Artificial valve, valve leaflet for artificial valve and preparation method of valve leaflet

Abstract

The invention discloses an artificial valve, a valve leaflet for the artificial valve and a preparation method of the valve leaflet, the valve leaflet comprises a body, the edge part comprises a free edge and a fixed edge which are opposite, and the body is made of a first high polymer material; the first reinforcing edge is distributed along the fixing edge, the first reinforcing edge is made of a second high polymer material and is provided with a pore structure, and the first high polymer material enters the pore structure and is fixed with the first reinforcing edge. The artificial valve leaflet is good in blood compatibility, high in tearing strength and long in service life, and the effective opening area and the reflux ratio of a valve made of the valve leaflet are better.

Description

Artificial valve, leaflet for artificial valve and preparation method thereof Technical Field

[0001] The present application relates to the technical field of medical materials, and in particular to artificial valves, leaflets for artificial valves, and preparation methods thereof. Background Art

[0002] Currently, artificial heart valves have received extensive attention and research as a treatment for heart valve disease. Artificial heart valves primarily include the aortic valve, pulmonary valve, mitral valve, and tricuspid valve. They replace the function of natural heart valves, controlling the unidirectional flow of blood and thus enabling normal function of the human heart.

[0003] Common artificial heart valves are mainly divided into mechanical valves, biological valves, and polymer valves according to the type of leaflet material. First of all, mechanical valves have a long service life, but they are mainly implanted through surgery, which causes great damage to the human body. At the same time, their biocompatibility is poor, so long-term use of anticoagulants is required, which may cause complications. Biological valves are currently more widely used and cause less damage to the human body, but they have problems such as short service life and poor tolerance. Therefore, in recent years, the research on polymer valves has received widespread attention. This is mainly because the characteristics of the polymer material itself give it good biocompatibility, long service life, good flexibility, and flexibility to obtain good fluid mechanics properties.

[0004] For example, the polymer leaflet materials with a wide range of applications currently include polyurethanes, polyolefins, and polysiloxanes. These materials have been widely used in the preparation of implantable medical devices and have been proven to have excellent high elasticity, good biocompatibility, and flexibility. At the same time, compared with biological membranes, polymer leaflets also have the advantages of simple processing technology, uniform thickness and performance, and mass production. However, as people have found, when polymer materials are sutured to the valve frame, the leaflets will encounter uneven force on the leaflets when they are subjected to force, and the leaflets are prone to tearing, which seriously limits the development of polymer valves. Therefore, how to improve the tear resistance of polymer leaflets through optimization of polymer leaflet structure and innovative structural design is one of the most serious problems in the current development of polymer valves.

[0005] Summary of the Invention

[0006] Based on this, an artificial valve, a leaflet for an artificial valve and a preparation method thereof are provided to solve the problem of poor tear strength of polymer film materials.

[0007] The present application provides a leaflet for an artificial valve, comprising:

[0008] A body, wherein the edge portion includes a free edge and a fixed edge relative to each other, and the body is made of a first polymer material;

[0009] The first reinforcing edge is distributed along the fixed edge. The first reinforcing edge is made of the second polymer material and has a pore structure. The first polymer material enters the pore structure and is fixed to the first reinforcing edge.

[0010] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution. They are merely further supplements or optimizations. Under the premise that there are no technical or logical contradictions, each optional method can be combined separately for the above-mentioned overall solution, or multiple optional methods can be combined.

[0011] Optionally, the leaflet for an artificial valve further includes:

[0012] The second reinforcement edge is distributed along the free edge. The second reinforcement edge is made of a third polymer material and has a pore structure. The first polymer material enters the pore structure and is fixed to the second reinforcement edge.

[0013] Optionally, the first reinforcement edge and the second reinforcement edge are made of the same material.

[0014] Optionally, the first reinforcement edge and the second reinforcement edge are an integral structure.

[0015] Optionally, the second reinforcement edge is generally strip-shaped and extends with equal width along the free edge.

[0016] Optionally, the first reinforcement edge extends outwards adjacent to the free edge to form a hanging ear sewn to the bracket.

[0017] Optionally, the first reinforced edge is in the shape of a sheet with uniform thickness, and the thickness of the first reinforced edge is 0.01-0.3 mm; the second reinforced edge is in the shape of a sheet with uniform thickness, and the thickness of the second reinforced edge is 0.01-0.3 mm.

[0018] Optionally, the first reinforced edge is in the shape of a sheet with uniform thickness, and the thickness of the first reinforced edge is 0.05 to 0.2 mm; the second reinforced edge is in the shape of a sheet with uniform thickness, and the thickness of the second reinforced edge is 0.05 to 0.2 mm.

[0019] Optionally, the first reinforcement edge and the second reinforcement edge have the same thickness.

[0020] Optionally, the leaflet includes: a first region avoiding the first reinforcement edge and / or the second reinforcement edge and a second region overlapping with the first reinforcement edge and / or the second reinforcement edge, and the first region and the second region are substantially of equal thickness.

[0021] Optionally, the thickness of the leaflet is 0.07 to 0.5 mm.

[0022] Optionally, the first polymer material is at least one of polyurethane, polyolefins, and polysiloxanes.

[0023] Optionally, the second polymer material is in the form of fabric, and the raw material is one of polyester, aramid, nylon, silk, and polyurethane.

[0024] Optionally, the third polymer material is in the form of fabric, and the raw material is one of polyester, aramid, nylon, silk, and polyurethane.

[0025] Optionally, the fabric is non-woven fabric or woven fabric.

[0026] Optionally, the fabric is a weft-knitted fabric with a porosity of 30-80%.

[0027] Optionally, the first polymer material is polyurethane or polyolefin, and the second polymer material and the third polymer material are each independently polyester or nylon.

[0028] Optionally, the first polymer material is polyurethane, and the second polymer material and the third polymer material are both polyester.

[0029] Optionally, the first polymer material, the second polymer material, and the third polymer material are prepared using the same type of monomers.

[0030] Optionally, the first polymer material is polyurethane with a number average molecular weight of 30,000 to 200,000 and a hard segment content of 35 to 50%;

[0031] The second high molecular material and the third high molecular material are both polyurethane, with a number average molecular weight of 80,000 to 250,000 and a hard segment content of 45 to 60%. They are in the form of electrostatically spun non-woven fabrics.

[0032] Optionally, the first polymer material is polyurethane with a number average molecular weight of 70,000 and a hard segment content of 42%;

[0033] The second polymer material and the third polymer material are both polyurethane, with a number average molecular weight of 120,000 and a hard segment content of 52%; and are in the form of electrostatically spun non-woven fabrics.

[0034] The present application also provides a leaflet processing method and a leaflet obtained by using the processing method.

[0035] The processing method comprises:

[0036] Providing a sheet-shaped reinforcing material, wherein the reinforcing material itself has a porous structure and a reserved area;

[0037] Compounding the first polymer material in a fluid state with the reinforcing material;

[0038] The first polymer material is solidified, and the reinforcing material and / or the solidified first polymer material are cut according to a preset shape to obtain the leaflet, and the position of the leaflet with the reinforcing material is the reinforcing edge.

[0039] Optionally, the reserved area is a hollow area on the reinforcing material, and the edge of the hollow area is partially open, or the edge of the hollow area is a closed curve.

[0040] Optionally, the first polymer material in a flowing state includes: a solution form or a molten state form, and the viscosity of the first polymer material in a flowing state is 0.4-2.0 Pa.s.

[0041] Optionally, the melting temperature of the first polymer material in molten state is 150-300°C.

[0042] Optionally, when the edge of the hollow area is a closed curve, the reinforcing material includes:

[0043] A first reinforcement area, one side of which faces the reserved area and corresponds to the position of the fixed edge of the valve leaflet, and the other side of which extends away from the reserved area;

[0044] The second reinforcement area has one side facing the reserved area and corresponding to the position of the free edge of the valve leaflet, and the other side extending away from the reserved area.

[0045] Optionally, the first reinforcement area and the second reinforcement area can be made of a second polymer material and woven as a whole, and then hollowed out and cut to form the reserved area, or the first reinforcement area and the second reinforcement area can be woven as a whole and avoid the reserved area during the weaving process.

[0046] The present application provides an artificial valve, comprising:

[0047] Stent, with a blood flow channel inside;

[0048] One or more leaflets, each leaflet adopts the leaflet described in this application, the first reinforcing edge is fixed to the bracket, and the free edge of the leaflet and the inner wall of the bracket, or the free edges of multiple leaflets cooperate with each other to control the blood flow channel.

[0049] The artificial valve leaflet provided in this application has good blood compatibility, high tear resistance, and long service life. The valve made of the valve leaflet has a better effective opening area and regurgitation ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic structural diagram of a forming mold;

[0051] FIG2 is a schematic diagram of the structure of the fabric with a reserved area after cutting;

[0052] FIG3 is a schematic diagram of the structure of the fabric with the reserved area after cutting;

[0053] FIG4 is a schematic diagram of the structure of the fabric with the reserved area after cutting;

[0054] FIG5 is a schematic diagram of a leaflet structure with a first reinforced edge;

[0055] FIG6 is a schematic diagram of the structure of the fabric with the reserved area after cutting;

[0056] FIG7 is a schematic diagram of a leaflet structure having both a first reinforcement edge and a second reinforcement edge;

[0057] FIG8 is a graph showing the test results of platelet adsorption.

[0058] In the figure: 1. leaflet; 11. body; 2. reinforcement edge; 21. first reinforcement edge; 22. second reinforcement edge; 31. free edge; 32. fixed edge; 5. reinforcement material; 51. first reinforcement area; 52. second reinforcement area; 6. reserved area; 7. mold; 71. settlement area. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0060] In order to better describe and illustrate the embodiments of the present application, reference may be made to one or more drawings, but the additional details or examples used to describe the drawings should not be considered as limiting the scope of the invention of the present application, any of the currently described embodiments or preferred methods.

[0061] It should be noted that when a component is referred to as being "connected" to another component, it may be directly connected to the other component or there may be an intermediate component. When a component is referred to as being "disposed on" another component, it may be directly disposed on the other component or there may be an intermediate component.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0063] As shown in FIG5 , the leaflet for an artificial valve includes:

[0064] The body 11 has an edge portion including a free edge 31 and a fixed edge 32 facing each other, and the body 11 is made of a first polymer material;

[0065] The first reinforcement edge 21 is distributed along the fixed edge 32 . The first reinforcement edge 21 is made of the second polymer material and has a pore structure. The first polymer material enters the pore structure and is fixed to the first reinforcement edge 21 .

[0066] The fixed edge 32 of the main body 11 is usually the part where the suture passes through during suturing, and is more likely to tear due to the presence of pinholes. The present application provides a first reinforcing edge 21 at the fixed edge 32 of the main body 11 of the leaflet 1, that is, the easily torn part and / or the stress concentration part of the polymer leaflet 1 is reinforced to improve the tear resistance of the leaflet 1 and extend the service life of the valve. At the same time, the free edge 31 of the main body 11 is not reinforced to ensure the softness of the leaflet 1 and the sensitivity of opening and closing the blood flow channel.

[0067] The first reinforcing edge 21 is distributed along the fixed edge 32 to improve the strength of the fixed edge 32. When sutures are used to perforate and connect to the bracket, the strength, fatigue resistance and tear resistance of the connection part can be improved while ensuring the sensitivity of the free edge 31.

[0068] The first polymer material enters the void structure of the second polymer material. After solidification, the first polymer material and the reinforcing material form a close microstructural bond, making the fixed relationship between the first polymer material and the reinforcing material 5 tighter and the bonding strength greater.

[0069] The first reinforcement edge 21 is generally strip-shaped and extends along the fixed edge 32 with equal width, or,

[0070] The first reinforcement edge 21 is generally strip-shaped, and its width has a gradual trend in the process of extending along the fixed edge 32 , wherein the midpoint of the fixed edge 32 is the widest and gradually narrows toward the intersection with the free edge 31 .

[0071] As shown in FIG7 , the leaflet 1 for an artificial valve further includes:

[0072] The second reinforcement edge 22 is distributed along the free edge 31 . The second reinforcement edge 22 itself has a pore structure. The first polymer material enters the pore structure and is fixed to the second reinforcement edge 22 .

[0073] The second reinforcement edge 22 is made of a third polymer material, which can be the same material as the first reinforcement. It is further preferred that the first reinforcement edge 21 and the second reinforcement edge 22 are an integral structure.

[0074] Similarly, the second reinforcement edge 22 is generally strip-shaped and extends with equal width along the free edge 31 .

[0075] When the artificial valve is working, the free edge 31 of the leaflet 1 moves continuously to close and open the blood flow channel inside the valve. In order to further improve the fatigue resistance of the free edge 31, the second reinforcement edge 22 can be used to reinforce the free edge 31.

[0076] The first reinforcing edge 21 extends outward adjacent to the free edge 31 to form a lug for sewing to the bracket. If a second reinforcing edge 22 is present, the lug extends generally from the intersection of the first and second reinforcing edges 21, 22. The outward expansion of the first reinforcing edge 21 is understood to mean away from the center of the body 11, for example, upward and / or further to the left and right in FIG7 .

[0077] As shown in Figure 7, the width of the second reinforced edge 22 (shown as d in the figure) is 0.1-5mm. Generally, the stress at the center hole position of the valve (i.e., position d) is relatively large, and reinforcement is performed at the free edge 31 to reduce the risk of tearing of the leaflet 1. At the same time, since the width of the reinforced position is small, it will not affect the flexibility of the leaflet 1.

[0078] When the leaflet 1 is sewn onto the stent, the ear portion needs to ensure the connection strength with the stent to ensure the effect of the free edge 31 in controlling blood flow. The ear portion is made of both the main body 11 and the reinforcement edge 2 materials.

[0079] In this application, unless otherwise stated, the reinforcing edge 2 is understood to be any one of the first reinforcing edge 21 and the second reinforcing edge 22, and the physical and chemical properties such as materials and dimensions of the two can be configured independently. In the case of an integrated structure, it can also be understood as the common properties of the two.

[0080] The reinforcement edge 2 is a sheet with uniform thickness, and the thickness of the reinforcement edge 2 is 0.01-0.3 mm, preferably 0.05-0.2 mm. Too thick is not conducive to obtaining a smaller compressed size, especially increasing the hardness at the second reinforcement edge 22 will reduce the sensitivity of the leaflet 1 to open and close.

[0081] The thickness of the reinforced edge 2 is substantially the same at all locations to avoid stress concentration due to different thicknesses.

[0082] The leaflet 1 includes a first region avoiding the reinforcement edge 2 and a second region overlapping with the reinforcement edge 2 , and the first region and the second region are substantially of equal thickness.

[0083] In the case of only the first reinforced edge 21 , the leaflet 1 includes: a first region avoiding the first reinforced edge 21 and a second region overlapping with the first reinforced edge 21 , and the first region and the second region are substantially of equal thickness.

[0084] When the first reinforcement edge 21 and the second reinforcement edge 22 are set at the same time, the leaflet 1 includes: a first area avoiding the first reinforcement edge 21 and the second reinforcement edge 22 and a second area overlapping with the first reinforcement edge 21 and the second reinforcement edge 22, and the first area and the second area are substantially the same thickness.

[0085] The first region and the second region have the same thickness, which can avoid loading obstacles caused by excessive thickness of the reinforcement edge 2. After the entire valve is compressed, there will be no obvious difference in the outer diameter of each part.

[0086] The thickness of the leaflet 1 is 0.01 to 0.5 mm. Furthermore, the thickness of the leaflet 1 is 0.07 to 0.5 mm.

[0087] The first region and the second region present an integrated structure due to the distribution of the polymer material and the penetration and fusion between them and the reinforcing edge 2. As for the body 11 itself, it can be formed by casting the first polymer material.

[0088] Under ideal conditions, the thickness of the leaflet 1 is the same at all locations, that is, the thickness is basically the same. Minor differences caused by process limitations during the preparation process can be ignored and are still considered to be basically the same.

[0089] The first polymer material is at least one of polyurethane, polyolefins, and polysiloxanes.

[0090] The first polymer material is usually a castable or thermoformable material. The first polymer material, as the body 11 , must meet basic requirements for the leaflet 1 , such as sufficient strength and creep resistance.

[0091] The first polymer material is an elastic material, that is, the first polymer material has appropriate elasticity after being cured and has stronger fatigue resistance to meet the performance requirements of the leaflet 1.

[0092] The second polymer material and the third polymer material are both in the form of fabrics, and the raw materials of the two are independently one of polyester, aramid, nylon, silk and polyurethane.

[0093] The fabric can be non-woven or woven. Non-woven fabrics can be produced by electrospinning, and woven fabrics can be produced by warp and weft interlacing, or by warp knitting or weft knitting.

[0094] The fabric is preferably a weft-knitted structure with a porosity of 30-80%. The necessary porosity ensures the connection strength after compounding. The fabric wire diameter D is mainly considered in relation to the thickness H of the leaflet 1. The yarn overlap in the thickness direction is N layers, and N*D is less than or equal to H, for example, at least 50% of H.

[0095] The first polymer material and the material of the reinforcing edge 2 need to have good biocompatibility and material compatibility with each other. In the tear-prone parts of the leaflet 1, the material of the reinforcing edge 2 plays a reinforcing role, thereby improving the creep resistance and edge tear resistance of the leaflet 1.

[0096] The first polymer material is preferably polyurethane or polyolefin; the second polymer material and the third polymer material are each preferably polyester or nylon.

[0097] For example, the first polymer material is polyurethane, and the second polymer material and the third polymer material are both polyester.

[0098] The first polymer material, the second polymer material and the third polymer material are prepared by using the same type of monomers.

[0099] The monomers are the same but may have different molecular weights, viscosities or block structures, for example, the first polymer material is polyurethane with a number average molecular weight of 30,000 to 200,000 and a hard segment content of 35 to 50%;

[0100] The second high molecular material and the third high molecular material are both polyurethane, with a number average molecular weight of 80,000 to 250,000 and a hard segment content of 45 to 60%. They are in the form of electrostatically spun non-woven fabrics.

[0101] Polyurethane is prepared by the reaction of isocyanate and polyol. The hard segment mainly refers to the isocyanate residue after the reaction. In some cases, the hard segment also includes small molecule chain extenders.

[0102] The first polymer material is polyurethane with a number average molecular weight of 70,000 and a hard segment content of 42%;

[0103] The second polymer material and the third polymer material are both polyurethane, with a number average molecular weight of 120,000 and a hard segment content of 52%; and are in the form of electrostatically spun non-woven fabrics.

[0104] The present application also provides a leaflet processing method, comprising:

[0105] A sheet-shaped reinforcing material 5 is provided. The reinforcing material 5 itself has a porous structure and a reserved area 6, as shown in Figures 2 to 4;

[0106] Compounding the first polymer material in a fluid state with the reinforcing material 5;

[0107] The first polymer material is solidified, and the reinforcing material 5 and / or the solidified first polymer material are cut according to a preset shape to obtain the leaflet 1 , where the position of the leaflet 1 with the reinforcing material is the reinforcing edge.

[0108] The reinforcing material is understood to be either the second polymer material or the third polymer material. Typically, the second polymer material and the third polymer material are the same material, also known as the reinforcing material. In special cases, if the second polymer material and the third polymer material are different materials, the second polymer material and the third polymer material are collectively referred to as the reinforcing material. The portion where the first polymer material and the reinforcing material 5 are composited corresponds to the reinforcing edge 2.

[0109] Compounding the first polymer material in a fluid state with the reinforcing material 5 includes at least one of the following operations:

[0110] (a) making the first polymer material in a flowing state have a desired thickness and immersing the reinforcing material 5 therein;

[0111] (b) Dropping and / or coating the first polymer material on the reinforcing material 5 .

[0112] During the compounding process of the fluid first polymer material and the reinforcing material 5, the fluid first polymer material is distributed to the reserved area 6 and enters the pore structure of the reinforcing material 5 around the reserved area 6. The first polymer material enters the void structure of the second polymer material. After solidification, the first polymer material and the reinforcing material form a close microstructural bond, making the fixed relationship between the first polymer material and the reinforcing material 5 tighter and the bonding strength greater.

[0113] The reserved area 6 is a hollow area on the reinforcing material 5 . When only the first reinforcing edge 21 is used, the edge of the hollow area may be partially open (see FIG. 4 ), for example, open on one side of the free edge 31 .

[0114] The edge of the hollowed-out area is preferably a closed curve (see Figures 2 and 3). A portion of the edge of the hollowed-out area corresponds to the fixed edge 32 of the body 11, and this portion forms the first reinforced edge 21 after processing. Another portion of the edge of the hollowed-out area corresponds to the free edge 31 of the body 11, and this portion forms the second reinforced edge 22 after processing. Both the first reinforced edge 21 and the second reinforced edge 22 form a single unitary structure, both before and after lamination.

[0115] The blank areas in Figures 2-4 are reserved areas 6, the shaded areas are reinforcement material 5, and the dotted lines correspond to the leaflet edges. After the first polymer material is cured and formed, it can be sheared along the dotted lines to form leaflets 1. As shown in Figure 3, the outer edge of the reinforcement material 5 is not limited to a specific shape and can be a common square, diamond, or circular shape, or an irregular shape that closely matches the shape of the settling area of ​​the mold.

[0116] As shown in FIG4 , the shape of the reserved area 6 is not limited to correspond to the shape of the valve, and it only needs to be able to form a leaflet of a predetermined shape during shearing.

[0117] When the first polymer material is distributed to the reserved area 6 , the first polymer material in a flowing state can be coated or injected into the reserved area 6 , and the first polymer material fills the reserved area 6 and completely immerses the fabric pores of the reinforcing material 5 .

[0118] For example, the reinforcing material 5 is placed horizontally, the periphery of the reserved area 6 is fixed, and then the first polymer material is distributed into the reserved area 6 .

[0119] When fixing, the reinforcing material 5 can be clamped up and down. Due to the fluid state of the first polymer material, it can penetrate into the clamped part. The clamping fixation can ensure the positioning effect and obtain the expected thickness accurately.

[0120] Preferably, the entire area corresponding to the reinforcing edge 2 is clamped. In order to promote the penetration of the first polymer material, a vacuum can be applied to the periphery of the clamping area (the side facing away from the reserved area 6).

[0121] This process can be achieved using a mold 7 . For example, the reinforcing material 5 is placed in the mold 7 , and the first polymer material in a flowing state is poured into the mold 7 . The structure of the mold 7 is shown in FIG. 1 .

[0122] The mold 7 can be made of materials such as tetrafluoroethylene and stainless steel, and has a sedimentation area 71 on the surface for laying the reinforcing material 5 and leveling the first polymer material. There is no strict limit on the depth of the sedimentation area 71, and the thickness of the leaflet 1 can be converted according to the material consumption.

[0123] As shown in Figure 2, when only the first reinforcing edge 21 exists, after cutting, the free edge 31 of the leaflet 1 is entirely formed by the solidified first polymer material, that is, the free edge 31 part of the leaflet 1, and there is no reinforcing material 5 (see Figure 5).

[0124] As shown in Figure 6, when the first reinforcement edge 21 and the second reinforcement edge 22 exist at the same time, after cutting along the dotted line in Figure 6, the free edge 31 of the leaflet 1 has the first reinforcement edge 21, and the fixed edge of the leaflet has the second reinforcement edge 22. The leaflet structure is shown in Figure 7.

[0125] As shown in Figure 7 , the width of position d ranges from 0.1 to 5 mm. Generally, stress is greater at the central orifice of the valve (i.e., position d). Therefore, reinforcement is performed at free edge 31 to reduce the risk of leaflet 1 tearing. Since the width of the reinforcement is relatively small, it does not affect the flexibility of leaflet 1.

[0126] The first polymer material in a flowing state includes: solution form or molten state form, and the viscosity of the first polymer material in the flowing state is 0.4-2.0 Pa.s to ensure sufficient leveling of the first polymer material in the reserved area 6 and sufficient penetration into the fabric pores of the reinforcing material 5.

[0127] The mass fraction of the first polymer material in solution is 1 to 20%. The solvent can be at least one of N'N-dimethylacetamide, N'N-dimethylformamide, dimethyl sulfoxide, cyclohexane, and xylene, or a mixed solvent of at least one of the four with acetone, toluene, tetrahydrofuran, or the like.

[0128] The preferred solvent for polyurethane is N'N-dimethylacetamide, the preferred solvent for polyolefin is cyclohexane, and the preferred solvent for polysiloxane is xylene.

[0129] The melting temperature of the first polymer material in a molten state is 150 to 300°C.

[0130] When the first polymer material in the form of a solution is solidified, the solvent is evaporated, that is, a solid structure is formed by simple solvent evaporation.

[0131] When the first polymer material in a molten state is formed, the temperature is lowered so that the first polymer material can obtain a fixed shape.

[0132] After the first polymer material is solidified, laser cutting can be used to obtain a leaflet 1 of a preset shape. The surface of the leaflet 1 can be further modified to be anti-coagulant to improve the blood compatibility of the leaflet 1.

[0133] In order to obtain a leaflet 1 product with uniform thickness, the following two steps are performed alternately 1 to 10 times, and then cut according to the preset shape:

[0134] a) compounding the first polymer material in a fluid state with the reinforcing material 5;

[0135] b) curing the first polymer material.

[0136] Each alternation includes performing step a) and step b) once.

[0137] It can avoid adverse consequences such as uneven thickness or wrinkling caused by one-time curing.

[0138] When the edge of the hollow area is a closed curve, the reinforcing material 5 includes the following parts surrounding the reserved area 6:

[0139] The first reinforcement area 51 has one side facing the reserved area 6 and corresponding to the position of the fixed edge 32 of the leaflet 1, and the other side extending away from the reserved area 6;

[0140] The second reinforcement area 52 has one side facing the reserved area 6 and corresponding to the position of the free edge 31 of the leaflet 1 , and the other side extending away from the reserved area 6 .

[0141] The first reinforcement area 51 and the second reinforcement area 52 surround each other to form a reserved area 6. When cutting according to the preset shape, the second reinforcement area 52 is cut off so that the free edge 31 is only the first polymer material. The first reinforcement area 51 can either correspond exactly to the first reinforcement edge 21 (that is, the periphery does not need to be cut), or it can be further expanded relative to the first reinforcement edge 21. The expanded part needs to be cut. The expanded part is more conducive to clamping and fixing, as well as the diffusion of the first polymer material, reducing the requirements for processing accuracy and process.

[0142] As shown in Figure 2, the angle of the hollow area corresponding to the junction between the free edge and the fixed edge is acute. This prevents curling of the edges during the first polymer solution casting process, ensuring a snug fit when the two materials are combined, significantly improving the yield rate. Fabrics of varying sizes, hollow area shapes, and areas are prepared to meet the leaflet requirements of different valve models, specifications, and designs.

[0143] As shown in FIG2 , although the second reinforced region 52 is ultimately trimmed, its presence during the molding process ensures the overall flatness of the first reinforced region 51, particularly in the areas on both sides of the free edge 31, thereby preventing localized wrinkles and undesirable internal stress. Of course, a portion of the second reinforced region 52 can be retained to form the second reinforced edge 22.

[0144] 2 and 3 , the first reinforcement area 51 and the second reinforcement area 52 can be made of the second polymer material and woven as a whole, and then hollowed out and cut to form the reserved area 6 , or the first reinforcement area 51 and the second reinforcement area 52 can be woven as a whole and avoid the reserved area 6 during the weaving process.

[0145] When hollowing out the integrally woven reinforcement material 5 for the first reinforcement area 51 and the second reinforcement area 52 , laser cutting can be used to adjust the cutting range according to the shape and size of the leaflet 1 to obtain a reserved area 6 of a desired shape.

[0146] In one embodiment, the method for manufacturing the leaflet 1 includes the following steps:

[0147] (1) A certain amount of polyurethane (the first polymer material) was dissolved in an N,N-dimethylacetamide solution, heated to 80°C, and stirred for 12 hours until the polyurethane was fully dissolved to prepare a polyurethane solution with a mass concentration of 12%.

[0148] (2) PET fabric (the second polymer material) was cut into the corresponding size using a laser cutter (as shown in Figure 2). The cut fabric was placed in a mold, and the polyurethane solution was poured into it. The fabric was then placed in a forced air drying oven at 60 degrees Celsius and dried for 12 hours.

[0149] The above operation was repeated 5 times to obtain a polymer composite membrane material with a thickness of 0.15 mm.

[0150] (3) The cutting position of the cutting machine is accurately positioned to obtain a locally reinforced leaflet 1. The structure of the leaflet 1 is shown in FIG5 . The locally reinforced first reinforcement edge 21 is located at the sewing position of the leaflet 1.

[0151] The performance characteristics of the locally reinforced leaflet 1 and the non-reinforced leaflet 1 (no PET fabric added, other preparation conditions are the same) prepared by the above embodiment are shown in Table 1.

[0152] Table 1

[0153] As can be seen from Table 1, compared with the non-reinforced leaflet 1, the tensile strength and Young's modulus of the reinforced leaflet 1 are significantly improved, the elongation at break is reduced, and the suturing force is significantly increased, indicating that the first reinforced edge 21 made of fabric can effectively improve the mechanical properties of the material and avoid the risk of tearing at the suture site.

[0154] In one embodiment, the method for manufacturing the leaflet 1 includes the following steps:

[0155] (1) Take a certain amount of polyurethane material (first polymer material) and heat it to 220°C to reach a molten state.

[0156] (2) PET fabric (the second polymer material) is cut into corresponding sizes using a laser cutting machine, and the cut fabric is placed in a mold; while hot, molten polyurethane is poured into the mold, and the mold is slowly cooled to room temperature, and the polymer material is formed.

[0157] (3) The cutting position of the cutting machine is accurately positioned. The leaflet 1 obtained by cutting is shown in FIG7 . The suture position of the leaflet 1 has a first reinforcement edge 21 . At the same time, the free edge 31 of the leaflet 1 has a second reinforcement edge 22 with a width of 0.1-5 mm, which further reduces the risk of tearing at the free edge 31 of the leaflet 1 .

[0158] As shown in Figure 7 , the width of position d is 0.1-5 mm. Generally, the central orifice of the valve (i.e., position d) experiences greater stress. Therefore, reinforcement is performed at free edge 31 to reduce the risk of leaflet 1 tearing. Since the width of the reinforcement is relatively small, it does not affect the flexibility of leaflet 1.

[0159] In one embodiment, the method for manufacturing the leaflet 1 includes the following steps:

[0160] (1) A certain amount of polyurethane (the first polymer material) was dissolved in an N,N-dimethylacetamide solution, heated to 80°C, and stirred for 12 hours until the polyurethane was fully dissolved to prepare a polyurethane solution with a mass concentration of 12%.

[0161] (2) PET fabric (the second polymer material) is cut into corresponding sizes using a laser cutting machine. The cut fabric is placed in a mold and poured with polyurethane solution; it is placed in a blast drying oven at a temperature of 60 degrees Celsius and dried for 12 hours.

[0162] The above operation was repeated 5 times to obtain a polymer composite membrane material with a thickness of 0.15 mm.

[0163] (3) The cutting position of the cutting machine is accurately positioned to obtain a locally reinforced leaflet 1. The structure of the leaflet 1 is shown in FIG5 . The locally reinforced first reinforcement edge 21 is located at the sewing position of the leaflet 1.

[0164] (4) Place the locally reinforced leaflet 1 in a plasma discharge machine, use CO2 gas as the reaction gas, and adjust the air flow to 20cm 3 / min, power is 180W, processing time is 10min.

[0165] The locally reinforced leaflet 1 was immersed in a heparin-based coating solution (which can also be an amphiphilic coating solution, such as carboxybetaine, sulfobetaine, or choline phosphate) at 5 μg / mL and a pH of 7.4. 100 mmol / L of EDC condensing agent was then added. The solution was then shaken on a shaker at 20°C for 2 hours. The fiber membrane was then removed and washed three times with PBS to obtain the surface-modified, locally reinforced leaflet 1.

[0166] Adhesion to platelets:

[0167] The LDH content released by platelets adsorbed on the material is measured to detect the material's adhesion to platelets. Specific experimental process:

[0168] (1) After the sample membrane is exposed to fresh platelet-rich plasma at 37°C for 30 minutes, the membrane is carefully washed with PBS;

[0169] (2) After air drying, add 150 μL of LDH release reagent diluted 10-fold with PBS to the well plate and shake the 96-well plate to mix evenly. Then, place it in a 37°C incubator and incubate for 1 hour.

[0170] (3) Take 120 μL of supernatant from each well and add it to a new 96-well plate. Then, add three solutions (lactic acid solution, enzyme solution, and 1X INT solution) in a volume ratio of 1:1:1 to prepare the detection solution. Add 60 μL of detection solution to the supernatant of each well, mix well, and incubate on a horizontal shaker for 25 minutes (the incubation time can be selected within the range of 20-30 minutes) under light-proof conditions at room temperature. Then, use a microplate reader to detect the absorbance of the solution at 490 nm. The test results show that the surface-treated polymer film has good anti-platelet adhesion.

[0171] The present application also provides a valve, comprising:

[0172] Stent, with a blood flow channel inside;

[0173] One or more leaflets 1, the first reinforcement edge 21 is fixed to the stent, and the free edge 31 of the leaflet 1 and the inner wall of the stent, or the free edges 31 of the multiple leaflets 1 cooperate with each other to control the blood flow channel.

[0174] The stent is a tubular structure with a tubular inner cavity serving as a blood flow channel. Depending on the usage scenario, the stent may or may not be radially deformable.

[0175] Valve products are not limited to aortic valves, mitral valves, tricuspid valves, pulmonary valves, etc. Any valve product with the above structural characteristics can be used, and the leaflet 1 is selected according to actual needs.

[0176] Table 2

[0177] The specific preparation method of the experimental group is as follows:

[0178] (1) A certain amount of polyurethane (the first polymer material) was dissolved in an N,N-dimethylacetamide solution, heated to 80°C, and stirred for 12 hours until the polyurethane was fully dissolved to prepare a polyurethane solution with a mass concentration of 12%.

[0179] (2) PET fabric (second polymer material) was cut into corresponding sizes using a laser cutting machine (as shown in FIG2 ). The cut fabric was placed in a mold and 0.8 mL of polyurethane solution was poured into it. The fabric was then placed in a forced air drying oven at 60 degrees Celsius and dried for 12 hours.

[0180] The above operation was repeated 5 times to obtain a polymer composite membrane material with a thickness of 0.18 mm.

[0181] (3) Positioning the cutting position of the cutting machine, cutting the leaflet 1, and in the locally reinforced leaflet 1 obtained by cutting, as shown in FIG5 , the first reinforcement edge 21 is at the sewing position of the leaflet 1, and the free edge 31 of the leaflet has no reinforcement fabric.

[0182] (4) The leaflets are sewn onto the stent to form a 29 mm self-expanding polymer valve.

[0183] The difference between the control group and the experimental group is that all areas of leaflet 1 are reinforced with fabric.

[0184] As shown in Table 2, the valve fabricated with locally reinforced leaflet 1 showed an increased effective opening area and a reduced regurgitation ratio, indicating that the locally reinforced leaflet 1 is softer and more flexible. Furthermore, the free edge 31 of the leaflet 1 has a high degree of fit, resulting in less regurgitation. Fatigue resistance testing showed that the valve fabricated with locally reinforced leaflet 1 endured 400 million fatigue cycles, while the unreinforced polymer valve experienced tearing at the suture site after 20 million fatigue cycles. Note: The primary polymer material used in both valves is the same polyurethane material.

[0185] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0186] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A leaflet for an artificial valve, characterized in that: include: A body, wherein the edge portion includes a free edge and a fixed edge relative to each other, and the body is made of a first polymer material; The first reinforcing edge is distributed along the fixed edge. The first reinforcing edge is made of the second polymer material and has a pore structure. The first polymer material enters the pore structure and is fixed to the first reinforcing edge.

2. The leaflet for an artificial valve according to claim 1, wherein: Also includes: The second reinforcement edge is distributed along the free edge. The second reinforcement edge is made of a third polymer material and has a pore structure. The first polymer material enters the pore structure and is fixed to the second reinforcement edge.

3. The leaflet for an artificial valve according to claim 2, wherein: The first reinforcement edge and the second reinforcement edge are made of the same material.

4. The leaflet for an artificial valve according to claim 2, wherein: The first reinforcement edge and the second reinforcement edge are an integrated structure.

5. The leaflet for an artificial valve according to claim 2, wherein: The second reinforcement edge is generally strip-shaped and extends along the free edge with equal width.

6. The leaflet for an artificial valve according to claim 2, wherein: The first reinforcement edge is in the shape of a sheet with uniform thickness, and the thickness of the first reinforcement edge is 0.01-0.3 mm. The second reinforcement edge is in the shape of a sheet with uniform thickness, and the thickness of the second reinforcement edge is 0.01-0.3 mm.

7. The leaflet for an artificial valve according to claim 6, wherein: The first reinforcement edge is in the shape of a sheet with uniform thickness, and the thickness of the first reinforcement edge is 0.05-0.2 mm. The second reinforcement edge is in the shape of a sheet with uniform thickness, and the thickness of the second reinforcement edge is 0.05-0.2 mm.

8. The leaflet for an artificial valve according to claim 2, wherein: The first reinforcement side and the second reinforcement side have the same thickness.

9. The leaflet for an artificial valve according to claim 2, wherein: The leaflet includes: a first region avoiding the first reinforcement edge and / or the second reinforcement edge and a second region overlapping with the first reinforcement edge and / or the second reinforcement edge, and the first region and the second region are substantially of equal thickness.

10. The leaflet for an artificial valve according to claim 2, wherein: The third polymer material is in the form of fabric, and the raw material is one of polyester, aramid, nylon, silk, and polyurethane.

11. The leaflet for an artificial valve according to claim 10, wherein: The fabric is non-woven fabric or woven fabric.

12. The leaflet for an artificial valve according to claim 10, wherein: The fabric is a weft-knitted fabric with a porosity of 30-80%.

13. The leaflet for an artificial valve according to claim 2, wherein: The first polymer material is polyurethane or polyolefin, and the second polymer material and the third polymer material are independently polyester or nylon.

14. The leaflet for an artificial valve according to claim 13, wherein: The first polymer material is polyurethane, and the second polymer material and the third polymer material are both polyester.

15. The leaflet for an artificial valve according to claim 13, wherein: The first polymer material, the second polymer material and the third polymer material are prepared by using the same type of monomers.

16. The leaflet for an artificial valve according to claim 2, wherein: The first polymer material is polyurethane with a number average molecular weight of 30,000 to 200,000 and a hard segment content of 35 to 50%; The second high molecular material and the third high molecular material are both polyurethane, with a number average molecular weight of 80,000 to 250,000 and a hard segment content of 45 to 60%. They are in the form of electrostatically spun non-woven fabrics.

17. The leaflet for an artificial valve according to claim 16, wherein: The first polymer material is polyurethane with a number average molecular weight of 70,000 and a hard segment content of 42%; The second polymer material and the third polymer material are both polyurethane, with a number average molecular weight of 120,000 and a hard segment content of 52%; and are in the form of electrostatically spun non-woven fabrics.

18. The leaflet for an artificial valve according to claim 2, wherein: The first reinforcement edge is adjacent to the free edge and extends outward to form a hanging ear sewn to the bracket.

19. The leaflet for an artificial valve according to claim 2, wherein: The thickness of the leaflet is 0.07-0.5 mm.

20. The leaflet for an artificial valve according to claim 2, wherein: The first polymer material is at least one of polyurethane, polyolefins, and polysiloxanes.

21. The leaflet for an artificial valve according to claim 2, wherein: The second polymer material is in the form of fabric, and the raw material is one of polyester, aramid, nylon, silk, and polyurethane.

22. A method for processing a leaflet, characterized in that: include: Providing a sheet-shaped reinforcing material, wherein the reinforcing material itself has a porous structure and a reserved area; Compounding the first polymer material in a fluid state with the reinforcing material; The first polymer material is solidified, and the reinforcing material and / or the solidified first polymer material are cut according to a preset shape to obtain the leaflet, and the position of the leaflet with the reinforcing material is the reinforcing edge.

23. The leaflet processing method according to claim 22, characterized in that: The reserved area is a hollow area on the reinforcing material, and the edge of the hollow area is partially open, or the edge of the hollow area is a closed curve.

24. The leaflet processing method according to claim 23, characterized in that: The edge of the hollow area is a closed curve, and the reinforcing material includes: A first reinforcement area, one side of which faces the reserved area and corresponds to the position of the fixed edge of the valve leaflet, and the other side of which extends away from the reserved area; The second reinforcement area has one side facing the reserved area and corresponding to the position of the free edge of the valve leaflet, and the other side extending away from the reserved area.

25. The leaflet processing method according to claim 24, characterized in that: The first reinforcement area and the second reinforcement area can be made of a second polymer material and woven as a whole, and then hollowed out and cut to form the reserved area, or the first reinforcement area and the second reinforcement area can be woven as a whole and avoid the reserved area during the weaving process.

26. The leaflet processing method according to claim 22, characterized in that: The first polymer material in a flowing state includes: a solution form or a molten state form, and the viscosity of the first polymer material in a flowing state is 0.4-2.0 Pa.s.

27. The leaflet processing method according to claim 26, characterized in that: The melting temperature of the first polymer material in a molten state is 150 to 300°C.

28. A leaflet for an artificial valve, characterized in that: The product is obtained by the processing method according to any one of claims 22 to 27.

29. An artificial valve, characterized in that: include: Stent, with a blood flow channel inside; One or more leaflets, each leaflet adopts the leaflet described in any one of claims 1 to 21 or claim 28, wherein the first reinforcing edge is fixed to the bracket, and the free edge of the leaflet and the inner wall of the bracket, or the free edges of multiple leaflets cooperate with each other to control the blood flow channel.

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