Occluder and preparation method thereof

Abstract

The present invention relates to an occluder and a preparation method thereof, the occluder comprising an occluding frame and a first end cap and a second end cap arranged on the occluding frame, the occluding frame comprising 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 end cap and the second end cap, wherein at least one of the first end cap and the second end cap has a hole, when the first end cap has a hole, the hole extends from the surface of the first end cap to the inside of the first end cap; when the second end cap has a hole, the hole extends from the second end cap to the inside of the second end cap. The end cap of the occluder can achieve endothelialization relatively quickly.

Description

Technical Field

[0001] The present invention relates to the field of interventional medical devices, and in particular to an occluder and a preparation method thereof. Background Art

[0002] This section merely provides background information related to the present disclosure and is not necessarily prior art.

[0003] Percutaneous interventional therapy is a rapidly developing disease treatment method in recent years, and the application areas of this therapy are becoming more and more extensive. Among them, the use of transcatheter interventional therapy can place devices and / or drugs into the heart, arteries and veins of the human body. Among them, the device can be a heart occluder, a vascular occluder, a vascular filter, a vascular stent, etc.

[0004] Traditional cardiac occluders or vascular occluders are generally made of elastic shape memory alloys (e.g., nickel-titanium alloys). After release, the device can return to its original shape or close to its original shape and fit well with the tissue at the defect site. However, current shape memory alloy materials are generally non-corrosive or non-degradable in the body. After endothelialization is completed and complete occlusion is achieved, the device made of shape memory alloy material will remain in the body permanently, which may pose long-term clinical risks.

[0005] The occluder made of absorbable polymer materials can be degraded in the body, so that the occluder can be gradually degraded and the degradation products are absorbed by the body without residue in the body, which can avoid long-term clinical risks. However, absorbable polymer materials, such as polylactic acid, have a tight molecular chain structure, which makes it take a long time for biological tissues and occluders to penetrate each other, and the endothelialization time is long. In this way, not only is it longer to achieve complete occlusion, but it is also easy to form thrombi on the surface of the device, and the formed thrombi may fall off the device and cause serious problems such as thromboembolism.

[0006] Existing absorbable occluders usually include an occluding disk formed by braided wires that are woven and shaped, wherein the two free ends of the braided wires are usually gathered and fixed with a head. In order to make the occluder completely absorbable, the material of the head is also an absorbable polymer material, so the head is also difficult to endothelialize. Moreover, experiments have shown that the endothelialization of the head is more difficult and slower than the endothelialization of the braided wire. Since the head is used to gather and fix the braided wires, after the occluder is implanted in the body, before the endothelial cell membrane covers the head and the braided wires and connects the head and the braided wires into one, there is a possibility that the braided wires will break and cause the head to fall off. Once the head falls off, it enters the blood circulation system as a foreign body, creating a great clinical risk. Summary of the invention

[0007] Based on this, it is necessary to provide an occluder whose head can achieve endothelialization more quickly.

[0008] An occluder comprises an occluding frame and a first head and a second head arranged on the occluding frame, wherein 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 hole extends from the surface of the first head to the interior of the first head; when the second head has a hole, the hole extends from the surface of the second head to the interior of the second head.

[0009] In one embodiment, the porosity of the first end cap and / or the second end cap is 10% to 40%.

[0010] In one embodiment, 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.

[0011] In one embodiment, 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;

[0012] 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;

[0013] 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.

[0014] 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 diameters of the wires with holes to the wire diameters of the wires without holes is 1:1 to 2:1.

[0015] In one embodiment, 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.

[0016] In one embodiment, the pores are filled with a soluble substance.

[0017] A method for preparing an occluder comprises the following steps:

[0018] providing a frame, the frame comprising a plurality of mutually intersecting wires;

[0019] After mixing the main material with the soluble substance, the casing is prepared;

[0020] The sleeve is contacted with a solvent to dissolve the first soluble substance while the main material is not dissolved, and the soluble substance is dissolved to form holes on the sleeve;

[0021] 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 silk threads respectively; and

[0022] The frame is shaped to form the occluding frame.

[0023] In one of the embodiments, the mass ratio of the main material to the soluble substance is 50-95:50-5.

[0024] In one embodiment, the method for preparing the silk thread comprises:

[0025] After mixing the polymer with a soluble substance, the filament is prepared;

[0026] 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.

[0027] A method for preparing an occluder comprises the following steps:

[0028] providing a frame, the frame comprising a plurality of mutually intersecting wires;

[0029] After mixing the main material with the soluble substance, the casing is prepared;

[0030] Using the two sleeves to fix the two ends of the plurality of mutually intersecting silk threads respectively;

[0031] contacting at least one of the two sleeves with a solvent, so that the soluble substance is dissolved but the main material is not dissolved, and the soluble substance is dissolved to form holes on the sleeve;

[0032] The frame is shaped to form the occluding frame.

[0033] At least one of the first and second heads of the occluder is provided with holes extending from the surface to the inside, and the holes are conducive to endothelial cells crawling on the surface of the first head and / or the second head, so that endothelialization can be achieved more quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of an occluder according to an embodiment;

[0035] Figure 2 is a schematic cross-sectional view of a first end cover of an embodiment;

[0036] Figure 3 is a schematic cross-sectional view of a second end cap of an embodiment;

[0037] Figure 4 A top view of an embodiment of the invention in which the distal end of the wire is received in the first sealing head and before hot melting;

[0038] Figure 5 A top view of a proximal end of a wire of an embodiment of the present invention is received in a second end cap and before hot melting;

[0039] Figure 6 A schematic diagram of a state in which the locking piece of the occluder of another embodiment is not connected to the second end cap;

[0040] Figure 7 for Figure 6 A schematic diagram showing a state in which the locking piece of the occluder is connected to the second end cap;

[0041] Figure 8 A schematic diagram of a cross-weaving method of silk threads according to an embodiment;

[0042] Fig. 9 is a schematic longitudinal cross-sectional view of a silk thread according to an embodiment;

[0043] Fig.10 A flow chart of a method for preparing an occluder according to an embodiment;

[0044] Fig.11 This is a scanning electron microscope image of a sheet material of a mixture of polylactic acid and iohexol after being immersed in deionized water for 48 hours;

[0045] Fig.12 This is a scanning electron microscope image of the polylactic acid sheet material after being immersed in deionized water for 48 hours;

[0046] Fig.13 FIG. 4 is a flow chart of a method for preparing an occluder in another embodiment. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0049] In the field of interventional medical devices, the “distal end” is defined as the end away from the operator during surgery, and the “proximal end” is defined as the end close to the operator during surgery. “Axial” refers to the direction parallel to the line connecting the distal and proximal centers of the medical device, and “radial” refers to the direction perpendicular to the above axial direction.

[0050] See also Figure 1 , an occluder 100 according to one embodiment includes an occluding frame 20. The occluding frame 20 is a mesh structure formed by a plurality of wires intersecting each other. The material of the wires may be a non-degradable metal, for example, the wires may be nickel-titanium alloy wires, cobalt-chromium alloy wires or stainless steel wires. Alternatively, the material of the wires may also be a biodegradable material. 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), polyglycolic acid (PGA), polylactic acid-glycolic acid copolymer (PLGA), polyhydroxyalkanoic acid ester (PHA), polydioxanone (PDO) and polycaprolactone (PCL).

[0051] In this embodiment, the blocking frame 20 includes a first blocking unit 22, a second blocking unit 24 and a waist 26. The two ends of the waist 26 are respectively connected to the first blocking unit 22 and the second blocking unit 24, forming a two-plate and one-waist structure with large ends and a small middle. The first blocking unit 22, the second blocking unit 24 and the waist 26 are an integrated structure.

[0052] It can be understood that in other embodiments, the structure of the blocking frame 20 is not limited to a two-plate and one-waist structure with large ends and a small middle. For example, when one of the first blocking unit 22 and the second blocking unit 24 is omitted, the first blocking unit 22 or the second blocking unit 24 is connected to the waist 26 to form a blocking frame 20 with a substantially T-shaped cross section.

[0053] Each wire has two free ends. Figure 1The occluder 100 further includes a first end cap 40 disposed on the first occluding unit 22 and a second end cap 60 disposed on the second occluding unit 24. The first end cap 40 and the second end cap 60 are both used to converge and fix the wires. Specifically, the first end cap 40 is used to fix the distal free end of the wires, and the second end cap 60 is used to fix the proximal free end of the wires. In addition, in one embodiment, a movable connection assembly ( Figure 1 The movable connection assembly is used to be movably connected with the delivery system, so that after the occluder 100 is delivered to the lesion, the connection with the occluder 100 can be disconnected to release the occluder 100. Specifically, the second end cap 60 can be provided with threads, multiple strands of wire, etc., which are movably connected with the delivery system.

[0054] In one embodiment, the first end cap 40 and the second end cap 60 are both hollow cylindrical structures. Figure 2 As shown, the first end cap 40 has a receiving cavity 41 inside. Figure 3 As shown, the second end cap 60 has a receiving cavity 61 inside, and the two ends of the wire are respectively received and fixed in the receiving cavity 41 of the first end cap 40 and the receiving cavity 61 of the second end cap 60. In one embodiment, the wire is fixedly connected to the first end cap 40 and the second end cap 60 by hot melting.

[0055] At least one of the first head 40 and the second head 60 has a hole.

[0056] Please continue reading Figure 2 In one embodiment, the first end cap 40 is a hole structure, that is, the first end cap 40 has a plurality of holes 42. Moreover, the holes 42 extend from the surface of the first end cap 40 to the inside of the first end cap 40. The holes 42 do not penetrate the first end cap 40 to maintain the structural integrity of the first end cap 40. That is, the opening end of the hole 42 is located on the outer surface of the first end cap 40. The outer surface refers to the outer peripheral surface.

[0057] In one embodiment, all holes 42 on the first end cap 40 extend from the outer surface of the first end cap 40 to the inside of the first end cap 40 (towards the direction of the receiving cavity 41 close to the first end cap 40), and the holes 42 do not penetrate the first end cap 40. That is, the first end cap 40 does not have holes 42 extending from the inner surface (inner peripheral surface) of the first end cap 40 to the inside of the first end cap 40 (towards the direction away from the receiving cavity 41 of the first end cap 40, that is, the direction away from the outer peripheral surface of the first end cap 40 and the direction away from the inner peripheral surface are both defined as the inside of the first end cap 40). When the occluder 100 is implanted in a biological body, in general, endothelial cells first crawl along the outer surface of the occluder 100 to form an endothelial cell membrane covering the occluder 100. The holes 42 extending from the outer surface to the inside of the first end cap 40 are provided on the first end cap 40, which is conducive to the crawling of endothelial cells. Furthermore, the first end cap 40 does not have a hole 42 extending from the inner surface of the first end cap 40 to the outside of the first end cap 40 , so that the first end cap 40 has sufficient strength.

[0058] like Figure 3 As shown, in one embodiment, the second end cap 60 is a hole structure, that is, the second end cap 60 has a plurality of holes 62. Moreover, the holes 62 extend from the surface of the second end cap 60 to the second end cap 60. The holes 62 do not penetrate the second end cap 60 to maintain the structural integrity of the second end cap 60. That is, the opening end of the hole 62 is located on the outer surface of the second end cap 60. The outer surface refers to the outer peripheral surface.

[0059] In one embodiment, all holes 62 on the second end cap 60 extend from the outer surface of the second end cap 60 to the inside of the second end cap 60 (towards the direction of the receiving cavity 61 close to the second end cap 60), and the holes 62 do not penetrate the second end cap 60. That is, the second end cap 60 does not have holes 62 extending from the inner surface (inner circumference) of the second end cap 60 to the outside of the second end cap 60 (towards the direction away from the receiving cavity 61 of the second end cap 60, that is, the direction away from the outer circumference of the second end cap 60 and the direction away from the inner circumference are both defined as the inside of the second end cap 60). The second end cap 60 is provided with holes 62 extending from the outer surface to the inside of the second end cap 60, which is conducive to the endothelial cell crawling. In addition, the second end cap 60 does not have holes 62 extending from the inner surface of the second end cap 60 to the outside of the second end cap 60, so that the second end cap 60 has sufficient strength.

[0060] In one embodiment, the hole 42 extends from the distal end surface of the first head 40 to the interior of the first head 40, and the hole 42 does not penetrate the first head 40. The hole 62 extends from the proximal end surface of the second head 60 to the interior of the second head 60, and the hole 62 does not penetrate the second head 60. The direction away from the distal end surface or away from the proximal end surface is defined as the interior.

[0061] It should be noted that, under the premise of ensuring the mechanical properties of the first end cap 40, the holes 42 extending from the outer circumference of the first end cap 40 to the inside of the first end cap 40, the holes extending from the inner circumference of the first end cap 40 to the outside of the first end cap 40, and the holes 42 extending from the distal end face of the first end cap 40 to the inside of the first end cap 40 can exist at the same time. Similarly, under the premise of ensuring the mechanical properties of the second end cap 60, the holes 62 extending from the outer circumference of the second end cap 60 to the inside of the second end cap 60, the holes extending from the inner circumference of the second end cap 60 to the outside of the second end cap 60, and the holes 62 extending from the distal end face of the second end cap 60 to the inside of the second end cap 60 can exist at the same time.

[0062] The first head 40 has a plurality of holes 42 and / or the second head 60 has a plurality of holes 62. When the occluder 100 is implanted in the body, the holes 42 facilitate endothelial cells to crawl on the surface of the first head 40, and the holes 62 facilitate endothelial cells to crawl on the surface of the second head 60, thereby achieving endothelialization more quickly.

[0063] See also Figure 4 In one embodiment, the first end cap 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. Figure 5 The second end cap 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, and 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. After hot melting, the distal ends 201 of the wires are melted into one with the first inner sleeve 45 and the first outer sleeve 43, and the proximal ends 202 of the wires are melted into one with the second inner sleeve 65 and the second outer sleeve 63.

[0064] In this way, the connection between the first end cap 40 and the wire and the connection between the second end cap 60 and the wire are more reliable. In addition, the hole 42 on the first end cap 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 the first outer sleeve 43. The hole 62 on the second end cap 60 extends from the outer surface of the second outer sleeve 63 to the inside of the second outer sleeve 63, and the hole 62 does not penetrate the second outer sleeve 63. In this way, the first end cap 40 and the second end cap 60 have the effect of promoting endothelial cell climbing, and the hole 42 and the hole 62 have little effect on the strength of the first end cap 40 and the second end cap 60, respectively.

[0065] When the number of holes 42 on the first end cap 40 is large, it is beneficial for endothelial cells to crawl on the first end cap 40. Similarly, when the number of holes 62 on the second end cap 60 is large, it is beneficial for endothelial cells to crawl on the second end cap 60. However, when the number of holes 42 is too large, the porosity of the first end cap 40 is too large, resulting in a weak connection between the first end cap 40 and the silk thread, and the silk thread is easy to fall off from the first end cap 40. When the number of holes 62 is too large, the second end cap 60 has too many holes, resulting in a weak connection between the second end cap 60 and the silk thread, and the silk thread is easy to fall off from the second end cap 60.

[0066] Therefore, in one embodiment, the porosity of the first end cap 40 is 10% to 40%, so as to take into account both the endothelial creeping and the connection strength between the first end cap 40 and the wire. In one embodiment, the porosity of the second end cap 60 is 10% to 40%, so as to take into account both the endothelial creeping and the connection strength between the second end cap 60 and the wire.

[0067] It should be noted that the porosity refers to the percentage of the opening area of ​​the hole on the head surface to the surface area of ​​the head. For example, when the first head 40 is a hollow cylinder, the porosity of the first head 40 refers to the percentage of the opening area of ​​the hole 42 on the side of the cylinder to the area of ​​the side of the cylinder. When the second head 60 is a hollow cylinder, the porosity of the second head 60 refers to the percentage of the opening area of ​​the hole 62 on the side of the cylinder to the area of ​​the side of the cylinder. The area of ​​the side of the first head 40 and the second head 60 can be obtained by calculation, and the opening area of ​​the hole 42 and the opening area of ​​the hole 62 can be measured by a microscope.

[0068] In one embodiment, the first head 40 has a hole 42 and the second head 60 has a hole 62, which facilitates the endothelial cells to crawl on the first head 40 and the second head 60, so that the first head 40 and the second head 60 are covered by the endothelial cell membrane more quickly.

[0069] Since the second end cap 60 is connected to the conveying system during the conveying process, the second end cap 60 should have sufficient mechanical strength to ensure the reliability of the connection. Therefore, in one embodiment, the porosity of the second end cap 60 is smaller than that of the first end cap 40, so that the first end cap 40 itself has a better endothelialization promoting effect, and the endothelialization promoting effect and mechanical strength of the second end cap 60 itself are taken into account.

[0070] In one embodiment, if Figure 6 and Figure 7As shown, the occluder 100 also includes a locking member 80. The locking member 80 extends axially in the occluding frame 20, and one end of the locking member 80 is fixedly connected to the first end cap 40, and the other end is detachably connected to the second end cap 60. When the locking member 80 is connected to the second end cap 60, the axial distance between the first occluding unit 22 and the second occluding unit 24 of the occluding frame 20 is fixed, so that the occluder 100 can reliably occlude the defect. Therefore, the second end cap 60 is not only connected to the conveying system, but also serves as an element that carries the locking member 80. When the locking member 80 is connected to the second end cap 60, the second end cap 60 is subjected to the continuous force of the locking member 80. In order to ensure the reliable connection between the locking member 80 and the second end cap 60, the second end cap 60 should have sufficient strength. Therefore, in one embodiment, the porosity of the second end cap 60 is 10% to 30%, so as to take into account the effect of endothelial cell crawling and reliable connection with the locking member 80 and the conveying device.

[0071] In one embodiment, the average pore size of the plurality of holes 42 of the first head 40 is 5 μm to 200 μm, and the average pore size of the plurality of holes 62 of the second head 60 is 5 μm to 200 μm, so that the first head 40 and the second head 50 have sufficient mechanical strength.

[0072] In one embodiment, the material of the first end cap 40 and the second end cap 60 is a degradable polymer. In one embodiment, the material of the first end cap 40 and the second end cap 60 is selected from at least one of poly(d-lactic acid) (PDLLA), poly(D-lactic acid) (PDLA), poly(L-lactic acid) (PLLA), poly(glycolic acid) (PGA), poly(lactic acid-co-glycolic acid) (PLGA), poly(hydroxyalkanoate) (PHA), polydioxanone (PDO) and polycaprolactone (PCL).

[0073] The materials of the first end cap 40 and the second end cap 60 may be the same or different.

[0074] The materials of the first seal 40 , the second seal 60 and the wire may be the same or different.

[0075] In one embodiment, at least some of the multiple intersecting threads have holes, and the holes extend from the outer surface of the threads to the inner surface of the threads. In addition, the holes do not penetrate the threads, so as to keep the threads continuous and avoid thread breakage. Figure 8 As shown, the wire with holes is marked as 210, and the wire without holes is marked as 220. The hole is marked as 212. The corresponding marking symbols are continued below, without limitation to whether the wire 210 and the wire 220 are in accordance with Figure 8 Braid in the manner shown.

[0076] Some of the threads 210 have holes 212, which are conducive to the endothelial cells crawling on the surface of the occluding frame 20 and quickly promoting endothelialization.

[0077] In one embodiment, among the multiple intersecting silk threads, a part of the silk threads 210 has holes 212, and another part of the silk threads 220 does not have holes 212. The silk threads 220 without holes 212 are arranged at intervals to form a support frame with gaps, and the silk threads 210 with holes 212 are located in the gaps of the support frame. When the wire diameters are consistent, the mechanical properties of the silk threads 220 without holes 212 are better than those of the silk threads 210 with holes 212. The silk threads 220 without holes 212 with better mechanical properties are formed into a support frame, and the silk threads 210 with holes 212 that are conducive to promoting endothelialization are filled in the gaps of the support frame to take into account both the mechanical properties of the blocking frame 20 and the effect of promoting endothelialization.

[0078] Please refer again Figure 8 In one embodiment, a plurality of silk threads 210 with holes 212 are used as the first group of silk threads, and a plurality of silk threads 220 without holes 212 are used as the second group of silk threads. In the first group of silk threads, a plurality of silk threads 210 with holes 212 are arranged in parallel and at intervals. In the second group of silk threads, a plurality of silk threads 220 with holes 212 are arranged in parallel and at intervals. The first group of silk threads and the second group of silk threads are cross-woven and shaped in a one-press-one and up-and-down cross-woven manner to form a blocking frame 20. In this way, the silk threads 210 with holes 212 and the silk threads 220 without holes 212 are evenly distributed in the blocking frame 20, so that the blocking frame 20 has sufficient mechanical properties, and endothelial cells can easily crawl on the blocking frame 20.

[0079] In one embodiment, a plurality of silk threads 210 with holes 212 are woven to form a first woven mesh, and a plurality of silk threads 220 without holes 212 are woven to form a second woven mesh, and the second woven mesh is contained inside the first woven mesh, and after shaping, a double-layer mesh structure blocking frame 20 is obtained. The double-layer mesh structure blocking frame 20 has good mechanical support performance, and the first woven mesh is located outside, and the hole structure of the first woven mesh is conducive to endothelial cells climbing on the blocking frame 20.

[0080] In one embodiment, the ratio of the number of the wires 210 with holes 212 to the number of the wires 220 without holes 212 is 1:2 to 0.5:1, and the ratio of the wire diameters of the wires 210 with holes 212 to the wire diameters of the wires 220 without holes 212 is 1:1 to 2:1, so that the blocking frame 20 has sufficient mechanical properties and endothelial cells can easily crawl on the blocking frame 20.

[0081] In one embodiment, the average diameter of the holes of the wire 210 having the holes 212 is 5-500 micrometers.

[0082] In one embodiment, at least one of the first end cap 40, the second end cap 60, and the wire 210 having the hole 212 is filled with a soluble substance. For example, the hole 42 on the first end cap 40 is filled with a soluble substance, the hole 62 on the second end cap 60 is filled with a soluble substance, and the hole 212 of the wire 210 is filled with a soluble substance.

[0083] The soluble substance can be dissolved in media such as blood, physiological saline, water, organic solvents, inorganic solvents, etc. When the occluder 100 is implanted in the body, the soluble substance dissolves to present a pore structure, thereby achieving the effect of promoting endothelial cell attachment.

[0084] The soluble substance is different from the material of the first head 40, the second head 60 and the thread 210, and should have different solubility characteristics, so that in a specific solvent, such as water, blood, etc., the soluble substance can be dissolved while the first head 40, the second head 60 and the thread 210 are not dissolved.

[0085] In one embodiment, the material of the first end cap 40 and the second end cap 60 is poly-L-lactic acid, the material of the soluble substance is poly-racemic lactic acid, and the solvent is acetone. Poly-racemic lactic acid is dissolved in acetone, while poly-L-lactic acid is insoluble in acetone, so that holes are formed on the first end cap 40 and the second end cap 60. After the tetrahydrofuran is fully volatilized, the obtained sample is cleaned to avoid solvent residue.

[0086] 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, polyvinyl pyrrolidone or polyethylene glycol.

[0087] In one embodiment, the soluble substance is a functional substance, for example, including but not limited to, a polypeptide, a protein, a drug, etc.

[0088] In one embodiment, the soluble substance is a substance that can be developed. The substance that can be developed is filled in the hole 212 of the wire 210, the first head 40 and / or the second head 60, so that during the implantation process, the substance that can be developed can indicate the shape and position of the occluder 100, so that the implantation proceeds smoothly. Therefore, the occluder 100 does not need to be additionally provided with a metal marker to indicate the shape and position of the occluder 100, and can be completely degraded to avoid metal markers remaining in the body.

[0089] In one embodiment, the plurality of intersecting threads in the blocking frame 20 do not have holes 212. Fig. 9As shown, at least a portion of the surface of the thread 220 is provided with a polymer coating 222. The polymer coating 222 is a porous structure having a plurality of micropores 2222. The porous structure is conducive to the crawling of endothelial cells on the thread 220.

[0090] 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 plays a supporting role, so the pore size and porosity of the polymer coating 222 can be relatively large to improve the endothelial-promoting effect.

[0091] It should be noted that the porosity here refers to the percentage of the opening area of ​​the micropores 2222 on the outer surface of the polymer coating 222 to the area of ​​the outer surface of the polymer coating 222. The opening area of ​​the micropores 2222 and the area of ​​the outer surface of the polymer coating 222 can be measured by a microscope.

[0092] 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(d-lactic acid) (PDLLA), poly(D-lactic acid) (PDLA), poly(L-lactic acid) (PLLA), poly(glycolic acid) (PGA), poly(lactic acid-co-glycolic acid) (PLGA), poly(hydroxyalkanoate) (PHA), polydioxanone (PDO), and polycaprolactone (PCL).

[0093] Furthermore, in one embodiment, a method for preparing an occluder is provided, such as Fig.10 As shown, the following steps are included:

[0094] Step 110: Provide a frame, wherein the frame includes a plurality of wires intersecting each other.

[0095] In one embodiment, a plurality of silk threads are cross-woven to form a tubular cavity frame with two ends open.

[0096] The plurality of threads all have holes. Alternatively, some threads have holes and the other threads do not have holes. The distribution of threads with holes and threads without holes can be as described above, which will not be repeated here. Alternatively, the plurality of threads do not have holes.

[0097] In one embodiment, the method for preparing the silk thread comprises the following steps:

[0098] After mixing the polymer with the soluble substance, the filament is prepared. When the filament is not required to have holes, the obtained filament is a filament.

[0099] When preparing a wire with holes, the wire material is contacted with a solvent to dissolve the soluble substance but not the polymer, thereby obtaining the wire with holes.

[0100] In one embodiment, the polymer and the soluble substance are mixed evenly, melted, cooled to form a solid mixture, and then the solid mixture is processed to form a thread without holes. The solid mixture can be processed into a thread without holes by spinning, extrusion, pulling, etc. When this method is used, the melting point of the soluble substance is higher than the melting point of the polymer. At the hot melting temperature, the polymer melts but the soluble substance does not melt. Please return to Figure 2 and Figure 3 After hot melting, the soluble substance 50 exists in the form of particles. For example, in one embodiment, the polymer is polylactic acid, and the soluble substance 50 is sodium chloride with a relatively high melting point.

[0101] In one implementation, the polymer and the soluble substance are dissolved in a solvent, and then allowed to stand for the solvent to evaporate, and after the solvent fully evaporates, a solid mixture is formed. Then, the solid mixture is processed to form a thread without holes.

[0102] If the selected polymer and soluble substance can be dissolved in the same solvent, the polymer and the soluble substance are dissolved in the same solvent. If the solubility of the selected polymer and the soluble substance in the same solvent is greatly different, the polymer is dissolved in a first solvent to obtain a first solution, and the soluble substance is dissolved in a second solvent to obtain a second solution, and the first solution and the second solution are mixed, and then allowed to stand for the solvent to evaporate. After the two solvents are fully evaporated, a solid mixture is formed. Alternatively, the polymer and the soluble substance are added to a mixed solvent of the first solvent and the second solvent at the same time, and the mixture is fully stirred to dissolve the polymer and the soluble substance.

[0103] It is understood that the amount of solvent is sufficient to completely dissolve the polymer and the soluble substance, and excessive solvent should not be used to avoid the solvent evaporating for too long.

[0104] In one embodiment, the average particle size of the soluble substance is 3-250 micrometers, so that the average pore size of the prepared silk thread is 5-500 micrometers.

[0105] In one embodiment, after preparing the wires with holes, the wires with holes are cross-woven to obtain a frame.

[0106] In one embodiment, after preparing the silk thread without holes, the silk thread without holes is cross-woven to form a frame, and then the soluble substance is dissolved to form holes on the silk thread. For example, the operation of dissolving the soluble substance can be performed after the frame is formed. The soluble substance can also be dissolved before the occluder is implanted. The occluder can also be directly implanted in the body, and the soluble substance dissolves under the impact of blood to form holes on the silk thread.

[0107] Dissolve 0.5g of iohexol powder in 5mL of methanol and stir until clear. Dissolve 1g of polylactic acid in 10mL of chloroform and slowly mix the two while stirring. Then let stand until the solvent evaporates to obtain a mixed sheet material. Soak the mixed sheet material in deionized water at 37°C for 48 hours and observe the surface morphology under a scanning electron microscope after drying. Fig.11 As shown, the surface of the mixed sheet material has an obvious pore structure. This is because polylactic acid is insoluble in deionized water, while iohexol is dissolved in deionized water, releasing the space originally occupied by iohexol, thereby forming a pore structure.

[0108] After 1g of polylactic acid was dissolved in 10mL of chloroform, the solvent was allowed to stand for a long time until it evaporated to obtain a sheet of polylactic acid with a smooth surface. The sheet of polylactic acid was soaked in deionized water at 37°C for 48 hours, and the surface morphology was observed under a scanning electron microscope after drying. Fig.12 As shown, the surface of the sheet-like polylactic acid after soaking is smooth without wrinkles or holes.

[0109] contrast Fig.11 and Fig.12 It can be seen intuitively that by introducing a soluble substance, and then utilizing the difference in solubility between the soluble substance and the polymer in a specific solvent to dissolve at least part of the soluble substance while the polymer does not dissolve, a pore structure is formed.

[0110] In one embodiment, the mass ratio of polymer to soluble substance is 50-95:50-5, so that the porosity of the thread is 20%-50%, which not only meets the requirements of mechanical properties but also has the effect of promoting endothelialization.

[0111] In one embodiment, a frame can be formed by 3D printing, and the wires of the frame are connected to each other in an integrated structure, which is different from the frame formed by weaving, in which the connection relationship or position relationship between the wires is overlapped. The wires in the frame formed by 3D printing can be pure polymer wires, or polymer wires embedded with soluble particles. When it is a polymer wire embedded with soluble particles, after the frame is prepared, the frame can be contacted with a solvent that can dissolve the soluble particles but not the polymer, so that at least part of the soluble particles are dissolved and the polymer is not dissolved, thereby forming a wire with holes.

[0112] Step 120: After mixing the main material with the soluble substance, a sleeve is prepared.

[0113] The main body material is the material of the first end cap and the second end cap. The main body material and the material of the wire can be the same or different.

[0114] When the materials of the first end cap and the second end cap are different, different main body materials are selected respectively to prepare sleeves made of different materials.

[0115] The soluble substances are the same as those described above and will not be described in detail here.

[0116] The main material and the soluble substance are mixed evenly to obtain a mixture, and a solid mixture is prepared by hot melting or solvent mixing, and then the sleeve is prepared by extrusion, spinning, or 3D printing. The hot melting and solvent mixing methods are the same as those described in the method for preparing the silk thread above, and will not be repeated here.

[0117] Step 130: The sleeve is contacted with a solvent to dissolve the soluble substance while the main material does not dissolve. After the soluble substance dissolves, holes are formed on the sleeve.

[0118] For example, the sleeve is immersed in a solvent so that the soluble substance dissolves and the space originally occupied by the soluble substance is released, thereby forming holes.

[0119] In one embodiment, when it is desired that the pores extend only from the outer surface of the sleeve to the inner surface of the sleeve, the inner surface of the sleeve should be prevented from contacting with the solvent to prevent the soluble material particles near the inner surface from being dissolved by the solvent. For example, the outer surface of the sleeve is repeatedly wiped with a solvent to prevent the inner surface from contacting with the solvent. Alternatively, after protecting the inner surface (inserting a protective plug into the inner cavity of the sleeve to shield the inner surface), the sleeve is immersed in the solvent.

[0120] Step 140: Use two sleeves with holes as the first head and the second head respectively, or use a sleeve without holes and a sleeve with holes as the first head and the second head respectively; and use the first head and the second head to fix the two ends of multiple crossed silk threads respectively.

[0121] The first end cap and the second end cap are fixed to the two ends of the plurality of mutually intersecting wires, wherein the first end cap converges and fixes one end, and the second end cap converges and fixes the other end. In one embodiment, the first end cap and the wires and the second end cap and the wires are respectively fixed by hot melting.

[0122] In one embodiment, when the first end cap is 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.

[0123] In one embodiment, when the second end cap is 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.

[0124] Step 150: shaping the frame into a blocking frame.

[0125] The frame is shaped into a desired structure, namely the blocking frame 20 .

[0126] In one embodiment, the frame is heat treated at 87-93° C. for 9-16 minutes to shape the frame into the blocking frame 20 .

[0127] The first and / or second heads of the occluder prepared by the above-mentioned preparation method of the occluder have holes, which are conducive to endothelial cell crawling, can achieve endothelialization faster, and are conducive to accelerating endothelialization. After implantation, the occluder can be quickly covered by the endothelial cell membrane, and complete occlusion can be achieved faster, with good treatment effect. In addition, it is conducive to preventing the first and / or second heads from falling off, and improving the safety of use.

[0128] In one embodiment, the occluder is further immersed in a solution containing a functional substance and dried, so that the functional substance is deposited in the hole after drying. After implantation, the functional substance dissolves in the blood and exerts a corresponding effect.

[0129] In one embodiment, the functional substance is a substance that can be developed. Since at least one of the first end cap and the second end cap and the wire have holes, the substance that can be developed is easily attached to one of the first end cap and the second end cap and the wire, and deposited in the holes, so that the prepared occluder itself has the characteristic of being able to be developed under medical imaging equipment.

[0130] In this way, a substance capable of developing is introduced onto the surface of the occluder 100 . After the implantation, the substance capable of developing is gradually dissolved under the impact of blood without causing adverse effects on the structure and mechanical properties of the occluder 100 itself.

[0131] In one embodiment, when the wires of the frame are wires without holes, after the frame is formed into a blocking frame, a step of preparing a polymer coating on the surface of the wires is further included.

[0132] In one embodiment, the method for preparing a polymer coating on the surface of a silk thread comprises the following steps:

[0133] A polymer is dissolved in a first solvent to obtain a mixed solution, and a second solvent is added to the mixed solution to obtain a mixture. A support frame is immersed in the mixture, and then the support frame is taken out of the mixture, cooled to the gel point temperature of the polymer, and roughened at the gel point temperature. The roughened support frame is cooled, and then freeze-dried under vacuum to form a polymer coating on multiple wires of the support frame, and the polymer coating has multiple micropores.

[0134] The first solvent and the second solvent are immiscible. In one embodiment, the supporting frame is immersed in the mixture for 1 to 20 minutes. The roughening is performed for 1 to 60 minutes.

[0135] In one embodiment, the method for preparing a polymer coating on the surface of a silk thread comprises the following steps:

[0136] 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 taken out of the mixture and dried to form a polymer film on the surface of the silk thread. The support frame is contacted with a second solvent to dissolve at least part of the soluble substance while the polymer is not dissolved, and a polymer coating is formed after drying, wherein the polymer coating has a plurality of micropores.

[0137] In one embodiment, the supporting frame is immersed in the mixture for 1 to 20 minutes.

[0138] When it is necessary to prepare a polymer coating on the first end cap and the second end cap, a method for preparing a polymer coating on a wire may be used.

[0139] See also Fig.13 , a method for preparing an occluder according to another embodiment comprises the following steps:

[0140] Step 210: Provide a frame, wherein the frame includes a plurality of wires intersecting each other.

[0141] Step 220: After mixing the main material with the soluble substance, a sleeve is prepared.

[0142] Step 230: Use two sleeves to fix the two ends of the multiple intersecting silk threads respectively.

[0143] Step 240: at least one of the two sleeves is contacted with a solvent to dissolve the soluble substance while the main material does not dissolve, and the soluble substance dissolves to form holes on the sleeve.

[0144] Step 250: shaping the frame into a blocking frame.

[0145] The difference between the preparation method of this embodiment and the above-mentioned embodiment is that in this embodiment, the wire is first fixed with a sleeve, and then the sleeve is formed into a hole. In addition, the order of step 240 and step 250 can be replaced.

[0146] It is understandable that the preparation method may further include the steps of immersing the occluder in a solution containing the functional substance and drying the solution, so that the functional substance is deposited in the pores after drying.

[0147] It can also be understood that in other embodiments, step 240 can be omitted, so that the soluble substance is embedded in the main body material, that is, the holes on the first head and / or the second head are filled with the soluble substance. Before implantation, the first head and / or the second head are contacted with a solvent capable of dissolving the soluble substance, so that at least part of the soluble substance is dissolved, thereby forming holes on the first head and / or the second head. Alternatively, after implantation, under the impact of blood flow, at least part of the soluble substance is dissolved, thereby exposing the holes on the first head and / or the second head.

[0148] The invention is further described below through more specific embodiments.

[0149] Example 1

[0150] After the poly-L-lactic acid powder and sodium chloride (average particle size of 50 microns) are mixed uniformly at a mass ratio of 85:15, they are heat-melted at 200°C for 20 minutes, cooled to obtain a solid mixture, and the solid mixture is spun to obtain a silk thread. The silk thread is soaked in deionized water at 37°C for 5 hours to dissolve at least part of the sodium chloride to obtain a silk thread with holes. A group of 20 silk threads with holes arranged in parallel and at intervals with a diameter of 0.40 mm is used as a longitude silk thread and a group of 20 silk threads with holes arranged in parallel and at intervals with a diameter of 0.40 mm is used as a latitude silk thread. The longitude silk threads and the latitude silk threads are cross-woven up and down to form a tubular structure with an open frame at both ends. After the poly-L-lactic acid powder and sodium chloride (average particle size of 80 microns) were mixed uniformly at a mass ratio of 85:15, they were heat-melted at 210°C for 15 minutes, and a solid mixture was obtained after cooling. The solid mixture was processed into a sleeve, and the two sleeves were immersed in deionized water at 37°C for 2 hours to dissolve at least a portion of the sodium chloride, thereby obtaining two sleeves with a hole structure. The two sleeves with holes were used as the first head and the second head to fix the wires at both ends of the frame to close the openings at both ends of the frame. Further, the frame was heat-treated at 87°C for 9 minutes to shape the frame into a blocking frame including a first blocking unit, a second blocking unit and a waist, and an occluder was obtained.

[0151] The porosity of the first end cap and the second end cap are both 10%, and the average pore size of the holes is 120 μm; the porosity of each wire is 38%, and the average pore size of the holes is 70 μm.

[0152] Example 2

[0153] After the polyracemic lactic acid powder and iohexol (average particle size of 3 microns) are mixed uniformly at a mass ratio of 55:45, they are heat-melted at 170°C for 20 minutes, cooled to obtain a solid mixture, and the solid mixture is spun to obtain a silk thread. The silk thread is soaked in deionized water at 20°C for 3 hours to dissolve at least part of the iohexol to obtain a silk thread with holes. A group of 30 silk threads with holes and a diameter of 0.30 mm, arranged in parallel and at intervals, are used as longitude silk threads and a group of 30 silk threads with holes and a diameter of 0.30 mm, arranged in parallel and at intervals, are used as latitude silk threads. The longitude silk threads and the latitude silk threads are interlaced and woven up and down to form a tubular structure with open ends. Poly-L-lactic acid powder and iohexol (average particle size of 3 microns) are mixed in a 50:50 mass ratio through a mixed solvent of chloroform / methanol. After the solvent is completely volatilized, a solid mixture is formed, and then the fixed mixture is processed into a sleeve, and the two sleeves are fixed to the silk threads at both ends of the frame to close the openings at both ends of the frame. The frame is heat treated at 87°C for 16 minutes to shape the frame into a sealing frame including a first sealing unit, a second sealing unit and a waist. Further, the two sleeves are soaked in deionized water at 37°C for 2 hours to dissolve at least part of the iohexol, thereby forming a first head and a second head both having holes.

[0154] The porosity of the first end cap and the second end cap are both 38%, the average pore size of the holes is 5 μm, the porosity of each wire is 85%, and the average pore size of the holes is 5 μm.

[0155] Example 3

[0156] After the poly-L-lactic acid powder and polyvinyl alcohol (average particle size of 250 microns) are mixed uniformly at a mass ratio of 95:5, they are heat-melted at 180°C for 15 minutes, cooled to obtain a solid mixture, and the solid mixture is spun to obtain a silk thread. The silk thread is soaked in deionized water at 25°C for 4 hours to dissolve at least part of the polyvinyl alcohol to obtain a silk thread with holes. A group of 20 silk threads with a diameter of 0.40 mm, arranged in parallel and at intervals, are used as longitude silk threads with holes and a group of 20 poly-L-lactic acid silk threads with a diameter of 0.40 mm, arranged in parallel and at intervals without holes are used as latitude silk threads. The longitude silk threads and the latitude silk threads are interlaced and woven up and down to form a tubular structure with open ends. After mixing poly-L-lactic acid powder and sodium chloride (average particle size of 25 microns) in a mass ratio of 70:30, heat-melt at 200°C for 15 minutes, cool to obtain a solid mixture, and then process the fixed mixture into a sleeve, and fix the two sleeves to the wires at both ends of the frame to close the openings at both ends of the frame. The frame was heat-treated at 93°C for 9 minutes to shape the frame into a sealing frame including a first sealing unit, a second sealing unit and a waist. Further, the two sleeves were immersed in deionized water at 37°C for 1 hour to dissolve at least part of the sodium chloride, thereby forming a first head and a second head both having holes.

[0157] The porosity of the first end cap and the second end cap are both 20%, and the average pore size of the holes is 40 μm. In the wires with holes, the porosity of each wire is 20%, and the average pore size of the holes is 200 μm.

[0158] Example 4

[0159] After the polyracemic lactic acid powder and iohexol (average particle size of 80 microns) are uniformly mixed at a mass ratio of 60:40, they are heat-melted at 90°C for 20 minutes, cooled to obtain a solid mixture, and the solid mixture is spun to obtain a silk thread. The silk thread is soaked in deionized water at 37°C for 2 hours to dissolve at least part of the iohexol to obtain a silk thread with holes. A group of 30 silk threads with holes arranged in parallel and at intervals with a diameter of 0.30 mm is used as a longitude silk thread and a group of 30 silk threads with holes arranged in parallel and at intervals with a diameter of 0.30 mm is used as a latitude silk thread, and the longitude silk threads and the latitude silk threads are interlaced and woven up and down to form a tubular structure with an open frame at both ends. Poly-L-lactic acid powder and iohexol (average particle size of 80 microns) are mixed in a 50:50 mass ratio through a mixed solvent of chloroform / methanol. After the solvent is completely volatilized, a solid mixture is formed, and then the fixed mixture is processed into a sleeve, and the two sleeves are fixed to the silk threads at both ends of the frame to close the openings at both ends of the frame. The frame is heat treated at 90°C for 15 minutes to shape the frame into a sealing frame including a first sealing unit, a second sealing unit and a waist. Further, the two sleeves are soaked in deionized water at 37°C for 1 hour to dissolve at least part of the iohexol, thereby forming a first head and a second head both having holes.

[0160] The porosity of the first end cap and the second end cap are both 40%, and the average pore size of the holes is 200 μm; the porosity of each wire is 15%, and the average pore size of the holes is 110 μm.

[0161] After cleaning, packaging and sterilization, the occluder was immersed in a sterile saturated aqueous solution of iohexol for 0.5 hours, and after drying, iohexol was deposited in the holes on the first occluder, the second occluder and the silk thread. This process was repeated once.

[0162] Example 5

[0163] The commercially available polyracemic lactic acid threads are woven to form a frame, and the polyracemic lactic acid threads do not have holes. A group of 20 polyracemic lactic acid threads with a wire diameter of 0.40 mm, arranged in parallel and at intervals, are used as longitude threads and a group of 20 polyracemic lactic acid threads with a wire diameter of 0.40 mm, arranged in parallel and at intervals, are used as latitude threads. The longitude threads and latitude threads are interlaced and woven up and down to form a tubular structure with open ends. After polyracemic lactic acid powder and sodium chloride (average particle size of 40 microns) are mixed evenly at a mass ratio of 80:20, they are hot-melted at 90°C for 20 minutes, cooled to obtain a solid mixture, and then the fixed mixture is processed into a sleeve, and the two sleeves are respectively fixed to the threads at both ends of the frame to close the openings at both ends of the frame. The frame is heat-treated at 89°C for 13 minutes to shape the frame into a sealing frame including a first blocking unit, a second blocking unit and a waist.

[0164] A solution containing polyracemic lactic acid and 1,4-dioxane (the ratio of the mass of polyracemic lactic acid to the volume of 1,4-dioxane is 6%) is prepared, and after constant temperature stirring at 60°C for 3 hours, deionized water is added (the volume of deionized water accounts for 5% of the volume of the solution of polyracemic lactic acid and 1,4-dioxane), and constant temperature stirring at 60°C is continued for 2 hours to obtain a mixture, and then the blocking frame is immersed in the mixture. After 9 minutes, the blocking frame is slowly pulled out of the liquid surface, cooled to 2°C, kept for 30 minutes for coarsening, and then transferred to liquid nitrogen at -196°C for cooling for 1 hour, and finally freeze-dried for 24 hours to form a porous polyracemic lactic acid coating on the surface of the silk thread.

[0165] Furthermore, the two sleeves were immersed in deionized water at 37° C. for 6 hours to dissolve at least a portion of the sodium chloride, thereby forming a first sealing head and a second sealing head both having holes.

[0166] The porosity of the first end cap and the second end cap are both 20%, and the average pore size of the holes is 50 μm. The porosity of the porous polyracemic lactic acid coating is 50%, and the average pore size is 44 μm.

[0167] Comparative Example 1

[0168] The commercially available poly(lactic acid) threads are woven to form a frame, and the poly(lactic acid) threads do not have holes. A group of 20 poly(lactic acid) threads with a wire diameter of 0.40 mm, arranged in parallel and at intervals, are used as longitude threads and a group of 20 poly(lactic acid) threads with a wire diameter of 0.40 mm, arranged in parallel and at intervals, are used as latitude threads. The longitude threads and the latitude threads are woven up and down to form a tubular structure with open ends. Two poly(lactic acid) sleeves are used as the first and second heads to fix the threads at both ends of the frame to close the openings at both ends of the frame. The frame is heat treated at 90°C for 15 minutes to shape the frame into a blocking frame including a first blocking unit, a second blocking unit and a waist, and an occluder is obtained.

[0169] The occluders of Example 2 and Comparative Example 1 were implanted in different Bama pigs, respectively. Two months after implantation, the occluder of Example 2 had been completely endothelialized, while the occluding frame of the occluder of Comparative Example 1 was only partially covered by the endothelial cell membrane, while the first head and the second head were not yet covered by the endothelial cell membrane.

[0170] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0171] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An occluder, comprising an occluding frame and a first occluding head and a second occluding head arranged on the occluding frame, characterized in that: The sealing frame includes a plurality of mutually intersecting wires, and the two ends of the plurality of mutually intersecting wires 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 interior 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 interior 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, characterized in that: A polymer coating is disposed on at least a portion of the surface of the wire, and the polymer coating has a plurality of micropores.

6. The occluder according to claim 1, characterized in that: 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 the 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 preparation method of 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: 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; 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.

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