcement solution; Step S3, preparing a plurality of oriented nanofiber membrane layers by electrospinning the reinforcement solution; Step S4, forming a vascular stent by pasting several layers of nanofiber membranes on a high-speed drum collector.

5. The vascular stent according to claim 4, characterized in that: In the step S1, the molecular weight of polycaprolactone is 40,000-100,000, and the molecular weight of polydioxanone is 20,000-30,000.

6. The vascular stent according to claim 4, characterized in that: In step S1, the acidic solution is a trifluoroacetic acid solution with a concentration of 10%-20%.

7. The vascular stent according to claim 4, characterized in that: In the step S2, the particle size of the magnesium-rare earth alloy nanoparticles is 30nm-80nm, and the nanoparticles are modified by polyacrylic acid.

8. The vascular stent according to claim 4, characterized in that: In the step S2, the mixed solution and the magnesium-rare earth alloy nanoparticles are mixed in a ratio of 20-25:1-5, and stirred at a temperature of 40-50° C. for 10-20 minutes.

9. The vascular stent according to claim 4, characterized in that: The method for modifying magnesium-rare earth alloy nanoparticles by polyacrylic acid comprises the following steps: Step S21, washing the magnesium-rare earth alloy nanoparticles with deionized water, and drying the washed nanoparticles; Step S22, dissolving polyacrylic acid with a molecular weight of 500000-1000000 in deionized water to obtain a polyacrylic acid solution with a concentration of 0.5%-5%; Step S23, adding the dried magnesium-rare earth alloy nanoparticles to hydrofluoric acid with a concentration of 10%-20% for activation treatment, and drying the activated magnesium-rare earth alloy nanoparticles; Step S24, mixing the magnesium-rare earth alloy nanoparticles and the polyacrylic acid solution at a mass ratio of 1:5-10 to modify the magnesium-rare earth alloy nanoparticles, and stirring for 30-60 minutes; Step S25, taking out the modified magnesium-rare earth alloy nanoparticles and washing them with deionized water, and placing the washed magnesium-rare earth alloy nanoparticles in an oven at 40-60° C. to dry for 10-15 minutes.

10. The vascular stent according to claim 4, characterized in that: In step S4, the inner diameter of the vascular stent is 3-4 mm, and the fiber structures in two adjacent layers of the nanofiber membranes in the vascular stent are perpendicular to each other.

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