CN114680951B

CN114680951B - Occluder and preparation method thereof

Info

Publication number: CN114680951B
Application number: CN202011607224.0A
Authority: CN
Inventors: 廖洪芳; 陈贤淼
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2024-12-31
Anticipated expiration: 2040-12-29
Also published as: CN114680951A

Abstract

The invention relates to a plugging device and a preparation method thereof, the plugging device comprises a plugging frame, a first sealing head and a second sealing head which are arranged on the plugging frame, wherein the plugging frame comprises a plurality of mutually crossed wires, two ends of the mutually crossed wires are respectively fixed by the first sealing head and the second sealing head, at least one of the first sealing head and the second sealing head is provided with a hole, when the first sealing head is provided with a hole, the hole extends from the surface of the first sealing head to the inside of the first sealing head, and when the second sealing head is provided with a hole, the hole extends from the second sealing head to the inside of the second sealing head. The sealing head of the plugging device can realize endothelialization relatively quickly.

Description

Plugging device and preparation method thereof

Technical Field

The invention relates to the field of interventional medical instruments, in particular to an occluder and a preparation method thereof.

Background

This section provides merely background information related to the present disclosure and is not necessarily prior art.

Percutaneous interventional therapy is a treatment for diseases that has progressed very rapidly in recent years, and the field to which this therapy is applicable is also becoming widespread. Wherein, the device and/or the medicine can be placed on the heart, the artery and vein of the human body and other parts by adopting a transcatheter interventional therapy method. Wherein, the apparatus can be heart occluder, vascular filter, vascular stent, etc.

Conventional devices such as heart occluders or vascular occluders are typically made of resilient shape memory alloy (e.g., nitinol) materials that return to their original or near original shape after release and conform well to the tissue at the defect site. However, the current shape memory alloy materials are generally non-corrodible or non-degradable materials in organisms, and after endothelialization is completed and complete plugging is achieved, the devices made of the shape memory alloy materials are permanently stored in the body, and long-term clinical risks may exist.

The plugging device made of the absorbable polymer material can be degraded in the organism, so that the plugging device can be degraded gradually, and after degradation products are absorbed by the organism, no residue exists in the organism, and long-term clinical risks can be avoided. However, the absorbable polymer material, such as polylactic acid, has a compact molecular chain structure, which makes the biological tissue and the occluder mutually permeate for a long time and endothelialize for a long time, so that the time for complete occlusion is long, thrombus is easy to form on the surface of the device, and the formed thrombus can fall off from the device to cause serious problems such as thromboembolism.

Existing absorbable occluders typically comprise an occluding disc formed by braiding filaments, wherein the free ends of both filaments are typically gathered and secured with an end cap. In order to make the plugging device completely absorbable, the material of the sealing head is also absorbable polymer material, so the sealing head has the problem of difficult endothelialization. Moreover, experiments show that the endothelialization of the end socket is more difficult and slower than that of the braided wire. Because the seal head is used for converging and fixing the braided wires, after the plugging device is implanted into a body, before the seal head and the braided wires are covered by an endothelial cell membrane to integrate the seal head and the braided wires, the braided wires are broken, so that the seal head is likely to fall off. Once the closure head falls off, it enters the blood circulation system as a foreign body, creating a great clinical risk.

Disclosure of Invention

Based on the above, it is necessary to provide an occluder with a head capable of realizing endothelialization relatively quickly.

The plugging device comprises a plugging frame, a first sealing head and a second sealing head, wherein the first sealing head and the second sealing head are arranged on the plugging frame, the plugging frame comprises a plurality of threads which are mutually intersected, two ends of the threads which are mutually intersected are respectively fixed by the first sealing head and the second sealing head, at least one of the first sealing head and the second sealing head is provided with a hole, when the first sealing head is provided with a hole, the hole extends from the surface of the first sealing head to the interior of the first sealing head, and when the second sealing head is provided with a hole, the hole extends from the surface of the second sealing head to the interior of the second sealing head.

In one embodiment, the porosity of the first end socket and/or the second end socket is 10% -40%.

In one embodiment, at least a portion of the plurality of interdigitated wires has holes therein that extend from a surface of the wire toward an interior of the wire.

In one embodiment, in the plurality of mutually-crossed wires, one part of wires is provided with holes, the other part of wires is not provided with holes, the wires without holes are arranged at intervals to form a supporting frame with gaps, and the wires with holes are positioned in the gaps of the supporting frame;

Or a plurality of threads with holes are used as a first group of threads, a plurality of threads without holes are used as a second group of threads, and the first group of threads and the second group of threads are mutually intersected to form the plugging frame;

Or a plurality of silk threads with holes form a first woven mesh, a plurality of silk threads without holes form a second woven mesh, and the second woven mesh is accommodated in the first woven mesh, so that the plugging frame is of a double-layer grid structure.

In one embodiment, the ratio of the number of the wires with holes to the number of the wires without holes is 1:2 to 0.5:1, and the ratio of the wire diameter of the wires with holes to the wire diameter of the wires without holes is 1:1 to 2:1.

In one embodiment, at least a portion of the surface of the wire is provided with a polymer coating having a plurality of micropores thereon.

In one embodiment, the holes are filled with a soluble substance.

A method for preparing an occluder, comprising the following steps:

Providing a frame comprising a plurality of interdigitated wires;

Mixing a main body material with a soluble substance to prepare a sleeve;

contacting the sleeve with a solvent to dissolve the first soluble substance but not the host material, the soluble substance forming a hole in the sleeve after dissolution;

respectively using two casings with holes as a first end socket and a second end socket, or respectively using one casing without holes and one casing with holes as the first end socket and the second end socket, respectively fixing two ends of the multiple mutually-intersected wires by the first end socket and the second end socket, and

Shaping the frame to form the plugging frame.

In one embodiment, the mass ratio of the main material to the soluble substance is 50-95:50-5.

In one embodiment, the method of making the filament comprises:

Mixing a polymer with a soluble substance to prepare a wire;

The silk is contacted with a solvent to dissolve the soluble substance and the polymer is not dissolved, and holes are formed on the silk after the soluble substance is dissolved to obtain the silk, or a polymer coating is formed on the silk to obtain the silk.

A method for preparing an occluder, comprising the following steps:

Providing a frame comprising a plurality of interdigitated wires;

Mixing a main body material with a soluble substance to prepare a sleeve;

fixing the two ends of the plurality of mutually crossed wires with two sleeves respectively;

Contacting at least one of the two sleeves with a solvent to dissolve the soluble substance without dissolving the host material, wherein the soluble substance forms a hole in the sleeve after dissolving;

shaping the frame to form the plugging frame.

At least one of the first sealing head and the second sealing head of the plugging device is provided with holes extending from the surface to the inside, and the holes are beneficial to endothelial cells to climb on the surface of the first sealing head and/or the second sealing head, so that endothelialization can be realized faster.

Drawings

FIG. 1 is a schematic view of an occluder in an embodiment;

FIG. 2 is a schematic cross-sectional view of a first head of an embodiment;

FIG. 3 is a schematic cross-sectional view of a second head of an embodiment;

FIG. 4 is a top view of a distal end of a filament of an embodiment received in a first head and prior to heat staking;

FIG. 5 is a top view of a proximal end of a filament of an embodiment received in a second head and prior to heat staking;

FIG. 6 is a schematic view showing a state that a locking member of the occluder of another embodiment is not connected to a second closure head;

FIG. 7 is a schematic view showing a state in which a locking member of the occluder shown in FIG. 6 is connected to a second closure head;

FIG. 8 is a schematic illustration of a cross-weave pattern of filaments according to one embodiment;

FIG. 9 is a schematic longitudinal cross-sectional view of a wire of an embodiment;

FIG. 10 is a flow chart of a method of making an occluder in accordance with an embodiment;

FIG. 11 is a scanning electron microscope image of a polylactic acid and iohexol mixture sheet material after being immersed in deionized water for 48 hours;

FIG. 12 is a scanning electron microscope image of a polylactic acid sheet material after being immersed in deionized water for 48 hours;

fig. 13 is a flowchart of a method of manufacturing an occluder in another embodiment.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit or scope of the invention, which is therefore not limited to the specific embodiments disclosed below.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the field of interventional medical devices, "distal" is defined as the end of the procedure that is distal to the operator, and "proximal" is defined as the end of the procedure that is proximal to the operator. "axial" refers to a direction parallel to the line connecting the distal center and the proximal center of the medical device, and "radial" refers to a direction perpendicular to the axial direction.

Referring to fig. 1, an occluder 100 in one embodiment comprises an occluding frame 20. The plugging frame 20 is a net structure formed by intersecting a plurality of wires. The material of the silk thread can be non-degradable metal, for example, the silk thread can be nickel-titanium alloy silk, cobalt-chromium alloy silk or stainless steel wire, etc. Or the silk thread can be made of biodegradable materials. For example, the biodegradable material is selected from at least one of poly (l-lactic acid) (PLLA), poly (racemic lactic acid) (PDLLA), poly (D-lactic acid) (PDLA), poly (glycolic acid) (PGA), poly (lactic-co-glycolic acid) (PLGA), polyhydroxyalkanoate (PHA), polydioxanone (PDO), and Polycaprolactone (PCL).

In this embodiment, the occlusion frame 20 includes a first occlusion unit 22, a second occlusion unit 24, and a waist portion 26. The two ends of the waist part 26 are respectively connected with the first plugging unit 22 and the second plugging unit 24 to form a two-disc one-waist structure with large ends and small middle parts. The first occlusion unit 22, the second occlusion unit 24 and the waist portion 26 are of unitary construction.

It will be appreciated that in other embodiments, the structure of the occlusion frame 20 is not limited to a two-disc, one-waist structure with two large ends and a small middle. For example, when one of the first occlusion unit 22 and the second occlusion unit 24 is omitted, the first occlusion unit 22 or the second occlusion unit 24 is connected to the waist portion 26 to form the occlusion frame 20 having a substantially T-shaped cross section.

Each wire has two free ends. Referring again to fig. 1, the occluding device 100 further includes a first head 40 disposed on the first occluding unit 22 and a second head 60 disposed on the second occluding unit 24. The first head 40 and the second head 60 are both used to pool and secure the filaments. Specifically, the first head 40 is used to secure the distal free end of the wire and the second head 60 is used to secure the proximal free end of the wire. In addition, in an embodiment, the second end socket 60 is provided with a movable connection component (not shown in fig. 1), and the movable connection component is used for being movably connected with a conveying system, so that after the occluder 100 is conveyed to a lesion, the connection with the occluder 100 can be disconnected to release the occluder 100. Specifically, the second end socket 60 may be provided with a thread, a multi-strand wire, or the like, which is movably connected to the conveying system.

In one embodiment, the first head 40 and the second head 60 are each hollow cylindrical structures. As shown in fig. 2, the first seal head 40 has a housing cavity 41 therein. As shown in fig. 3, the second seal head 60 has a receiving chamber 61 therein, and both ends of the wire are received and fixed in the receiving chamber 41 of the first seal head 40 and the receiving chamber 61 of the second seal head 60, respectively. In one embodiment, the filaments are fixedly connected to the first head 40 and the second head 60 by means of hot melt.

At least one of the first head 40 and the second head 60 has a hole.

With continued reference to fig. 2, in one embodiment, the first seal head 40 has a hole structure, i.e., the first seal head 40 has a plurality of holes 42. And, the hole 42 extends from the surface of the first head 40 toward the inside of the first head 40. The holes 42 do not extend through the first head 40 to maintain the structural integrity of the first head 40. I.e. the open end of the hole 42 is located on the outer surface of the first head 40. The outer surface refers to the outer peripheral surface.

In an embodiment, all the holes 42 on the first seal head 40 extend from the outer surface of the first seal head 40 toward the inside of the first seal head 40 (toward the direction close to the receiving cavity 41 of the first seal head 40), and the holes 42 do not penetrate the first seal head 40. That is, the first head 40 does not have a hole 42 extending from the inner surface (inner peripheral surface) of the first head 40 toward the inside of the first head 40 (toward the housing chamber 41 of the first head 40, that is, both the direction away from the outer peripheral surface of the first head 40 and the direction away from the inner peripheral surface are defined as the inside of the first head 40). After the occluder 100 is implanted in an organism, generally, endothelial cells first climb along the outer surface of the occluder 100 to form endothelial cell membranes covering the occluder 100, and the first seal 40 is provided with holes 42 extending from the outer surface to the interior of the first seal 40, which is beneficial for endothelial cell climbing. Also, the first head 40 does not have the hole 42 extending from the inner surface of the first head 40 to the outside of the first head 40, so that the first head 40 has sufficient strength.

In one embodiment, as shown in fig. 3, the second seal head 60 has a hole structure, i.e., the second seal head 60 has a plurality of holes 62. And, the hole 62 extends from the surface of the second head 60 toward the second head 60. The holes 62 do not extend through the second head 60 to maintain the structural integrity of the second head 60. I.e. the open end of the hole 62 is located on the outer surface of the second head 60. The outer face refers to the outer peripheral surface.

In an embodiment, all the holes 62 on the second seal head 60 extend from the outer surface of the second seal head 60 toward the inside of the second seal head 60 (toward the direction close to the receiving cavity 61 of the second seal head 60), and the holes 62 do not penetrate the second seal head 60. That is, the second head 60 does not have the hole 62 extending from the inner surface (inner peripheral surface) of the second head 60 to the outside of the second head 60 (the direction toward the housing chamber 61 of the second head 60, that is, the direction away from the outer peripheral surface of the second head 60 and the direction away from the inner peripheral surface are both defined as the inside of the second head 60). Holes 62 extending from the outer surface to the interior of the second seal head 60 are arranged on the second seal head 60, which is beneficial to endothelial cell climbing. And, the second head 60 does not have the hole 62 extending from the inner surface of the second head 60 to the outside of the second head 60 so that the second head 60 has sufficient strength.

In one embodiment, the hole 42 extends from the distal end of the first head 40 toward the interior of the first head 40, and the hole 42 does not extend through the first head 40. The hole 62 extends from the proximal end of the second head 60 toward the interior of the second head 60, and the hole 62 does not extend through the second head 60. The direction away from the distal end face or the proximal end face is defined as internal.

The hole 42 extending from the outer periphery of the first head 40 toward the inside of the first head 40, the hole extending from the inner periphery of the first head 40 toward the outside of the first head 40, and the hole 42 extending from the distal end of the first head 40 toward the inside of the first head 40 may exist at the same time while ensuring the mechanical properties of the first head 40. Similarly, the hole 62 extending from the outer periphery of the second head 60 toward the inside of the second head 60, the hole extending from the inner periphery of the second head 60 toward the outside of the second head 60, and the hole 62 extending from the distal end of the second head 60 toward the inside of the second head 60 may coexist on the premise of ensuring the mechanical properties of the second head 60.

The first seal head 40 has a plurality of holes 42 and/or the second seal head 60 has a plurality of holes 62, and when the occluder 100 is implanted in the body, the holes 42 are beneficial to endothelial cells to climb over the surface of the first seal head 40, and the holes 62 are beneficial to endothelial cells to climb over the surface of the second seal head 60, so that endothelialization can be achieved more quickly.

Referring to fig. 4, in an embodiment, the first seal head 40 includes a first outer sleeve 43 and a first inner sleeve 45, the first inner sleeve 45 is received in the first outer sleeve 43, and a gap is formed between the first inner sleeve 45 and the first outer sleeve 43. Referring to fig. 5, the second seal head 60 includes a second outer sleeve 63 and a second inner sleeve 65, the second inner sleeve 65 is received in the second outer sleeve 63, and a gap is formed between the second inner sleeve 65 and the second outer sleeve 63. The distal ends 201 of the plurality of wires are received in the gap between the first inner sleeve 45 and the first outer sleeve 43, the proximal ends 202 of the plurality of wires are received in the gap between the second inner sleeve 65 and the second outer sleeve 63, and after heat-fusing, the distal ends 201 of the wires are fused together with the first inner sleeve 45 and the first outer sleeve 43, and the proximal ends 202 of the wires are fused together with the second inner sleeve 65 and the second outer sleeve 63.

In this way, the connection of the first head 40 to the wire and the connection of the second head 60 to the wire are more reliable. In addition, the hole 42 on the first sealing head 40 extends from the outer surface of the first outer sleeve 43 to the inside of the first outer sleeve 43, and the hole 42 does not penetrate through the first outer sleeve 43. The hole 62 on the second head 60 extends from the outer surface of the second outer sleeve 63 toward the inside of the second outer sleeve 63, and the hole 62 does not penetrate the second outer sleeve 63. So set up for first head 40 and second head 60 have the effect that promotes endothelial cell to climb, and hole 42 and hole 62 are less to the influence of first head 40 and second head 60's intensity respectively.

When the number of holes 42 on the first seal head 40 is large, the endothelial cells can climb over the first seal head 40. Similarly, when the number of holes 62 on the second head 60 is greater, endothelial cells are facilitated to climb over the second head 60. However, when the number of the holes 42 is too large, the porosity of the first seal head 40 is too large, so that the connection between the first seal head 40 and the wire is weak, and the wire is easily separated from the first seal head 40. When the number of the holes 62 is too large, the holes of the second seal head 60 are too large, so that the connection between the second seal head 60 and the wire is weak, and the wire is easy to fall off from the second seal head 60.

Therefore, in an embodiment, the porosity of the first seal head 40 is 10% -40% to achieve both endothelial climbing and the connection strength between the first seal head 40 and the wire. In an embodiment, the porosity of the second seal head 60 is 10% -40% so as to achieve both endothelial climbing and connection strength between the second seal head 60 and the wire.

The porosity is the percentage of the open area of the hole on the surface of the closure head to the surface area of the closure head. For example, when the first head 40 is hollow cylindrical, the porosity of the first head 40 refers to the percentage of the open area of the hole 42 on the cylinder side to the area of the cylinder side. When the second head 60 is hollow cylindrical, the porosity of the second head 60 refers to the percentage of the open area of the hole 62 on the side of the cylinder to the area of the side of the cylinder. The areas of the sides of the first head 40 and the second head 60 can be calculated, and the opening area of the hole 42 and the opening area of the hole 62 can be measured by a microscope.

In one embodiment, the first seal 40 has holes 42 and the second seal 60 has holes 62, which facilitate endothelial cell climbing over the first seal 40 and the second seal 60, so that the first seal 40 and the second seal 60 are more quickly covered by endothelial cell membranes.

Since the second seal head 60 is connected to the conveying system during the conveying process, the second seal head 60 should have sufficient mechanical strength to ensure the reliability of the connection. Therefore, in an embodiment, the porosity of the second seal head 60 is smaller than that of the first seal head 40, so that the first seal head 40 has a better endothelialization promoting effect, and the endothelialization promoting effect and the mechanical strength of the second seal head 60 are both considered.

In one embodiment, as shown in fig. 6 and 7, the occluding device 100 further includes a locking member 80. The locking member 80 extends in the axial direction in the plugging frame 20, and one end of the locking member 80 is fixedly connected with the first sealing head 40, and the other end is detachably connected with the second sealing head 60. When the locking member 80 is connected to the second head 60, the axial distance of the first and second occlusion units 22, 24 of the occlusion frame 20 is fixed, so that the occluder 100 can reliably occlude the defect site. Therefore, the second sealing head 60 is not only connected with the conveying system, but also serves as a component for bearing the locking member 80, when the locking member 80 is connected with the second sealing head 60, the second sealing head 60 is subjected to continuous force of the locking member 80, and in order to ensure reliable connection of the locking member 80 with the second sealing head 60, the second sealing head 60 should have sufficient strength. Therefore, in one embodiment, the porosity of the second seal head 60 is 10% -30%, so as to achieve the effect of endothelial cell climbing and reliable connection with the locking member 80 and the delivery device.

In one embodiment, the average pore size of the plurality of holes 42 of the first seal head 40 is 5 μm to 200 μm, and the average pore size of the plurality of holes 62 of the second seal head 60 is 5 μm to 200 μm, so that the first seal head 40 and the second seal head 50 have sufficient mechanical strength.

In one embodiment, the material of the first head 40 and the second head 60 is a degradable polymer. In one embodiment, the material of the first and second caps 40, 60 is selected from at least one of poly (racemic lactic acid) (PDLLA), poly (D-lactic acid) (PDLA), poly (L-lactic acid) (PLLA), poly (glycolic acid) (PGA), poly (lactic-co-glycolic acid) (PLGA), polyhydroxyalkanoates (PHA), polydioxanone (PDO), and Polycaprolactone (PCL).

The materials of the first head 40 and the second head 60 may be the same or different.

The materials of the first head 40, the second head 60 and the filaments may be the same or different.

In one embodiment, at least some of the plurality of interdigitated wires have holes therein that extend from the outer surface of the wire toward the interior of the wire. In addition, the holes do not penetrate the silk thread, so that the silk thread is kept continuous, and breakage of the silk thread is avoided. As shown in fig. 8, a wire with holes is labeled 210 and a wire without holes is labeled 220. The holes are labeled 212. The following continues with the corresponding reference symbols without limitation whether the filaments 210 and 220 are woven in the manner shown in fig. 8.

The holes 212 on the partial wires 210 are beneficial to the endothelial cells to climb on the surface of the plugging frame 20 and promote endothelialization rapidly.

In one embodiment, a portion of the wires 210 have holes 212 and another portion of the wires 220 do not have holes 212, and the wires 220 without holes 212 are spaced apart to form a support frame with gaps, and the wires 210 with holes 212 are positioned in the gaps of the support frame. When the diameters of the filaments are uniform, the mechanical properties of the filaments 220 without the holes 212 are better than those of the filaments 210 with the holes 212. The silk thread 220 with good mechanical properties and without holes 212 is formed into a supporting frame, and the silk thread 210 with holes 212 which is favorable for promoting endothelialization fills gaps of the supporting frame, so that the mechanical properties and endothelialization promoting effects of the plugging frame 20 are both considered.

Referring again to fig. 8, in one embodiment, a plurality of wires 210 with holes 212 are used as a first set of wires and a plurality of wires 220 without holes 212 are used as a second set of wires. In the first set of wires, a plurality of wires 210 having holes 212 are arranged in parallel and spaced apart. In the second set of wires, a plurality of wires 220 having holes 212 are arranged in parallel and spaced apart relationship. The first set of wires and the second set of wires are cross-woven and shaped in a one-press-one, up-down cross-weave manner to form the occlusion frame 20. In this way, the wires 210 with holes 212 and the wires 220 without holes 212 in the plugging frame 20 are uniformly distributed, so that the plugging frame 20 has enough mechanical properties, and endothelial cells can easily climb on the plugging frame 20.

In an embodiment, a plurality of wires 210 with holes 212 are woven to form a first woven mesh, a plurality of wires 220 without holes 212 are woven to form a second woven mesh, the second woven mesh is accommodated in the first woven mesh, and the plugging frame 20 with a double-layer grid structure is obtained after shaping. The plugging frame 20 with the double-layer grid structure has better mechanical supporting performance, the first woven mesh is positioned outside, and the hole structure of the first woven mesh is beneficial to endothelial cells to climb and cover on the plugging frame 20.

In one embodiment, the ratio of the number of wires 210 with holes 212 to the number of wires 220 without holes 212 is 1:2-0.5:1, and the ratio of the wire diameter of the wires 210 with holes 212 to the wire diameter of the wires 220 without holes 212 is 1:1-2:1, so that the plugging frame 20 has sufficient mechanical properties and endothelial cells can easily climb on the plugging frame 20.

In one embodiment, the average pore size of the pores of the wire 210 with pores 212 is 5-500 microns.

In one embodiment, at least one of the first head 40, the second head 60, and the wire 210 having the holes 212 is filled with a soluble substance. For example, the holes 42 of the first head 40 are filled with a soluble substance, the holes 62 of the second head 60 are filled with a soluble substance, and the holes 212 of the wires 210 are filled with a soluble substance.

The soluble substance is soluble in a medium such as blood, physiological saline, water, an organic solvent, an inorganic solvent, etc., and after the occluder 100 is implanted in a body, the soluble substance is dissolved to take on a hole structure, so that an effect of promoting endothelial cell climbing is obtained.

The soluble substance is different from the materials of the first head 40, the second head 60, and the filament 210 and should have different dissolution characteristics such that in a particular solvent, e.g., water, blood, etc., the soluble substance is soluble while the first head 40, the second head 60, and the filament 210 are insoluble.

In an embodiment, the material of the first seal head 40 and the second seal head 60 is poly-l-lactic acid, the material of the soluble substance is poly-dl-lactic acid, and the solvent is acetone. The poly-racemic lactic acid is dissolved in acetone, while the poly-L-lactic acid is not dissolved in acetone, so that holes are formed on the first seal head 40 and the second seal head 60. After sufficient volatilization of the tetrahydrofuran, the resulting sample was washed to avoid solvent residue.

In one embodiment, the soluble substance is a water-soluble material. For example, the soluble substance is at least one of sodium chloride, polyvinyl alcohol, gelatin, polyvinylpyrrolidone or polyethylene glycol.

In one embodiment, the soluble substance is a functional substance, such as, for example, including, but not limited to, a polypeptide, a protein, a drug, and the like.

In one embodiment, the soluble material is a developable material. The developable substance is filled in the holes 212 of the wire 210, the first seal head 40 and/or the second seal head 60, so that the developable substance can indicate the shape and position of the occluder 100 in the implantation process, and the implantation is performed smoothly. Therefore, the occluding device 100 does not need to be additionally provided with a metal marker to indicate the shape and position of the occluding device 100, and can be completely degraded, so that the metal marker remains in the body.

In one embodiment, none of the plurality of interdigitated wires in the occlusion frame 20 has holes 212 in themselves. As shown in fig. 9, but at least a portion of the surface of the wire 220 is provided with a polymer coating 222. The polymer coating 222 is a porous structure having a plurality of micropores 2222. The pore structure facilitates the climbing of endothelial cells over the wire 220.

In one embodiment, the average pore size of the micropores of the polymer coating 222 is 5 μm to 500 μm and the porosity is 20% to 85%. The wire 220 without holes serves as a support, so the pore size and porosity of the polymer coating 222 may be relatively large to enhance the endothelial promoting effect.

The porosity herein refers to the percentage of the area of the micropores 2222 that is open on the outer surface of the polymer coating 222 to the area of the outer surface of the polymer coating 222. The open area of the micro-pores 2222 and the area of the outer surface of the polymer coating 222 may be measured by microscopy.

In one embodiment, the material of the polymer coating 222 is an absorbable polymer. In one embodiment, the material of the polymer coating 222 is selected from at least one of poly (racemic lactic acid) (PDLLA), poly (D-lactic acid) (PDLA), poly (L-lactic acid) (PLLA), poly (glycolic acid) (PGA), poly (lactic-co-glycolic acid) (PLGA), polyhydroxyalkanoates (PHA), polydioxanone (PDO), and Polycaprolactone (PCL).

Further, in an embodiment, a method for preparing an occluder is provided, as shown in fig. 10, including the following steps:

Step 110, providing a frame comprising a plurality of intersecting wires.

In one embodiment, a plurality of wires are interwoven to form a lumen frame with two open ends.

The plurality of wires are provided with holes. Or part of the wires have holes and the other part of the wires do not have holes. The distribution of the wires with holes and the wires without holes may be as described above, and will not be described here. Or none of the wires have holes.

In one embodiment, the method of making the filament comprises the steps of:

After mixing the polymer with the soluble substance, a wire is prepared. When the wire is not required to have holes, the obtained wire is the wire.

When a wire with holes is to be prepared, the wire is contacted with a solvent to dissolve the soluble material while the polymer is insoluble, resulting in a wire with holes.

In one embodiment, the polymer is mixed with the soluble material uniformly, hot melted, cooled to form a solid mixture, and the solid mixture is processed to form a wire without holes. The solid mixture may be processed to form a wire without holes by spinning, extrusion, drawing, etc. With this method, the melting point of the soluble material is higher than the melting point of the polymer, and at the hot melt temperature the polymer melts while the soluble material does not. Returning to fig. 2 and 3, after hot melting, the soluble material 50 is present in particulate form. For example, in one embodiment, the polymer is polylactic acid and the soluble material 50 is sodium chloride having a relatively high melting point.

In one implementation, the polymer and the soluble material are dissolved in a solvent, and then left to stand until the solvent is sufficiently volatilized to form a solid mixture. The solid mixture is then processed to form a wire without holes.

If the polymer and the soluble material are selected to be soluble in the same solvent, the polymer and the soluble material are dissolved in the same solvent. If the solubility difference of the selected polymer and the soluble substance in the same solvent is large, the polymer is dissolved in a first solvent to obtain a first solution, the soluble substance is dissolved in a second solvent to obtain a second solution, the first solution and the second solution are mixed, and then the mixture is stood until the solvents volatilize, and a solid mixture is formed after the two solvents volatilize sufficiently. Or adding the polymer and the soluble substance into the mixed solvent of the first solvent and the second solvent at the same time, and stirring the mixture uniformly and dissolving the polymer and the soluble substance.

It will be appreciated that the amount of solvent is such that the polymer and soluble material are completely dissolved, and that no excess solvent is used, so as to avoid excessive solvent evaporation.

In one embodiment, the average particle size of the soluble material is 3 to 250 microns such that the average pore size of the pores of the prepared filaments is 5 to 500 microns.

In one embodiment, the perforated wires are cross-woven with each other to form the frame after the perforated wires are prepared.

In one embodiment, after the non-apertured filaments are prepared, the non-apertured filaments are cross-woven with one another to form a frame, and then the soluble material is dissolved to form apertures in the filaments. For example, the operation of dissolving the soluble substance may be performed after the frame is formed. The soluble material may also be dissolved prior to implantation of the occluding device. The occluder can also be implanted directly into the body, and under the impact of blood, the soluble substance dissolves to form a hole in the wire.

0.5G of iohexol powder is dissolved in 5mL of methanol, stirred until the mixture is clear, 1g of polylactic acid is dissolved in 10mL of chloroform, the two are slowly mixed and continuously stirred, and then the mixture is fully stood until the solvent volatilizes, so that a mixed flaky material is obtained. The mixed sheet material was immersed in deionized water at 37 ℃ for 48 hours, dried and observed for surface morphology under a scanning electron microscope. As shown in fig. 11, the surface of the mixed sheet material has a remarkable pore structure because polylactic acid is not dissolved in deionized water, iohexol is dissolved in deionized water, and the space originally occupied by iohexol is released, thereby forming a pore structure.

After 1g of polylactic acid is dissolved in 10mL of chloroform, the mixture is fully stood until the solvent volatilizes, and the flaky polylactic acid with a flat surface is obtained. The flaky polylactic acid is soaked in deionized water at 37 ℃ for 48 hours, and the surface morphology is observed under a scanning electron microscope after being dried. As shown in fig. 12, the soaked sheet-like polylactic acid has a flat surface and no wrinkles and holes.

Comparing fig. 11 and 12, it can be intuitively seen that the pore structure is formed by introducing a soluble substance and then dissolving at least part of the soluble substance without dissolving the polymer by using the solubility difference between the soluble substance and the polymer in a specific solvent.

In one embodiment, the mass ratio of the polymer to the soluble substance is 50-95:50-5, so that the porosity of the silk thread is 20% -50%, and the silk thread has the effect of promoting endothelialization while meeting the requirement of mechanical properties.

In an embodiment, the frame may be formed by using a 3D printing mode, and the wires of the frame are in an integral structure connected with the wires, unlike in the case of knitting to form the frame, the connection relationship or the position relationship between the wires is lap joint. The filaments in the 3D printed frame may be pure polymer filaments, or polymer filaments embedded with soluble particles. In the case of a polymer yarn embedded with soluble particles, after the frame is prepared, the frame may be contacted with a solvent capable of dissolving the soluble particles but not the polymer, so that at least a portion of the soluble particles are dissolved and the polymer is not dissolved, thereby forming a yarn having holes.

Step 120, after mixing the host material with the soluble substance, a cannula is prepared.

The main body material is the material of first head and second head. The material of the body and the material of the wire may be the same or different.

When the materials of the first seal head and the second seal head are different, respectively selecting different main body materials to prepare sleeves with different materials.

The soluble material is the same as the soluble material described above and will not be described here again.

The main material and the soluble substance are uniformly mixed to obtain a mixture, a solid mixture is prepared by adopting a hot melting or solvent mixing mode, and then the sleeve is prepared by adopting extrusion, spinning and 3D printing modes. The method of hot melting and solvent mixing is the same as described in the method of preparing the wire above and will not be described here.

Step 130, the sleeve is contacted with a solvent to dissolve the soluble substance and the main material is not dissolved, and the holes are formed on the sleeve after the soluble substance is dissolved.

For example, the cannula is immersed in a solvent such that after the soluble material is dissolved, the space that the soluble material would otherwise occupy is released, thereby forming a void.

In one embodiment, when it is desired that the holes extend only from the exterior surface of the sleeve to the interior of the sleeve, contact of the interior surface of the sleeve with the solvent should be avoided to avoid dissolution of soluble material particles near the interior surface by the solvent. For example, the outer surface of the sleeve is repeatedly wiped with solvent while the inner surface is prevented from contacting the solvent. Or after protecting the inner surface (inserting a protective plug into the lumen of the cannula to shield the inner surface), the cannula is immersed in a solvent.

And 140, respectively taking two sleeves with holes as a first end socket and a second end socket, or respectively taking one sleeve without holes and one sleeve with holes as the first end socket and the second end socket, and respectively fixing two ends of a plurality of mutually-intersected wires by the first end socket and the second end socket.

The first end socket and the second end socket are respectively fixed at two ends of a plurality of mutually-intersected silk threads. Wherein, first head gathers and fixes one end, and the second head gathers and fixes the other end. In one embodiment, the first end enclosure and the wire and the second end enclosure and the wire are respectively fixed by hot melting.

In an embodiment, when the first end enclosure is of a double-sleeve structure, a sleeve without holes is used as the first inner sleeve, and a sleeve with holes is used as the first outer sleeve.

In an embodiment, when the second end enclosure is of a double-sleeve structure, a sleeve without holes is used as the second inner sleeve, and a sleeve with holes is used as the second outer sleeve.

And 150, shaping the frame to form a plugging frame.

The frame is shaped to the desired configuration, i.e., the occlusion frame 20.

In one embodiment, the frame is heat treated at 87-93 ℃ for 9-16 minutes to set the frame into a plugged frame 20.

Holes are formed in the first sealing head and/or the second sealing head of the plugging device prepared by the preparation method of the plugging device, so that endothelial cells can climb, endothelialization can be realized quickly, and endothelialization can be accelerated. After implantation, the occluder can be rapidly coated by endothelial cell membranes, and can realize complete occlusion quickly, and has good treatment effect. And in addition, the first end socket and/or the second end socket are/is prevented from falling off, and the use safety is improved.

In one embodiment, the method further comprises the steps of immersing the occluder in a solution containing the functional substance and drying the occluder such that the dried functional substance is deposited in the pores. After implantation, the functional substances dissolve in the blood and exert corresponding effects.

In one embodiment, the functional material is a developable material. Because at least one of the first sealing head and the second sealing head and the silk thread are provided with holes, developable substances are easy to attach to one of the first sealing head and the second sealing head and the silk thread and deposit in the holes, so that the prepared plugging device has the characteristic of being developable under medical imaging equipment.

In this way, a developable substance is introduced on the surface of the occluding device 100, and after the implantation is completed, the developable substance is gradually dissolved under the impact of blood without adversely affecting the structure and mechanical properties of the occluding device 100 itself.

In one embodiment, when the wires of the frame are wires without holes, the step of preparing a polymer coating on the surface of the wires is further included after shaping the frame into a plugged frame.

In one embodiment, the method of preparing a polymer coating on the surface of a wire comprises the steps of:

And dissolving the polymer in the first solvent to obtain a mixed solution, and adding the second solvent into the mixed solution to obtain a mixture. The support frame is immersed in the mixture, then removed from the mixture, cooled to the gel point temperature of the polymer, and roughened at the gel point temperature. And cooling the coarsened supporting frame, and then freeze-drying under vacuum to form a polymer coating on the plurality of wires of the supporting frame, wherein the polymer coating is provided with a plurality of micropores.

Wherein the first solvent and the second solvent are immiscible. In one embodiment, the support frame is immersed in the mixture for a period of 1 to 20 minutes. The roughening time is 1-60 minutes.

The polymer and the soluble substance are dissolved in a first solvent to obtain a mixture. The support frame is immersed in the mixture. The support frame is dried after being removed from the mixture, forming a polymer film on the surface of the filaments. The support frame is contacted with a second solvent to dissolve at least a portion of the soluble material and to insolubilize the polymer, and dried to form a polymer coating having a plurality of micropores thereon.

In one embodiment, the support frame is immersed in the mixture for a period of 1 to 20 minutes.

When it is desired to prepare the polymer coating on the first head and the second head, a method of preparing the polymer coating on the wire may be employed.

Referring to fig. 13, a method for preparing an occluder in another embodiment includes the following steps:

step 210 of providing a frame comprising a plurality of intersecting wires.

Step 220, after mixing the main body material with the soluble substance, preparing the sleeve.

And 230, respectively fixing two ends of the plurality of mutually crossed wires by using two sleeves.

Step 240, contacting at least one of the two sleeves with a solvent to dissolve the soluble substance without dissolving the host material, and forming holes in the sleeve after the soluble substance is dissolved.

Step 250, shaping the frame to form a plugging frame.

The manufacturing method of this embodiment differs from the above embodiment in that the wire is fixed with the sleeve and then the sleeve is perforated. Also, the order of steps 240 and 250 may be replaced.

It will be appreciated that the method of preparation may further comprise the steps of immersing the occluding device in a solution containing the functional substance and drying such that the functional substance is deposited in the pores after drying.

It will also be appreciated that in other embodiments, step 240 may be omitted such that the soluble substance is embedded in the host material, i.e., the holes on the first head and/or the second head are filled with the soluble substance. Before implantation, the first end socket and/or the second end socket are/is contacted with a solvent capable of dissolving the soluble substance, so that at least part of the soluble substance is dissolved, and a hole is formed on the first end socket and/or the second end socket. Or after implantation, at least a portion of the soluble substance dissolves under the impact of the blood flow, thereby exposing the holes in the first and/or second closure head.

Further details are provided below by way of more specific examples.

Example 1

Uniformly mixing poly-L-lactic acid powder and sodium chloride (average particle size is 50 microns) in a mass ratio of 85:15, performing hot melting at 200 ℃ for 20 minutes, cooling to obtain a solid mixture, and spinning the solid mixture to obtain threads. The threads were immersed in deionized water at 37 ℃ for 5 hours to dissolve at least a portion of the sodium chloride, resulting in threads with holes. A group of threads with holes, which are parallel and spaced and have 20 diameters of 0.40mm, are used as longitude threads, and a group of threads with holes, which are parallel and spaced and have 20 diameters of 0.40mm, are used as latitude threads, and the longitude threads and the latitude threads are crossed up and down to form a framework with a lumen structure and two open ends. Uniformly mixing poly-L-lactic acid powder and sodium chloride (average particle size is 80 microns) in a mass ratio of 85:15, carrying out hot melting for 15 minutes at 210 ℃, cooling to obtain a solid mixture, processing the solid mixture into sleeves, soaking the two sleeves in deionized water at 37 ℃ for 2 hours to dissolve at least part of sodium chloride, thereby obtaining two sleeves with hole structures, and respectively taking the two sleeves with holes as threads at two ends of a first seal head and a second seal head fixing frame to seal openings at two ends of the frame. Further, the frame was heat-treated at 87 ℃ for 9 minutes to shape the frame into a plugging frame including a first plugging unit, a second plugging unit and a waist portion, to obtain a plugging device.

Wherein the porosities of the first end socket and the second end socket are 10%, the average pore diameter of the holes is 120 mu m, the porosity of each silk thread is 38%, and the average pore diameter of the holes is 70 mu m.

Example 2

Uniformly mixing poly (racemic lactic acid) powder and iohexol (with an average particle size of 3 microns) in a mass ratio of 55:45, performing hot melting at 170 ℃ for 20 minutes, cooling to obtain a solid mixture, and spinning the solid mixture to obtain a silk thread. The silk thread is soaked in deionized water at 20 ℃ for 3 hours, so that at least part of iohexol is dissolved, and the silk thread with holes is obtained. A group of 30 wires with holes, which are 0.30mm in diameter and are arranged in parallel at intervals, are used as longitude wires, a group of 30 wires with holes, which are 0.30mm in diameter and are arranged in parallel at intervals, are used as latitude wires, and the longitude wires and the latitude wires are staggered up and down to form a framework with a lumen structure and two open ends. The method comprises the steps of mixing poly-L-lactic acid powder and iohexol (with an average particle size of 3 microns) in a mass ratio of 50:50 by a mixed solvent of chloroform/methanol, forming a solid mixture after the solvent is completely volatilized, processing the fixed mixture into sleeves, and respectively fixing wires at two ends of a frame by the two sleeves to close openings at two ends of the frame. The frame was heat treated at 87 ℃ for 16 minutes to set the frame into a plugged frame comprising a first plugging unit, a second plugging unit and a waist. Further, the two sleeves were immersed in deionized water at 37 ℃ for 2 hours to dissolve at least a portion of the iohexol, thereby forming a first head and a second head each having holes.

Wherein the porosities of the first end socket and the second end socket are 38%, the average pore diameter of the holes is 5 mu m, the porosity of each silk thread is 85%, and the average pore diameter of the holes is 5 mu m.

Example 3

Uniformly mixing poly-L-lactic acid powder and polyvinyl alcohol (with average particle size of 250 micrometers) in a mass ratio of 95:5, performing hot melting at 180 ℃ for 15 minutes, cooling to obtain a solid mixture, and spinning the solid mixture to obtain a silk thread. The filaments were immersed in deionized water at 25 ℃ for 4 hours to dissolve at least a portion of the polyvinyl alcohol and obtain filaments with holes. And taking a group of 20 parallel and spaced silk threads with the diameter of 0.40mm as longitude silk threads with holes, and a group of parallel and spaced poly-L-lactic acid silk threads without holes with the diameter of 0.40mm as latitude silk threads, and weaving the longitude silk threads and the latitude silk threads in a staggered manner up and down to form a framework with a lumen structure and two open ends. Uniformly mixing poly-L-lactic acid powder and sodium chloride (average particle size of 25 micrometers) in a mass ratio of 70:30, performing hot melting at 200 ℃ for 15 minutes, cooling to obtain a solid mixture, processing the fixed mixture into sleeves, and respectively fixing wires at two ends of a frame by the two sleeves to close openings at two ends of the frame. The frame was heat treated at 93 ℃ for 9 minutes to set the frame into a plugged frame comprising a first plugged unit, a second plugged unit, and a waist. Further, the two sleeves were immersed in deionized water at 37 ℃ for 1 hour to dissolve at least a portion of the sodium chloride, thereby forming a first head and a second head each having holes.

Wherein the porosities of the first end socket and the second end socket are both 20%, the average pore diameter of the holes is 40 mu m, the porosity of each wire is 20% in the wires with the holes, and the average pore diameter of the holes is 200 mu m.

Example 4

Uniformly mixing poly (racemic lactic acid) powder and iohexol (with the average particle size of 80 microns) in a mass ratio of 60:40, performing hot melting at 90 ℃ for 20 minutes, cooling to obtain a solid mixture, and spinning the solid mixture to obtain the silk thread. The filaments were immersed in deionized water at 37 ℃ for 2 hours to dissolve at least a portion of iohexol and obtain filaments with holes. A group of 30 wires with holes, which are 0.30mm in diameter and are arranged in parallel at intervals, are used as longitude wires, a group of 30 wires with holes, which are 0.30mm in diameter and are arranged in parallel at intervals, are used as latitude wires, and the longitude wires and the latitude wires are staggered up and down to form a framework with a lumen structure and two open ends. The poly-L-lactic acid powder and iohexol (average particle size is 80 microns) are mixed and dissolved in a mixed solvent of chloroform/methanol according to a mass ratio of 50:50, after the solvent is completely volatilized, a solid mixture is formed, the fixed mixture is processed into sleeves, and the two sleeves are respectively used for fixing threads at two ends of the frame so as to close openings at two ends of the frame. The frame was heat treated at 90 ℃ for 15 minutes to set the frame into a plugged frame comprising a first plugged unit, a second plugged unit, and a waist. Further, the two sleeves were immersed in deionized water at 37 ℃ for 1 hour to dissolve at least a portion of the iohexol, thereby forming a first head and a second head each having holes.

Wherein the porosities of the first end socket and the second end socket are both 40%, the average pore diameter of the holes is 200 mu m, the porosity of each silk thread is 15%, and the average pore diameter of the holes is 110 mu m.

Cleaning, packaging and sterilizing the plugging device, soaking in sterile iohexol saturated water solution for 0.5 hour, and drying to deposit iohexol in the holes on the first sealing head, the second sealing head and the wire. This process was repeated 1 time.

Example 5

Commercially available poly (racemic lactic acid) threads were woven to form a frame, which had no holes. And taking a group of poly-racemized lactic acid wires which comprise 20 poly-racemized lactic acid wires with the diameters of 0.40mm and are arranged in parallel at intervals as longitudinal wires and a group of poly-racemized lactic acid wires which comprise 20 poly-racemized lactic acid wires with the diameters of 0.40mm and are arranged in parallel at intervals as latitudinal wires, and interweaving the longitudinal wires and the latitudinal wires up and down to form a framework with a lumen structure and two open ends. Uniformly mixing poly (racemic lactic acid) powder and sodium chloride (average particle size of 40 micrometers) at a mass ratio of 80:20, performing hot melting at 90 ℃ for 20 minutes, cooling to obtain a solid mixture, processing the fixed mixture into sleeves, and respectively fixing wires at two ends of a frame by the two sleeves to close openings at two ends of the frame. The frame was heat treated at 89 ℃ for 13 minutes to set the frame into a plugged frame comprising a first plugging unit, a second plugging unit and a waist.

Preparing a solution containing poly-racemized lactic acid and 1, 4-dioxane (the ratio of the mass of the poly-racemized lactic acid to the volume of the 1, 4-dioxane is 6%), stirring at a constant temperature of 60 ℃ for 3 hours, adding deionized water (the volume of the deionized water accounts for 5% of the volume of the solution of the poly-racemized lactic acid and the 1, 4-dioxane), continuously stirring at a constant temperature of 60 ℃ for 2 hours to obtain a mixture, immersing a plugging frame in the mixture, slowly pulling the plugging frame out of the liquid surface after 9 minutes, cooling to 2 ℃, maintaining for 30 minutes for coarsening, transferring to liquid nitrogen at-196 ℃ for cooling for 1 hour, and finally freeze-drying for 24 hours to form a porous poly-racemized lactic acid coating on the surface of a silk thread.

Further, the two sleeves were immersed in deionized water at 37 ℃ for 6 hours to dissolve at least a portion of the sodium chloride, thereby forming a first head and a second head each having holes.

Wherein the porosities of the first sealing head and the second sealing head are 20%, the average pore diameter of the holes is 50 mu m, the porosities of the porous poly-racemization lactic acid coating are 50%, and the average pore diameter is 44 mu m.

Comparative example 1

Commercially available poly (racemic lactic acid) threads were woven to form a frame, which had no holes. And taking a group of poly-racemized lactic acid wires which comprise 20 poly-racemized lactic acid wires with the diameters of 0.40mm and are arranged in parallel at intervals as longitudinal wires and a group of poly-racemized lactic acid wires which comprise 20 poly-racemized lactic acid wires with the diameters of 0.40mm and are arranged in parallel at intervals as latitudinal wires, and interweaving the longitudinal wires and the latitudinal wires up and down to form a framework with a lumen structure and two open ends. Two poly-racemization lactic acid sleeves are used as the silk threads at the two ends of the first sealing head and the second sealing head fixing frame so as to close the openings at the two ends of the frame. The frame was heat treated at 90 ℃ for 15 minutes to set the frame into a plugging frame comprising a first plugging unit, a second plugging unit and a waist, to obtain a plugging device.

The occluders of example 2 and comparative example 1 were implanted in different eight pigs, respectively, and at 2 months post implantation, the occluder of example 2 had been fully endothelialized, whereas the occluding frame of the occluder of comparative example 1 was only partially covered by endothelial cell membranes, whereas the first and second caps had not been covered by endothelial cell membranes.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. An occluder, comprising an occluding frame and a first head and a second head arranged on the occluding frame, characterized in that the occluding frame comprises a plurality of mutually intersecting silk threads, and the two ends of the plurality of mutually intersecting silk threads are respectively fixed by the first head and the second head, wherein at least one of the first head and the second head has a hole, and when the first head has a hole, the average pore size of the hole of the first head is 5μm to 200μm, and the hole extends from the surface of the first head to the inside of the first head; when the second head has a hole, the average pore size of the hole of the second head is 5μm to 200μm, and the hole extends from the surface of the second head to the inside of the second head; the porosity of the first head and/or the second head is 10% to 40%.

2 . The occluder according to claim 1 , characterized in that at least some of the plurality of mutually intersecting threads have holes, and the holes extend from the surface of the thread to the inside of the thread.

3. The occluder according to claim 2, characterized in that among the plurality of mutually intersecting silk threads, some of the silk threads have holes, and the other silk threads do not have holes, the silk threads without holes are arranged at intervals to form a support frame with gaps, and the silk threads with holes are located in the gaps of the support frame;

Alternatively, a plurality of the wires with holes are used as a first group of wires, and a plurality of the wires without holes are used as a second group of wires, and the first group of wires and the second group of wires are crossed with each other to form the blocking frame;

Alternatively, a plurality of the silk threads with holes form a first woven mesh, and a plurality of the silk threads without holes form a second woven mesh, and the second woven mesh is accommodated in the first woven mesh, so that the blocking frame has a double-layer grid structure.

4. The occluder according to claim 3, characterized in that the ratio of the number of the wires with holes to the number of the wires without holes is 1:2 to 0.5:1, and the ratio of the wire diameters of the wires with holes to the wire diameters of the wires without holes is 1:1 to 2:1.

5 . The occluder according to claim 1 , wherein at least a portion of the surface of the wire is provided with a polymer coating, and the polymer coating has a plurality of micropores.

The occluder according to claim 1 , wherein the holes are filled with soluble substances.

7. A method for preparing an occluder, comprising the following steps:

providing a frame, the frame comprising a plurality of mutually intersecting wires;

After mixing the main material with the soluble substance, the casing is prepared;

The sleeve is contacted with a solvent, so that the soluble substance is dissolved while the main material is not dissolved, and the soluble substance is dissolved to form holes on the sleeve; the average pore size of the holes is 5 μm to 200 μm;

Two sleeves with holes formed therein are used as the first end cap and the second end cap, respectively, or a sleeve without holes and a sleeve with holes are used as the first end cap and the second end cap; and the first end cap and the second end cap are used to fix the two ends of the plurality of mutually crossed wires respectively; the porosity of the first end cap and/or the second end cap is 10% to 40%; and

The frame is shaped to form an occluding frame.

8. The method for preparing an occluder according to claim 7, characterized in that the mass ratio of the main material to the soluble substance is 50-95:50-5.

9. The method for preparing the occluder according to claim 7, characterized in that the method for preparing the silk thread comprises:

After mixing the polymer with a soluble substance, the filament is prepared;

The filament is contacted with a solvent to dissolve the soluble substance but not the polymer, and the soluble substance dissolves to form holes on the filament to obtain the filament; or a polymer coating is formed on the filament to obtain the filament.

10. A method for preparing an occluder, comprising the following steps:

Using the two sleeves to fix the two ends of the plurality of mutually intersecting silk threads respectively;

At least one of the two sleeves is contacted with a solvent, so that the soluble substance is dissolved while the main material is not dissolved, and the soluble substance is dissolved to form holes on the sleeve; the average pore size of the holes is 5 μm to 200 μm, and the porosity is 10% to 40%;

The frame is shaped to form an occluding frame.