Preparation method of fabric-based artificial heart valve composite material

Abstract

According to the preparation method of the fabric-based artificial heart valve composite material, the poor solvent is used for treating the fabric, then the polymer solution is coated on the surface of the fabric to prepare the polymer layer, and different effects between the poor solvent and the solvent and solute of the polymer solution can be utilized in the process, so that the composite material can be prepared. The polymer is effectively prevented from entering the fabric, and the influence on the softness of the fabric due to the introduction of the polymer layer is avoided. Through the method, the fabric-based artificial heart valve composite material which has the softness of fabric and is smooth in surface is prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a preparation method of a fabric-based artificial heart valve composite material. Background Art

[0002] Artificial valves prepared from polymer materials have broad application prospects in the fields of surgical valves, transcatheter valves, valved conduits, tissue engineering valves, etc. due to their advantages of good biocompatibility, long service life, and easy control of production conditions. In existing research, the leaflet materials of textile-based artificial heart valves are generally pure fabrics composed of polymer fibers / yarns or fabric-based composite materials. However, pure fabrics have problems such as leakage, easy structural deformation, and rough surfaces that are prone to thrombus formation. Composites obtained by combining with polymers have reduced leakage, improved structural stability, and improved roughness, and have advantages over pure fabrics in the blood use environment.

[0003] In the prior art, in the patent text with the application number CN202080017730.6, the publication date of October 19, 2021, and the title "Medical implant assembly comprising a composite biotextile and method of manufacture", a composite biotextile for preparing a medical implant assembly is disclosed, which includes a polyolefin fiber structure and a polyurethane elastomer coating. The coating can be mainly formed on the surface of the fiber structure or made into a solution to penetrate between the strands and fibers and partially or even completely cover the fibers and impregnate the structure. In the above technical solution, when preparing the coating on the surface of the fiber structure, the coating solution is used to penetrate and impregnate the structure to endow the structure with the properties of a polyurethane elastomer coating.

[0004] In view of this, it is necessary to design an improved preparation method of a fabric-based artificial heart valve composite material to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a fabric-based artificial heart valve composite material.

[0006] To achieve the above invention purpose, the present invention provides a preparation method of a fabric-based artificial heart valve composite material, including the following steps:

[0007] S1. Immerse the fabric in a poor solvent and then take it out so that the fabric is wetted by the poor solvent;

[0008] S2. Coat a polymer solution on one side of the fabric immersed in the poor solvent, and after drying, form a continuous polymer layer, thus obtaining the fabric-based artificial heart valve composite material; the polymer solution is obtained by dissolving a polymer in an organic solvent, and the poor solvent is immiscible with the polymer.

[0009] Preferably, the surface roughness of the polymer layer is 200 - 2000 nm.

[0010] Preferably, the polymer is one or more of polyurethane, polycarbonate - polyurethane copolymer, polysiloxane - polyurethane copolymer, and styrene / isobutene copolymer; the organic solvent is one or more of N,N - dimethylformamide, N,N - dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, and dioxolane.

[0011] Preferably, in step S2, the mass concentration of the polymer solution is 5 - 30 w / v%.

[0012] Preferably, the thickness of the polymer layer is 1 - 50 μm.

[0013] Preferably, in step S1, the surface porosity of the fabric is below 30%; the fabric structure is one or more of plain weave, twill weave, and satin weave.

[0014] Preferably, in step S1, the poor solvent is one or more of water, alcohols, and ketones.

[0015] Preferably, in step S1, before immersing the fabric into the poor solvent, it needs to be treated by plasma; the treatment power of the plasma treatment is 50 - 300 W, the treatment time is 30 - 300 s, the treatment temperature is 0 - 4 °C, and the gas environment is one of oxygen, hydrogen, air, argon, or helium.

[0016] Particularly, the fabric - based artificial heart valve composite material can be prepared by the above - mentioned preparation method. One side of the fabric - based artificial heart valve composite material is provided with a polymer layer, and at least a part of the other side surface of the fabric - based artificial heart valve composite material is not covered by the polymer; and the fabric - based artificial heart valve composite material can be used in the field of heart valves.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The preparation method of the fabric - based artificial heart valve composite material provided by the present invention first treats the fabric with a poor solvent and then coats a polymer solution on one side surface of the fabric to prepare a polymer layer. This process can effectively prevent the polymer from entering the interior of the fabric by utilizing the different interactions between the poor solvent and the solvent and solute of the polymer solution, avoiding affecting the softness of the fabric itself due to the introduction of the polymer layer. Secondly, the present invention also regulates the process parameters (polymer type, coating thickness, organic solvent type, fabric properties) of the preparation process to accurately prepare a composite material with excellent performance.

[0019] 2. The fabric-based artificial heart valve composite material provided by the present invention prepares a polymer layer only on one side of the fabric. The polymer layer has the same organizational structure as the fabric surface, and at least a part of the other surface of the fabric is not covered by the polymer, that is, the other side maintains the original surface structure, enabling the composite material to maximize the maintenance of the surface performance of the fabric and reducing the impact on the fabric structure and performance during the modification process. The composite material prepared by the preparation method proposed by the present invention has the characteristics of softness and smooth surface, and is suitable as an artificial heart valve material. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional electron micrograph of the composite material prepared in Example 1 of the present invention;

[0021] Figure 2 It is a surface electron micrograph of the composite material prepared in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to the drawings and specific embodiments.

[0023] Here, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the drawings, while other details less related to the present invention are omitted.

[0024] In addition, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0025] The present invention provides a preparation method for a fabric-based artificial heart valve composite material, which includes the following steps:

[0026] S1. Immerse the fabric in a poor solvent and then take it out to make the fabric wetted by the poor solvent;

[0027] S2. Coat a polymer solution on one side of the fabric immersed in the poor solvent, and after drying, a continuous polymer layer is formed on the fabric surface, that is, the fabric-based artificial heart valve composite material is prepared.

[0028] Preferably, in step S1, before immersing the fabric in the poor solvent, plasma treatment is required in an environment of 0 - 4°C. By using this treatment method, the surface wettability of the fabric can be improved, which is conducive to the penetration of the poor solvent into the interior of the fabric. Among them, the treatment power of the plasma treatment is 50 - 300 W, the treatment time is 30 - 300 s, and the treatment process is carried out in an environment of oxygen, hydrogen, air, argon or helium. In some other embodiments, a polymer solution can also be coated on the other surface of the fabric, but it is necessary to ensure that at least a part of this side is not covered by the polymer layer, so as to maximize the maintenance of the surface properties of the fabric by the composite material and reduce the impact on the structure and properties of the fabric during the modification process.

[0029] Preferably, in step S1, the material of the fabric is one or several of polyester, polyethylene, polypropylene, polyamide and polyvinyl chloride; the fabric structure is plain weave, twill or satin weave. More preferably, the fabric structure is plain weave because in the plain weave structure, the interweaving points of the warp and weft are the most, and the fabric structure is the most stable, which is conducive to further application to heart valve materials.

[0030] Preferably, in step S1, the surface porosity of the fabric is below 30%. Using the fabric that meets the above properties to further prepare the composite material can effectively utilize the hindering effect of the poor solvent on the polymer solution, avoid the polymer solution entering the interior of the fabric and contacting the internal fibers, and affect the softness of the fabric itself.

[0031] Preferably, in step S1, the poor solvent is immiscible with the polymer in the polymer solution, including but not limited to one or several of water, alcohols, and ketones.

[0032] Preferably, in step S2, the mass concentration of the polymer solution is 5 - 30 w / v%, which is obtained by dissolving the polymer in an organic solvent; the polymer is one or several of polyurethane, polycarbonate - polyurethane copolymer, polysiloxane - polyurethane copolymer, styrene / isobutylene copolymer, and the organic solvent is one or several of N,N - dimethylformamide, N,N - dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, dioxolane.

[0033] Preferably, in step S2, the drying temperature is 40 - 80°C and the time is 6 - 48 h.

[0034] Preferably, in step S2, the surface coating method includes but is not limited to one of knife coating, spin coating, roll coating and flow coating.

[0035] Preferably, in step S2, the thickness of the polymer layer is 1 - 50 μm. The composite material prepared under this condition can simultaneously have the softness of the fabric and the surface structure of the fabric, and the polymer layer is smooth and flat.

[0036] Preferably, in step S2, the surface roughness of the polymer layer is 200 - 2000 nm.

[0037] The preparation method of the fabric-based artificial heart valve composite material of the present invention will be further described below in conjunction with specific embodiments:

[0038] Example 1

[0039] The polyester woven fabric used in this example was purchased from Suzhou Zhixian Technology Co., Ltd. The woven fabric structure was plain weave, and the porosity was 12%.

[0040] This example prepared a fabric-based artificial heart valve composite material, and its preparation method included the following steps:

[0041] S1. After subjecting the polyester woven fabric to plasma treatment, immerse it in water, take it out and lay it flat on the coating platform; the power of the plasma treatment is 300 W, the treatment time is 50 s, and the gas environment during the treatment process is argon.

[0042] S2. After coating the upper surface of the fabric on the coating platform with a 15 w / v% solution of polyurethane in N,N-dimethylacetamide, take it off and dry it at 60 °C for 12 h to form a continuous polyurethane film on one side surface of the polyester woven fabric, and the other side surface is not filled with polyurethane, thus obtaining the fabric-based artificial heart valve composite material. The average thickness of the polyurethane layer in the composite material is 17.94 μm.

[0043] The cross-sectional electron micrograph of the composite material prepared in this example is as Figure 1 shown, and the surface electron micrograph is as Figure 2 shown. It can be seen from the figure that the polyurethane layer in the composite material is evenly distributed on one side surface of the polyester woven fabric, and the composite material well replicates the tissue structure on the surface of the woven fabric, and the surface of the material is smooth and flat. This is because: first immerse the woven fabric in water, and then coat the surface with a solution of polyurethane in N,N-dimethylacetamide. Since water is immiscible with polyurethane but miscible with N,N-dimethylacetamide, after the coating is completed, the N,N-dimethylacetamide and water in the solution are miscible, which promotes the decrease in the solubility of polyurethane in the solution and its gradual precipitation. This phenomenon intensifies during the drying process, and finally a polyurethane layer is formed on the surface of the woven fabric. During the above process, since the polymer is only on the surface of the fabric and does not enter the fibers inside the fabric, the softness of the fabric itself can be maintained, which is beneficial for the opening and closing of the valve leaf when it is used as a heart valve material; secondly, the presence of the polyurethane layer reduces the surface roughness of the fabric and reduces the adhesion of substances such as blood cells to the surface of the valve leaf.

[0044] To investigate the softness of the composite material prepared in this embodiment, its stiffness was tested under the same conditions as that of untreated blank polyester woven fabric. The specific method of the test principle was as follows: First, the composite material and the woven fabric were cut into circular pieces with a diameter of 40 mm, and then they were placed on a paper softness tester to measure the four angles of the circular pieces respectively and calculate the average value. The results showed that treating the fabric by the method proposed in the present invention could well maintain the softness of the fabric itself. The roughness test method was as follows: The composite material and the woven fabric were cut into square pieces with a size of 1 cm × 1 cm, which were fixed on the electron microscope stage with conductive adhesive and then put into the electron microscope chamber for microscopic observation; the roughness test field of view was selected, the 3D roughness plug-in was started for roughness test, and the average value of Ra was calculated. The results showed that the surface roughness of the composite material on the coated side was significantly lower than that of the fabric, which was beneficial to the smooth passage of blood.

[0045] Examples 2 to 5

[0046] The differences between Examples 2 to 5 and Example 1 were only as follows: The types of raw materials and process parameters in step S2 were different from those in Example 1, and the other steps were basically the same as those in Example 1, so they would not be elaborated here. The comparisons of the types of raw materials, process parameters and the properties of the composite materials prepared under the corresponding conditions in Examples 1 to 5 were shown in Table 1. It could be seen from the table that the method proposed in the present invention was applicable to the preparation of composite materials using various polymers.

[0047] Table 1 Comparison of the types of raw materials, process parameters and the properties of the composite materials prepared under the corresponding conditions in Examples 1 to 5

[0048]

[0049] Examples 6 to 9

[0050] The differences between Examples 6 to 9 and Example 1 were only as follows: The coating thickness of the polymer layer was different from that in Example 1, and the other steps were the same as those in Example 1, so they would not be elaborated here. The comparisons of the coating thickness and the properties of the composite materials prepared under the corresponding conditions in Example 1 and Examples 6 to 9 were shown in Table 2. It could be seen from the table that within the given coating thickness range of the present invention, the prepared composite materials not only had low surface roughness, but also could well maintain the softness of the fabric itself.

[0051] Table 2 Comparison of the coating thickness and the properties of the composite materials prepared under the corresponding conditions in Example 1 and Examples 6 to 9

[0052]

[0053]

[0054] Examples 10 to 14

[0055] Examples 10 to 14 are only different from Example 1 in that the porosity and tissue structure of the fabric are different from those of Example 1, and the other steps are the same as those of Example 1, so they will not be elaborated here. The fabric properties of Example 1 and Examples 10 to 14 and the properties of the composite materials prepared under the corresponding conditions are compared in Table 3. It can be seen from the table that after treating fabrics with different porosities and tissue structures by the method proposed in the present invention, composite materials with low surface roughness and good softness can be obtained.

[0056] Table 3 Comparison of fabric properties of Example 1 and Examples 10 to 14 and properties of composite materials prepared under corresponding conditions

[0057]

[0058] The above examples are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A preparation method of a fabric-based artificial heart valve composite material, characterized in that, It includes the following steps: S1. Immerse the fabric in a poor solvent and then take it out so that the fabric is infiltrated by the poor solvent; S2. Coat a polymer solution on one side of the fabric infiltrated with the poor solvent, and form a continuous polymer layer after drying, thus obtaining a fabric-based artificial heart valve composite material; the polymer solution is obtained by dissolving a polymer in an organic solvent, and the poor solvent is immiscible with the polymer.

2. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that, The surface roughness of the polymer layer is 200 - 2000 nm.

3. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that, The polymer is one or more of polyurethane, polycarbonate-polyurethane copolymer, polysiloxane-polyurethane copolymer, styrene / isobutene copolymer; the organic solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, chloroform, dichloromethane, hexafluoroisopropanol, dioxolane.

4. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that, In step S2, the mass concentration of the polymer solution is 5 - 30 w / v%.

5. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that, The thickness of the polymer layer is 1 - 50 μm.

6. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that, In step S1, the surface porosity of the fabric is below 30%; the fabric structure is one or more of plain weave, twill weave, satin weave.

7. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that, In step S1, the poor solvent is one or more of water, alcohols, ketones.

8. The preparation method of the fabric-based artificial heart valve composite material according to claim 1, characterized in that In step S1, the fabric needs to be subjected to plasma treatment before being immersed in the poor solvent; the treatment power of the plasma treatment is 50 - 300 W, the treatment time is 30 - 300 s, the treatment temperature is 0 - 4 °C, and the gas environment is one of oxygen, hydrogen, air, argon or helium.

9. A fabric-based artificial heart valve composite material prepared by the preparation method according to any one of claims 1 - 8, wherein a polymer layer is provided on one side of the fabric-based artificial heart valve composite material, and at least a part of the other side surface of the fabric-based artificial heart valve composite material is not covered by the polymer.

10. An application of the fabric-based artificial heart valve composite material according to claim 9 in the field of heart valves.

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