Prosthetic heart valve composite material and manufacturing method therefor

Abstract

Provided in the present application are a prosthetic heart valve composite material and a manufacturing method therefor. A polymer layer having a certain thickness is formed on the inner and outer areas of edges of valve leaflets, such that an edge-sealing structure formed by the polymer layer can be used to protect the valve, so as to protect fiber-polymer bonding interfaces of the valve leaflets and fix the relative position of fibers, thereby improving the stability of the overall structure of the valve leaflets and protecting the valve leaflets from deforming during use. The edge-sealing structure is configured to comprise a first polymer layer attached to the surfaces of the valve leaflets and a second polymer layer extending outward from the edges of the valve leaflets, so that the bonding force between the edge-sealing structure and the valve leaflets is effectively enhanced, and the edge-sealing structure is tightly bonded to the valve leaflets. In this way, the problem in the prior art that the overall structure of leaflets made of fibers and polymers is prone to deformation or splitting during use is effectively solved.

Description

A composite material for artificial heart valves and its preparation method Technical Field

[0001] This application relates to the field of medical device technology, and in particular to an artificial heart valve composite material and its preparation method. Background Technology

[0002] Transcatheter aortic replacement surgery (TACR) has become an important treatment option for patients undergoing heart valve replacement due to its low risk, minimal trauma, rapid operation, and quick postoperative recovery. Currently, clinically used transcatheter artificial heart valves mainly consist of self-expanding / balloon-expandable metal stents and biological tissues (bovine pericardium, porcine pericardium, porcine aortic valve, etc.) as valve leaflets. Biological tissues offer good biocompatibility and can mimic natural valves, but they also have drawbacks such as easy calcification, short lifespan, high cost, and batch-specific effects.

[0003] Using polymer materials to fabricate artificial heart valves holds promise for overcoming the shortcomings of biological tissues. Textile-based artificial heart valves, processed using textile technology, offer numerous advantages. They allow for precise control over the composition, thickness, and structure of the scaffold material to optimize the interventional process and adjust the final geometry and biomechanical properties of the product. They also show broad application prospects in surgical valves, transcatheter valves, valved conduits, and tissue-engineered valves. Compared to biological tissues, polymer materials have a longer lifespan and are easier to obtain, which helps reduce batch-to-batch variations and enables mass production.

[0004] Existing research on textile-based artificial heart valve leaflets typically uses pure fabrics or fabric-based composites composed of polymer fibers / yarns. However, pure fabrics suffer from problems such as leakage, structural deformation, and rough surfaces that can lead to thrombosis. Composite materials, obtained by bonding with polymers, exhibit reduced leakage, improved structural stability, and reduced surface roughness, offering advantages over pure fabrics in blood-use environments. However, composite materials also present challenges. For instance, edges cut using lasers, blades, or thermal cutting expose the interface between the yarn and polymer. As the leaflet's operating time increases, this interface gradually breaks down, damaging the edge composite structure and increasing the risk of calcification and thrombosis.

[0005] In the prior art, patent CN116650174A discloses a fabric structure for edge locking of polymer textile leaflets, its preparation method, and its application. The fabric structure involves polymer textile leaflets woven with warp and weft threads. The cut edges of the polymer textile leaflets are set at an angle to the warp and weft threads. An edge locking structure is formed by needles 1-1.5 mm from the leaflet edge, and this edge locking structure is set at an angle to the warp and weft threads to prevent leaflet edge unraveling, improve the tightness of the leaflet edge, and prevent the overall leaflet structure from deforming. However, the above edge locking structure only fixes the relative position of the yarns and does not improve the interfacial bonding between the yarns and the polymer. That is, the two will still split at the interface, resulting in pores, causing blood deposits, and leading to the risk of thrombosis and calcification.

[0006] In view of this, it is necessary to design an improved artificial heart valve composite material and its preparation method to solve the above problems. Summary of the Invention

[0007] The purpose of this application is to provide an artificial heart valve composite material and its preparation method.

[0008] To achieve the aforementioned objectives, this application provides an artificial heart valve composite material, comprising:

[0009] Petals;

[0010] The sealing structure, formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 0.05-5 mm and a thickness of 25-100 μm; the second polymer layer has a width of 0.01-2 mm and a thickness of 50-200 μm, and the thickness of the artificial heart valve composite material is 50-200 μm.

[0011] Preferably, the leaflets comprise:

[0012] Fabrics;

[0013] Two third polymer layers are respectively disposed on both sides of the fabric;

[0014] At least one fourth polymer layer is disposed on the surface of at least one of the third polymer layers, and the contact surfaces of the third polymer layer and the fourth polymer layer are interlocked, wherein the surface roughness of the side of the fourth polymer layer away from the third polymer layer is 80-150 nm.

[0015] Preferably, the method for preparing the petal includes the following steps:

[0016] The fabric is immersed in a first polymer solution and dried for the first time to obtain a fabric with third polymer layers on both sides; a second polymer solution is coated on a smooth first substrate surface; the fabric with the third polymer layer is immersed in a poor solvent to form a fourth polymer layer on the surface of at least one of the third polymer layers; the fabric is laid flat on the first substrate so that one of the third polymer layers on the fabric surface comes into contact with the second polymer solution; after a second drying, a fourth polymer layer is formed on the surface of one of the third polymer layers, the side of the fourth polymer layer away from the third polymer layer is smooth, and the poor solvent can promote the interlocking of the contact surfaces of the third polymer layer and the fourth polymer layer.

[0017] Furthermore, this application also provides a method for preparing the above-mentioned artificial heart valve composite material, wherein the composite material is prepared by forming an edge-sealing structure at the edge of the valve leaflet using a one-step or two-step method;

[0018] The one-step method includes the following steps: a second film material is disposed on the surface of a substrate; a first film material and a leaflet are disposed within a hollow area of ​​the second film material; a first polymer region is formed between the edge of the first film material and the edge of the leaflet; a first polymer layer is formed within the first polymer region; a second polymer region is formed between the edge of the hollow area on the second film material near the leaflet and the edge of the first film material; a second polymer layer is formed within the second polymer region; wherein the size of the hollow area is larger than the leaflet, and both the first film material and the leaflet can be accommodated within the hollow area;

[0019] The two-step method includes the following steps: laying the leaflets flat on the substrate surface, and then forming closed polymer solution layers around the edges of the leaflets on both sides of the leaflet to form a sealing structure at the edges of the leaflets.

[0020] Preferably, the one-step method includes the following steps:

[0021] After the leaflets are laid flat on the substrate surface, a first film material is laid flat on the leaflet surface, and then a second film material is laid flat, ensuring that the center of the leaflets and the first film material coincides with the center of the second film material, and that the leaflets and the first film material are completely contained within the hollow area of ​​the second film material; a first polymer region is formed between the edge of the first film material and the edge of the leaflets, and a second polymer region is formed between the edge of the second film material near the leaflets and the edge of the first film material; wherein, the size of the first film material is smaller than that of the leaflets;

[0022] A polymer solution layer is coated onto the surface of a substrate covered with a first membrane material, a second membrane material, and a leaflet. The first and second membrane materials are then peeled off, forming a first polymer solution layer in a first polymer region and a second polymer solution layer in a second polymer region. The entire substrate is then immersed in a first solvent to allow the polymer solution layer to initially set. After drying and curing, the leaflet is tightly bonded to the first and second polymer layers and then separated from the substrate, thus obtaining an artificial heart valve leaflet composite material. The first polymer layer has a width of 1-5 mm and a thickness of 25-100 μm; the second polymer layer has a width of 0.1-2 mm and a thickness of 50-200 μm; and the artificial heart valve leaflet composite material has a thickness of 50-200 μm.

[0023] Preferably, the width of the first polymer region is 1-5 mm, and the width of the second polymer region is 0.1-2 mm; the first solvent is a poor solvent for the polymer in the polymer solution, and it is one or more of water, alcohols, and ketones.

[0024] Preferably, the two-step method includes the following steps:

[0025] The leaflet is placed on the substrate surface, and a closed polymer solution layer is formed at the edge of the leaflet by manual or machine injection. The polymer solution layer consists of at least one polymer solution flow line, which covers both the leaflet and the outside of the leaflet. The fluid covering the leaflet forms the first polymer layer, and the fluid outside the leaflet forms the second polymer layer. The leaflet is removed and dried, and the above steps are repeated to form polymer solution flow lines on the other side of the leaflet. After overall drying, an edge sealing structure is formed at the edge of the leaflet to obtain the artificial heart valve composite material. The width of the first polymer layer is 0.05-1 mm, and the thickness is 25-100 μm. The width of the second polymer layer is 0.01-0.1 mm, and the thickness is 50-200 μm. The thickness of the artificial heart valve composite material is 50-200 μm.

[0026] Preferably, the width of the polymer solution flow lines is 0.5-2 mm, and the width of the sealing structure is 0.06-1.1 mm.

[0027] Preferably, the polymer solution has a mass-volume fraction of 10-25 w / v, the solute is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, and styrene-isobutylene copolymer, and the solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane.

[0028] Preferably, the first and second membrane materials are made of one or more of polytetrafluoroethylene, polyester, polyvinyl chloride, polypropylene, polyethylene, and silicone, and both have a thickness of 30-100 μm; the substrate has a thickness of 3-8 mm and is made of at least one of glass, stainless steel, polyacetal, and polytetrafluoroethylene.

[0029] The beneficial effects of this application are:

[0030] The method for preparing artificial heart valve composite material provided in this application involves forming a polymer layer of a certain thickness in the inner and outer regions of the leaflet edge. The sealing structure formed by the polymer layer can protect the valve, thereby protecting the interface between the fiber and polymer formed by the leaflet and fixing the relative position of the fibers. This improves the stability of the overall leaflet structure, prevents deformation of the leaflet during use, and extends the service life of the composite material. By setting the sealing structure as a first polymer layer attached to the leaflet surface and a second polymer layer extending outward from the leaflet edge, the bonding force between the sealing structure and the leaflet is effectively enhanced, making the sealing structure tightly bonded to the leaflet.

[0031] The method for preparing artificial heart valve composite material provided in this application uses a first membrane material and a second membrane material as templates for the edge sealing structure. The first polymer region and the second polymer region formed by the two materials and the leaflet edge are further used to form the edge sealing structure. This allows for the controllable formation of an edge sealing structure integrated with the leaflet in the edge region of the leaflet in a one-step process. The formation of this structure extends the polymer length of the leaflet on the cutting section, which not only improves the tightness of the leaflet edge but also protects the bonding interface between the fibers and the polymer in the leaflet. This prevents the interface from being directly exposed to the blood environment during use, avoids cracking of the bonding interface caused by cyclic loads, and improves the compatibility of the composite material with the usage environment.

[0032] The method for preparing artificial heart valve composite material provided in this application involves forming a closed polymer solution layer at the edge of the valve leaflet through a push-in method. After the polymer solution layer dries, a sealing structure is formed at the edge of the valve leaflet. During the push-in process, the polymer solution is squeezed out and comes into contact with the valve leaflet. Its thickness can be precisely controlled by adjusting the flow rate of the push-in solution, resulting in high controllability. Furthermore, the formation of the sealing structure also extends the polymer length of the valve leaflet on the cutting section, which not only improves the tightness of the valve leaflet edge but also protects the bonding interface between the fibers and the polymer in the valve leaflet. This prevents the interface from being directly exposed to the blood environment during use, avoids cracking of the bonding interface caused by cyclic loads, and improves the compatibility of the composite material with the usage environment. Attached Figure Description

[0033] Figure 1 is a cross-sectional SEM image of the artificial heart valve composite material prepared in Example 1 of this application;

[0034] Figure 2 is a planar SEM image of the artificial heart valve composite material prepared in Example 1 of this application;

[0035] Figure 3 shows the SEM image of the unsealed leaflet after fatigue test;

[0036] Figure 4 is a SEM image of the artificial heart valve composite material prepared in Example 1 of this application after fatigue test;

[0037] Figure 5 is an optical photograph showing the relative position of the streamlines and leaflets in Embodiment 4 of this application;

[0038] Figure 6 is a cross-sectional SEM image of the artificial heart valve composite material prepared in Example 4 of this application;

[0039] Figure 7 is a SEM image of the artificial heart valve composite material prepared in Example 4 of this application after fatigue test. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the structures and / or processing steps closely related to the solution of this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0042] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0043] This application provides a composite material for an artificial heart valve, comprising:

[0044] Petals;

[0045] The edge-sealing structure, formed in the edge region of the leaflet and tightly bonded to it, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the leaflet edge. The first polymer layer enhances the bonding strength between the second polymer layer and the leaflet, ensuring the bonding strength between the edge-sealing structure and the leaflet. Its width is 0.05-5 mm and its thickness is 25-100 μm. The second polymer layer has a width of 0.01-2 mm and a thickness of 50-200 μm, and the composite material has a thickness of 50-200 μm. It should be noted that "extending outward" refers to extending away from the leaflet body, which is the area of ​​the leaflet surrounded by the leaflet edge.

[0046] Furthermore, this application also provides a method for preparing the above-mentioned artificial heart valve composite material, which is obtained by forming a sealing structure at the edge of the valve leaflet using a one-step or two-step method.

[0047] Specifically, the one-step preparation process includes the following steps:

[0048] The leaflets are fixed to the surface of the substrate. After the first film material is laid flat on the surface of the leaflets, the second film material is laid flat on the leaflets. The second film material has a hollow area with a size larger than that of the leaflets. After laying the second film material, it is ensured that the center of the leaflets and the center of the first film material coincides with the center of the second film material. The size of the first film material is smaller than that of the leaflets. A first polymer area is formed between the edge of the first film material and the edge of the leaflets. A second polymer area is formed between the edge of the second film material near the leaflets and the edge of the first film material. It should be noted that the "hollow area" on the second film material is a through hole that runs through the thickness direction of the second film material.

[0049] Next, a polymer solution layer is coated onto the surface of the substrate, which is covered with the first membrane material, the second membrane material, and the leaflet. The first and second membrane materials are then peeled off, forming the first polymer solution layer in the first polymer region and the second polymer solution layer in the second polymer region. The substrate is then immersed in a first solvent to allow the polymer solution layer to initially set. After drying and curing, the substrate and the polymer layer are tightly bonded together and then separated from the substrate, thus obtaining the artificial heart valve leaflet composite material. The first polymer layer has a width of 1-5 mm and a thickness of 25-100 μm; the second polymer layer has a width of 0.1-2 mm and a thickness of 50-200 μm.

[0050] As one embodiment of this application, the materials of the first membrane material and the second membrane material include, but are not limited to, polytetrafluoroethylene (PTFE), polyester (PET), polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), and silicone. The thickness of both is 30-100μm, and the size of the first membrane material and the second membrane material is equal to the enlarged / reduced shape of the leaflet.

[0051] As one embodiment of this application, the substrate is made of materials including but not limited to glass, stainless steel, polyacetal, and polytetrafluoroethylene, and its thickness is 3-8 mm.

[0052] In one embodiment of this application, the width of the first polymer region is 1-5 mm, and the width of the second polymer region is 0.1-2 mm. By controlling the dimensions of the two polymer regions within the above range, the widths of the first and second polymer layers can be controlled within a certain range to improve the bonding strength between the sealing structure and the leaflet. If the width of the first polymer region is too small, the bonding strength between the second polymer layer and the leaflet is insufficient, while if the width is too large, it will result in material waste; if the width of the second polymer region is too large, the sealing structure will be too long and prone to tearing during fatigue.

[0053] In one embodiment of this application, the polymer solution has a mass-volume fraction of 10-25 w / v, the solute of the polymer solution is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, and styrene-isobutylene copolymer, and the solvent of the polymer solution is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane.

[0054] In one embodiment of this application, the first solvent is a poor solvent for the polymer in the polymer solution, that is, the polymer has a weak solubility in the first solvent, and the substrate is immersed in the first solvent for 10-60 seconds. The first solvent is specifically one or more of water, alcohols, and ketones.

[0055] In one embodiment of this application, the thickness of the composite material is 50-200 μm.

[0056] Furthermore, the two-step preparation process includes the following steps:

[0057] The leaflet is fixed to the substrate surface. A closed polymer solution layer is formed around the leaflet edge using manual or machine injection. This polymer solution layer consists of at least one polymer solution flow line, which simultaneously covers both the leaflet and its outer surface. The fluid covering the leaflet forms the first polymer layer, and the fluid outside the leaflet forms the second polymer layer. The leaflet is removed and dried. The above steps are repeated to form polymer solution flow lines on the other side of the leaflet. After overall drying, a sealing structure is formed at the edge of the leaflet to obtain the artificial heart valve composite material. The first polymer layer has a width of 0.05-1 mm and a thickness of 25-100 μm; the second polymer layer has a width of 0.01-0.1 mm and a thickness of 50-200 μm; the composite material has a thickness of 50-200 μm; the width of the polymer solution flow line is 0.5-2 mm; and the width of the sealing structure is 0.06-1.1 mm.

[0058] As one embodiment of this application, the substrate surface has a certain degree of adhesion, such as silicone or traceless adhesive. In the above process, the use of the substrate can facilitate the injection process, and its adhesive surface can keep the leaflets flat during the injection process, eliminate gaps on the bottom surface of the leaflets, and prevent the flow lines from flowing to the bottom surface of the leaflets to avoid contaminating the other side of the leaflets. The "certain degree of adhesion" here means that the leaflets can be fixed without affecting the subsequent removal of the composite material from the substrate surface.

[0059] In one embodiment of this application, the polymer solution has a mass-volume fraction of 10-25 w / v, the solute of the polymer solution is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, and styrene-isobutylene copolymer, and the solvent of the polymer solution is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane.

[0060] In one embodiment of this application, the width of the polymer solution flow lines is 0.5-2 mm.

[0061] As one embodiment of this application, the width of the sealing structure is 0.06-1.1 mm, and the width direction is the radial direction of the leaflet. During the preparation process, the number of injections can be adjusted according to the width of the polymer solution flow line and the required size of the sealing structure.

[0062] It should be noted that the leaflets mentioned in this application are composite materials made of fabric / fiber as the reinforcing phase and thermoplastic polymer as the filler. In specific use, the composite material can be cut into leaflets of the required size according to actual needs. The material of the fabric or fiber is one or more of polyester, polyethylene, polypropylene, polyamide and polyvinyl chloride; the fabric structure is plain weave, twill weave or satin weave; the thermoplastic polymer includes one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer and styrene-isobutylene copolymer.

[0063] Furthermore, the leaflets include:

[0064] Fabrics;

[0065] Two third polymer layers are respectively disposed on both sides of the fabric;

[0066] At least one fourth polymer layer is disposed on the surface of at least one third polymer layer, and the contact surfaces of the third polymer layer and the fourth polymer layer are interlocked, wherein the surface roughness of the side of the fourth polymer layer away from the third polymer layer is 80-150 nm.

[0067] The preparation method includes the following steps: immersing a fabric in a first polymer solution, followed by a first drying to obtain a fabric with third polymer layers on both sides; coating a smooth first substrate surface with a second polymer solution; immersing the fabric with the third polymer layer in a poor solvent to form a fourth polymer layer on the surface of at least one third polymer layer; laying the fabric flat on the first substrate, so that one of the third polymer layers on the fabric surface contacts the second polymer solution; and then drying a second time to form a fourth polymer layer on the surface of one of the third polymer layers. The side of the fourth polymer layer away from the third polymer layer is smooth, and the poor solvent promotes the interlocking of the contact surfaces of the third and fourth polymer layers. It should be noted that in some other embodiments, the above method can also be used to prepare a second polymer layer on the surface of another first polymer layer; that is, the number of second polymer layers in the composite material can be selected as needed.

[0068] As one embodiment of this application, the fabric is a woven fabric, knitted fabric, or nonwoven fabric; the material of the fabric is one or more of polyester, polyethylene, polypropylene, polyamide, and polyvinyl chloride.

[0069] As one embodiment of this application, before immersing the fabric in a poor solvent, the fabric needs to be plasma treated. Fabric treated in this way is more conducive to the poor solvent entering the fabric. The plasma treatment conditions are a treatment power of 50-300W and a treatment time of 30-300s. The gas environment includes, but is not limited to, one of oxygen, hydrogen, air, argon, and helium.

[0070] In one embodiment of this application, the first polymer solution is obtained by dissolving a first polymer in a first organic solvent, the mass concentration of the first polymer solution is 1-15 w / v%, and the contact time of the fabric in the first polymer solution is 0.5-30 min; the first polymer is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, and styrene / isobutylene copolymer, and the first organic solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane.

[0071] In one embodiment of this application, the temperature for the first drying is 40-80°C and the time is 1-120 min.

[0072] In one embodiment of this application, the second polymer solution is obtained by dissolving a second polymer in a second organic solvent, and the mass-volume fraction of the second polymer solution is 5-30%. The second polymer is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, and styrene / isobutylene copolymer. The second organic solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane. In the above process, by selecting a polymer with the same or similar properties as the first polymer layer to form the second polymer solution, better compatibility between the first polymer layer and the second polymer solution is achieved, which facilitates the formation of an intercalation structure between them and enhances the stability within the coating and between the coating and the fabric.

[0073] In one embodiment of this application, the temperature for the second drying is 40-80°C and the time is 6-48 hours.

[0074] In one embodiment of this application, the thickness of the first polymer layer is less than 10 μm, and the coating thickness of the second polymer solution is 100-1000 μm. By controlling the above conditions, the coating thickness on the fabric surface can be adjusted to minimize the impact of the coating on the softness of the fabric itself.

[0075] As one embodiment of this application, the method of coating the second polymer solution includes, but is not limited to, blade coating, spin coating, roll coating, and flow coating.

[0076] As one embodiment of this application, the unsuitable solvent includes, but is not limited to, water, alcohols, and ketones, such as ethanol, isopropanol, and acetone. Both the first polymer and the second polymer are not easily soluble in the unsuitable solvent.

[0077] As one embodiment of this application, the material of the first substrate includes, but is not limited to, glass, metal, and silicone.

[0078] The artificial heart valve composite material and its preparation method proposed in this application will be further described below with reference to specific embodiments: Example 1

[0079] This embodiment prepares an artificial heart valve composite material, which includes:

[0080] The leaflets are 120 μm thick.

[0081] The sealing structure, which is formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 1 mm and a thickness of 60 μm; the second polymer layer has a width of 0.3 mm and a thickness of 120 μm.

[0082] Furthermore, the preparation method of the above-mentioned composite material includes the following steps:

[0083] A 50μm thick PET film is cut into a smaller petal shape to serve as the first film material. Another 50μm thick PET film is cut to remove a larger petal shape in the middle, resulting in a hollowed-out shielding film, which serves as the second film material. The petal is flatly attached to the substrate surface, and then the first film is attached to the petal surface. The second film is then attached to the substrate surface, placing the petal covered with the first film within the hollowed-out area of ​​the second film. The geometric centers of the first film, the second film, and the petal are aligned. A first polymer region with a width of 1mm is formed between the edge of the first film and the edge of the petal. A second polymer region with a width of 0.3mm is formed between the edge of the second film near the petal and the edge of the first film. The thickness of the petal is 120μm.

[0084] Next, a polyurethane-N,N-dimethylformamide solution with a mass-volume fraction of 18 w / v was coated onto the substrate to form a liquid film with a thickness of 800 μm. Then, the first and second films were peeled off from the substrate surface in sequence to form a first polymer solution layer in the first polymer region and a second polymer solution layer in the second polymer region. Next, the substrate was immersed in water for 60 seconds for preliminary shaping. Finally, the first and second polymer solution layers were dried by drying and tightly bonded to the leaflet to form a sealing structure. The leaflet was then removed to obtain the artificial heart valve composite material.

[0085] Furthermore, the petals used in the above process are prepared in the following manner:

[0086] S1: After plasma treatment of polyester woven fabric, it is immersed in a polyurethane tetrahydrofuran solution with a concentration of 10w / v% (i.e., the mass of solute in each unit volume of solution) for 3 minutes, taken out and dried at 60°C for 5 minutes to obtain a fabric with a third polymer layer on both sides.

[0087] S2: Using a spin-coating method, a 15% (w / v) dimethyl sulfoxide solution of polyurethane is coated onto a glass substrate. A fabric with a third polymer layer is immersed in ethanol, removed, and laid flat on the treated glass substrate. It is then dried at 70°C for 12 hours to form a fourth polymer layer on one side of the fabric with the third polymer layer. Then, the other side of the fabric with the third polymer layer is laid flat on the glass substrate coated with the 15% (w / v) dimethyl sulfoxide solution of polyurethane and dried at 70°C for 12 hours to form a fourth polymer layer on the other side of the fabric with the third polymer layer, thus obtaining a polymeric artificial heart valve composite material that can be used as a leaflet. It should be noted that the leaflets used in other embodiments of this application are all prepared according to the above method.

[0088] The SEM images of the composite material are shown in Figures 1 and 2. Due to the long length of the edge-sealing structure, it cannot be fully visualized in the SEM field of view; only a portion of the edge-sealing structure near the leaflet is visible. After being sewn into a valve, the composite material remained intact after 200 million opening and closing cycles (Figures 4a and 4b). Figure 3 shows the SEM image of the leaflet without edge sealing after 200 million opening and closing cycles. The comparison shows that the composite material obtained by preparing the edge-sealing structure at the leaflet edge in this method exhibits better stability during use. Figures 4a and 4b are SEM images of the junction between the leaflet and the edge-sealing structure at different angles. Figure 4a shows that the edge-sealing structure at the leaflet edge remains intact during use, while Figure 4b shows that no damage occurred at the junction of the leaflet and the edge-sealing structure. This is because the introduction of the edge-sealing structure protects the valve, especially the interface between the fiber and polymer-formed leaflet, and fixes the relative position of the fibers, effectively preventing deformation of the leaflet during use. Example 2

[0089] This embodiment prepares an artificial heart valve composite material, which includes:

[0090] The leaflets are 80 μm thick;

[0091] The sealing structure, which is formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 0.5 mm and a thickness of 40 μm; the second polymer layer has a width of 0.5 mm and a thickness of 80 μm.

[0092] Furthermore, the preparation method of the above-mentioned composite material includes the following steps:

[0093] A 30μm thick PP film is cut into a smaller petal shape to serve as the first film material. Another 30μm thick PP film is cut to remove a larger petal shape in the middle to obtain a hollowed-out shielding film, which serves as the second film material. The petal is flatly attached to the substrate surface, and then the first film is attached to the surface of the petal. The second film is then attached to the substrate surface, so that the petal covered with the first film is placed within the hollowed-out area of ​​the second film, ensuring that the geometric centers of the first film, the second film, and the petal coincide. A first polymer region with a width of 0.5mm is formed between the edge of the first film and the edge of the petal. A second polymer region with a width of 0.5mm is formed between the edge of the second film near the petal and the edge of the first film. The petal is 80μm thick, and its preparation method is the same as in Example 1, and will not be repeated here.

[0094] Next, a 20 w / v % polyurethane-N,N-dimethylformamide solution is coated onto the substrate to form a 500 μm thick liquid film. Then, the first and second films are peeled off from the substrate surface in sequence to form a first polymer solution layer in the first polymer region and a second polymer solution layer in the second polymer region. Next, the substrate is immersed in water for 30 seconds for preliminary shaping. Finally, the first and second polymer solution layers are dried and tightly bonded to the leaflet to form a sealing structure. The leaflet is then removed to obtain the artificial heart valve composite material. Example 3

[0095] This embodiment prepares an artificial heart valve composite material, which includes:

[0096] The leaflets are 50 μm thick;

[0097] The sealing structure, which is formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 2 mm and a thickness of 25 μm; the second polymer layer has a width of 1 mm and a thickness of 50 μm.

[0098] Furthermore, the preparation method of the above-mentioned composite material includes the following steps:

[0099] A 50μm thick silicone film is cut into a smaller petal shape to serve as the first film material. Another 50μm thick silicone film is cut to remove a larger petal shape in the middle, resulting in a hollowed-out shielding film to serve as the second film material. The petal is flatly attached to the substrate surface, and then the first film is attached to the surface of the petal. The second film is then attached to the substrate surface, with the petal covered by the first film placed within the hollowed-out area of ​​the second film. The geometric centers of the first film, the second film, and the petal are aligned. A first polymer region with a width of 2mm is formed between the edge of the first film and the edge of the petal. A second polymer region with a width of 1mm is formed between the edge of the second film near the petal and the edge of the first film. The thickness of the petal is 50μm.

[0100] Next, a polyurethane-dimethyl sulfoxide solution with a mass-volume fraction of 15 w / v is coated onto the substrate to form a liquid film with a thickness of 1000 μm. Then, the first and second films are peeled off in sequence to form a first polymer solution layer in the first polymer region and a second polymer solution layer in the second polymer region. Next, the substrate is immersed in water for 40 seconds for preliminary shaping. Finally, after drying, the liquid film is tightly bonded to the leaflet to form a sealing structure. The leaflet is then removed to obtain the artificial heart valve composite material. Example 4

[0101] This embodiment prepares an artificial heart valve composite material, which includes:

[0102] The leaflets are 150 μm thick.

[0103] The sealing structure, which is formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 0.2 mm and a thickness of 75 μm; the second polymer layer has a width of 0.06 mm and a thickness of 150 μm.

[0104] Furthermore, the preparation method of the above-mentioned composite material includes the following steps:

[0105] A polyurethane-based fabric-reinforced composite material was taken and cut into leaflet shape as the leaflet. Then, the leaflet was flatly attached to the surface of the silicone plate at a predetermined position. A closed polymer solution flow line with a line width of 1 mm was formed at the edge of the leaflet by manual injection. The relative position of the flow line and the leaflet is shown in Figure 5. The extruded fluid simultaneously covers the leaflet and the outside of the leaflet. The fluid covering the leaflet forms the first polymer layer, and the fluid outside the leaflet forms the second polymer layer. The polymer solution is a polyurethane-N,N-dimethylformamide solution with a mass-volume fraction of 18 w / v. After the leaflet is removed and dried, the above operation is repeated on the other side. The whole thing is dried to obtain the artificial heart valve composite material. The cross-sectional view of the composite material is shown in Figure 6. It was sewn into a valve and remained intact after 200 million opening and closing cycles (Figure 7), which is in stark contrast to the unsealed edge (Figure 3). Example 5

[0106] This embodiment prepares an artificial heart valve composite material, which includes:

[0107] The leaflets are 80 μm thick;

[0108] The sealing structure, which is formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 0.1 mm and a thickness of 40 μm; the second polymer layer has a width of 50 μm and a thickness of 80 μm.

[0109] Furthermore, the preparation method of the above-mentioned composite material includes the following steps:

[0110] A polyurethane-based fabric-reinforced composite material is taken and cut into leaflet shapes. The leaflets are then flatly attached to the surface of a silicone plate at predetermined positions. A complete polymer solution flow line with a line width of 0.5 mm is formed at the edge of the leaflet using a machine injection method. The extruded fluid simultaneously covers both the leaflet and the outside of the leaflet. The fluid covering the leaflet forms the first polymer layer, and the fluid on the outside of the leaflet forms the second polymer layer. The polymer solution is a polyurethane-N,N-dimethylacetamide solution with a mass-volume fraction of 20 w / v. After removing and drying the leaflet, the above operation is repeated on the other side. The entire assembly is then dried to obtain the artificial heart valve composite material. Example 6

[0111] This embodiment prepares an artificial heart valve composite material, which includes:

[0112] The leaflets are 50 μm thick;

[0113] The sealing structure, which is formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 0.4 mm and a thickness of 25 μm; the second polymer layer has a width of 0.1 mm and a thickness of 50 μm.

[0114] Furthermore, the preparation method of the above-mentioned composite material includes the following steps:

[0115] A polyurethane-based fabric-reinforced composite material is taken and cut into leaflet shapes. The leaflets are then flatly attached to the surface of a silicone plate at predetermined positions. A complete polymer solution flow line with a line width of 2 mm is formed at the edge of the leaflet using a machine injection method. The extruded fluid simultaneously covers both the leaflet and the outside of the leaflet. The fluid covering the leaflet forms the first polymer layer, and the fluid on the outside of the leaflet forms the second polymer layer. The polymer solution is a polyurethane-dimethyl sulfoxide solution with a mass-volume fraction of 15 w / v. After removing and drying the leaflet, the above operation is repeated on the other side. The entire assembly is then dried to obtain the artificial heart valve composite material.

[0116] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A composite material for artificial heart valves, characterized in that, include: Petals; The sealing structure, formed in the edge region of the leaflet and tightly bonded to the leaflet, includes a first polymer layer attached to the leaflet and a second polymer layer extending outward from the edge of the leaflet. The first polymer layer has a width of 0.05-5 mm and a thickness of 25-100 μm; the second polymer layer has a width of 0.01-2 mm and a thickness of 50-200 μm, and the thickness of the artificial heart valve composite material is 50-200 μm.

2. The artificial heart valve composite material according to claim 1, characterized in that, The leaflets include: Fabrics; Two third polymer layers are respectively disposed on both sides of the fabric; At least one fourth polymer layer is disposed on the surface of at least one of the third polymer layers, and the contact surfaces of the third polymer layer and the fourth polymer layer are interlocked, wherein the surface roughness of the side of the fourth polymer layer away from the third polymer layer is 80-150 nm.

3. The prosthetic heart valve composite of claim 1, wherein, The method for preparing the petal includes the following steps: The fabric is immersed in a first polymer solution and dried for the first time to obtain a fabric with third polymer layers on both sides; a second polymer solution is coated on a smooth first substrate surface; the fabric with the third polymer layer is immersed in a poor solvent to form a fourth polymer layer on the surface of at least one of the third polymer layers; the fabric is laid flat on the first substrate so that one of the third polymer layers on the fabric surface comes into contact with the second polymer solution; after a second drying, a fourth polymer layer is formed on the surface of one of the third polymer layers, the side of the fourth polymer layer away from the third polymer layer is smooth, and the poor solvent can promote the interlocking of the contact surfaces of the third polymer layer and the fourth polymer layer.

4. A method of producing a prosthetic heart valve composite material as claimed in any one of claims 1 to 3, characterized in that, The composite material is prepared by forming an edge-sealing structure at the edge of the leaflet using a one-step or two-step method. The one-step method includes the following steps: a second film material is disposed on the surface of a substrate; a first film material and a leaflet are disposed within a hollow area of ​​the second film material; a first polymer region is formed between the edge of the first film material and the edge of the leaflet; a first polymer layer is formed within the first polymer region; a second polymer region is formed between the edge of the hollow area on the second film material near the leaflet and the edge of the first film material; a second polymer layer is formed within the second polymer region; wherein the size of the hollow area is larger than the leaflet, and both the first film material and the leaflet can be accommodated within the hollow area; The two-step method includes the following steps: laying the leaflets flat on the substrate surface, and then forming closed polymer solution layers around the edges of the leaflets on both sides of the leaflet to form a sealing structure at the edges of the leaflets.

5. The preparation method according to claim 4, characterized in that, The one-step method includes the following steps: After the leaflets are laid flat on the substrate surface, a first film material is laid flat on the leaflet surface, and then a second film material is laid flat, ensuring that the center of the leaflets and the first film material coincides with the center of the second film material, and that the leaflets and the first film material are completely contained within the hollow area of ​​the second film material; a first polymer region is formed between the edge of the first film material and the edge of the leaflets, and a second polymer region is formed between the edge of the second film material near the leaflets and the edge of the first film material; wherein, the size of the first film material is smaller than that of the leaflets; A polymer solution layer is coated onto the surface of a substrate covered with a first membrane material, a second membrane material, and a leaflet. The first and second membrane materials are then peeled off, forming a first polymer solution layer in a first polymer region and a second polymer solution layer in a second polymer region. The entire substrate is then immersed in a first solvent to allow the polymer solution layer to initially set. After drying and curing, the leaflet is tightly bonded to the first and second polymer layers and then separated from the substrate, thus obtaining an artificial heart valve leaflet composite material. The first polymer layer has a width of 1-5 mm and a thickness of 25-100 μm; the second polymer layer has a width of 0.1-2 mm and a thickness of 50-200 μm; and the artificial heart valve leaflet composite material has a thickness of 50-200 μm.

6. The preparation method according to claim 5, characterized in that, The width of the first polymer region is 1-5 mm, and the width of the second polymer region is 0.1-2 mm; the first solvent is a poor solvent for the polymer in the polymer solution, and it is one or more of water, alcohols, and ketones.

7. The preparation method according to claim 4, characterized in that, The two-step method includes the following steps: The leaflet is placed on the substrate surface, and a closed polymer solution layer is formed at the edge of the leaflet by manual or machine injection. The polymer solution layer consists of at least one polymer solution flow line, which covers both the leaflet and the outside of the leaflet. The fluid covering the leaflet forms the first polymer layer, and the fluid outside the leaflet forms the second polymer layer. The leaflet is removed and dried, and the above steps are repeated to form polymer solution flow lines on the other side of the leaflet. After overall drying, an edge sealing structure is formed at the edge of the leaflet to obtain the artificial heart valve composite material. The width of the first polymer layer is 0.05-1 mm, and the thickness is 25-100 μm. The width of the second polymer layer is 0.01-0.1 mm, and the thickness is 50-200 μm. The thickness of the artificial heart valve composite material is 50-200 μm.

8. The preparation method according to claim 7, characterized in that, The width of the polymer solution flow lines is 0.5-2 mm, and the width of the sealing structure is 0.06-1.1 mm.

9. The preparation method according to claim 4, characterized in that, The polymer solution has a mass-volume fraction of 10-25 w / v, and the solute is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, and styrene-isobutylene copolymer, and the solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane.

10. The preparation method according to claim 4, characterized in that, The first and second membrane materials are made of one or more of polytetrafluoroethylene, polyester, polyvinyl chloride, polypropylene, polyethylene, and silicone, and both have a thickness of 30-100μm; the substrate has a thickness of 3-8mm and is made of at least one of glass, stainless steel, polyacetal, and polytetrafluoroethylene.

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