One-piece polymer leaflet and manufacturing method thereof

Abstract

The present invention discloses an integrally formed polymer leaflet, and its manufacturing method includes: adding the polymer material to a first mold formed by combining a sleeve and a male mold after pre-treatment, the first mold being a formed body formed by the sleeve being sleeved on the outer periphery of the male mold until the polymer material completely covers the male mold; then extending the female mold into the sleeve and pressing it onto the male mold to form a second mold, wherein a leaflet space is formed between the male mold and the female mold in the sleeve, and the polymer material in the second mold is subjected to a shaping treatment after the mold is closed; finally, after the mold is opened, an integrally formed polymer leaflet is obtained in the leaflet space. The present invention configures the polymer material into a solution or a melt or prepares a film-forming material, then uses a mold for casting or compression molding, and finally demolds to obtain an integrally formed polymer leaflet; the obtained integrally formed leaflet has the characteristics of being suture-free and not prone to stress concentration tearing due to suture, thereby improving the service life of the polymer leaflet.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to an integrally formed polymer leaflet and a manufacturing method thereof. Background Art

[0002] Heart valve disease is one of the common heart diseases. The main treatment method is valve replacement through open surgery or interventional surgery to achieve the purpose of treatment. The mainstream choices for valve leaflet materials are bovine pericardium and porcine pericardium. However, on the one hand, the material obtained from biological tissue is scarce and the cost is high. On the other hand, the production cost of biological valve leaflets is high and the lifespan of the biological tissue used is short. Existing studies hope to use polymer valve leaflets to replace biological valve leaflets. Some polymer materials make this idea possible due to their good stability and durability.

[0003] Polymer leaflets are prone to stress concentration, and the leaflets need to be sutured before they can be used. Stress concentration is prone to occur at the suture points of the leaflets. Stress concentration means that when the polymer material has stress defects such as damage, it is often easy to break first at the defect point. Generally, the leaflets and the valve frame are connected by suturing. Suturing will form holes on the leaflets by threading the needle back and forth, so this phenomenon can easily cause the entire valve leaflet to fail. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrally molded polymer leaflet, wherein the polymer material is configured into a solution or a melt or prepared into a film material, then cast or molded using a mold, and finally demolded to obtain an integrally molded polymer leaflet; the obtained integrally molded leaflet has the characteristics of being suture-free and not prone to stress concentration tearing due to sutures, thereby improving the service life of the polymer leaflet.

[0005] In order to achieve the above-mentioned object, the present invention provides a method for manufacturing an integrally formed polymer leaflet, which adopts the following technical solutions:

[0006] A method for manufacturing an integrally formed polymer leaflet, comprising:

[0007] The polymer material is pre-treated and added to the first mold formed by combining a sleeve and a male mold. The first mold is a body formed by the sleeve being sleeved on the outer periphery of the male mold until the polymer material completely covers the male mold; the female mold is then inserted into the sleeve and pressed onto the male mold to form a second mold, wherein a leaflet space is formed between the male mold and the female mold located in the sleeve. After the mold is closed, the polymer material in the second mold is shaped; finally, after the mold is opened, an integrally formed polymer leaflet is obtained in the leaflet space.

[0008] Preferably, the male mold includes a first base, a first convex column located on the first base, and the top surface of the first convex column is set to be a combined shape of multiple leaflets;

[0009] The female mold includes a second base, a second convex column located on the second base, and the top surface of the second convex column matches the top surface shape of the male mold, so that a leaflet space of a specific shape is formed between the first convex column and the second convex column;

[0010] The sleeve is hollow inside and is used to be sleeved on the outer periphery of the first convex column and the second convex column. The first base, the second base and the two ends of the sleeve extending in the axial direction are correspondingly and tightly fitted.

[0011] Furthermore, the outer diameters of the first and second bosses are comparable, and the inner wall of the sleeve is 0.1-2 mm larger than the outer diameters of the first and second bosses.

[0012] Furthermore, the length of the sleeve is L1, and the total length of the first and second convex columns after the female and male molds are closed is L2, L1 is greater than L2, and L1-L2=the final thickness of the leaflet.

[0013] Furthermore, the pretreatment is: using a solvent to configure the polymer material into a solution, or melting the polymer material to obtain a molten liquid; putting a sleeve on the first protrusion of the male mold, pouring the solution or molten liquid into the first mold formed by the combination of the sleeve and the male mold until the male mold is completely immersed, and then extending the female mold into the sleeve and pressing it onto the male mold, wherein the two ends of the female mold and the male mold after being combined are respectively tightened with the two ends of the sleeve extending along the axial direction to prevent the solution from leaking out.

[0014] Furthermore, before adding the solution or melt, the valve frame is pre-mounted on the male mold, and the apex, bending curve, and lowest point of the valve frame are completely fitted with the male mold, so that the leaflets are integrally formed on the valve frame.

[0015] Furthermore, the pretreatment is: preparing the polymer material into a polymer film, winding the polymer film evenly layer by layer on the top surface of the male mold, and then successively putting a sleeve on the outer periphery of the male mold to form a first mold, and covering it with a female mold to form a second mold.

[0016] Furthermore, the second mold after mold closing is placed in a high-temperature oven for heating to 50-350° C. for 1-60 minutes, and the mold is opened to obtain the integrally formed leaflet.

[0017] Furthermore, when the polymer film is partially wrapped on the male mold, the valve frame is put on the male mold, and the remaining polymer film is continued to be wrapped on the male mold, so that the leaflets can be integrally formed on the valve frame, avoiding the need to sew the leaflets and the valve frame.

[0018] Preferably, the polymer material is selected from any one or more combinations of polyester, polyurethane, polyurethane urea, polylactic acid, SIBS, PTFE, and polyethylene.

[0019] A second object of the present invention is to provide an integrally formed polymer leaflet, which is prepared according to the above-mentioned manufacturing method.

[0020] Compared with the prior art, the present invention directly forms the leaflets and the valve frame into one piece without suturing, so no stress concentration will occur. Its beneficial effects are:

[0021] The present invention uses human CT scanning or in vitro simulation data to produce a valve forming mold, configures the polymer material into a solution or melts it or prepares a membrane material, uses the mold for casting or compression molding, and finally demolds to obtain an integrally formed polymer leaflet; the obtained integrally formed leaflet has the characteristics of being suture-free and not prone to stress concentration tearing due to suture, thereby improving the service life of the polymer leaflet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings and examples.

[0023] Figure 1 This is a schematic diagram of a male mold according to an embodiment of the present invention.

[0024] Figure 2 The present invention corresponds to Figure 1 Schematic diagram of the female mold under the illustrated embodiment.

[0025] Figure 3 The present invention corresponds to Figure 1 Schematic diagram of the sleeve under the illustrated embodiment.

[0026] Figure 4 Matching the present invention Figure 1 Schematic diagram of the flap frame of the male mold shown.

[0027] Figure 5 For the present invention Figure 1 The positive mold shown is Figure 2 The figure shows a simple schematic diagram of the female mold after closing.

[0028] The meanings of the symbols in the accompanying drawings are as follows:

[0029] 1-sleeve; 10-male mold; 100-first base; 101-first protrusion; 11-female mold; 110-second base; 111-second protrusion. DETAILED DESCRIPTION

[0030] The present invention is further explained in detail below in conjunction with the drawings and descriptions of specific embodiments. However, the descriptions including the embodiments below are only intended to enable ordinary technicians in the technical field to which the present invention belongs to more clearly understand the principles and essence of the present invention, and are not intended to limit the present invention in any form.

[0031] In the description of the present invention, it should be understood that the terms "top surface", "base", "axial", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality", "multiple", and "several" mean at least two / kinds, for example, two / kinds, three / kinds, etc., unless otherwise clearly and specifically defined.

[0033] According to a preferred embodiment of the present invention, Figure 1-3 As shown, a method for manufacturing an integrally molded polymer leaflet comprises: pre-treating the polymer material and adding it to a first mold formed by combining a sleeve 1 and a male mold 10, wherein the first mold is a body formed by sleeve 1 being sleeved on the outer periphery of the male mold 10 until the male mold 10 is completely covered; then the female mold 11 is extended into the sleeve 1 and pressed onto the male mold 10 to form a second mold, wherein a leaflet space is formed between the male mold 10 and the female mold 11 located in the sleeve 1, and after the mold is closed, the polymer material in the second mold is shaped; and finally, after the mold is opened, an integrally molded polymer leaflet is obtained in the leaflet space.

[0034] According to this embodiment, the polymer material covers the male mold 10, and the leaflet space is formed between the male mold 10 and the female mold 11. Combined with the specific structure of the mold, multiple leaflets can be formed into an integral polymer leaflet. First, because the multiple leaflets are integrally formed, the suturing between the multiple leaflets is avoided, and the risk of tearing caused by the conventional single leaflet suturing is avoided; secondly, the bottom of the integrally formed leaflet (combined with the following text, the cylindrical part is formed due to the convex column section of the male mold 10 hanging on the wall) has a cylindrical extension section, which can be bonded or clamped to the surgical or interventional valve stent (corresponding to the Figure 4 The combination of the leaflet and the skirt, and the leaflet and the valve frame shown in the figure avoids the risk of tearing caused by suturing between the leaflet and the skirt, and the leaflet and the valve frame, and can effectively extend the service life of the valve using the same material; based on this, the present invention provides a simple to prepare, one-piece polymer leaflet molding method.

[0035] Preferably, the male mold 10 includes a first base 100 and a first protrusion 101 located on the first base 100. The top surface of the first protrusion 101 is configured to be a combination of multiple leaflets. Specifically, the first base 100 is configured to be disc-shaped.

[0036] The female mold 11 includes a second base 110 and a second protrusion 111 located on the second base 110. The top surface of the second protrusion 111 matches the top surface shape of the male mold 10, so that a leaflet space of a specific shape is formed between the first protrusion and the second protrusion. Specifically, the second base 110 is also set to be disc-shaped.

[0037] The sleeve 1 is hollow inside and is used to be sleeved on the outer periphery of the first boss 101 and the second boss 111 . The first base 100 and the second base 110 are correspondingly and tightly fitted with the two ends of the sleeve 1 extending in the axial direction (H direction).

[0038] At this point, multiple leaflets can be integrally formed between the male mold 10 and the female mold 11 of the present invention.

[0039] More preferably, the outer diameters of the first and second bosses 101, 111 are comparable, and the inner wall of the sleeve 1 is 0.1-2 mm larger than the outer diameters of the first and second bosses 101, 111, so that the solution or melt can be poured into the mold formed by combining the sleeve 1 and the male mold 10 until the male mold 10 is completely immersed. At this time, the female mold 11 is used to close the mold to complete the one-piece molding of multiple leaflets. Specifically, the length of the sleeve 1 is L1, and the total length of the first and second bosses 101, 111 after the male and female molds are closed is L2, L1 is greater than L2, and L1-L2 is the final thickness of the resulting leaflet. Because the leaflet is relatively thin, in actual applications, L1 is generally slightly greater than L2.

[0040] In practical applications, for example, the top surface of the first protrusion 101 is set to a combination shape of three petals, and any of the petals has two intersecting oblique sides and an arc-shaped side connected between the two oblique sides, wherein the two oblique sides are along Figure 1 The paper aspect shown has a certain vertical height.

[0041] Of course, according to actual needs, the top surface shape and leaflet thickness between the female mold 11 and the male mold 10 can be designed accordingly to match the leaflet usage requirements in different application scenarios.

[0042] The female mold 11, male mold 10, and sleeve 1 used to form the mold can be made of metal or non-metal. The mold's shape is derived from human CT scans or in vitro simulation data. Furthermore, the mold surface can be treated with a PTFE pre-coat or a release agent coating to facilitate demolding after the integrated polymer leaflet is formed by molding.

[0043] There are several ways to pre-treat polymer materials, including the following: A mold can be used to integrally mold polymer valve leaflets using melt, solution, or film molding:

[0044] First, the pretreatment is: use a solvent to configure the high-density material into a solution; put the sleeve 1 on the first protrusion 101 of the male mold 10, pour the solution into the first mold formed by the combination of the sleeve 1 and the male mold 10, until the male mold 10 is completely immersed, and then extend the female mold 11 into the sleeve 1 and press it onto the male mold 10, wherein the two ends of the female mold 11 and the male mold 10 after the mold is combined are respectively tightened with the two ends of the sleeve 1 extending along the axial direction to prevent the solution from leaking.

[0045] Secondly, the pretreatment is as follows: melting the polymer material to obtain a molten liquid; putting the sleeve 1 on the first protrusion 101 of the male mold 10, pouring the molten liquid into the first mold formed by the combination of the sleeve 1 and the male mold 10, until the male mold 10 is completely immersed, and then extending the female mold 11 into the sleeve 1 and pressing it onto the male mold 10, wherein the two ends of the female mold 11 and the male mold 10 after the mold is closed are respectively tightened with the two ends of the sleeve 1 extending along the axial direction to prevent the molten liquid from leaking out.

[0046] Based on the above pretreatment, after the female mold 11 and the male mold 10 are closed, vacuum or pressurization is performed to make the molding more stable and faster. More preferably, before adding the solution or melt, the petal frame is pre-set on the male mold, and the apex, bending curve, and lowest point of the petal frame are completely in line with the male mold, so that the leaflets can be integrally molded onto the petal frame, avoiding the need to sew the leaflets and the petal frame. Therefore, for the solution or melt, by pre- Figure 4 The valve frame is shown in Figure 1 On the yang membrane shown, after solution or melt casting and solidification, the leaflets naturally wrap around the valve frame and avoid suturing.

[0047] Thirdly, the pretreatment is as follows: prepare the polymer material into a polymer film, evenly wrap the polymer film layer by layer on the top surface of the male mold 10, and then put the sleeve 1 on the outer periphery of the male mold 10 to form a first mold, and cover it with the female mold 11 to form a second mold; put the second mold after closing into a high-temperature oven, heat it to 50-350°C, control the heating time to 1-60min, and then open the mold to obtain an integrally formed polymer leaflet. More preferably, when the polymer film is partially wrapped on the male mold 10, put the leaflet frame on the male mold 10, and continue the remaining winding steps to form the leaflet integrally onto the leaflet frame, thus avoiding the suturing of the leaflet and the leaflet frame. Therefore, through this film winding method, the polymer film is first wrapped halfway on the male mold 10. Figure 1 On the male mold shown, nest Figure 4 The petal frame shown is then wrapped with the other half of the polymer film, so that the petal frame is sandwiched in the middle. After heating and other shaping treatments, the polymer films on both sides are integrated, so that the petal frame is wrapped therein to avoid suturing.

[0048] Based on this, valve molding molds are created using human CT scans or in vitro simulation data. The polymer material can be prepared into a solution, melted, or prepared into a membrane material. This is then cast or pressed into shape using the mold, and finally demolded to create a one-piece polymer leaflet. This one-piece leaflet is suture-free and prevents stress concentration and tearing caused by sutures, extending the lifespan of the polymer leaflet.

[0049] In the above embodiments, the polymer material is preferably selected from any one or more combinations of polyester, polyurethane, polyurethane urea, polylactic acid, SIBS, PTFE, and polyethylene.

[0050] Based on the above-mentioned production method, refer to the specific diagram. Figure 3 The sleeve 1 shown is placed on Figure 1 On the male mold 10 shown, the size difference between the inner wall of the sleeve 1 and the first protrusion 101 of the male mold 10 is 0.1-2mm. Pour the solution or melt into the first mold after the sleeve 1 and the male mold 10 are combined until the male mold 10 is completely immersed. Figure 2 The female mold 11 is pressed on the male mold 10, and the discs at the bottom of the female mold 11 and the male mold 10 are respectively tightly closed with the two ends of the sleeve 1 along the axial direction to prevent the solution from leaking out; the length of the sleeve is L1, and after the male and female molds are closed (such as Figure 5 (As shown in the simplified diagram, the total length of the first and second intermediate protrusions 101, 111 is L2, with L1 being slightly greater than L2, and L1-L2 being the final thickness of the leaflet. After the mold is finally opened, an integrally molded polymer leaflet can be produced.)

[0051] Example 1

[0052] The polyester particles are heated and melted, the sleeve length is 50.1mm, the inner diameter is 26mm, the total height of the middle convex column after the male and female molds are closed is 50mm, and the outer diameter is 25mm; the sleeve 1 is put on the male mold 10 to form a first mold, the bottom disc of the male mold 10 is tightly closed with the sleeve 1, and then the solution is poured into it and added to a height of about 40mm; then the female mold 11 is buckled, and the excess molten liquid will flow out from the top. Specifically, after the excess molten liquid flows out from the gap between the female mold 11 and the sleeve 1, the end of the female mold 11 away from the male mold 10 is tightly closed with the end of the sleeve 1, and the second mold after closing is placed in a vacuum drying oven for cooling and drying, and the molding pressure is controlled to be 0.04mpa, and the molding time is 1h. After opening the mold, an integrated leaflet with a thickness of 100um is taken out.

[0053] Example 2

[0054] The polyurethane particles are dissolved in dimethylformamide to form a solution with a concentration of 10% (w / v), and the solution is prepared into a film with a thickness of 100um by using the electrospinning method. The film is wrapped around the male mold 10 in three layers, and the surgical valve stent (valve frame) is put on the male mold 10, and then three layers of film are wrapped around the male mold 10; then the sleeve 1 is put on the outer periphery of the male mold 10, and then the female mold 11 is closed and placed in an oven. The heating temperature is controlled at 100℃ and the heating time is 20 minutes. Due to the composite process, the multi-layer film will be heat-fused together, causing the leaflet to become tight. The mold is opened to take out the integrated leaflet with a thickness of 100um and composited with the leaflet frame.

[0055] Based on the multi-layer membrane composite method of this embodiment, the thickness consistency of the membranes on both sides of the valve frame can be effectively controlled, the thickness is easier to control, and the multi-layer membrane can be produced by methods such as electrospinning, so that the leaflet has a porous structure, which is conducive to the proliferation of endothelial cells on the surface of the leaflet.

[0056] Example 3

[0057] This example is basically the same as Example 1, with the only difference being that: "polyester particles" are replaced with "polyurethane urea particles"; the molding pressure is controlled to be 5 MPa, the molding time is 30 min, and after the mold is opened, an integrated leaflet with a thickness of 100 μm is taken out.

[0058] Example 4

[0059] This example is basically the same as Example 2, except that: "polyurethane particles" are replaced with "polylactic acid particles"; the heating temperature is controlled to 90°C and the time is 30 minutes; after the mold is opened, an integrated leaflet with a thickness of 100um is taken out.

[0060] Example 5

[0061] This example is essentially the same as Example 2, except that the phrase "polyurethane particles are electrospun to obtain a film" is replaced with "PTFE is thermally stretched to obtain an ePTFE film." The heating temperature is controlled at 350°C for 1 hour. After the mold is opened, a 100 μm thick integrated leaflet is removed.

[0062] The properties of the integrally formed polymer leaflet prepared according to the above embodiment are as follows:

[0063] For example, if a leaflet is formed using conventional polyurethane particles and then sutured and combined with a valve frame, it will generally break at the suture after 3,000 to 5,000 times in fatigue testing. However, if a leaflet is formed integrally with the valve frame of the present invention using the same material, there is no need for suturing and no stress concentration, and the fatigue test times of the leaflets obtained in Examples 1-5 can reach 200 to 400 million times.

[0064] The above description of the preferred embodiments of the present invention is intended to serve as a guide. Based on the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A method for manufacturing an integrally formed polymer leaflet, characterized in that: include: After pre-treatment, the polymer material is added to the first mold formed by combining a sleeve and a male mold. The first mold is formed by the sleeve being inserted into the outer periphery of the male mold until the polymer material completely covers the male mold. The female mold is then inserted into the sleeve and pressed onto the male mold to form a second mold. A leaflet space is formed between the male and female molds located in the sleeve. After the molds are closed, the polymer material in the second mold is shaped. Finally, after the mold is opened, an integrally formed polymer leaflet is obtained in the leaflet space. The pretreatment is: using a solvent to prepare the polymer material into a solution, or melting the polymer material to obtain a molten liquid; Before adding the solution or melt, the valve frame is pre-mounted on the male mold, and the apex, bending curve, and lowest point of the valve frame are completely fitted with the male mold, so that the leaflets are integrally formed on the valve frame.

2. The method for manufacturing an integrally formed polymer leaflet according to claim 1, characterized in that: The male mold includes a first base, a first convex column located on the first base, and the top surface of the first convex column is set to be a combined shape of multiple leaflets; The female mold includes a second base, a second convex column located on the second base, and the top surface of the second convex column matches the top surface shape of the male mold, so that a leaflet space of a specific shape is formed between the first convex column and the second convex column; The sleeve is hollow inside and is used to be sleeved on the outer periphery of the first convex column and the second convex column. The first base, the second base and the two ends of the sleeve extending in the axial direction are correspondingly and tightly fitted.

3. The method for manufacturing an integrally formed polymer leaflet according to claim 2, characterized in that: The outer diameters of the first and second protrusions are similar, and the inner wall of the sleeve is 0.1-2 mm larger than the outer diameters of the first and second protrusions.

4. The method for manufacturing an integrally formed polymer leaflet according to claim 2, characterized in that: The length of the sleeve is L1, and the total length of the first and second convex columns after the female and male molds are closed is L2. L1 is greater than L2, and the final thickness of the leaflet is L1-L2.

5. The method for manufacturing an integrally formed polymer leaflet according to claim 2, characterized in that: Put the sleeve on the first protrusion of the male mold, pour the solution or molten liquid into the first mold formed by the combination of the sleeve and the male mold until the male mold is completely immersed, and then extend the female mold into the sleeve and press it onto the male mold, wherein the two ends of the female mold and the male mold after being combined are respectively tightened with the two ends of the sleeve extending along the axial direction.

6. The method for manufacturing an integrally formed polymer leaflet according to claim 2, characterized in that: The pretreatment is as follows: preparing the polymer material into a polymer film, evenly wrapping the polymer film layer by layer on the top surface of the male mold, then successively putting a sleeve on the outer periphery of the male mold to form a first mold, and covering it with a female mold to form a second mold; placing the second mold after the mold is closed into a high-temperature oven for heating to 50-350°C for 1-60 minutes, and opening the mold to obtain an integrally formed leaflet.

7. The method for manufacturing an integrally formed polymer leaflet according to claim 6, characterized in that: When the polymer film is partially wrapped around the male mold, the valve frame is put onto the male mold, and the remaining polymer film is continued to be wrapped around the male mold, so that the leaflet can be integrally formed onto the valve frame.

8. The method for manufacturing an integrally formed polymer leaflet according to claim 1, characterized in that: The polymer material is selected from any one or more combinations of polyester, polyurethane, polyurethane urea, polylactic acid, SIBS, PTFE, and polyethylene.

9. An integrally formed polymer leaflet, prepared according to the manufacturing method according to any one of claims 1 to 8.

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