Double-layer thermofused stent, manufacturing method and release device for double-layer thermofused stent

Abstract

This application provides a double-layer thermofused scaffold, its manufacturing method, and a double-layer thermofused scaffold release device. The double-layer thermofused scaffold includes a frame, a porous fiber membrane, and a drug coating. The frame is a hollow cylinder, comprising an inner frame and an outer frame. The inner frame is located within the outer frame and forms a mesh structure with it. The inner and outer frames are thermofused together at their contact points. The frame is made of a biodegradable material. The porous fiber membrane is disposed on the surface of the frame, with a porosity greater than 70%, and is also made of a biodegradable material. The drug coating is distributed in the pores of the porous fiber membrane and can prevent cells and tissues from adhering to and proliferating on the scaffold surface.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a double-layer thermofusion stent, a method for manufacturing the same, and a double-layer thermofusion stent release device. Background Technology

[0002] Tubal infertility is one of the leading causes of female infertility, with interstitial tubal obstruction or stenosis being particularly common. Traditional treatment often involves tubal stent placement; however, current stents have several drawbacks: traditional stents are mostly made of metal or non-degradable polymers, which can remain in the body long-term, continuously irritating the tubal tissue as foreign bodies, leading to inflammation and increasing the risk of restenosis, severely impacting treatment effectiveness and patient health. Furthermore, the stent surface lacks an effective anti-adhesion coating, allowing tubal tissue to proliferate on the stent surface post-surgery, causing secondary blockage and reducing the success rate of stent placement. Additionally, current stents are typically single-layered, lacking sufficient strength and radial support, further increasing the risk of restenosis and secondary blockage. Summary of the Invention

[0003] The main objective of this application is to provide a biodegradable, non-adhesive, high-strength double-layer thermoplastic stent and its manufacturing method.

[0004] Another major objective of this application is to provide a double-layer thermofusion stent release device that can prevent stent locking during release.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] According to one aspect of this application, a double-layer thermofused scaffold is provided, comprising a frame, a porous fiber membrane, and a drug coating. The frame includes a cylindrical inner frame and a cylindrical outer frame, the inner frame being located within and in contact with the outer frame to form a mesh structure. The inner frame and the outer frame are thermofused together at their contact points. The frame is made of a biodegradable material. The porous fiber membrane is disposed on the surface of the frame, the porous fiber membrane having a porosity greater than 70%, and the porous fiber membrane is made of a biodegradable material. The drug coating is distributed in the pores of the porous fiber membrane and is capable of preventing cell and tissue adhesion and proliferation on the scaffold surface.

[0007] According to one embodiment of this application, the inner frame and the outer frame are wound from the same thread, and the thread is first wound to form one of the inner frame and the outer frame, and then wound to form the other one.

[0008] According to one embodiment of this application, the inner frame includes a plurality of parallel inner threads, the inner threads being inclined in a first direction relative to the central axis of the inner frame; the outer frame includes a plurality of parallel outer threads, the outer threads being inclined in a second direction relative to the central axis of the outer frame, the second direction being opposite to the first direction.

[0009] According to one embodiment of this application, the frame is made of polylactic acid-glycolic acid copolymer and nano-hydroxyapatite.

[0010] According to one embodiment of this application, the pore size of the porous fiber membrane is 280nm-350nm.

[0011] According to another aspect of this application, this application also provides a method for manufacturing one or more double-layer thermofused stents, comprising the following steps: step S1: fabricating the frame; step S2: forming the porous fiber membrane on the surface of the frame; step S3: preparing a solution of the drug coating, and impregnating the drug coating into the pores of the porous fiber membrane using a vacuum impregnation method.

[0012] According to one embodiment of this application, step S1 includes: step S11: making yarn using biodegradable material; step S12: first winding the yarn on a weaving fixture to form one of the inner frame and the outer frame, and then winding the yarn to form the other one, to obtain a frame intermediate structure; step S13: assembling the frame intermediate structure onto a heat shrink tube, heating it so that the contact points of the inner frame and the outer frame are fused together to form the frame.

[0013] According to one embodiment of this application, step S12 includes: winding the yarn around the circumference of the weaving fixture at an angle inclined to a first direction relative to the central axis of the inner frame to form the inner frame, and then winding the yarn around the circumference at an angle inclined to a second direction relative to the central axis of the outer frame to form the outer frame, wherein the second direction is opposite to the first direction.

[0014] According to one embodiment of this application, the diameter of the filament is 180um-220um.

[0015] According to one embodiment of this application, step S2 includes: step S21: preparing a biodegradable material solution; step S22: assembling the frame onto an electrospinning device and weaving the porous fiber membrane on the surface of the frame.

[0016] According to one embodiment of this application, step S3 includes: step S31: mixing rapamycin and hyaluronic acid evenly to form a solution of the drug coating; step S32: impregnating the drug coating into the pores of the porous fiber membrane using a vacuum impregnation method, and then performing freeze-drying treatment.

[0017] According to one embodiment of this application, the freeze-drying process includes multiple processing steps at different temperatures.

[0018] According to another aspect of this application, this application also provides a double-layer thermofused stent release device, including the double-layer thermofused stent and a conduit as described above. The conduit includes an inner tube and an outer tube, the double-layer thermofused stent is disposed inside the inner tube, and the outer tube drives the inner tube to move to release the double-layer thermofused stent. A groove is provided on the wall of the inner tube corresponding to the double-layer thermofused stent, and the groove is arranged along the axial direction of the inner tube.

[0019] According to one embodiment of this application, the length of the groove along the axial direction of the inner tube is 5mm-50mm, and the width of the groove is 0.1mm-1mm.

[0020] According to one embodiment of this application, a groove is provided on the pipe wall at the end of the inner tube and connects to the end face corresponding to the end of the inner tube.

[0021] According to one embodiment of this application, the outer tube includes a first segment and a second segment, the inner diameter of the first segment is smaller than the inner diameter of the second segment, and a limiting part is provided at one end of the inner tube. The maximum size of the limiting part is larger than the inner diameter of the first segment and smaller than the inner diameter of the second segment. The outer tube drives the inner tube to move through the limiting part.

[0022] As can be seen from the above technical solution, the advantages and positive effects of the double-layer thermofusion stent proposed in this application are as follows:

[0023] The double-layer thermofusion stent proposed in this application has a double-layer structure. The inner and outer frames form a mesh structure, which can improve the strength of the stent, increase the radial support force of the stent, and avoid postoperative restenosis and secondary blockage.

[0024] The double-layer thermofusion stent proposed in this application has a porous fiber membrane on its surface, and the drug coating is placed in the pores of the porous fiber membrane. This can prevent adhesion and avoid postoperative proliferation of fallopian tube tissue on the stent surface, which could lead to secondary blockage of the lumen.

[0025] The double-layer thermoplastic stent proposed in this application has a frame and a porous fiber membrane made of biodegradable materials. The stent can degrade in the human body, avoiding long-term stimulation of the fallopian tube tissue and preventing the occurrence of inflammatory reactions. Attached Figure Description

[0026] The various objectives, features, and advantages of this application will become more apparent from the following detailed description of preferred embodiments in conjunction with the accompanying drawings. The drawings are merely illustrative illustrations of this application and are not necessarily drawn to scale. In the drawings, the same reference numerals always denote the same or similar parts. Wherein:

[0027] Figure 1 This is a schematic diagram of the structure of the double-layer thermofusion support of this application.

[0028] Figure 2 yes Figure 1 Top view.

[0029] Figure 3 yes Figure 2 An enlarged schematic diagram of point I.

[0030] Figure 4 yes Figure 3 A schematic diagram of removing the drug coating.

[0031] Figure 5 The diagram shows the state of the wire winding of the double-layer thermoplastic support of this application.

[0032] Figure 6 yes Figure 5 Top view.

[0033] Figure 7 This is a schematic diagram of the intermediate structure of the frame obtained after the wire winding of the double-layer thermoplastic support of this application is completed.

[0034] Figure 8 yes Figure 7 Top view.

[0035] Figure 9 yes Figure 8 Enlarged view of section II.

[0036] Figure 10 This is a schematic diagram of the frame obtained after the middle structure of the double-layer thermoplastic support frame of this application is thermoplasticized.

[0037] Figure 11 yes Figure 10 Top view.

[0038] Figure 12 yes Figure 11 Enlarged view of section III.

[0039] Figure 13 This is a schematic diagram of the inner tube of the double-layer thermofusion stent release device of this application.

[0040] Figure 14 yes Figure 13 A sectional view along the AA direction.

[0041] Figure 15 This is a schematic diagram of the outer tube of the double-layer thermofusion stent release device of this application.

[0042] Figures 16 to 18 This is a schematic diagram of the loading process of the double-layer thermoplastic support of this application.

[0043] Figures 19 to 21 This is a schematic diagram of the release process of the double-layer thermofusion stent of this application.

[0044] The annotations in the attached figures are explained as follows:

[0045] 1-Double-layer thermoplastic support;

[0046] 2-Catheter;

[0047] 3-Balloon;

[0048] 4-Luer joint;

[0049] 5-Guidewire;

[0050] 6-Developing ring;

[0051] 10-Framework;

[0052] 11-Woven workwear;

[0053] 12-Silk thread;

[0054] 13-Protrusion;

[0055] 20-Porous fiber membrane;

[0056] 21-Inner tube;

[0057] 22-Outer tube;

[0058] 30-Drug coating;

[0059] 100 - Through hole;

[0060] 101 - Inner Frame;

[0061] 102 - Outer frame;

[0062] 211-Slotting;

[0063] 212-Limiting Part

[0064] 221 - First paragraph;

[0065] 222 - Second paragraph;

[0066] D1 - First direction;

[0067] D2 - Second direction. Detailed Implementation

[0068] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0069] In the following description of various exemplary embodiments of this application, reference is made to the accompanying drawings, which form part of this application, and which illustrate by way of example different exemplary structures, systems, and steps that can implement various aspects of this application. It should be understood that other specific solutions to components, structures, exemplary devices, systems, and steps may be used, and structural and functional modifications may be made without departing from the scope of this application. Furthermore, while the terms “above,” “between,” “within,” etc., may be used in this specification to describe different exemplary features and elements of this application, these terms are used herein only for convenience, such as the orientation according to the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of this application.

[0070] It is understood that the terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to these processes, methods, products, or devices.

[0071] Relative terms such as “down” or “bottom” and “up” or “top” may be used herein to describe the relationship of one element to another, as illustrated in the figures. It should be understood that relative terms are intended to include different orientations of the device beyond those shown in the figures. For example, if a device in one of the figures is flipped, an element described as “down” or “bottom” of another element will be oriented “up” or “top” of that element. Thus, the exemplary term “down” can include both “down” and “up” orientations, and the term “bottom” can include both “bottom” and “top” orientations, depending on the specific orientation of the figure. Similarly, if a device in one of the figures is flipped, an element described as “down” or “bottom” of another element will be oriented “up” or “top” of that element. Thus, the exemplary term “bottom” or “below” can include both “up” and “down” orientations.

[0072] See Figures 1 to 4The double-layer thermofused scaffold 1 of this application includes a frame 10, a porous fiber membrane 20, and a drug coating 30. The frame 10 is a hollow cylinder with a central through-hole 100. The frame 10 includes an inner frame 101 and an outer frame 102, both cylindrical in shape. The inner frame 101 is located within the outer frame 102 and contacts it to form a cross-linked mesh structure. The inner frame 101 and the outer frame 102 are thermofused together at their contact points. The frame 10 is made of a biodegradable material. The porous fiber membrane 20 is disposed on the surface of the frame 10. The porosity of the porous fiber membrane 20 is greater than 70%, and the membrane is also made of a biodegradable material. The drug coating 30 is distributed in the pores of the porous fiber membrane 20 and can prevent cells and tissues from adhering to and proliferating on the surface of the scaffold 1.

[0073] The double-layer thermofused stent 1 of this application has a double-layer structure for the frame 10. The inner frame 101 and the outer frame 102 form a cross-mesh structure, which can improve the strength of the stent and increase its radial support. The thermofused connection makes the connection between the inner frame 101 and the outer frame 102 more secure, further enhancing the strength of the frame 10. A porous fiber membrane 20 is provided on the surface of the stent, and a drug coating 30 is disposed in the pores of the porous fiber membrane 20, which can prevent adhesion and avoid postoperative proliferation of fallopian tube tissue on the surface of the stent 1, thus preventing secondary blockage of the fallopian tube lumen.

[0074] The double-layer thermofused stent 1, frame 10 and porous fiber membrane 20 proposed in this application are all made of biodegradable materials. The stent 1 can degrade in the human body, avoiding long-term stimulation of the fallopian tube tissue by the stent 1 and avoiding the occurrence of inflammatory reactions.

[0075] In this embodiment, the frame 10 is made of polylactic-co-glycolic acid copolymer (PLGA) and nano-hydroxyapatite (HA); the ratio of lactic acid (LA) to glycolic acid (GA) is LA:GA = 75:25, or alternatively LA:GA = 70:30 or LA:GA = 80:20. These ratios control the degradation rate of the stent 1, allowing it to gradually degrade into harmless substances that can be absorbed by the body within 3-6 months. Simultaneously, uniformly mixing 3%-8% by mass of nano-hydroxyapatite particles into the PLGA enhances the bioactivity of the stent 1 and promotes fallopian tube tissue repair. In this embodiment, the mass fraction of the nano-hydroxyapatite particles is 5%.

[0076] In this embodiment, the porous fiber membrane 20 has a pore size of 280nm-350nm to provide sufficient space for the drug coating 30. Specifically, the pore size can be 300nm, 320nm, 330nm, 340nm, etc.

[0077] See Figures 5 to 9In this embodiment, the double-layer thermoplastic support 1 of this application is formed by winding the inner frame 101 and the outer frame 102 from the same wire 12. The wire 12 is first wound to form the inner frame 101, and then wound to form the outer frame 102. In some other embodiments, the outer frame 102 can be wound first, and then the inner frame 101 can be wound. The inner frame 101 includes multiple parallel inner wires, which are inclined in a first direction D1 relative to the central axis of the inner frame 101. The outer frame 102 includes multiple parallel outer wires, which are inclined in a second direction D2 relative to the central axis of the outer frame 102, and the second direction D2 is opposite to the first direction D1. The central axis of the inner frame 101 and the central axis of the outer frame 102 are on a straight line.

[0078] The material of the suture 12 is the same as that of the frame 10. In this embodiment, the suture 12 is made of polylactic acid-glycolic acid copolymer (PLGA) as the main material. 5% by mass of nano-hydroxyapatite (HA) particles are uniformly mixed into the PLGA to form a mixed copolymer. This mixed copolymer is then extruded to produce sutures 12 with a diameter of 180µm-220µm. Specifically, sutures 12 with a diameter of 200µm, 190µm, or 210µm can be used. This enhances the bioactivity of the stent 1, promotes fallopian tube tissue repair, and allows the stent 1 to gradually degrade into harmless substances that can be absorbed by the body within 3-6 months. The double-layer mesh design improves the stent's strength and enhances its radial support, reducing the risk of postoperative restenosis and secondary blockage.

[0079] See Figures 1 to 12 The manufacturing method of the double-layer thermofused stent 1 of this application includes the following steps: Step S1: fabricating a frame 10; Step S2: forming a porous fiber membrane 20 on the surface of the frame 10; Step S3: preparing a solution of drug coating 30, and impregnating the drug coating 30 into the pores of the porous fiber membrane 20 by vacuum impregnation.

[0080] The manufacturing method of the double-layer thermoplastic stent 1 in this application uses biodegradable materials to make the frame 10 and the porous fiber membrane 20. The stent 1 can degrade in the human body, avoiding long-term stimulation of the fallopian tube tissue by the stent 1 and avoiding the occurrence of inflammatory reactions. The drug coating 30 is impregnated in the pores of the porous fiber membrane 20. The method is simple, the impregnation effect is good, and it can prevent adhesion and avoid postoperative proliferation of fallopian tube tissue on the surface of the stent 1, which would lead to secondary blockage of the lumen.

[0081] In this embodiment, see Figures 5 to 12Step S1 includes: Step S11: Fabricating the thread 12 using biodegradable materials; in this embodiment, the thread 12 uses polylactic acid-glycolic acid copolymer (PLGA) as the main material, and 5% by mass of nano-hydroxyapatite (HA) particles are uniformly mixed into PLGA to form a mixed copolymer before extrusion. This can enhance the bioactivity of the stent 1, promote the repair of fallopian tube tissue, and allow the stent 1 to gradually degrade into harmless substances that can be absorbed by the human body within 3-6 months. Step S12: On the weaving fixture, the thread 12 is first wound to form one of the inner frame 101 and the outer frame 102, and then wound to form the other one, thus obtaining the intermediate structure of the frame.

[0082] In this embodiment, see Figures 5 to 9 On the weaving fixture 11, yarn 12 is wound circumferentially at an angle inclined to a first direction D1 relative to the central axis of the inner frame 101 to form the inner frame 101. Then, yarn 12 is wound circumferentially at an angle inclined to a second direction D2 relative to the central axis of the outer frame 102 to form the outer frame 102, wherein the second direction D2 is opposite to the first direction D1, to form a cross-shaped mesh structure. The inclination angles for winding the inner frame 101 and the outer frame 102 can be the same or different. The specific weaving process is as follows:

[0083] First, a thread 12 is wound around the circumference of the braiding fixture 11 with a gap of 0.3-0.8mm (0.5mm in this embodiment). The thread 12 is inclined at a 20-degree angle relative to the central axis of the inner frame 101 towards the first direction D1, forming the inner frame 101. The winding can be done clockwise or counterclockwise. The braiding fixture 11 has multiple protrusions 13 for winding the thread. Then, a second thread 12 is wound around the circumference with a 20-degree angle relative to the central axis of the outer frame 102 towards the second direction D2, forming the outer frame 102. This results in a double-layered, cross-mesh structure made of a single thread 12, forming the middle structure of the frame. The double-layered mesh structure improves the strength of the stent 1, enhances its radial support, and reduces the risk of postoperative restenosis and secondary blockage.

[0084] In this embodiment, step S1 further includes: step S13: after assembling the intermediate frame structure into a heat shrink tube, heating is performed to weld the inner frame 101 and the outer frame 102 at their contact points to form the frame 10. In this embodiment, the intermediate frame structure is coaxially assembled into a perfluoroethylene propylene (FEP) tear-resistant heat shrink tube, placed in a constant temperature oven, and the temperature inside the oven is increased in multiple stages to obtain the frame 10.

[0085] In this embodiment, the temperature in the oven is increased in three stages, as shown in Table 1 below:

[0086] Table 1: Temperature Stages of Frame 10 Hot Melting

[0087] Phase 1 35-40 3-8 Phase Two 60-80 12-20 Phase Three 150-200 3-8

[0088] In this embodiment, the first stage is 37.5°C, held for 5 minutes; then the temperature is increased to 68°C to enter the second stage, held for 15 minutes; then the temperature is increased to 160°C and held for 5 minutes. Since the melting temperature of PLGA is generally around 196°C, when the middle structure of the frame is heated to a certain temperature in the oven (e.g., 150-260°C), the FEP heat shrink tube begins to generate inward shrinkage force. At this time, when the temperature reaches near the melting temperature of PLGA, the contact positions of the inner frame 101 and the outer frame 102 of the frame 10 are simultaneously fused together by the inward radial force of the heat shrink tube. The multi-stage heating mode ensures that the inward radial force of the heat shrink tube is uniform when the contact positions of the inner frame 101 and the outer frame 102 of the frame 10 are fused, thereby resulting in a higher elastic modulus of the frame 10.

[0089] In this embodiment, step S2 includes: Step S21: preparing a biodegradable material solution; In this embodiment, polylactic acid-co-caprolactone polymer (PLCL) is used, wherein the ratio of lactic acid (LA):caprolactone CL = 70:30, and the molecular weight (Mn = 50-80kDa). The PLCL concentration is 5% w / v (i.e., 5g of 20kDa PLCL is dissolved in 100mL of hexafluoroisopropanol (HFIP)), and the solution is magnetically stirred for 24-48 hours until completely dissolved, forming a homogeneous PLCL solution with a viscosity of approximately 50-100 mPa·s at 25°C, thereby preparing the biodegradable material solution.

[0090] In this embodiment, step S2 further includes: step S22: assembling the frame 10 onto an electrospinning device, and weaving a porous fiber membrane 20 onto the surface of the frame 10. In this embodiment, the frame 10 is assembled onto the carrier of a high-voltage electrospinning machine, and a homogeneous PLCL solution is woven onto the frame 10, wherein the weaving parameters are shown in Table 2 below:

[0091] Table 2: Textile Parameters

[0092]

[0093] After high-voltage electrospinning, a porous fiber membrane 20 with a pore size of about 280-350 nm and a porosity of >70% is obtained on the surface of the frame 10.

[0094] In this embodiment, step S3 includes: step S31: mixing rapamycin and hyaluronic acid evenly to form a solution of drug coating 30; wherein, the preparation process of the solution of drug coating 30 is as follows:

[0095] First, dissolve rapamycin by adding rapamycin powder to ethanol and ultrasonically vibrating for 20-50 minutes until completely dissolved (if solubility is insufficient, the ethanol ratio can be appropriately increased to 5:5 v / v). Simultaneously, dissolve hyaluronic acid (HA) by slowly sprinkling hyaluronic acid powder into deionized water and stirring at low speed (≤200 rpm) until completely swollen (avoiding high-speed shearing that could damage the molecular chains), forming a transparent colloid. Then, mix and homogenize by slowly pouring the rapamycin ethanol solution into the hyaluronic acid aqueous solution while stirring. Add a surfactant; in this example, Tween-80 can be used, but other types of surfactants can be used in other examples. Continue stirring for 1-1.5 hours until homogeneous. Tween-80 can be omitted. If enhanced adhesion is required, a chitosan adhesive solution can be added at this stage (chitosan needs to be pre-dissolved in a 1% acetic acid aqueous solution to form a chitosan solution). The solution composition of the prepared drug coating 30 is shown in Table 3 below.

[0096] Table 3: Solution Composition of Drug Coating 30

[0097] Hyaluronic acid (HA) 1–5% (w / v) solvent system Ethanol-water (3:7 v / v) surfactants Tween-80 (0.1%) Adhesive Chitosan (0.5–1%)

[0098] In this embodiment, step S3 includes: Step S32: The drug coating 30 is impregnated into the pores of the porous fiber membrane 20 using a vacuum impregnation method. The vacuum impregnation process involves placing the frame 10 with the porous fiber membrane 20 on its surface in a container of the drug coating 30 solution (impregnation liquid), connecting the container to a vacuum device, and performing a vacuum treatment. After vacuuming, the frame 10 with the porous fiber membrane 20 is immersed in the drug coating 30 solution (impregnation liquid) for a period of time, allowing the drug coating 30 to be impregnated into the pores of the porous fiber membrane 20. The support 1 is then removed and freeze-dried. The freeze-drying process includes multiple stages at different temperatures. The parameters for the vacuum impregnation and freeze-drying processes are shown in Table 4 below.

[0099] Table 4: Parameters for Vacuum Impregnation and Freeze-Drying Treatments

[0100]

[0101] Vacuum impregnation allows the drug coating 30 to fully fill the pores of the porous fiber membrane 20, and different freeze-drying temperatures ensure that the drug coating 30 will not crack during freeze-drying.

[0102] The above is the first embodiment of the manufacturing method of the double-layer heat-fused stent 1 of this application. The second embodiment of the manufacturing method of the double-layer heat-fused stent 1 is described below. The steps of the second embodiment are the same as those of the first embodiment, except that the parameters in step S21 of step S2 are different. In the second embodiment, step S21: preparing a biodegradable material solution; in this embodiment, polylactic acid-co-caprolactone polymer (PLCL) is used, wherein the ratio of lactic acid (LA):caprolactone CL = 75:25, and the molecular weight (Mn = 50-80 kDa). The PLCL concentration is 5% w / v (i.e., 5g of 20kDa PLCL is dissolved in 100mL of hexafluoroisopropanol (HFIP)), and the solution is magnetically stirred for 24-48 hours until completely dissolved, forming a homogeneous PLCL solution with a viscosity of approximately 50-100 mPa·s at 25°C, thereby preparing the biodegradable material solution.

[0103] The manufacturing method of the double-layer hot-melt bracket 1 of this application also has a third embodiment, wherein the steps of the third embodiment are the same as those of the first embodiment, the only difference being the different textile parameters in step S22 of step S2. In the third embodiment, the textile parameters are shown in Table 5 below:

[0104] Table 5: Textile Parameters in the Third Embodiment

[0105]

[0106]

[0107] The manufacturing method of the double-layer hot-melt bracket 1 of this application also has a fourth embodiment, wherein the steps of the fourth embodiment are the same as those of the first embodiment, the only difference being that the parameters of the vacuum impregnation and freeze-drying processes in step S32 of step S3 are different. In the fourth embodiment, the parameters of the vacuum impregnation and freeze-drying processes are shown in Table 6 below:

[0108] Table 6: Parameters for Vacuum Impregnation and Freeze-Drying Treatments

[0109]

[0110] The manufacturing method of the double-layer thermoplastic support 1 of this application also has a fifth embodiment, wherein the steps of the fifth embodiment are the same as those of the first embodiment, the only difference being the specific weaving parameters in step S12 of step S1. In the fifth embodiment, a thread 12 is wound around the circumference of the weaving fixture 11 at a 0.4mm gap, at an angle of 30 degrees relative to the central axis of the inner frame 101 in the first direction D1, to form the inner frame 101. The winding can be clockwise or counterclockwise. The weaving fixture 11 is provided with multiple protrusions 13 for winding the thread. Then, a second thread 12 is wound around the circumference at an angle of 30 degrees relative to the central axis of the outer frame 102 in the second direction D2; the outer frame 102 is formed; then a double-layer cross-mesh structure made of a single thread 12 is obtained, resulting in the middle structure of the frame.

[0111] The manufacturing method of the double-layer thermoplastic support 1 of this application also has a sixth embodiment, wherein the steps of the sixth embodiment are the same as those of the first embodiment, the only difference being the specific weaving parameters in step S12 of step S1. In the sixth embodiment, a thread 12 is wound around the circumference of the weaving fixture 11 at a 0.6mm gap, at an angle of 20 degrees relative to the central axis of the inner frame 101 in the first direction D1, to form the inner frame 101. The winding can be clockwise or counterclockwise. The weaving fixture 11 is provided with multiple protrusions 13 for winding the thread. Then, a second thread 12 is wound around the circumference at an angle of 30 degrees relative to the central axis of the outer frame 102 in the second direction D2, forming the outer frame 102. After that, a double-layer cross-mesh structure made of a single thread 12 is obtained, which is the middle structure of the frame.

[0112] The manufacturing method of the double-layer thermoplastic support 1 of this application also has a seventh embodiment, wherein the steps of the seventh embodiment are the same as those of the first embodiment, the only difference being the specific weaving parameters in step S12 of step S1. In the seventh embodiment, a thread 12 is wound around the circumference of the weaving fixture 11 at a 0.7mm gap, at an angle of 25 degrees relative to the central axis of the inner frame 101 in the first direction D1, to form the inner frame 101. The winding can be clockwise or counterclockwise. The weaving fixture 11 is provided with multiple protrusions 13 for winding the thread. Then, a second thread 12 is wound around the circumference at an angle of 35 degrees relative to the central axis of the outer frame 102 in the second direction D2, to form the outer frame 102. After that, a double-layer cross-mesh structure made of a single thread 12 is obtained, which is the middle structure of the frame.

[0113] like Figures 13 to 21As shown, the stent 1 of this application, used in conjunction with the catheter 2, forms a double-layer thermofused stent release device, including the double-layer thermofused stent 1 and the catheter 2 as described above. The catheter 2 includes an inner tube 21 and an outer tube 22. The double-layer thermofused stent 1 is disposed within the inner tube 21, and the outer tube 22 drives the inner tube 21 to move and release the double-layer thermofused stent 1. Wherein, as... Figures 13 to 14 As shown, a groove 211 is provided on the wall of the inner tube 21 corresponding to the double-layer thermoplastic support 1, and the groove 211 is arranged along the axial direction of the inner tube 21. A limiting part 212 is provided at one end of the inner tube 21 opposite to the groove 211. Figure 15 As shown, the outer tube 22 is a reducing tube and is connected to the Luer connector 4. The outer tube 22 includes a first section 221 and a second section 222. The inner diameter of the first section 221 is smaller than the inner diameter of the second section 222. The maximum size of the limiting part 212 of the inner tube 21 is larger than the inner diameter of the first section 221 and smaller than the inner diameter of the second section 222. The outer tube 22 drives the inner tube 21 to move through the limiting part 212.

[0114] The inner tube 21 of this application is provided with a slot 211, which can prevent the support 1 from getting stuck in the cavity of the inner tube 21 due to the large radial force of the support during the release process.

[0115] In this embodiment, the length of the slot 211 along the axial direction of the inner tube 21 is 5mm-50mm, for example, it can be 10mm, 15mm, 20mm, 30mm, 38mm, 45mm, etc. The width of the slot 211 is 0.1mm-1mm, for example, it can be 0.2mm, 0.5mm, 0.8mm, etc. In actual use, the width and length values ​​are corresponding; that is, when the length is small, the width is also small; when the length is large, the width is relatively large. Overall, the slot 211 can both prevent the support 1 from easily seizing in the cavity of the inner tube 21 due to the large radial force of the support during the release process, and ensure the strength of the inner tube 21.

[0116] In this embodiment, a slot 211 is provided on the pipe wall at the end of the inner tube 21 and connects to the end face corresponding to the end of the inner tube 21. This facilitates the release of the support.

[0117] In this embodiment, the outer tube 22 can be made of polyamide (PA), block polyetheramide resin (PEBAX), or polyurethane (PU), etc., and the inner tube 21 can be made of polytetrafluoroethylene (PTFE) or other medical materials.

[0118] In this embodiment, Figures 16 to 18This is a schematic diagram of the loading process of the double-layer thermofused stent 1 of this application. First, the stent 1 is compressed and loaded into the balloon 3. A guide wire 5 is disposed inside the balloon 3. The guide wire 5 is connected to a Luer connector 4 and passes through the inner tube 21. (See reference...) Figure 16 The Luer connector 4 and the support 1 mounted on the balloon 3 are located at opposite ends of the inner tube 21. The inner tube 21 is then moved so that the support 1 and balloon 3 are located inside the inner tube 21, at the position where the inner tube 21 has a slot 211, at which point the inner tube 21 covers the surface of the compressed support 1. Then, the outer tube 22 is fitted over the inner tube 21 from the support 1 and balloon 3. The end of the first segment 221 of the outer tube 22, with its smaller inner diameter, is provided with a developing ring 6. The developing ring 6 is used to display images. The minimum inner diameter of the outer tube 22 is greater than the outer diameter of the inner tube 21.

[0119] In this embodiment, Figures 19 to 21 This is a schematic diagram of the release process of the double-layer thermoplastic stent 1 of this application. When the stent 1 needs to be released, the outer tube 22 moves towards the Luer joint 4 under the action of external force. Because the inner tube 21 has a limiting part 212, and the outer tube 22 is a reducing tube, when the outer tube 22 moves to... Figure 20 When the position shown is reached, the outer tube 22 will drive the limiting part 212 of the inner tube 21 to move together, thereby driving the inner tube 21 to move together towards the Luer connector 4. As the inner tube 21 moves, the compressed stent 1 gradually detaches from the inner tube 21, thereby completing the release of the stent 1. During this release process, since the inner tube 21 is provided with a slot 211, it can avoid the stent 1 being subjected to a large radial force from the balloon 3 during the release process, which would cause the stent 1 to lock up in the lumen of the inner tube 21.

[0120] In summary, the double-layer thermofused scaffold 1 proposed in this application includes a frame 10, a porous fiber membrane 20, and a drug coating 30. The frame 10 is cylindrical and includes an inner frame 101 and an outer frame 102. The inner frame 101 is located inside the outer frame 102 and contacts the outer frame 102 to form a cross-mesh structure. The double-layer structure of the frame 10, with the inner frame 101 and outer frame 102 forming a cross-mesh structure, can improve the scaffold strength and increase the radial support force of the scaffold. The inner frame 101 and outer frame 102 are thermofused together at their contact points, making the connection between the inner frame 101 and outer frame 102 more robust and further enhancing the strength of the frame 10. The porous fiber membrane 20 is disposed on the surface of the frame 10, and the porosity of the porous fiber membrane 20 is greater than 70%. The porous fiber membrane 20 is made of a biodegradable material. Both the frame 10 and the porous fiber membrane 20 are made of biodegradable materials. The stent 1 can degrade in the human body, avoiding long-term stimulation of the fallopian tube tissue and preventing inflammatory reactions. The drug coating 30 is distributed in the pores of the porous fiber membrane 20 and can prevent cells and tissues from adhering and proliferating on the stent surface, thus preventing postoperative proliferation of fallopian tube tissue on the stent surface and secondary blockage of the fallopian tube lumen.

[0121] The manufacturing method of the double-layer thermoplastic stent 1 proposed in this application includes the following steps: Step S1: Fabricating a frame 10 using a biodegradable material; Step S2: Forming a porous fiber membrane 20 on the surface of the frame 10; By using a biodegradable material to fabricate the frame 10 and the porous fiber membrane 20, the stent 1 can degrade in the human body, avoiding long-term stimulation of the fallopian tube tissue by the stent 1 and preventing the occurrence of inflammatory reactions; Step S3: Preparing a solution of a drug coating 30, and impregnating the drug coating 30 into the pores of the porous fiber membrane 20 using a vacuum impregnation method. Impregnating the pores of the porous fiber membrane 20 with the drug coating 30 is a simple method with good impregnation effect, which can prevent adhesion and avoid postoperative proliferation of fallopian tube tissue on the surface of the stent 1, leading to secondary blockage of the lumen.

[0122] The double-layer thermofusion stent release device proposed in this application includes a double-layer thermofusion stent 1 and a conduit 2 as described above. The conduit 2 includes an inner tube 21 and an outer tube 22. The double-layer thermofusion stent 1 is disposed inside the inner tube 21, and the outer tube 22 drives the inner tube 21 to move and release the double-layer thermofusion stent 1. A groove 211 is provided on the wall of the inner tube 21 corresponding to the double-layer thermofusion stent 1, and the groove 211 is arranged along the axial direction of the inner tube 21. This prevents the stent 1 from easily seizing up within the lumen of the inner tube 21 during release due to the large radial force on the stent.

[0123] It is understood that the various embodiments / implementations provided in this application can be combined with each other without creating contradictions, and will not be described one by one here.

[0124] In the above exemplary embodiments, the double-layer thermofused stent, manufacturing method, and release device proposed in this application are described using the fallopian tube as an example. Those skilled in the art will readily understand that various modifications, additions, substitutions, deletions, or other changes may be made to the specific embodiments to apply the relevant designs of this application to other parts of the body; these changes are still within the scope of the principles of the double-layer thermofused stent, manufacturing method, and release device proposed in this application.

[0125] It should be noted that the double-layer thermoplastic stent, manufacturing method, and release device shown in the accompanying drawings and described in this specification are merely a few examples among many double-layer thermoplastic stents, manufacturing methods, and release devices that can employ the principles of this application. It should be clearly understood that the principles of this application are by no means limited to any details or components of the double-layer thermoplastic stent, manufacturing method, and release device shown in the accompanying drawings or described in this specification.

[0126] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0127] In the description of the embodiments of the application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the application.

[0128] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the claimed embodiments. When describing elements / components / etc. described and / or illustrated herein, the terms "a," "a," and "the above" are used to indicate the presence of one or more elements / components / etc. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0129] The above are merely preferred embodiments of the application examples and are not intended to limit the application examples. For those skilled in the art, the application examples can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the application examples should be included within the protection scope of the application examples.

Claims

1. A method for manufacturing a double-layer thermoplastic support, characterized in that, The double-layer thermofusion support includes: The frame includes a cylindrical inner frame and a cylindrical outer frame. The inner frame is located inside the outer frame and is in contact with the outer frame to form a mesh structure. The inner frame and the outer frame are thermally fused together at the contact points. The frame is made of a biodegradable material. A porous fiber membrane is disposed on the surface of the frame, the porous fiber membrane has a porosity greater than 70%, and the porous fiber membrane is made of a biodegradable material; The drug coating is distributed in the pores of the porous fiber membrane and can prevent cells and tissues from adhering to and proliferating on the scaffold surface; The inner frame and the outer frame are made of the same wire, and the wire is first wound to form one of the inner frame and the outer frame, and then wound to form the other one. The manufacturing method includes: Step S1: Fabricate the frame; Step S2: Form the porous fiber membrane on the surface of the frame; Step S3: Prepare a solution of the drug coating, and impregnate the drug coating into the pores of the porous fiber membrane using a vacuum impregnation method.

2. The manufacturing method of the double-layer thermoplastic support as described in claim 1, characterized in that, The inner frame includes multiple parallel inner threads, which are inclined in a first direction relative to the central axis of the inner frame; the outer frame includes multiple parallel outer threads, which are inclined in a second direction relative to the central axis of the outer frame, the second direction being opposite to the first direction.

3. The method for manufacturing a double-layer thermoplastic stent as described in any one of claims 1 to 2, characterized in that, The frame is made of polylactic acid-glycolic acid copolymer and nano-hydroxyapatite.

4. The method for manufacturing a double-layer thermoplastic stent as described in any one of claims 1 to 2, characterized in that, The porous fiber membrane has a pore size of 280nm-350nm.

5. The manufacturing method of the double-layer thermoplastic support as described in claim 1, characterized in that, Step S1 includes: Step S11: Fabricate threads using biodegradable materials; Step S12: On the weaving fixture, first wind the yarn to form one of the inner frame and the outer frame, then wind the yarn to form the other one, to obtain the frame middle structure; Step S13: Assemble the intermediate structure of the frame onto a heat shrink tube, and heat it to weld the inner frame and the outer frame together at the contact point to form the frame.

6. The manufacturing method of the double-layer thermoplastic support as described in claim 5, characterized in that, Step S12 includes: on a weaving fixture, winding the yarn around the circumference at an angle inclined to a first direction relative to the central axis of the inner frame to form the inner frame, and then winding the yarn around the circumference at an angle inclined to a second direction relative to the central axis of the outer frame to form the outer frame, wherein the second direction is opposite to the first direction.

7. The method for manufacturing a double-layer thermoplastic support as described in claim 5 or 6, characterized in that, The diameter of the filament is 180um-220um.

8. The manufacturing method of the double-layer thermoplastic support as described in claim 1, characterized in that, Step S2 includes: Step S21: Prepare a biodegradable material solution; Step S22: Assemble the frame onto an electrospinning device and spin the porous fiber membrane on the surface of the frame.

9. The manufacturing method of the double-layer thermoplastic support as described in claim 1, characterized in that, Step S3 includes: Step S31: Mix rapamycin and hyaluronic acid evenly to form the solution of the drug coating; Step S32: The drug coating is impregnated into the pores of the porous fiber membrane using a vacuum impregnation method, and then freeze-dried.

10. The method for manufacturing a double-layer thermoplastic support as described in claim 9, characterized in that, The freeze-drying process includes multiple stages of processing at different temperatures.

11. A double-layer thermoplastic stent release device, characterized in that, include Double-layer thermofusion stent and catheter, The double-layer thermoplastic support includes: The frame includes a cylindrical inner frame and a cylindrical outer frame. The inner frame is located inside the outer frame and is in contact with the outer frame to form a mesh structure. The inner frame and the outer frame are thermally fused together at the contact points. The frame is made of a biodegradable material. A porous fiber membrane is disposed on the surface of the frame, the porous fiber membrane has a porosity greater than 70%, and the porous fiber membrane is made of a biodegradable material; The drug coating is distributed in the pores of the porous fiber membrane and can prevent cells and tissues from adhering to and proliferating on the scaffold surface; The inner frame and the outer frame are made of the same wire, and the wire is first wound to form one of the inner frame and the outer frame, and then wound to form the other one. The catheter includes an inner tube and an outer tube, the inner tube is disposed inside the outer tube, the double-layer thermofused stent is disposed inside the inner tube, and the outer tube drives the inner tube to move to release the double-layer thermofused stent. The inner tube has a groove on its wall corresponding to the double-layer thermoplastic support, and the groove is arranged along the axial direction of the inner tube.

12. The double-layer thermoplastic support release device as described in claim 11, characterized in that, The length of the groove along the axial direction of the inner tube is 5mm-50mm, and the width of the groove is 0.1mm-1mm.

13. The double-layer thermoplastic support release device as described in claim 11, characterized in that, The slot is provided on the pipe wall at the end of the inner tube and connects to the end face corresponding to the end of the inner tube.

14. The double-layer thermoplastic stent release device according to any one of claims 11 to 13, characterized in that, The outer tube includes a first section and a second section. The inner diameter of the first section is smaller than the inner diameter of the second section. One end of the inner tube is provided with a limiting part. The maximum size of the limiting part is larger than the inner diameter of the first section but smaller than the inner diameter of the second section. The outer tube drives the inner tube to move through the limiting part.

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