A method for manufacturing a closure structure

Abstract

The application relates to a manufacturing method of a plugging structure, comprising the following steps: S100, acquiring PDO wires, a cylindrical base block and a PLLA flow resistance film; S200, weaving the PDO wires around the outer side of the cylindrical base block and integrally wrapping the whole cylindrical base block to form a first assembly; S300, immersing the first assembly into isopropyl alcohol to perform ultrasonic cleaning to obtain a cleaned assembly; S400, performing photoetching on at least one end surface of the cleaned assembly to obtain a second assembly; S500, dismounting the cylindrical base block on the second assembly to obtain a woven fabric; S600, performing heat setting on the woven plugging device to obtain a woven plugging device; and S700, sewing the PLLA flow resistance film to the inside of the woven fabric. The plugging structure is provided with super-hydrophilic structures on the side in contact with blood, so that thrombus is avoided from being formed on the plugging structure.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically to a method for manufacturing a sealing structure. Background Technology

[0002] Traditional metal occluders have smooth surfaces, resulting in slow endothelialization (typically 3-6 months) and a long-term risk of thrombosis. Biodegradable occluders, compared to traditional metal occluders, shorten the endothelialization time to some extent (typically 1-3 months). However, cardiac implantable devices immediately affect hemodynamics within the heart after implantation, subsequently influencing thrombus formation on the device surface and the endothelialization process. In recent years, research into anticoagulation and endothelialization has focused on several directions: First, optimizing device design to reduce post-implantation surface area and better conform to surrounding tissue structures; second, using biocompatible and biodegradable polymers to provide a supportive path for cell climbing during the endothelialization stage, with no residue in long-term degradation; third, surface modification of device or cholinergic membrane materials, such as fluorinated coatings (PTFE) cholinergic membranes, drug-impregnated coatings, or bioactive coatings (heparin, albumin, phosphorylcholine). Current surface modifications and coatings can reduce platelet activation and inflammatory responses to some extent, but existing coating technologies (such as heparin coatings) lack durability and are prone to detachment in the early stages of implantation. They cannot provide a sustained endothelialization-promoting coating, and their long-term effects are unclear. Furthermore, the effects of drug-coated coatings are not entirely controllable for different patients and are influenced by the patient's blood environment. Therefore, there is still a need in the field for biodegradable cardiac occluders with long-term anticoagulation and more stable endothelialization-promoting functions. Summary of the Invention

[0003] In view of this, the present invention provides a method for manufacturing a sealing structure, wherein a first tooth structure of a first preset array is formed on the target end face of the prepared sealing structure, so that a super-slippery and super-hydrophilic structure is formed on the side of the sealing structure that is in contact with blood, thereby avoiding the formation of thrombi on the sealing structure.

[0004] The technical solution adopted in this invention: A method for manufacturing a sealing structure includes the following steps: S100, obtain PDO filaments, cylindrical substrates and PLLA flow-blocking membranes; S200: Weave PDO filaments around the outside of the cylindrical base block and wrap the entire cylindrical base block to form a first assembly; S300. The first assembly is immersed in isopropanol for ultrasonic cleaning to obtain the cleaned assembly. S400: Photolithography is performed on at least one end face of the cleaned assembly to obtain a second assembly; S500, Remove the columnar base block from the second assembly to obtain the woven fabric; S600, Heat set the woven fabric to obtain the woven plug; S700, Sew the PLLA flow barrier membrane into the interior of the braided occluder; In step S400, the end face of the second assembly that is photolithographically etched is the target end face. A first tooth structure of a first preset array is formed on the target end face. The first preset array is a ring array or matrix. The first tooth structure includes a first micrometer tooth. The tooth width D of the first micrometer tooth is 8-10 μm, the tooth height H is 24-30 μm, and the distance P between two adjacent first micrometer teeth is 1-2 μm.

[0005] Preferably, a second preset array of first nanotooth teeth is also formed on the outer end face of each of the first micrometer teeth. When the outer end face of the first micrometer tooth is circular, the second preset array is a ring array; When the outer end face of the first micrometer tooth is rectangular, the second preset array is a matrix; The first nanotooth has a tooth width D of 100-500 nm and a tooth height H of 0.2-3 μm. On the outer end face of a single first nanotooth, the distance P between two adjacent first nanotooths is 1-2 μm.

[0006] Preferably, the PLLA flow-blocking membrane includes an end membrane. In step S300, the end membrane is immersed in isopropanol for ultrasonic cleaning; In step S400, the cleaned end film is photolithographically etched to obtain a photolithographic end film; In step S700, the target end membrane is bonded to the inner side of the target end face; In step S400, a second tooth structure of a third preset array is formed on the photolithographic end film. The third preset array is a ring array or matrix. The second tooth structure includes a second micrometer tooth. The width of the second micrometer tooth is 5-7 μm, the tooth height is 15-21 μm, and the spacing P between two adjacent second micrometer teeth is 1-2 μm.

[0007] Preferably, a fourth predetermined array of second nanotooth teeth is also formed on the outer end face of each second micrometer tooth. When the outer end face of the second micrometer tooth is circular, the fourth preset array is a ring array; When the outer end face of the second micrometer tooth is rectangular, the fourth preset array is a matrix; The second nanotooth has a tooth width of 100-500 nm and a tooth height H of 0.4-4.5 μm. On the outer end face of a single second nanotooth, the distance P between two adjacent second nanotooths is 1-2 μm.

[0008] Preferably, the cleaned assembly and the photolithographic end film are collectively referred to as the target body, and step S400 includes... S410. Photoresist is spin-coated onto the target end face of the target body using a spin coater to form a photoresist layer with a thickness of 120-160μm on the target end face. Then, it is baked in an oven at 90℃ for 2 minutes to obtain the target body with photoresist. S420. Expose the target end face of the adhesive-coated target body through a grayscale mask, and then bake it in an oven at 90°C for 3 minutes to obtain the primary product. S430. Immerse the primary product in SU-8 developer for 2 minutes to remove the photoresist in the unexposed areas, rinse with deionized water for 30 seconds, blow dry with nitrogen, and finally cure in a 90°C oven for 10 minutes to obtain the second assembly and photolithographic end film.

[0009] Preferably, in step S420, the exposure time is 60s and the light intensity is 10 mW / cm².

[0010] Preferably, the method further includes the step of: S800: Apply solution A and solution B to the primary sealing structure obtained in step S700 to form a hydrogel layer at the outer edge transition of the photolithographic end of the primary sealing structure. Solution A is an Alg / HA-BP solution; Solution B is a CaSO4 solution with added YAP / TAZ activating peptide, wherein the concentration of YAP / TAZ activating peptide is 10 μM and the concentration of Ca2+ is 80 mM.

[0011] Preferably, step S800 specifically includes: S10, Obtain HA-BP and Alg-RGD-BP; S20. Dissolve Alg-RGD-BP and HA-BP in HEPES to obtain an Alg / HA-BP solution, wherein the mass ratio of Alg-RGD-BP to HA-BP is 4:1 and the mass ratio of Alg-RGD-BP to Alg / HA-BP is 1:100. S30. Cover the surface of the primary sealing structure with silicone or PTFE, wherein the surface of the primary sealing structure other than the outer edge transition of the photolithographic end is the covering surface. S40. Apply solution A and solution B sequentially to the outer edge transition of the target end face of the primary sealing structure. At the outer edge transition, solutions A and B cross-link to form a hydrogel layer. Preferably, HA-BP is obtained using the following method: MeHA was dissolved in triethanolamine buffer and stirred overnight to obtain solution number one. Add 5.5 eq of thiol-BP and 7.5 mM of tris(2-carboxyethyl)phosphine hydrochloride to solution No. 1, stir and react for 48 h to obtain solution No. 2; Solution No. 2 was dialyzed with deionized water for 3 days to obtain solution No. 3; Solution No. 3 was frozen overnight at -30°C, then transferred to a lyophilizer for lyophilization to obtain HA-BP, which was then stored at -20°C.

[0012] Preferably, Alg-RGD-BP is obtained using the following method: Dissolve 0.2 g of sodium alginate in 20 mL of L2-(N-morpholino)ethanesulfonic acid buffer, stir, and let stand overnight to obtain solution No. 4; Add excess N-hydroxysulfosuccinimide, excess 1-ethyl-(3-dimethylaminopropyl)carbodiimide and excess bisphosphate to solution No. 4, stir and react for 24 h to obtain solution No. 5; Solution No. 5 was dialyzed with deionized water for 3 days to obtain solution No. 6; Solution No. 6 was frozen overnight at -30°C, then transferred to a lyophilizer to obtain Alg-RGD-BP, which was stored at -20°C. The beneficial effects of this invention are: This invention uses photolithography on at least one end face of the cleaned assembly to form a first tooth structure of a first preset array on the target end face. The first tooth structure is a first micrometer tooth with a tooth width D of 8-10 μm, a tooth height H of 24-30 μm, and a spacing P of 1-2 μm between two adjacent first micrometer teeth. Therefore, the first tooth structure of the first preset array constitutes a superhydrophilic structure. When the sealing structure is applied, the target end face mainly comes into contact with the flowing blood. The formation of a super-slippery and superhydrophilic structure on the target end face prevents blood from accumulating on the target end face, avoiding the formation of thrombi on the sealing structure and facilitating the subsequent attachment of cells to the target end face. Attached Figure Description

[0013] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of the structure of the left atrial appendage occluder prepared according to the present invention; Figure 2 This is a schematic diagram of a left atrial appendage occluder placed in the left atrial appendage; Figure 3 This is a schematic diagram of the first tooth structure; Figure 4 This is a comparison of the contact angles of blood droplets on the smooth surface of PLLA and the target end membrane; Figure 5 A comparison of the coefficient of friction and frictional force of PLLA smooth surface and comb-shaped structure surface; Figure 6 It is a comparison of endothelial cell proliferation before and after dynamic hydrogel coating; Figure 7 This is a picture of an atrial septal occluder, where the white part inside is a PLLA flow-blocking membrane; Figure 8 This is a comparison of the friction force and coefficient of friction of PDO smooth surface and comb-shaped structure surface. Detailed Implementation

[0014] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail, but well-known methods, processes, procedures, and elements are not described in detail in order to avoid obscuring the essence of the present invention.

[0015] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0016] Unless the context explicitly requires it, the words "comprising," "including," and similar terms throughout the specification and claims should be interpreted as encompassing rather than being exclusive or exhaustive; that is, meaning "including but not limited to."

[0017] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] See Figures 1-8 This invention provides a method for manufacturing an occlusion structure, such as a left atrial appendage occluder or an atrial septum / ventricular septum occluder, the method comprising the steps of: S100, obtain PDO filaments, cylindrical substrates and PLLA (poly-L-lactic acid) flow-blocking membrane; S200: Weave PDO filaments around the outside of the cylindrical base block and wrap the entire cylindrical base block to form a first assembly; S300. The first assembly is immersed in isopropanol for ultrasonic cleaning to obtain the cleaned assembly. S400: Photolithography is performed on at least one end face of the cleaned assembly to obtain a second assembly; S500, Remove the columnar base block from the second assembly to obtain the woven fabric; S600. Heat set the braided sealing material to obtain the braided sealing device; S700, Sew the PLLA flow barrier membrane into the interior of the braided occluder; In step S400, the end face of the second assembly that is photolithographically etched is the target end face. A first tooth structure of a first preset array is formed on the target end face. The first preset array is a ring array or matrix. The first tooth structure includes a first micrometer tooth. The tooth width D of the first micrometer tooth is 8-10 μm, the tooth height H is 24-30 μm, and the distance P between two adjacent first micrometer teeth is 1-2 μm.

[0019] The PDO yarn has a diameter of 0.1 mm. In step S200, a braided part with a braiding density of approximately 50 mesh is formed on the outside of the cylindrical base block. The braided part and the cylindrical base block together constitute the first assembly. Since the cylindrical base block is cylindrical and has two flat end faces, the first assembly is also cylindrical as a whole and has two basically flat end faces.

[0020] In step S300, the first assembly is immersed in isopropanol for ultrasonic cleaning for 10 minutes to remove surface contaminants. Then, the first assembly is subjected to plasma treatment with a mixture of Ar / O2 (the mixing ratio of the two is 3:1), which reduces the contact angle of the PDO filament surface from 75° to about 8.2°, thereby improving the hydrophilicity of the PDO filament surface.

[0021] If the occlusion structure is a left atrial appendage occluder, only one end face of the left atrial appendage occluder is in contact with blood. Therefore, in step S400, only one end face of the cleaned assembly needs to be photolithographically processed. If the occlusion structure is an atrial septal / ventricular septal occluder, in step S400, photolithography needs to be performed on the two end faces of the cleaned assembly.

[0022] Because photolithography was performed on the target end face, a first tooth structure of a first preset array was formed on the target end face. The first tooth structure is a first micrometer tooth with a tooth width D of 8-10 μm and a tooth height H of 24-30 μm. The distance P between two adjacent first micrometer teeth is 1-2 μm. Therefore, the first tooth structure of the first preset array constitutes a superhydrophilic structure. When the sealing structure is applied, the target end face mainly comes into contact with the flowing blood. Since a superhydrophilic structure is formed on the target end face, the blood will not coagulate on the target end face, avoiding the formation of thrombi on the sealing structure and facilitating the subsequent cell attachment to the target end face.

[0023] Taking the left atrial appendage occluder as an example, the target end face of the braided occluder of the left atrial appendage occluder forms a superhydrophilic structure. Therefore, after the left atrial appendage occluder is implanted, the target end face is in direct contact with the blood. Since the contact angle between the blood droplet and the target end face is less than 10°, the target end face is not superhydrophilic relative to the blood. Therefore, when the blood flows through the target end face, the blood droplet can spread out on the target end face, thus forming a blood film. Therefore, when the blood flows on the target end face, the blood droplet actually flows on the blood film, thereby reducing the friction when the blood flows on the target end face. In this way, the blood droplet will not aggregate on the target end face, and thus no thrombus will form on the target end face. After the left atrial appendage occluder is implanted, the tissue cells will climb along the left atrial appendage occluder. Since no thrombus will form on the target end face, the tissue cells can gradually cover the target end face of the left atrial appendage occluder, thereby closing the left atrial appendage. The PDO wire and PLLA choke membrane have biodegradable properties, so the cell tissue will eventually close the left atrial appendage, thereby achieving the purpose of the surgery.

[0024] In addition, it should be noted that when blood flows on the target end face, the flowing blood will continuously and dynamically replace the blood forming the blood film. In other words, the blood forming the blood film is also dynamic, so the blood film will not solidify to form a thrombus.

[0025] Each of the first micrometer teeth also has a second preset array of first nanometer teeth formed on its outer end face. When the outer end face of the first micrometer tooth is circular, the second preset array is a ring array; When the outer end face of the first micrometer tooth is rectangular, the second preset array is a matrix; The first nanotooth has a tooth width D of 100-500 nm and a tooth height H of 0.2-3 μm. On the outer end face of a single first nanotooth, the distance P between two adjacent first nanotooths is 1-2 μm.

[0026] The first nanotooth has a smaller tooth width and a certain tooth height. Therefore, the second array composed of the first nanotooth has better overall superhydrophilic properties, thereby avoiding the formation of thrombi on the target end face.

[0027] In this invention, a superhydrophilic structure is formed on the target end face. The superhydrophilic structure consists of first tooth structures arranged in a first preset array. Each first tooth structure includes a first micrometer tooth and multiple first nanotooths arranged in a second preset array on the outer end face of the first micrometer tooth. That is, the outer end face of the first nanotooth is in direct contact with the blood. Since the tooth width of the first nanotooth is only 100-500 nm and the spacing between the first nanotooths is 1-2 μm, and the radius of the blood droplet is approximately 25-50 μm, when the blood droplet contacts the target end face, the outermost first nanotooth presses against the blood, thereby reducing the contact area between the target end face and the blood droplet and reducing the friction between the two. Experiments show that this reduces the contact angle between the blood droplet and the target end face (see below), thereby preventing the formation of thrombi on the target end face.

[0028] In addition, the spacing P between the first nanotooth is 1-2 μm. Blood contains red blood cells, white blood cells and platelets. Among these three, platelets have the smallest radial size of 2-4 μm. Therefore, neither red blood cells, white blood cells or platelets in the blood will fall into the gaps between the tooth structure, thus eliminating the possibility of thrombus formation in terms of physical structure.

[0029] This invention forms first nanotooths arranged in a second preset array on first micrometer teeth. If nanotooths are formed directly on the target end face, the height of the nanotooths will be relatively high, increasing the difficulty of photolithography. This invention forms first nanotooths on first micrometer teeth, which reduces the height of the first nanotooths to a certain extent, so that the first nanotooths can have better hardness to support the blood and ensure the superhydrophilic effect of the target end face.

[0030] The PLLA flow-blocking membrane includes an end membrane. In step S300, the end membrane is immersed in isopropanol for ultrasonic cleaning; In step S400, the cleaned end film is photolithographically etched to obtain a photolithographic end film; In step S700, the target end membrane is bonded to the inner side of the target end face; In step S400, a second tooth structure of a third preset array is formed on the photolithographic end film. The third preset array is a ring array or matrix. The second tooth structure includes a second micrometer tooth. The width of the second micrometer tooth is 5-7 μm, the tooth height is 15-21 μm, and the spacing P between two adjacent second micrometer teeth is 1-2 μm.

[0031] In step S300, the end membrane and the first assembly are immersed in isopropanol for ultrasonic cleaning for 10 minutes to remove surface contaminants. Then, the first assembly and the end membrane are subjected to plasma treatment with a mixture of Ar / O2 (the mixing ratio of the two is 3:1), which reduces the contact angle of the PDO filament surface from 75° to about 8.2° and the contact angle of the end membrane surface from 80° to about 5°, thereby improving the hydrophilicity of the PDO filament surface.

[0032] Because braided occluders are made of PDO filaments, they inevitably have many pores. Therefore, when forming the occlusion structure, the PLLA flow barrier membrane is sewn into the inside of the braided occluder to prevent blood from entering the occlusion structure. As a result, in actual application, blood will inevitably come into contact with the PLLA flow barrier membrane, and blood will form a thrombus on the outside of the PLLA flow barrier membrane.

[0033] Therefore, this invention uses photolithography on the end membrane (the part of the PLLA flow barrier membrane that is in direct contact with blood) to form a superhydrophilic structure on the outer side of the end membrane that is similar to that on the target end face, so that the outer side of the end membrane also has superhydrophilic ability. Since only the end membrane of the entire PLLA flow barrier membrane is in contact with blood, it can prevent blood from forming thrombi on the PLLA flow barrier membrane, thereby avoiding the formation of thrombi on the sealing structure.

[0034] Each of the second micrometer teeth also has a fourth preset array of second nanometer teeth formed on its outer end face. When the outer end face of the second micrometer tooth is circular, the fourth preset array is a ring array; When the outer end face of the second micrometer tooth is rectangular, the fourth preset array is a matrix; The second nanotooth has a tooth width of 100-500 nm and a tooth height H of 0.4-4.5 μm. On the outer end face of a single second nanotooth, the distance P between two adjacent second nanotooths is 1-2 μm.

[0035] The second micrometer tooth structure is similar to the first micrometer tooth structure and has the same function, the difference being the specific size. The second nanometer tooth structure is similar to the first nanometer tooth structure and has the same function, the difference being the specific size. Therefore, the specific distance and effect will not be elaborated here.

[0036] It should be noted that when the occlusion device is a left atrial appendage occluder, only one end membrane is needed; when the occlusion device is an atrial septal / ventricular septal occluder, two end membranes are needed.

[0037] Figure 4As shown, the contact angle of a blood droplet with a radius of 25 μm on the smooth surface of the PLLA flow-blocking film (without photolithography) is 80°. According to the Cassie-Baxter theory, the theoretical contact angle of the comb-shaped surface is 5° (it can be clearly confirmed that the target end face of the present invention has superhydrophilic properties).

[0038] Figure 5 As shown, the solid-liquid contact area of ​​the smooth surface without photolithography is 3.2 × 10⁻⁶. −9 The surface area is m², the coefficient of friction is 0.12, and the surface friction force is 0.006 μN; while on the comb-like surface, the theoretical apparent solid-liquid contact area is 1.5 × 10⁻⁶ m². −11 The surface area is m², the coefficient of friction is 0.048, which is 60.00% lower than that of a smooth surface, and the surface friction force is 0.000037 μN, which is 99.35% lower than that of a smooth surface.

[0039] Figure 8 As shown, the PDO smooth surface without photolithography has a contact angle of 75°, a friction coefficient of 0.148, and a surface friction force of 18.14 μN. However, after photolithography, the contact angle of the four samples is less than 10°, which is a superhydrophilic surface, and the friction force and friction coefficient are reduced by more than 90%.

[0040]

[0041] Compared to the above two methods, the frictional force of blood droplets on the target membrane is reduced by nearly 110 times. Therefore, blood droplets are less likely to accumulate or remain on the target membrane, thus avoiding the formation of thrombi on the target membrane.

[0042] The cleaned assembly and the photolithographic end film are collectively referred to as the target body. Step S400 includes... S410. Photoresist is spin-coated onto the target end face of the target body using a spin coater to form a photoresist layer with a thickness of 120-160μm on the target end face. Then, it is baked in an oven at 90℃ for 2 minutes to obtain the target body with photoresist. S420. Expose the target end face of the adhesive-coated target body through a grayscale mask, and then bake it in an oven at 90°C for 3 minutes to obtain the primary product. S430. Immerse the primary product in SU-8 developer for 2 minutes to remove the photoresist in the unexposed areas, rinse with deionized water for 30 seconds, blow dry with nitrogen, and finally cure in a 90°C oven for 10 minutes to enhance structural stability, thus obtaining the second assembly and the photolithographic end film.

[0043] In step S420, the exposure time is 60 s and the light intensity is 10 mW / cm².

[0044] It also includes the following steps: S800: Apply solution A and solution B to the primary sealing structure obtained in step S700 to form a hydrogel layer at the outer edge transition of the photolithographic end of the primary sealing structure. Solution A is an Alg / HA-BP solution; Solution B is a CaSO4 solution with added YAP / TAZ activating peptide, wherein the concentration of YAP / TAZ activating peptide is 10 μM and the concentration of Ca2+ is 80 mM.

[0045] The thickness of the hydrogel layer is 10-20μm. Taking the left atrial appendage occluder as an example, the hydrogel layer is located on the surface of the left atrium that is in contact with blood (except for the photolithography end). The surface of the left atrial appendage occluder that is not in contact with blood is not provided with a hydrogel layer to avoid the friction between it and the left atrial appendage being too small and causing it to fall off.

[0046] The hydrogel layer facilitates the attachment of tissue cells (endothelial cells) to the hydrogel layer and allows them to proliferate to the edge of the photolithographic end. Since the photolithographic end is typically concave, tissue cells can easily cover it, thus sealing the entire sealing structure. Figure 6 (This indicates a 3-fold increase in endothelial cell proliferation rate).

[0047] Step S800 is as follows: S10, Obtain HA-BP and Alg-RGD-BP; S20. Dissolve Alg-RGD-BP and HA-BP in HEPES to obtain an Alg / HA-BP solution, wherein the mass ratio of Alg-RGD-BP to HA-BP is 4:1 and the mass ratio of Alg-RGD-BP to Alg / HA-BP is 1:100. S30. Cover the surface of the primary sealing structure with silicone or PTFE (the surface that does not require a hydrogel layer), and the surface of the primary sealing structure other than the outer edge transition of the photolithographic end is the covering surface; S40. Apply solution A and solution B sequentially to the outer edge transition of the photolithographic end of the primary sealing structure, and crosslink solutions A and B at the outer edge transition to form a hydrogel layer.

[0048] HA-BP is obtained using the following method: MeHA (methacrylated hyaluronic acid) was dissolved in triethanolamine buffer and stirred overnight to obtain solution No. 1. Add 5.5 eq of thiol-BP (thiol-bisphosphate) and 7.5 mM of TCEP (tris(2-carboxyethyl)phosphine hydrochloride) to solution No. 1, stir and react for 48 h (stirring continuously for 48 h) to obtain solution No. 2; Solution No. 2 was dialyzed with deionized water for 3 days to obtain solution No. 3; Solution No. 3 was frozen overnight at -30°C, then transferred to a lyophilizer and lyophilized to obtain HA-BP, which was then stored at -20°C to obtain HA-BP.

[0049] Alg-RGD-BP is obtained using the following method: Dissolve 0.2g of sodium alginate in 20mL of MES (L2-(N-morpholino)ethanesulfonic acid) buffer, stir, and let stand overnight to obtain solution No. 4; Add excess Sulfo-NHS (N-hydroxysulfosuccinimide), excess EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide), and excess BP (bisphosphate) to solution No. 4, stir and react for 24 h to obtain solution No. 5; Solution No. 5 was dialyzed with deionized water for 3 days to obtain solution No. 6; Solution No. 6 was frozen overnight at -30°C, then transferred to a lyophilizer to obtain Alg-RGD-BP, which was stored at -20°C.

[0050] In addition, in step S40, the hydrogel layer can be formed by spin coating or spray coating.

[0051] Spin coating method: Tilt the surface of the plug (photolithography end) and rotate the edge of the plug to immerse it in Alg / HA-BP solution (45° angle, 5 seconds), then pull it up; immerse it in solution B, rotate it 3 times to uniformly crosslink and form hydrogel, then pull it up.

[0052] Spraying method: First spray solution A, then spray solution B, which crosslinks to form a hydrogel layer.

[0053] The hydrogel layer has a hardness of 8-10 kPa and a relaxation time of 20 s. It should be understood that the above embodiments are merely exemplary and not restrictive. Various obvious or equivalent modifications or substitutions that can be made by those skilled in the art regarding the above details without departing from the basic principles of the present invention will be included within the scope of the claims of the present invention.

Claims

1. A method for manufacturing a sealing structure, characterized in that, Including the following steps: S100, obtain PDO filaments, cylindrical substrates and PLLA flow-blocking membranes; S200: Weave PDO filaments around the outside of the cylindrical base block and wrap the entire cylindrical base block to form a first assembly; S300. The first assembly is immersed in isopropanol for ultrasonic cleaning to obtain the cleaned assembly. S400: Photolithography is performed on at least one end face of the cleaned assembly to obtain a second assembly; S500, Remove the columnar base block from the second assembly to obtain the woven fabric; S600, Heat set the woven fabric to obtain the woven plug; S700, Sew the PLLA flow barrier membrane into the interior of the braided occluder; In step S400, the end face of the second assembly that is photolithographically etched is the target end face. A first tooth structure of a first preset array is formed on the target end face. The first preset array is a ring array or a matrix. The first tooth structure includes a first micrometer tooth. The tooth width D of the first micrometer tooth is 8-10 μm, the tooth height H is 24-30 μm, and the distance P between two adjacent first micrometer teeth is 1-2 μm. Each of the first micrometer teeth also has a second preset array of first nanometer teeth formed on its outer end face. When the outer end face of the first micrometer tooth is circular, the second preset array is a ring array; When the outer end face of the first micrometer tooth is rectangular, the second preset array is a matrix; The tooth width D of the first nanotooth is 100-500nm and the tooth height H is 0.2-3μm. On the outer end face of a single first nanotooth, the distance P between two adjacent first nanotooths is 1-2μm. The PLLA flow-blocking membrane includes an end membrane. In step S300, the end membrane is immersed in isopropanol for ultrasonic cleaning; In step S400, the cleaned end film is photolithographically etched to obtain a photolithographic end film; In step S700, the target end membrane is bonded to the inner side of the target end face; In step S400, a second tooth structure of a third preset array is formed on the photolithographic end film. The third preset array is a ring array or matrix. The second tooth structure includes a second micrometer tooth. The tooth width of the second micrometer tooth is 5-7 μm, the tooth height is 15-21 μm, and the spacing P between two adjacent second micrometer teeth is 1-2 μm. Each of the second micrometer teeth also has a fourth preset array of second nanometer teeth formed on its outer end face. When the outer end face of the second micrometer tooth is circular, the fourth preset array is a ring array; When the outer end face of the second micrometer tooth is rectangular, the fourth preset array is a matrix; The second nanotooth has a tooth width of 100-500 nm and a tooth height H of 0.4-4.5 μm. On the outer end face of a single second nanotooth, the distance P between two adjacent second nanotooths is 1-2 μm. The cleaned assembly and the photolithographic end film are collectively referred to as the target body. Step S400 includes... S410. Photoresist is spin-coated onto the target end face of the target body using a spin coater to form a photoresist layer with a thickness of 120-160μm on the target end face. Then, it is baked in an oven at 90℃ for 2 minutes to obtain the target body with photoresist. S420. Expose the target end face of the adhesive-coated target body through a grayscale mask, and then bake it in an oven at 90°C for 3 minutes to obtain the primary product. S430. Immerse the primary product in SU-8 developer for 2 minutes to remove the photoresist in the unexposed areas, rinse with deionized water for 30 seconds, blow dry with nitrogen, and finally cure in a 90°C oven for 10 minutes to obtain the second assembly and photolithographic end film. In step S420, the exposure time is 60 s and the light intensity is 10 mW / cm².

2. The method for manufacturing the sealing structure according to claim 1, characterized in that, It also includes the following steps: S800: Apply solution A and solution B to the primary sealing structure obtained in step S700 to form a hydrogel layer at the outer edge transition of the target end face of the primary sealing structure. Solution A is an Alg / HA-BP solution; Solution B is a CaSO4 solution containing YAP / TAZ activating peptide, wherein the concentration of YAP / TAZ activating peptide is 10 μM, and CaSO4 is... 2+ Concentration 80mM.

3. The method for manufacturing the sealing structure according to claim 2, characterized in that, Step S800 is as follows: S10, Obtain HA-BP and Alg-RGD-BP; S20. Dissolve Alg-RGD-BP and HA-BP in HEPES to obtain an Alg / HA-BP solution, wherein the mass ratio of Alg-RGD-BP to HA-BP is 4:1 and the mass ratio of Alg-RGD-BP to Alg / HA-BP is 1:

100. S30. Cover the surface of the primary sealing structure with silicone or PTFE, wherein the surface of the primary sealing structure other than the outer edge transition of the photolithographic end is the covering surface. S40. Apply solution A and solution B sequentially to the outer edge transition of the photolithographic end of the primary sealing structure, and crosslink solutions A and B at the outer edge transition to form a hydrogel layer.

4. The method for manufacturing the sealing structure according to claim 3, characterized in that, HA-BP is obtained using the following method: MeHA was dissolved in triethanolamine buffer and stirred overnight to obtain solution number one. Add 5.5 eq of thiol-BP and 7.5 mM of tris(2-carboxyethyl)phosphine hydrochloride to solution No. 1, stir and react for 48 h to obtain solution No. 2; Solution No. 2 was dialyzed with deionized water for 3 days to obtain solution No. 3; Solution No. 3 was frozen overnight at -30°C, then transferred to a lyophilizer for lyophilization to obtain HA-BP, which was then stored at -20°C.

5. The method for manufacturing the sealing structure according to claim 4, characterized in that, Alg-RGD-BP is obtained using the following method: Dissolve 0.2 g of sodium alginate in 20 mL of L2-(N-morpholino)ethanesulfonic acid buffer, stir, and let stand overnight to obtain solution No. 4; Add excess N-hydroxysulfosuccinimide, excess 1-ethyl-(3-dimethylaminopropyl)carbodiimide and excess bisphosphate to solution No. 4, stir and react for 24 h to obtain solution No. 5; Solution No. 5 was dialyzed with deionized water for 3 days to obtain solution No. 6; Solution No. 6 was frozen overnight at -30°C, then transferred to a lyophilizer to obtain Alg-RGD-BP, which was stored at -20°C.

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