Leaflet structure, method of making a leaflet structure, and valve prosthesis

Abstract

This application relates to the field of medical device technology, and discloses a leaflet structure, a method for preparing the leaflet structure, and a valve prosthesis. The leaflet structure includes a leaflet body, which includes an outflow surface. The outflow surface includes a force concentration section, which is located near the center of the distal end of the outflow surface. A unidirectional fluid guiding structure is provided on the outflow surface to guide fluid from the edge of the force concentration section to its center. By providing the unidirectional fluid guiding structure, the fluid concentration in the force concentration section is greater than that on both sides of the force concentration section, increasing the blood flow pressure in the force concentration section. This ensures that the blood flow pressure in the force concentration section is consistent with that on both sides of the force concentration section, allowing the force concentration section to fully open and reducing or preventing situations where the force concentration section cannot open. This allows the leaflet structure to fully unfold and improves its service life.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a leaflet structure, a method for preparing the leaflet structure, and a valve prosthesis. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] like Figure 1 and Figure 2 As shown, an artificial valve typically includes a leaflet structure 100 and a support structure 210. One end of the leaflet structure 100 is connected to the support structure 210, and the other end is a free end. The free end of the leaflet structure 100 can open or close under the action of blood flow to achieve unidirectional blood flow on the leaflet structure. However, when the leaflet structure is open, due to the influence of fluid dynamics and the structure of the leaflet structure 100 itself, a portion of the inner side of the leaflet structure 100 cannot fully open. This incompletely open portion is concentrated in the middle of the free end of the leaflet structure, obstructing blood flow and hindering blood circulation. During blood flow, the leaflets experience concentrated stress on both sides of the incompletely open portion of the leaflet structure 100. Therefore, during the reciprocating opening and closing of the leaflet structure 100, this incompletely open portion is easily damaged, thus reducing the lifespan of the artificial valve. Summary of the Invention

[0004] The purpose of this application is to at least solve the problem that the leaflet structure of artificial valves has a portion that cannot fully open, making it susceptible to damage and reducing the lifespan of the artificial valve. This purpose is achieved through the following technical solution:

[0005] The first aspect of this application proposes a leaflet structure, including a leaflet body, the leaflet body including an outflow surface, the outflow surface including a force concentration portion, the force concentration portion being disposed near the middle of the distal end of the outflow surface, and further including a unidirectional fluid guiding structure disposed on the outflow surface, the unidirectional fluid guiding structure being used to guide fluid from the edge of the force concentration portion to the center of the force concentration portion.

[0006] According to the valve structure of this application, by providing a one-way fluid guiding structure on the outflow surface, when blood flows through the outflow surface, the one-way fluid guiding structure can guide the fluid (i.e., blood) from the edge of the force concentration section to the center of the force concentration section. This results in a greater fluid accumulation in the force concentration section than on both sides of the force concentration section, with the largest fluid accumulation at the center of the force concentration section. This increases the blood flow pressure in the force concentration section, making the blood flow pressure in the force concentration section consistent with the blood flow pressure on both sides of the force concentration section. This allows the force concentration section to open fully, reducing or avoiding the situation where the force concentration section cannot open, allowing the valve structure to fully unfold, and improving the service life of the valve structure.

[0007] In addition, the leaflet structure of this application may also have the following additional technical features:

[0008] In some embodiments of this application, in a first direction, the hydrophilicity of the unidirectional fluid-guiding structure on the force concentration portion is greater than the hydrophilicity of the unidirectional fluid-guiding structures on both sides of the force concentration portion, wherein the first direction is perpendicular to the direction of the leaflet body from the proximal end to the distal end.

[0009] In some embodiments of this application, in the first direction, the hydrophilicity of the unidirectional liquid guiding structure increases from both sides of the unidirectional liquid guiding structure toward the force concentration portion.

[0010] In some embodiments of this application, the unidirectional fluid guiding structure includes a plurality of protrusions, which are dispersedly arranged.

[0011] In the first direction, the height of the protrusion on the force concentration part is less than the height of the protrusions on both sides of the force concentration part, and / or the cross-sectional area of ​​the protrusion on the force concentration part is less than the cross-sectional area of ​​the protrusions on both sides of the force concentration part.

[0012] In some embodiments of this application, the unidirectional fluid guiding structure includes a plurality of protrusions, which are arranged sequentially at intervals along a first direction, and each of the protrusions extends along the direction from the proximal end to the distal end;

[0013] In the first direction, the distance between the protrusions on the force concentration part is greater than the distance between the protrusions on both sides of the force concentration part.

[0014] In some embodiments of this application, the leaflet body includes a woven mesh skeleton that forms the outflow surface and the unidirectional liquid guiding structure;

[0015] In the first direction, the weaving density of the mesh skeleton on the force concentration part is greater than the weaving density of the mesh skeleton on both sides of the force concentration part.

[0016] In some embodiments of this application, the mesh skeleton includes multiple braided filaments, and the diameter of the braided filaments corresponding to the stress concentration part is greater than the diameter of the filaments on both sides of the stress concentration part.

[0017] A second aspect of this application provides a valve prosthesis, comprising:

[0018] A support structure, wherein a tubular channel is formed on the inner side of the support structure;

[0019] The first aspect of this application provides a leaflet structure, wherein the leaflet structure is disposed inside the support structure, and the fixed end of the leaflet structure is connected to the support structure.

[0020] According to the valve prosthesis of this application, the valve prosthesis includes the leaflet structure provided in the first aspect of this application and has at least the same beneficial effects as the leaflet structure provided in the first aspect of this application.

[0021] The third aspect of this application discloses a method for preparing a leaflet structure, used to prepare the leaflet structure proposed in the first aspect of this application. The leaflet structure includes a leaflet body, the leaflet body includes an outflow surface, the outflow surface includes a force concentration portion, the force concentration portion is disposed near the middle of the distal end of the outflow surface, and the method for preparing the leaflet structure includes:

[0022] Provide the leaflet body;

[0023] A unidirectional fluid-guiding structure is processed on the outflow surface of the leaflet body to obtain a leaflet structure that can guide fluid from the edge of the force concentration part to the center of the force concentration part.

[0024] According to the method for preparing the valve leaflet structure of this application, the processed valve leaflet structure has a one-way fluid guiding structure on the outflow surface. When blood flows through the outflow surface, the one-way fluid guiding structure can guide the fluid (i.e., blood) from the edge of the force concentration part to the center of the force concentration part. This results in a greater fluid accumulation in the force concentration part than on both sides of the force concentration part, with the largest fluid accumulation at the center of the force concentration part. This increases the blood flow pressure in the force concentration part, making the blood flow pressure in the force concentration part consistent with the blood flow pressure on both sides of the force concentration part. This allows the force concentration part to open fully, reducing or avoiding the situation where the force concentration part cannot open, allowing the valve leaflet structure to fully unfold and improving the service life of the valve leaflet structure.

[0025] In addition, the method for preparing the leaflet structure according to this application may also have the following additional technical features:

[0026] In some embodiments of this application, processing a unidirectional liquid-guiding structure on the outflow surface of the leaflet body includes:

[0027] The leaflet body is immersed in a PDMS solution to obtain the leaflet body with a PDMS coating on the outflow surface;

[0028] A stamping element with a preset pattern structure is provided. The stamping element is used to press the leaf body with a PDMS coating on the outflow surface to obtain a leaf structure in which the height of the protrusion on the force concentration part is less than the height of the protrusion on both sides of the force concentration part along a first direction, and / or the cross-sectional area of ​​the protrusion on the force concentration part is less than the cross-sectional area of ​​the protrusion on both sides of the force concentration part, wherein the first direction is perpendicular to the direction of the leaf body from the proximal end to the distal end. Attached Figure Description

[0029] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0030] Figure 1 A schematic diagram of the leaflet structure in the open state according to Embodiment 1 of this application is shown.

[0031] Figure 2 A schematic diagram of the leaflet structure in a closed state according to Embodiment 1 of this application is shown.

[0032] Figure 3 A schematic diagram of the leaflet structure according to Embodiment 1 of this application is shown;

[0033] Figure 4 A schematic diagram of a leaflet structure according to another embodiment of this application is shown;

[0034] Figure 5 A schematic diagram of the leaflet structure according to Embodiment 2 of this application is shown;

[0035] Figure 6 A schematic diagram of another leaflet structure according to Embodiment 2 of this application is shown;

[0036] Figure 7 A schematic diagram of another leaflet structure according to Embodiment 2 of this application is shown;

[0037] Figure 8 for Figure 7 A schematic diagram from one of the perspectives;

[0038] Figure 9 A schematic diagram of yet another leaflet structure according to Embodiment 2 of this application is shown;

[0039] Figure 10 A schematic diagram of the leaflet structure according to Embodiment 3 of this application is shown;

[0040] Figure 11 for Figure 10 A schematic diagram of the TT cross-section in the diagram;

[0041] Figure 12 A schematic diagram of the leaflet structure according to Embodiment 4 of this application is shown;

[0042] Figure 13 A schematic diagram of a valve prosthesis according to Embodiment 5 of this application is shown.

[0043] Figure 14 for Figure 13 A schematic diagram from one of the perspectives;

[0044] Figure 15 A schematic diagram of the engraving element according to Embodiment Six of this application is shown;

[0045] Figure 16 A flowchart illustrating the preparation method of the leaflet structure according to Embodiment Six of this application is shown schematically;

[0046] Figure 17 A flowchart illustrating the fabrication of a unidirectional fluid guiding structure on the outflow surface of the leaflet body according to Embodiment Six of this application is shown schematically.

[0047] The attached figures are labeled as follows:

[0048] 100. Leaflet structure; 110. Leaflet body; 111. Proximal end; 112. Distal end; 113. Sidewall; 114. Reticulated skeleton; 115. Inflow surface; 116. Outflow surface; 117. Fixed part; 118. Free part; 119. Stress concentration part; 120. Protrusion; 130. Groove; 141. First region; 142. Second region; 143. Third region; 144. Fourth region; 145. Fifth region;

[0049] 200. Valve prosthesis; 210. Stent structure; 211. Drainage membrane;

[0050] 300. Engraved part; 310. Groove;

[0051] A. With the direction of blood flow; B. Against the direction of blood flow; C. Second direction; D. First direction. Detailed Implementation

[0052] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0053] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0054] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0055] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0056] Example 1

[0057] Embodiment 1 of the present invention provides a leaflet structure 100, including a leaflet body 110 and a one-way fluid guiding structure. The leaflet body 110 includes an outflow surface 116, and the outflow surface 116 includes a force concentration portion 119, which is disposed near the middle of the distal end 112 of the outflow surface 116. The one-way fluid guiding structure is disposed on the outflow surface 116 and is used to guide fluid from the edge of the force concentration portion 119 to the center of the force concentration portion 119.

[0058] The leaflet structure 100 can be used in the valve prosthesis 200, which can be inserted into the mitral, tricuspid, or aortic valve to replace or replace a damaged aortic, mitral, tricuspid, or pulmonary valve in the human body.

[0059] Reference Figures 1 to 3 The leaflet structure 100 includes a leaflet body 110, which can be made of biological tissue such as bovine pericardium or porcine pericardium, or woven from filaments. The leaflet body 110 includes a fixed portion 117 and a free portion 118, which are typically an integral structure. The fixed portion 117 is approximately semi-circular in shape, with its arc-shaped edge forming a fixed end, also known as the proximal end 111, which is connected to the support structure 210 of the valve prosthesis 200. The free portion 118 is elongated, with the fixed portion 117 integrally connected to it. The end of the free portion 118 furthest from the fixed portion 117 forms a free end, also known as the distal end 112. The force concentration portion 119 is located near the middle of the distal end 112 of the outflow surface 116, meaning that the force concentration portion is located in the middle region of the distal end 112 of the outflow surface 116.

[0060] The distal end 112 can move toward the side closer to the center of the stent structure 210 or toward the side farther from the center of the stent structure 210. The valve prosthesis 200 includes an open state and a closed state. When the valve prosthesis 200 is in the open state, the distal ends 112 of two adjacent leaflet structures 100 are spaced apart to form an opening for blood flow. When the valve prosthesis 200 is in the closed state, the distal ends 112 of two adjacent leaflet structures 100 are abutted.

[0061] Reference Figure 1 and Figure 2 The sidewall 113 of the leaflet body 110 includes an outflow surface 116 and an inflow surface 115 disposed opposite to each other. The side through which blood flows in the direction of blood flow is defined as the outflow surface 116, and the other side opposite to the outflow surface 116 is defined as the inflow surface 115. This embodiment exemplifies the inflow surface 115 and the outflow surface 116 in the working state of the valve prosthesis 200 inserted into the pulmonary valve. Here, direction A is defined as the direction of blood flow, which refers to the direction in which blood passes through the leaflet structure 100 when the valve prosthesis 200 is open; direction B is the direction of blood flow against the direction of blood flow, which is the opposite direction to the direction of blood flow A. (Refer to...) Figure 1 As shown, when blood flows in the direction of blood flow, the valve prosthesis 200 is in the open state, and blood flows through the inner side of the multiple leaflet structures 100; (Refer to...) Figure 2 As shown, when blood flows against the flow direction, the valve prosthesis 200 is in a closed state to prevent backflow.

[0062] The proximal end 111 and distal end 112 of the outflow surface 116 are defined as the blood flowing in the direction of blood flow A. The position that the blood passes through first is the proximal end 111, and the position that it passes through last is the distal end 112.

[0063] The center of the force concentration part 119 refers to the center of the force concentration part 119 in the direction perpendicular to the fixed end toward the free end (i.e., the first direction D), and the corresponding edge of the force concentration part 119 can be understood as the two sides of the force concentration part 119 in the first direction.

[0064] According to the valve structure of this embodiment, by providing a one-way fluid guiding structure on the outflow surface 116, when blood flows through the outflow surface 116, the one-way fluid guiding structure can guide the fluid (i.e., blood) from the edge of the force concentration part to the center of the force concentration part 119. This results in the fluid accumulation in the force concentration part 119 being greater than the fluid accumulation on both sides of the force concentration part 119, with the largest fluid accumulation at the center of the force concentration part 119. This increases the blood flow pressure in the force concentration part 119, making the blood flow pressure on the force concentration part 119 consistent with the blood flow pressure on both sides of the force concentration part 119. This allows the force concentration part 119 to fully open, reducing or avoiding the situation where the force concentration part 119 cannot open, allowing the valve structure 100 to fully unfold, and improving the service life of the valve structure 100.

[0065] In the first direction D, the hydrophilicity of the unidirectional liquid-guiding structure on the force concentration part 119 is greater than that of the unidirectional liquid-guiding structures on both sides of the force concentration part 119. The first direction D is a direction perpendicular to the leaflet body 110 from the proximal end to the distal end.

[0066] like Figure 3 As shown, the outflow surface 116 includes a first region 141, a second region 142, and a third region 143 adjacent to each other in a direction perpendicular to the fixed end toward the free end (i.e., the first direction D). The second region 142 is located in the middle of the outflow surface 116 in the first direction D, and corresponds to the force concentration part 119. The first region 141 and the third region 143 are located on both sides of the second region 142 in the first direction. A one-way liquid guiding structure is provided in each of the first region 141, the second region 142, and the third region 143. The hydrophilicity of the one-way liquid guiding structure in the second region 142 is greater than that in the first region 141, and the hydrophilicity of the one-way liquid guiding structure in the second region 142 is greater than that in the third region 143.

[0067] It should be noted that hydrophobicity and hydrophilicity are relative concepts. The stronger the hydrophobicity, the weaker the hydrophilicity, and vice versa. In this embodiment, the hydrophobicity and hydrophilicity of the first region 141 and the second region 142 can be tested by methods such as contact angle testing or Zeta potential analysis (Zeta is also known as Zeta potential, which refers to the potential of the shear surface).

[0068] In this way, by setting the outflow surface 116 to be more hydrophilic in the middle and more hydrophobic on both sides in the first direction D, the outflow surface 116 forms a structure that is more hydrophilic in the middle and more hydrophobic on both sides. When the fluid flows through the outflow surface 116, under the action of the wetting gradient effect, the fluid will migrate from the hydrophobic side to the hydrophilic side, thereby causing the fluid to migrate from both sides of the force concentration part 119 to the force concentration part 119, improving the force situation of the outflow surface 116. As a result, during the process of the valve structure 100 switching from the closed state to the open state, the outflow surface 116 can be fully expanded, increasing the blood flow.

[0069] In the first direction D, the hydrophilicity of the unidirectional liquid-guiding structure increases from both sides of the force concentration part 119 toward the center of the force concentration part 119.

[0070] That is, the hydrophilicity gradually increases from both sides of the force concentration portion 119 towards the center of the force concentration portion 119, or the hydrophobicity gradually decreases from both sides of the force concentration portion 119 towards the center of the force concentration portion 119, so that the surface of the outflow surface 116 forms a gradient of decreasing hydrophobicity and increasing hydrophilicity. For example, in one embodiment, such as Figure 4 As shown, the outflow surface 116 includes a first region 141, a second region 142, a third region 143, a fourth region 144, and a fifth region 145. These regions are arranged adjacent to each other in the first direction D. The hydrophilicity of the unidirectional liquid-guiding structure of the first region 141 is less than that of the unidirectional liquid-guiding structure of the second region 142, and the hydrophilicity of the unidirectional liquid-guiding structure of the second region 142 is less than that of the unidirectional liquid-guiding structure of the third region 143. The hydrophilicity of the liquid-guiding structure varies. The hydrophilicity of the unidirectional liquid-guiding structure in the third region 143 is greater than that in the fourth region 144, and the hydrophilicity of the unidirectional liquid-guiding structure in the fourth region 144 is greater than that in the fifth region 145. Therefore, the hydrophilicity increases from the first region 141 to the third region 143, and from the fifth region 145 to the third region 143. This allows the hydrophilicity of the unidirectional liquid-guiding structure to increase from both sides of the force concentration portion 119 towards its center. It is understood that the division of the first region 141, second region 142, third region 143, fourth region 144, and fifth region 145 is merely illustrative. This embodiment does not limit the number of regions on the outflow surface 116; it can have five, six, or even ten regions, as long as the hydrophilicity of the unidirectional liquid-guiding structure increases from both sides of the force concentration portion 119 towards its center.

[0071] This creates a gradual wetting gradient effect on the outflow surface 116 from both sides towards the center in the first direction D. When blood is at any position on the outflow surface 116, it will flow towards the center of the force concentration part 119 due to the difference in hydrophilicity between its position and its adjacent positions. This facilitates the flow and guidance of blood from both sides towards the center of the force concentration part 119, increases the blood flow pressure in the force concentration part 119, and allows the valve leaflet structure 100 to fully unfold during the opening process, which is conducive to the passage of blood. At the same time, it also improves the stress condition of the outflow surface 116 and increases the service life of the valve leaflet structure 100.

[0072] In this embodiment, the unidirectional flow-guiding structure in different regions of the outflow surface 116 can be a coating structure. The specific differences in hydrophilicity and hydrophobicity can be obtained by applying different hydrophobic or hydrophilic coatings to the outflow surface 116. For example, in one embodiment, a hydrophobic coating can be applied to the first region 141, and a hydrophilic coating can be applied to the second region 142, so that the hydrophilicity of the first region 141 is less than that of the second region 142. The hydrophobic coating can be PDMS, paraffin, etc., and the hydrophilic coating can be PEG, polyacrylic acid, etc. Accordingly, the outflow surface 116 is divided into multiple regions, and hydrophobic coatings with different hydrophobicities are applied to each of the multiple regions to achieve an increase in the hydrophilicity of the outflow surface 116 from both sides to the middle.

[0073] Example 2

[0074] The difference between this embodiment and Embodiment 1 is that, as Figures 5 to 8 As shown, the unidirectional fluid guiding structure includes a plurality of protrusions 120, which are spaced apart. In the first direction D, the height L of the protrusions 120 on the force concentration part 119 is less than the height of the protrusions 120 on both sides of the force concentration part 119, and / or the cross-sectional area of ​​the protrusions 120 on the force concentration part 119 is less than the cross-sectional area of ​​the protrusions 120 on both sides of the force concentration part 119.

[0075] In this embodiment, the protrusion 120 refers to a structure that protrudes from the surface of the outlet surface 116. The height L of the protrusion 120 refers to the distance between the two end faces of the protrusion 120 perpendicular to the outlet surface 116. The cross-sectional area of ​​the protrusion 120 refers to the cross-sectional area of ​​the protrusion 120 parallel to the outlet surface 116. The cross-sectional area of ​​the protrusion 120 on the force concentration part 119 is smaller than the cross-sectional area of ​​the protrusions 120 on both sides of the force concentration part 119. The cross-sectional area of ​​the protrusion 120 is set to 5 square micrometers to 300 square micrometers. Specifically, the cross-sectional area of ​​the protrusion 120 can be 5 square micrometers, 20 square micrometers, 50 square micrometers, 100 square micrometers, 150 square micrometers, or 300 square micrometers. In this embodiment, the protrusion 120 presents a micro-pattern structure, that is, a micro-pattern structure in which the width dimension of the protrusion 120 and the spacing between two adjacent protrusions 120 are micrometers. The structural dimensions of the protrusion 120 in this embodiment can be obtained by observation using an electron microscope or a scanning electron microscope. For example... Figures 5-7 As shown, the protrusion 120 can be cylindrical, cuboid, or triangular prism. The protrusion 120 can be formed by electrospinning on the surface of the leaflet body 110, or by coating the surface of the leaflet body 110 with a hydrophilic or hydrophobic coating, and then laser etching or imprinting the corresponding coating.

[0076] In this embodiment, as Figures 7 to 8 As shown, multiple protrusions 120 have a columnar structure and are arrayed on the outflow surface 116. Any two adjacent protrusions 120 are spaced apart, forming a grid-like structure. The spacing between two adjacent protrusions 120 is between 20 micrometers and 200 micrometers, specifically 20 micrometers, 40 micrometers, 50 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, 150 micrometers, 180 micrometers, and 200 micrometers. Along the first direction D, the height L of the protrusions 120 in the force concentration section 119 is less than the height L of the protrusions 120 on both sides of the force concentration section 119. The height L is between 2 micrometers and 30 micrometers, specifically 2 micrometers, 5 micrometers, 10 micrometers, 15 micrometers, 20 micrometers, 25 micrometers, and 30 micrometers. 。It is understandable that, for micropatterns, within a certain height range, the height of the protrusion 120 and the contact angle between the outflow surface 116 and the fluid are directly proportional. The greater the height of the protrusion 120, the larger the contact angle between the fluid and the outflow surface 116, thus making the outflow surface 116 more hydrophobic (i.e., less hydrophilic). Through the height difference of the protrusions 120, a hydrophobicity difference is formed on the outflow surface 116. On the basis of the hydrophilicity difference already existing on the outflow surface 116 of the leaflet body 110, the difference in hydrophilicity difference is further amplified by setting the pattern structure on the outflow surface 116, thereby increasing the guiding effect of the outflow surface 116 on the fluid, further promoting the flow of blood towards the center of the force concentration part 119, and reducing the probability that the leaflet structure 100 fails to fully unfold. It is understood that in some embodiments, the height of the protrusion 120 may be set to increase from the center of the force concentration portion 119 to both sides of the force concentration portion 119 in order to increase the difference in hydrophobicity or hydrophilicity of the interface, thereby further enhancing the guiding effect of the outflow surface 116 on the fluid.

[0077] In other embodiments, the protrusions 120 are designed such that the end face surface area of ​​the protrusions 120 in the force concentration part 119 is smaller than the end face surface area of ​​the protrusions 120 on both sides of the force concentration part 119. The end face refers to the end face of the protrusion 120 that is far away from the outflow surface 116. It can be understood that within a certain range, the larger the end face surface area of ​​the protrusion 120, the larger its contact angle with the fluid. The larger the contact angle, the stronger the hydrophobicity and the weaker the hydrophilicity. Thus, through the difference in the end face surface area of ​​the protrusions 120, the outflow surface 116 forms a hydrophobicity difference between the force concentration part 119 and the area on both sides, further increasing the hydrophilicity difference of the sidewall surface structure and enhancing the guiding effect of the outflow surface 116 on the fluid.

[0078] In this embodiment, the cross-sectional area of ​​the protrusion 120 on the force concentration part 119 can be set to be smaller than the cross-sectional area of ​​the protrusion 120 on both sides of the force concentration part 119, and the height L of the protrusion 120 on the force concentration part 119 can be designed to be smaller than the height L of the protrusion 120 on both sides of the force concentration part 119.

[0079] In other embodiments, such as Figure 9As shown, the spacing between the protrusions 120 on the force concentration section 119 is greater than the spacing between the protrusions 120 on both sides of the force concentration section 119. The spacing between two adjacent protrusions 120 is inversely proportional to the contact angle of the fluid on the outflow surface 116. The larger the spacing, the smaller the contact angle, thus making the hydrophilicity of the outflow surface 116 greater in the force concentration section 119 than on both sides of the force concentration section 119. This further increases the hydrophilicity-hydrophobicity difference of the sidewall surface structure and enhances the guiding effect of the outflow surface 116 on the fluid. The spacing between two adjacent protrusions 120 can be between 0.5 and 3 times the diameter of the protrusion 120. Specifically, it can be set to 0.5, 1, 1.5, 2, 2.5, or 3 times the diameter of the adjacent protrusion 120.

[0080] Example 3

[0081] The difference between this embodiment and Embodiment 1 is that, referring to... Figure 10 and Figure 11 As shown, the unidirectional liquid guiding structure includes a plurality of protrusions 120 disposed on the outflow surface 116. Each protrusion 120 extends in a strip shape along the first direction D. The plurality of protrusions 120 are arranged in parallel in sequence along the second direction C, which is perpendicular to the first direction D.

[0082] It should be noted that the protrusion 120 in this embodiment exhibits a micro-patterned structure, that is, the width of the protrusion 120 and the spacing between two adjacent protrusions 120 are micrometer-sized micro-patterned structures. The structure and dimensions of the protrusion 120 in this embodiment can be obtained by observation using an electron microscope or a scanning electron microscope. The protrusion 120 can be cylindrical, cuboid, or triangular prism-shaped. The protrusion 120 can be formed by electrospinning on the surface of the leaflet body 110, or by coating the surface of the leaflet body 110 with a hydrophobic or hydrophilic coating, and then laser etching or imprinting the corresponding coating.

[0083] In this embodiment, as Figure 10 As shown, the second direction C is the direction from the proximal end 111 to the distal end 112, and the first direction D is the direction perpendicular to the proximal end 111 to the distal end 112. Multiple protrusions 120 are spaced apart from each other along the second direction C, and a groove 130 extending along the first direction D is formed between adjacent protrusions 120. The width of the groove 130 is between 10 micrometers and 100 micrometers, specifically 10 micrometers, 20 micrometers, 30 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, etc. In this embodiment, referring to... Figure 11As shown, each protrusion 120 extends along the first direction D. The height L of each protrusion 120 at the force concentration part 119 is less than the height L on both sides of the force concentration part 119, and the height L of the protrusion 120 increases from the force concentration part 119 to both sides.

[0084] In this embodiment, as Figure 10 As shown, the width W of each protrusion 120 at the position of the force concentration part 119 is smaller than the width W on both sides, and the width W of each protrusion 120 is determined by the force concentration part 119.

[0085] Increase towards both sides.

[0086] Thus, by the difference in height L and / or width W of each protrusion 120 in the direction of the force concentration portion 119 toward both sides along the first direction D, a structural hydrophilicity / hydrophobicity is formed on the outflow surface 116.

[0087] The difference enables the fluid to be guided on the outlet surface 116. Furthermore, by setting protrusions 120 extending along the first direction D and multiple protrusions 120 spaced apart along the second direction C, the protrusions 120 form grooves 130 on the surface of the outlet surface 116 along the first direction D. As a result, the fluid moves directionally from both sides of the force concentration part 119 toward the center of the force concentration part 119 under the guidance of the grooves 130, further enhancing the flow guidance from both sides of the force concentration part 119 to the center of the force concentration part 119.

[0088] Example 4

[0089] The difference between this embodiment and Embodiment 1 is that, as Figure 13 As shown, the leaflet body 110 includes a woven mesh skeleton 114, which forms an outflow surface 116 and a unidirectional liquid guiding structure.

[0090] In the first direction D, the weaving density of the mesh skeleton 114 on the force concentration part 119 is greater than the weaving density of the mesh skeleton 114 on both sides of the force concentration part 119.

[0091] It should be noted that weaving density refers to the number of intersections of the weaving threads per unit area. The mesh skeleton 114 forms the supporting structure of the leaf body 110.

[0092] In this embodiment, the mesh skeleton 114 requires the weaving threads to cross each other during weaving. The same weaving thread typically needs to cross multiple weaving threads (weaving threads typically need to be cross-woven; the cross-woven threads can be divided into warp and weft threads; the same warp thread needs to cross multiple weft threads, and the same weft thread needs to cross multiple warp threads). In one specific implementation, the number of weaving threads (corresponding to weft threads) that cross at the position corresponding to the stress concentration part 119 for the same length (the weaving thread at this point can be a warp thread, and the weft threads that cross subsequently are weft threads) is greater than the number of weaving threads (also corresponding to weft threads) that cross at the positions corresponding to the sides of the stress concentration part 119. This results in the number of intersections of the weaving threads in the stress concentration part 119 of the mesh skeleton 114 being greater than the number of intersections on the sides, thereby achieving a weaving density in the middle of the mesh skeleton 114 that is greater than the weaving density near the sides. For example, in one embodiment, the mesh skeleton 114 includes a first region 141, a second region 142 and a third region 143. The second region 142 corresponds to the force concentration part 119 and is located in the middle of the first direction D. The first region 141 and the third region 143 are located on both sides of the second region 142 in the first direction D. The number of weaving intersections of the braided wires in the second region 142 is greater than the number of weaving intersections of the braided wires in the first region 141 and is greater than the number of weaving intersections of the braided wires in the third region 143.

[0093] In this embodiment, different areas on the surface of the mesh skeleton 114 are also coated with a hydrophobic coating or a hydrophilic coating. The hydrophobicity of the hydrophobic coating or the hydrophilic coating increases from the force concentration part 119 toward both sides of the first direction D. The surface of the coating may be provided with the above-mentioned protrusions 120.

[0094] Because the mesh skeleton 114 has a lower weaving density in the corresponding areas on both sides of the stress concentration part 119, the mesh skeleton 114 in the areas on both sides is more easily deformed. As a result, during the process of the valve structure 100 from closing to opening, the blood flow pressure on the sidewall 113 is greater, and the braided filaments are more likely to shift from the stress concentration part to both sides, reducing the distance between the two adjacent protrusions 120 on both sides. This increases the contact angle of the fluid on both sides of the stress concentration part 119, increases the hydrophobicity on both sides of the stress concentration part 119, and increases the difference in hydrophobicity of the outflow surface 116 from the stress concentration part 119 to both sides of the stress concentration part 119, thereby enhancing the guiding effect on the fluid.

[0095] It is understood that in other embodiments, the number of braided filaments on both sides of the force concentration portion 119 is limited, so that the number of braided filaments on both sides of the force concentration portion 119 is greater than the number of braided filaments in the force concentration portion 119. This results in the area of ​​the mesh openings of the mesh skeleton 114 on both sides of the force concentration portion 119 being smaller than the area of ​​the mesh openings near the force concentration portion 119. As a result, the braiding density of the mesh skeleton 114 in the force concentration portion 119 is greater than the braiding density near the free end.

[0096] It is understood that in other embodiments, the mesh skeleton 114 includes multiple braided filaments, and the diameter of the braided filaments corresponding to the stress concentration part 119 is larger than the diameter of the filaments on both sides of the corresponding stress concentration part 119. Here, the diameter of the braided filaments refers to the diameter of a single filament.

[0097] The diameter of the braided filaments corresponding to the force concentration part 119 is larger than the diameter of the filaments on both sides of the force concentration part 119. This is beneficial because during the opening or closing of the leaflet structure 100, the braided filaments on both sides of the force concentration part 119 are more easily deformed, causing the braided filaments to gather towards both sides of the force concentration part 119. This, in turn, helps the braided filaments to pull the protrusions 120 towards both sides of the force concentration part 119, thereby facilitating the formation of a higher hydrophobic difference between the force concentration part 119 and the two sides, promoting the flow of blood from both sides of the force concentration part 119 to the force concentration part 119.

[0098] It is understood that in other embodiments, the elasticity of at least a portion of the braided filaments on both sides of the force concentration portion 119 in the first direction D is better than that of the braided filaments in the force concentration portion 119. By varying the elasticity of the braided filaments, the same effect can be achieved that facilitates the deformation of the mesh skeleton 114 on both sides of the force concentration portion 119 during the opening or closing of the leaf structure 100.

[0099] Example 5

[0100] Reference Figure 13 and Figure 14 As shown, this embodiment also provides a valve prosthesis 200, including a stent structure 210 and a leaflet structure 100. A lumen channel is formed on the inner side of the stent structure 210. The leaflet structure 100 is the leaflet structure 100 proposed in this embodiment, which is disposed on the inner side of the stent structure 210, and the fixed end, i.e., the proximal end 111, of the leaflet structure 100 is connected to the stent structure 210. A flow-blocking membrane 211 is disposed on the sidewall 113 of the stent structure 210, and the flow-blocking membrane 211 and the closed leaflet structure 100 together constitute a semi-closed region.

[0101] The valve prosthesis 200 of this embodiment has at least the beneficial effects of the leaflet structure 100 proposed in this application.

[0102] Example 6

[0103] Reference Figures 15 to 17 As shown, this embodiment also provides a method for preparing a leaflet structure 100, used to prepare the leaflet structure 100 proposed in this embodiment. The leaflet structure 100 includes a leaflet body 110, the leaflet body 110 includes an outflow surface 116, the outflow surface 116 includes a force concentration portion 119, and the force concentration portion 119 is disposed near the middle of the distal end 112 of the outflow surface 116. The method for preparing the leaflet structure 100 includes:

[0104] Step S1: Provide the leaflet body 110.

[0105] The leaflet body 110 can be made of biological tissues such as bovine pericardium or porcine pericardium, or it can be woven from filaments.

[0106] Step S2: A unidirectional fluid guiding structure is processed on the outflow surface 116 of the leaflet body 110 to obtain a leaflet structure 100 that can guide fluid from the edge of the force concentration part 119 to the center of the force concentration part 119.

[0107] According to the preparation method of the valve structure 100 in this embodiment, the valve structure 100 is provided with a one-way fluid guiding structure on the outflow surface 116. When blood flows through the outflow surface 116, the one-way fluid guiding structure can guide the fluid (i.e., blood) from the edge of the force concentration part 119 to the center of the force concentration part 119. This makes the amount of fluid gathered in the force concentration part 119 greater than the amount of fluid gathered on both sides of the force concentration part 119, and the amount of fluid gathered at the center of the force concentration part 119 is the greatest. This increases the blood flow pressure in the force concentration part, making the blood flow pressure in the force concentration part 119 consistent with the blood flow pressure on both sides of the force concentration part. This allows the force concentration part 119 to open fully, reducing or avoiding the situation where the force concentration part cannot open, allowing the valve structure to fully unfold, and improving the service life of the valve structure.

[0108] like Figure 17 As shown, in one embodiment of this invention, a unidirectional liquid guiding structure is processed on the outflow surface of the leaflet body, including:

[0109] Step S21: Immerse the leaflet body 110 in PDMS solution to obtain a leaflet body with a PDMS coating on the outflow surface 116.

[0110] Before being immersed in the PDMS solution, the leaflet body 110 is dried to give it a porous structure. The specific drying method for the leaflet body 110 can be freeze-drying, typically for about 12 hours; or critical point drying, typically for about 2 hours.

[0111] In step S21, the PDMS solution is specifically used to impregnate the porous structure of the leaflet tissue for 1 to 6 hours to ensure sufficient impregnation, thereby obtaining a leaflet body 110 with a PDMS coating on the outflow surface 116.

[0112] It should be noted that the leaflet body 110 is usually immersed at low temperature, that is, the leaflet body 110 is immersed in a PDMS solution at a low temperature, and a curing agent can usually be added to the PDMS solution. Curing is usually carried out within the range of 10℃-37℃. The crosslinking rate is slower at low temperature than at room temperature, which can promote the filling of PDMS in the porous structure.

[0113] Step S22: Provide an engraving part 300 with a preset graphic structure on its surface, and use the engraving part 300 to press out a leaf body with a PDMS coating on the flow surface 116, thereby obtaining a leaf structure in the first direction D in which the height of the protrusion 120 on the force concentration part 119 is less than the height of the protrusion 120 on both sides of the force concentration part 119, and / or the cross-sectional area of ​​the protrusion on the force concentration part is less than the cross-sectional area of ​​the protrusion on both sides of the force concentration part.

[0114] The etched part 300 can be a photolithographic silicon wafer. The processing method of the photolithographic silicon wafer is roughly as follows: select a silicon wafer substrate, the shape and size of which can be the same as the leaf structure 100; then use laser engraving to impart a certain preset graphic structure on the silicon wafer substrate according to the set program.

[0115] The preset graphic structure is adapted to the shape of the protrusion 120. The preset graphic structure is usually a groove 310 on the engraving part 300, and each groove 310 forms a protrusion 120. The depth of each groove 310 corresponds to the height L of the protrusion 120 to be formed, and the width of each groove 310 corresponds to the cross-sectional area of ​​the protrusion 120 to be formed. That is, the larger the width of the groove, the larger the cross-sectional area of ​​the corresponding protrusion 120.

[0116] like Figure 15 As shown, the groove 310 of the engraved part 300 can be a circular groove, and the correspondingly processed leaf structure 100 has such Figures 10 to 12 The cylindrical protrusion 120 shown; the engraving part 300 may have a groove 310 or a square groove, and the correspondingly processed leaf structure 100 has such Figures 4 to 6 The rectangular protrusion 120 shown; the engraved part 300 can have a groove or a triangular groove, and the correspondingly processed leaf-shaped structure 100 has such Figures 5 to 7 The triangular prism-shaped protrusion 120 shown.

[0117] The PDMS-coated leaflet body 110 on the outflow surface 116 is pressed using an engraving part 300. Specifically, the PDMS-coated leaflet body 110 on the outflow surface 116 is placed on the engraving part 300, and a flat pressing method (specifically, the engraving part 300 presses the leaflet body 110) is used to control the thickness h of the leaflet structure 100 to be equal to h0 plus 0.01 mm to 0.1 mm. Specifically, h = (h0 + 0.01) mm, h = (h0 + 0.05) mm, or h = (h0 + 0.1) mm. Here, h0 is the thickness of the leaflet body 110, that is, the overall thickness of the leaflet structure 100 with the protrusion 120 is 0.1 mm to 1 mm thicker than the thickness h0 of the leaflet body 110. When both sides of the leaflet body 110 have protrusions 120, an imprinting element 300 can be provided on both sides of the leaflet body 110. Then, by pressing the imprinting elements 300 on both sides, protrusions 120 are formed on both sides of the leaflet body 110. When one side of the leaflet body 110 has a protrusion 120, the leaflet body 110 can be loaded into a mold with the side where the protrusion 120 needs to be formed facing outwards from the mold. When imprinting is required, the side of the leaflet body 110 where the protrusion 120 needs to be formed faces the imprinting element 300, and the leaflet body 110 is placed on the imprinting element 300. The imprinting element 300 flattens the leaflet body 110, forming the protrusion 120 on the leaflet body 110.

[0118] During or after pressing the leaflet body 110 with a PDMS coating on the flow surface 116 using the embossing part 300, the device is placed in an environment with a temperature of 30°C to 60°C and maintained for a certain period of time to promote PDMS curing. Then, the leaflet structure 100 is gently peeled off from the embossing part to obtain the leaflet structure 100 with protrusions.

[0119] It should be noted that the engraved part 300 is pre-processed, that is, before step S22, the engraved part 300 with corresponding grooves is pre-processed according to the height L and / or cross-sectional area of ​​the protrusion 120 of the leaf structure 100. The engraved part 300 can be a reusable component or a disposable component.

[0120] It is understood that in some embodiments, a valve structure 100 is obtained by step S22 through the embossing member 300 corresponding to the groove shape, in which a plurality of protrusions 120 are sequentially spaced along the first direction D, and the distance between adjacent protrusions 120 gradually decreases along the direction from the force concentration part 119 to both sides. This creates a hydrophobic difference on the outflow surface 116 through the difference in the distance between the plurality of protrusions 120, so that the valve structure 100 can guide blood to the force concentration part 119.

[0121] Furthermore, after step S22, that is, after the protrusion 120 is constructed on the leaflet body 110, the leaflet structure 100 can be treated with plasma to make the hydrophilicity of the stress concentration part 119 different from that of its two sides. Specifically, the surface of the leaflet structure 100 can be plasma-treated using a low-temperature plasma device or a plasma treatment device. After the plasma treatment of the surface of the leaflet structure 100, the functional groups on the surface of the leaflet body 110 are changed to enhance the hydrophilicity.

[0122] Furthermore, the superhydrophobic surface can be transformed into a superhydrophilic surface through partial plasma treatment. Specifically, the surface of the force concentration part 119 is treated with a superhydrophilic surface, which can further promote the flow of blood from the superhydrophobic region to the superhydrophilic region, that is, promote the aggregation of blood in the force concentration part 119.

[0123] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A leaflet structure, characterized in that, The leaflet structure comprises a leaflet body, the leaflet body comprises an outflow surface, the outflow surface is a side surface through which blood flows in the blood flow direction, and the outflow surface comprises a stress concentration part, the stress concentration part is arranged near the middle part of the distal end of the outflow surface, wherein the proximal end and the distal end of the outflow surface are defined in the blood flow direction, the position through which blood flows first is the proximal end, and the position through which blood flows later is the distal end; The leaflet structure further comprises a unidirectional liquid guiding structure arranged on the outflow surface, in a first direction, the hydrophilicity of the unidirectional liquid guiding structure on the stress concentration part is greater than the hydrophilicity of the unidirectional liquid guiding structure on both sides of the stress concentration part, so that the unidirectional liquid guiding structure is used for guiding fluid from the edge of the stress concentration part to the center of the stress concentration part, wherein the first direction is perpendicular to the direction of the leaflet body from the proximal end to the distal end.

2. The leaflet structure of claim 1, wherein, In the first direction, the hydrophilicity of the unidirectional liquid guiding structure increases from both sides of the stress concentration part to the center of the stress concentration part.

3. The leaflet structure of claim 1, wherein, The unidirectional liquid guiding structure comprises a plurality of protruding parts, and the plurality of protruding parts are arranged in a scattered manner. In the first direction, the height of the protruding part on the stress concentration part is less than the height of the protruding part on both sides of the stress concentration part, and / or the cross-sectional area of the protruding part on the stress concentration part is less than the cross-sectional area of the protruding part on both sides of the stress concentration part.

4. The leaflet structure of claim 1, wherein, The unidirectional liquid guiding structure comprises a plurality of protruding parts, and the plurality of protruding parts are arranged in a scattered manner. In the first direction, the spacing between the protruding parts on the stress concentration part is greater than the spacing between the protruding parts on both sides of the stress concentration part.

5. The leaflet structure of claim 1, wherein, The leaflet body comprises a woven mesh skeleton, and the woven mesh skeleton forms the outflow surface and the unidirectional liquid guiding structure. In the first direction, the weaving density of the woven mesh skeleton on the stress concentration part is greater than the weaving density of the woven mesh skeleton on both sides of the stress concentration part.

6. The leaflet structure of claim 5, wherein, The woven mesh skeleton comprises a plurality of woven wires, and the wire diameter corresponding to the stress concentration part is greater than the wire diameter corresponding to both sides of the stress concentration part.

7. A valve prosthesis, characterized in that It comprises: A stent structure, the inner side of the stent structure forms a lumen channel; The leaflet structure of any one of claims 1-6 is arranged on the inner side of the stent structure, and the leaflet structure is connected with the stent structure.

8. A method for producing a leaflet structure for producing a leaflet structure according to any one of claims 1 to 6, characterized in that The leaflet structure comprises a leaflet body, the leaflet body comprises an outflow surface, the outflow surface comprises a stress concentration part, the stress concentration part is arranged near the middle part of the distal end of the outflow surface, and the preparation method of the leaflet structure comprises: Providing the leaflet body; Processing a unidirectional liquid guiding structure on the outflow surface of the leaflet body to obtain a leaflet structure for guiding fluid from the edge of the stress concentration part to the center of the stress concentration part.

9. The method of claim 8, wherein the leaflet structure is prepared by, The processing of the unidirectional liquid guiding structure on the outflow surface of the leaflet body comprises: Soaking the leaflet body in a PDMS solution to obtain the leaflet body provided with a PDMS coating on the outflow surface; The present application provides a marking member with a preset pattern structure on a surface, and a leaf structure obtained by pressing the leaf body with a PDMS coating on the outflow surface using the marking member, wherein the height of the protruding part on the stress concentration part is less than the height of the protruding parts on both sides of the stress concentration part, and / or the cross-sectional area of the protruding part on the stress concentration part is less than the cross-sectional area of the protruding parts on both sides of the stress concentration part in the first direction perpendicular to the direction of the leaf body from the proximal end to the distal end.

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