Covered stent coated with electrostatic spinning membrane and preparation method of covered stent

Abstract

The invention provides a covered stent coated with an electrostatic spinning membrane and a preparation method thereof.The covered stent comprises a metal stent and a covering membrane, the metal stent is composed of a spiral metal wire, the metal wire is provided with a plurality of zigzag parts which are evenly arranged and connected end to end, every two adjacent zigzag parts are in a wave crest shape and a wave trough shape respectively, and the multiple zigzag parts enable the metal wire to be in a wave shape; the covering film covers the surface of the metal support to form a tubular structure, and the tubular structure can be kept shaped after bending deformation at the lesion position so that the tubular structure can be matched with the lesion position in shape. The covered stent has a high specific surface area and an adjustable porous structure, the micron-sized aperture of the covered stent can effectively prevent blood permeation, the high porosity allows a proper amount of tissue or cells to penetrate, vascularization and tissue integration of the implanted stent are promoted, and therefore the risk of stent displacement or instability is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a covered stent coated with an electrospun membrane and a preparation method thereof. Background Art

[0002] A covered vascular stent is a medical device used to treat vascular diseases such as aneurysms, vascular stenosis, or aortic dissection. It combines a metal stent and an artificial membrane covering it. The metal stent adheres to the inner wall of the blood vessel to provide support for the diseased area, and the covered artificial membrane forms a physical barrier to effectively prevent blood leakage. At the same time, it provides good mechanical strength and toughness for the stent, reducing wear and stress concentration of the stent structure. For aneurysms, the covered stent can prevent the rupture of the aneurysm, and for arterial stenosis, the covered stent helps to maintain smooth blood flow.

[0003] Existing covered stents usually use woven fabrics to make the covering membrane, and then combine it with the metal stent by means such as sewing, hot pressing, bonding, heat melting, etc. Among them, sewing is the most commonly used process method. For example, the existing patent with the publication number CN118490414A, a covered stent and its release device, uses sewing to combine the metal stent and the covering membrane. However, the manual sewing process is complex and it is difficult to ensure the uniformity of the covering membrane. Especially on stents with curved or complex geometric shapes, problems such as uneven coverage or loose sewing may occur. Secondly, the suture may cause blood to coagulate in local areas and form thrombus. Therefore, the existing technology has certain limitations. Summary of the Invention

[0004] The present invention is made to solve the above problems, and aims to provide a covered stent coated with an electrospun membrane and a preparation method thereof.

[0005] The present invention provides a covered stent coated with an electrospun membrane, having the following characteristics: including a metal stent and a covering membrane. The metal stent is composed of a helical metal wire, and the metal wire has a plurality of uniformly arranged and end-to-end connected zigzag portions. Adjacent two zigzag portions are respectively in a wave-peak shape and a wave-trough shape, and the plurality of zigzag portions make the metal wire in a wavy shape. The covering membrane covers the surface of the metal stent to form a tubular structure.

[0006] Among them, the tubular structure can be bent and deformed at the diseased position and then remain shaped to adapt to the shape of the diseased position.

[0007] In the covered stent coated with an electrospun membrane provided by the present invention, it can also have the following characteristics: the metal wire is made of any one of nickel-titanium alloy, cobalt-based alloy, or stainless steel.

[0008] In the covered stent with an electrospun membrane provided by the present invention, it can also have the following characteristics: the covering film is made of any one of TPU, PA6, or PTFE.

[0009] In the covered stent with an electrospun membrane provided by the present invention, it can also have the following characteristics: the covering film is coated on the surface of the metal stent through an electrospinning process.

[0010] In the covered stent with an electrospun membrane provided by the present invention, it can also have the following characteristics: the thickness of the covering film is 10 - 100 μm, and the pore size is 0.8 - 10 μm.

[0011] The present invention also provides a preparation method for a covered stent, which is applicable to the covered stent with an electrospun membrane in any of the above items, and has the following characteristics, including the following steps:

[0012] S1. After sleeving the metal stent on the rotating tooling, place it at the receiving position inside the electrospinning device;

[0013] S2. Then dissolve the polymer masterbatch in an organic solvent to form a polymer spinning solution with a certain concentration that is uniform and stable;

[0014] S3. Then set the production parameters of the electrospinning device, stretch the polymer spinning solution into micro-nano scale fibers, and deposit the micro-nano scale fibers on the surface of the metal stent;

[0015] S4. Finally, place the metal stent in an environment of 90 °C to further solidify the micro-nano scale fibers, thereby forming a uniform covering film on the outer surface of the metal stent, and then completing the preparation of the covered stent.

[0016] Functions and effects of the invention

[0017] According to a covered stent with an electrospun membrane and a preparation method thereof involved in the present invention, since the covering film is an electrospun fiber membrane, the covered stent of the present invention has a high specific surface area and a controllable porous structure. Its micron-scale pore size can effectively prevent blood penetration, and the high porosity allows appropriate tissue or cells to penetrate, promoting the vascularization and tissue integration of the stent after implantation. Therefore, it helps to reduce the risk of stent displacement or instability. Also, because the covering film is coated on the surface of the metal stent through an electrospinning process, it can adapt to the surface of the stent with a complex shape and can achieve high-precision coverage according to the complex shape of the metal stent, forming a uniform and dense covering film on the surface of the stent. Description of the drawings

[0018] Figure 1 It is a schematic structural diagram of a covered stent with an electrospun membrane of the present invention;

[0019] Figure 2It is a schematic flowchart of a preparation method of a covered stent with an electrospun membrane according to the present invention.

[0020] Explanation of reference numerals:

[0021] 1. Metal stent; 2. Covering membrane. Specific embodiments

[0022] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the following embodiments will specifically describe the present invention in conjunction with the accompanying drawings.

[0023] Embodiment

[0024] Figure 1 It is a schematic structural diagram of a covered stent with an electrospun membrane according to the present invention.

[0025] As Figure 1 shown, this embodiment provides a covered stent with an electrospun membrane, including: a metal stent 1 and a covering membrane 2.

[0026] As Figure 1 shown, the metal stent 1 is composed of a helical metal wire, and the metal wire has a plurality of uniformly arranged and end-to-end connected zigzag portions. Adjacent two zigzag portions are respectively in a wave crest shape and a wave trough shape, and the plurality of zigzag portions make the metal wire in a wavy shape.

[0027] In this embodiment, the metal wire is preferably made of any one of nickel-titanium alloy, cobalt-based alloy, or stainless steel.

[0028] As Figure 1 shown, the covering membrane 2 covers the surface of the metal stent 1 to form a tubular structure. Among them, the tubular structure can be shaped after being bent at the diseased position to be adapted to the shape of the diseased position.

[0029] In this embodiment, the covering membrane 2 is preferably made of any one of TPU, PA6, or PTFE. Therefore, the covered stent of the present invention has a high specific surface area and a controllable porous structure. Its micron-sized pore diameter can effectively prevent blood penetration, and the high porosity allows appropriate tissue or cells to penetrate, promoting the vascularization and tissue integration of the stent after implantation. Therefore, it helps to reduce the risk of stent displacement or instability.

[0030] In this embodiment, the covering membrane 2 is preferably coated on the surface of the metal stent 1 by an electrospinning process. Therefore, it can adapt to the surface of the stent with a complex shape and can achieve high-precision coverage according to the complex shape of the metal stent 1, forming a uniform and dense covering membrane 2 on the surface of the metal stent 1.

[0031] In this embodiment, the thickness of the covering membrane 2 is preferably 10 - 100 μm, and the pore diameter is preferably 0.8 - 10 μm.

[0032] Figure 2 It is a schematic flow chart of a preparation method of a covered stent with an electrospun membrane according to the present invention.

[0033] As Figure 2 shown, the present invention also provides a preparation method of a covered stent, which is applicable to any of the above-mentioned covered stents with an electrospun membrane, and includes the following steps:

[0034] S1. After sleeving the metal stent 1 on the rotating tooling, place it at the receiving position inside the electrospinning device;

[0035] S2. Then dissolve the polymer masterbatch in an organic solvent to form a polymer spinning solution with a certain concentration that is uniform and stable;

[0036] S3. Then set the production parameters of the electrospinning device, stretch the polymer spinning solution into micro-nano scale fibers, and deposit the micro-nano scale fibers on the surface of the metal stent 1;

[0037] S4. Finally, place the metal stent 1 in an environment of 90 °C to further cure the micro-nano scale fibers, so as to form a uniform covering film 2 on the outer surface of the metal stent 1, and thus complete the preparation of the covered stent.

[0038] In this embodiment, the polymer masterbatch is preferably a TPU masterbatch, and the organic solvent is preferably N,N-dimethylformamide.

[0039] In this embodiment, the concentration mass fraction of the polymer spinning solution is preferably 15%.

[0040] In this embodiment, the production parameters of the electrospinning device are preferably a temperature of 25 °C, a temperature humidity of 45% RH, a voltage of 10 KV, a spinning distance of 15 cm, an injection pump propulsion speed of 0.2 ml / h, and a spinning time of 20 min.

[0041] The covered stent with an electrospun membrane prepared by the present invention has good flexibility, so it can adapt to the natural movement of blood vessels, especially pulsation and bending, avoid causing excessive pressure on blood vessels, and improve the practical effect of the present invention.

[0042] Functions and effects of the embodiment

[0043] A covered stent coated with an electrospun membrane and a preparation method thereof according to the present invention. Since the covering membrane is an electrospun fiber membrane, the covered stent of the present invention has a high specific surface area and a controllable porous structure. Its micron-sized pore diameter can effectively prevent blood penetration, and the high porosity allows appropriate tissue or cell penetration, promoting the vascularization and tissue integration of the stent after implantation. Therefore, it helps to reduce the risk of stent displacement or instability. Also, since the covering membrane is coated on the surface of the metal stent through the electrospinning process, it can adapt to the surface of the stent with a complex shape and can achieve high-precision coverage according to the complex shape of the metal stent, forming a uniform and dense covering membrane on the surface of the stent.

[0044] The above embodiments are preferred cases of the present invention and are not used to limit the protection scope of the present invention.

Claims

1. A covered stent coated with an electrospun membrane, characterized in that, Comprising: A metal stent and a film. The metal stent is composed of a helical metal wire. The metal wire has a plurality of evenly arranged and end-to-end connected zigzag portions. Adjacent two of the zigzag portions are respectively in a wave-peak shape and a wave-trough shape. The plurality of zigzag portions make the metal wire in a wavy shape. The film is coated on the surface of the metal stent to form a tubular structure. Wherein, the tubular structure can be shaped after being bent and deformed at the lesion position so as to be adapted to the shape of the lesion position.

2. The covered film stent coated with an electrospun film according to claim 1, wherein: Among them, The metal wire is made of any one of nickel-titanium alloy, cobalt-based alloy, or stainless steel.

3. The covered film stent coated with an electrospun film according to claim 1, wherein: Among them, The film is made of any one of TPU, PA6, or PTFE.

4. The covered film stent coated with an electrospun film according to claim 1, wherein: Among them, The film is coated on the surface of the metal stent through an electrospinning process.

5. The covered film stent coated with an electrospun film according to claim 1, wherein: Among them, The thickness of the film is 10 - 100 μm, and the pore size is 0.8 - 10 μm.

6. A preparation method of a covered stent covered with an electrospun membrane, applicable to the covered stent covered with an electrospun membrane according to any one of claims 1 to 5, characterized in that, Including the following steps: S1. After sleeving the metal stent on a rotating tooling, place it at the receiving position inside the electrospinning device. S2. Then dissolve the polymer masterbatch in an organic solvent to form a polymer spinning solution with a certain concentration that is uniform and stable. S3. Then set the production parameters of the electrospinning device, stretch the polymer spinning solution into micro-nano scale fibers, and make the micro-nano scale fibers deposit on the surface of the metal stent. S4. Finally, place the metal stent in an environment at 90 °C to further cure the micro-nano scale fibers, thereby forming a uniform film on the outer surface of the metal stent, and further completing the preparation of the covered film stent.

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