Degradable airway stent and preparation method thereof

Abstract

The application provides a degradable airway stent and a preparation method thereof. The degradable airway stent comprises a tubular support component made of a first biodegradable polymer material, and a plurality of open circular ring-shaped reinforcing ring components made of a second biodegradable polymer material, wherein the tensile strength of the second biodegradable polymer material is greater than that of the first biodegradable polymer material. The support component comprises a plurality of annular stent segments connected in sequence along the axial direction, and each annular stent segment comprises a plurality of grid units distributed along the circumferential direction. In the annular stent segments at the two ends of the support component, each grid unit is provided with an opening at the axial protruding position thereof. The grid rods on the opposite sides of each opening are respectively connected to the two ends of a reinforcing ring component, and the reinforcing ring component and the grid unit provided with the opening are not overlapped in the axial direction.

Description

Technical Field

[0001] This application belongs to the field of medical devices, specifically relating to a biodegradable airway stent and its preparation method. Background Technology

[0002] The trachea plays a vital role in the respiratory system. Various factors, including infection, tumors, trauma, prolonged intubation, tracheobronchomalacia, and tuberculosis, can lead to tracheal stenosis, causing symptoms such as difficulty breathing, post-obstruction infection, and cough. Airway stents, as an important component of interventional respiratory techniques, are crucial tools for treating tracheal stenosis and other diseases. They can rapidly reconstruct the airway, ensure patency, alleviate breathing difficulties, and significantly improve patients' quality of life.

[0003] Currently, commonly used airway stents in clinical practice mainly include silicone stents and metallic stents. Although airway stents offer significant therapeutic benefits, their application is also accompanied by various complications. The incidence and severity of these complications directly affect the treatment outcome. Complications related to airway stents include stent migration, granulation tissue formation, mucus plugging, inability to suppress cough, stent breakage, and infection. Furthermore, because silicone and metallic stents are non-degradable, long-term placement can easily lead to airway restenosis, requiring secondary surgery for removal and potentially causing tissue damage. In contrast, biodegradable stents can initially support the airway wall and then gradually degrade and be absorbed, significantly reducing adverse reactions and avoiding the need for secondary surgery.

[0004] Existing biodegradable airway stents mainly include fully biodegradable magnesium alloy stents and fully biodegradable PCL (polycaprolactone) stents, but both still have certain problems. The degradation products of magnesium alloy stents may be biotoxic, and in the humid environment of the airway, they are prone to rapid local degradation, leading to premature stent breakage and failure, potentially causing airway obstruction and suffocation risks. PCL stents have a low glass transition temperature (approximately -60°C), remaining in a highly elastic state at body temperature, resulting in insufficient radial support and difficulty in effectively resisting dynamic airway collapse or suppressing coughing. Furthermore, biodegradable airway stents made from traditional single materials cannot simultaneously satisfy radial support and flexibility, failing to prevent airway collapse and adapt to complex airway curvatures while achieving good apposition. Therefore, existing biodegradable airway stents face challenges in terms of biosafety, controllable degradation, mechanical support, and flexibility. Summary of the Invention

[0005] The purpose of this application is to provide a biodegradable airway stent and its preparation method, which aims to balance the radial support and flexibility of the biodegradable airway stent, so as to prevent airway collapse and provide excellent flexibility to adapt to the airway environment and achieve good adhesion.

[0006] To achieve the above objectives, this application provides a biodegradable airway stent, comprising:

[0007] A mesh-like support component, said support component being made of a first biodegradable polymer material;

[0008] And multiple open annular reinforcing ring components, the reinforcing ring components being made of a second biodegradable polymer material, the second biodegradable polymer material having a tensile strength greater than that of the first biodegradable polymer material;

[0009] The supporting component includes several annular support segments connected sequentially along the axial direction, and each annular support segment includes multiple grid units distributed along the circumferential direction.

[0010] In the annular support sections at both axial ends of the support member, each of the grid cells has an opening at its axial protruding position; the grid rods on opposite sides of each opening are respectively connected to the two ends of a reinforcing ring member, so that the reinforcing ring member and the grid cell with the opening do not overlap axially.

[0011] Optionally, the support component is woven from biodegradable fibers and forms a dense mesh structure.

[0012] Optionally, the support component has at least one of the following structural features:

[0013] The biodegradable fiber has a diameter of 0.05 mm to 0.20 mm;

[0014] The biodegradable fiber has a breaking elongation greater than 30%;

[0015] The linear knitting density of the support component is 8 stitches / cm to 16 stitches / cm;

[0016] The woven mesh angle of the support component in the axial direction is 60°~80°;

[0017] The number of weaving intersections in the circumferential direction of the support component is 12 to 36;

[0018] The surface porosity of the support component is 60%~85%;

[0019] The axial length of the support component is 20mm~60mm;

[0020] The diameter of the support component is 12mm~20mm.

[0021] Optionally, the reinforcing ring component is a semi-circular arc, a major arc, or a minor arc; at any axial end of the support component, the diameter of the envelope circumference defined by all the reinforcing ring components is greater than or equal to the diameter of the support component.

[0022] Optionally, at either end of the support member in the axial direction, the diameter of the envelope circumference defined by all the reinforcing ring components is 0.5 mm to 2.0 mm larger than the diameter of the support member.

[0023] Optionally, at any end of the support member, any two adjacent reinforcing ring members are spaced apart by a given distance, the given distance being 0.1mm to 0.5mm.

[0024] Optionally, the reinforcing ring component is made of a rod-shaped structure, the cross-sectional shape of which is circular or non-circular after being treated without damage.

[0025] Optionally, the reinforcing ring component has at least one of the following structural features:

[0026] The tensile strength of the rod-shaped structure is greater than 70 MPa;

[0027] The axial length of the reinforcing ring component is 1mm to 5mm;

[0028] The diameter of the reinforcing ring component is 0.5mm to 1.5mm.

[0029] Optionally, the first biodegradable polymer material is selected from at least one of the following materials: polylactic acid, L-polylactic acid, D-polylactic acid, polyglycolic acid, polycaprolactone, polyethylene glycol, polyphthalamide, polyethylene oxide, polyvinyl alcohol and copolymers thereof.

[0030] Optionally, the second biodegradable polymer material is selected from at least one of the following materials: polylactic acid, L-polylactic acid, D-polylactic acid, polyglycolic acid, polycaprolactone, polyethylene glycol, polyphthalamide, polyethylene oxide, polyvinyl alcohol, and copolymers thereof.

[0031] Optionally, the weight-average molecular weight of both the first biodegradable polymer material and the second biodegradable polymer material is 100,000 to 300,000 g / mol, and the degradation time is 6 to 18 months.

[0032] Optionally, the biodegradable airway stent further includes:

[0033] A drug coating is applied to the outer surface of the support component;

[0034] The drug coating may consist solely of a drug, or it may consist of a drug and a biodegradable polymer carrier.

[0035] Optionally, the reinforcing ring component is connected to the grid bars on opposite sides of the opening by at least one of welding, bonding, and fitting.

[0036] Optionally, the reinforcing ring component is formed by extrusion molding, injection molding, or 3D printing.

[0037] To achieve the above objectives, this application also provides a method for preparing a biodegradable airway stent, used to prepare any of the biodegradable airway stents described in the present application, the method comprising:

[0038] A mesh-like support component was prepared using a first biodegradable polymer material;

[0039] An open-ring reinforcing component is prepared using a second biodegradable polymer material, and multiple such reinforcing ring components are prepared.

[0040] The reinforcing ring components are respectively fixedly connected to the openings of each grid cell at both axial ends of the support component, and each reinforcing ring component and the corresponding grid cell do not overlap axially.

[0041] Compared with the prior art, the biodegradable airway stent and its preparation method provided in this application have at least the following advantages:

[0042] Biodegradable airway stents effectively support the airway wall in the early stages of implantation, expanding narrowed areas and softening the trachea, thereby rapidly relieving breathing difficulties and restoring airway patency. Subsequently, the stent gradually degrades and is absorbed during the tissue healing process. Its degradation products have good biocompatibility and no toxic side effects, reducing the incidence of adverse reactions and avoiding the need for a second removal surgery.

[0043] More importantly, the first biodegradable polymer material used in the support component has superior flexibility compared to the second biodegradable polymer material used in the reinforcing ring component. This characteristic allows the biodegradable airway stent to better conform to the airway wall, improving biocompatibility and reducing immune rejection and inflammatory responses that may be caused by stress concentration. It also ensures that the biodegradable airway stent can conform to the physiological curvature of the airway during implantation, thereby significantly improving its permeability and delivery. On the other hand, the second biodegradable polymer material used in the reinforcing ring component has superior mechanical strength compared to the first biodegradable polymer material used in the support component, thus significantly enhancing the radial support force and structural stability of the biodegradable airway stent, effectively improving its anchoring effect, and greatly reducing the risk of stent displacement or dislodgement. Attached Figure Description

[0044] Those skilled in the art will understand that the accompanying drawings are provided to better understand this application and do not constitute any limitation on the scope of this application. Wherein:

[0045] Figure 1 This is a three-dimensional structural schematic diagram of a biodegradable airway stent according to an embodiment of this application;

[0046] Figure 2 This is a front view of a biodegradable airway stent according to an embodiment of this application;

[0047] Figure 3 This is an end view of a biodegradable airway stent according to an embodiment of this application;

[0048] Figure 4 This is a structural schematic diagram of the angle of the woven mesh according to an embodiment of this application;

[0049] Figure 5 This is a schematic diagram of the structure of a reinforcing ring component according to an embodiment of this application;

[0050] Figure 6 This is a front view of a biodegradable airway stent according to another embodiment of this application.

[0051] The reference numerals in the attached figures are explained as follows:

[0052] 100 - Biodegradable airway support, 10 - Support component, 11 - Annular support segment, 12 - Grid unit, 13 - Opening, 20 - Reinforcing ring component, L1 - Axial length of support component, L2 - Axial length of reinforcing ring component, D1 - Diameter of support component, D2 - Envelope diameter of reinforcing ring component, D - Inner diameter of reinforcing ring component, d - Gap at opening, β - Woven grid angle, g - Given distance. Detailed Implementation

[0053] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the illustrations only show components related to this application and are not drawn according to the actual number, shape, and size of components in the actual implementation. In the actual implementation, the type, quantity, and proportion of each component can be arbitrarily changed, and the component layout may also be more complex.

[0054] Furthermore, while each embodiment described below possesses one or more technical features, this does not imply that users of this application must simultaneously implement all technical features in any embodiment, or can only separately implement some or all technical features in different embodiments. In other words, where implementation is possible, those skilled in the art can selectively implement some or all of the technical features in any embodiment, or selectively implement a combination of some or all of the technical features in multiple embodiments, based on the disclosure of this application and depending on design specifications or implementation requirements, thereby increasing the flexibility in implementing this application.

[0055] As used herein, the singular forms “a,” “an,” and “the” include plural objects, and the plural form “multiple” includes two or more objects, unless otherwise expressly indicated. As used herein, the term “or” is generally used to include the meaning of “and / or,” unless otherwise expressly indicated, and the terms “installed,” “connected,” and “linked” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Connections can be mechanical or electrical. Connections can be direct or indirect through an intermediate medium, and can be internal communication between two elements or an interaction between two elements. Relational terms such as “first,” “second,” etc., are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor do they indicate or imply relative importance or implicitly specify the number of indicated technical features. It should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0056] For ease of description, the following description uses the terms "proximal" and "distal," where "proximal" refers to the end closer to the operator and "distal" refers to the end farther from the operator; the phrase "axial direction" should be understood in this application as the direction along the central axis of the biodegradable airway stent, that is, the direction in which the biodegradable airway stent is advanced and de-escalated, the direction perpendicular to the "axial direction" is defined as the "radial direction," and the direction around the "central axis" is defined as the "circumferential direction."

[0057] To make the objectives, advantages, and features of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this application.

[0058] Different embodiments of this application provide a biodegradable airway stent 100, such as Figures 1 to 6 As shown, the device includes: a mesh-like support component 10 made of a first biodegradable polymer material; and multiple open annular reinforcing ring components 20 made of a second biodegradable polymer material. The second biodegradable polymer material has a higher tensile strength than the first biodegradable polymer material, thereby balancing the radial support and flexibility of the biodegradable airway stent 100. This prevents airway collapse while providing excellent flexibility to adapt to the airway environment and achieve good adhesion.

[0059] The tensile strength described in this article refers to the maximum ability of a biodegradable polymer material to resist breakage under standard tensile test conditions; its value is equal to the maximum engineering stress the material can withstand before failure. Therefore, the tensile strength of the support component 10 and the reinforcing ring component 20 specifically refers to the initial tensile strength, which must meet the initial mechanical requirements of supporting the airway wall (i.e., balancing radial support force and flexibility). Thus, the biodegradable airway support 100 is fabricated using different biodegradable materials to simultaneously achieve both radial support and flexibility.

[0060] Specifically, the support component 10 includes several annular support segments 11 connected sequentially along the axial direction. Figure 2 The dashed boxes used are intended to highlight the location of the annular support segments 11 for ease of understanding. Each annular support segment 11 is arranged in a ring shape, specifically, each annular support segment 11 includes a plurality of grid cells 12 distributed circumferentially. Each grid cell 12 is a quadrilateral grid, preferably a rhomboid grid. Thus, several annular support segments 11 are arranged to form a cylindrical structure.

[0061] Furthermore, in the annular support sections 11 at both axial ends of the support member 10, each grid cell 12 has an opening 13 at its axial protruding position, such as... Figure 5As shown, the grid bars on opposite sides of each opening 13 are respectively connected to both ends of a reinforcing ring component 20, ensuring that the reinforcing ring component 20 does not overlap with the grid cell 12 with the opening 13 in the axial direction. In other words, the reinforcing ring component 20 is disposed outside the grid cell 12 with the opening 13, so that the projections of the reinforcing ring component 20 and the grid cell 12 with the opening 13 on a plane parallel to the axial direction do not overlap. It can be understood that the number of reinforcing ring components 20 is consistent with the number of axially protruding structures of the grid cell 12 at both ends of the support component 10, and one reinforcing ring component 20 is provided at the opening 13 of each axially protruding structure. The "axially protruding position" or "axially protruding structure" mentioned herein should be understood as the tip of the grid when the opening 13 is not formed, with the tip protruding outward.

[0062] It should be understood that in the prior art, after the scaffold is braided or cut, the ends are not completely smoothed, causing the end of the structure to protrude and form a sharp point that may damage the tissue. This sharp point is the grid vertex formed at the junction of the two grid rods of the axially protruding structure.

[0063] On the contrary, such as Figure 5 As shown, this application opens the axially protruding structure to form an opening 13, and provides a reinforcing ring component 20 at the opening 13. Thus, even if the grid cell 12 at the end is broken at its axially protruding grid vertex, it can be closed by the reinforcing ring component 20 to form a closed-loop grid, and the reinforcing ring component 20 will not affect the deformation and expansion of the grid. Because the reinforcing ring component 20 is an open ring-shaped structure, its two ends in the extending direction can be fixedly connected to the two grid rods at the opening 13.

[0064] Accordingly, this application also provides a method for preparing a biodegradable airway stent, comprising:

[0065] A mesh-like support component 10 is prepared using a first biodegradable polymer material;

[0066] An open-ended circular reinforcing ring component 20 is prepared using a second biodegradable polymer material, and multiple reinforcing ring components 20 are prepared.

[0067] Multiple reinforcing ring components 20 are fixedly connected to the openings 13 of each grid cell 12 at both axial ends of the support component 10, and each reinforcing ring component 20 and the corresponding grid cell 12 are not overlapped in the axial direction.

[0068] The method of fixing the reinforcing ring component 20 is not limited. Optionally, the reinforcing ring component 20 is connected to the grid rods on opposite sides of the opening 13 by at least one of welding, bonding, and fitting. Those skilled in the art will understand that the grid rods can be cut support rods or braided filaments. Fitting refers to having a groove on the end face of the reinforcing ring component 20, which allows the grid rod to be inserted and fixed.

[0069] In this way, the biodegradable airway stent 100 can effectively support the airway wall in the early stages of implantation, thereby expanding the narrowed area and softening the trachea, thus rapidly relieving breathing difficulties and restoring airway patency. Subsequently, the biodegradable airway stent 100 can be gradually degraded and absorbed by itself during the tissue healing process. Its degradation products have good biosafety and no toxic side effects, reducing the incidence of adverse reactions and avoiding the need for a second removal surgery.

[0070] In particular, the first biodegradable polymer material used in the support component 10 has superior flexibility compared to the second biodegradable polymer material used in the reinforcing ring component 20. This design allows the biodegradable airway stent 100 to better conform to the airway wall, improving biocompatibility, while reducing immune rejection and inflammatory responses that may be caused by stress concentration. It also ensures that the biodegradable airway stent 100 can conform to the physiological curvature of the airway during implantation, thereby significantly improving its permeability and delivery.

[0071] On the other hand, the second biodegradable polymer material used in the reinforcing ring component 20 is superior to the first biodegradable polymer material used in the support component 10 in terms of mechanical strength, thereby significantly enhancing the radial support force and structural stability of the biodegradable airway stent 100, effectively improving its anchoring effect, and greatly reducing the risk of stent displacement or detachment.

[0072] Therefore, the support component 10 mainly serves to support the airway narrowing area against the wall. It is made of a relatively flexible biodegradable polymer material with high elongation at break and is mainly responsible for providing radial support. Its mechanical properties ensure good compliance and adhesion of the biodegradable airway stent 100 in the airway.

[0073] Optionally, the biodegradable airway stent 100 also includes a drug coating disposed on the outer surface of the support member 10. This drug coating may consist solely of a drug, or it may consist of a drug and a biodegradable polymer carrier. Thus, by disposing of the drug coating on its outer surface, the support member 10 can also provide sustained-release drug delivery.

[0074] This application does not limit the method of drug loading on the outer surface of the support member 10, such as spraying, brushing, dipping, etc. Optionally, the drug coating can be applied to the entire outer surface of the support member 10 by spraying.

[0075] Optionally, the medicated coating may include glucocorticoids, antitumor drugs, and antibacterial agents, giving it anti-infective and anti-tissue proliferation capabilities, controlling the risk of respiratory tract infections, and preventing secondary airway narrowing.

[0076] Optionally, the drug coating may include drugs such as antibiotics and antibacterial agents. For example, the drug coating may include at least one of the following drugs: sirolimus, paclitaxel, allicin, doxycycline, vancomycin, ciprofloxacin, gefitinib, mitomycin C, dexamethasone, methylprednisolone, cisplatin, silver nanoparticles, etc.

[0077] The biodegradable polymer carrier may include at least one of the following materials: polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, polycaprolactone, polydioxane, polyanhydride, tyrosine, polycarbonate, etc.

[0078] In terms of preparation, the support component 10 can be cut or woven. In this embodiment, the support component 10 is woven from biodegradable fibers (a first biodegradable polymer material) to form a dense mesh structure. The dense mesh structure means a porous morphology composed of continuous, dense mesh units 12, with high porosity. This design aims to prevent granulation tissue growth and solve the problem that the membrane hinders the biodegradation and absorption of the stent. In other words, the biodegradable airway stent 100 in this embodiment does not have a membrane.

[0079] Biodegradable fibers can be prepared through processes such as melt spinning, solution spinning, or gel spinning. Their diameters typically range from micrometers to nanometers, exhibiting extremely high aspect ratios and specific surface areas. In actual processing, biodegradable fibers can be twisted or composited into yarns, which are then woven to form the final structure. This woven fiber structure features micropores, high porosity, and a large specific surface area, which is beneficial for drug loading and cell adhesion, while also providing the supporting components with good flexibility and cell adhesion.

[0080] To achieve good flexibility and adhesion to the cell wall, the diameter of the biodegradable fiber is preferably 0.05 mm to 0.20 mm. This size range ensures that the fiber weave structure has sufficient bending compliance in vivo, while its fiber size and spacing help prevent granulation tissue growth and achieve stable adhesion to the cell wall.

[0081] Based on the dual requirements of flexibility and wall adhesion, the support component 10 is preferably made of biodegradable fiber with a breaking elongation greater than 30%. This ensures that the support component 10 has good deformation compliance during implantation and use, and can maintain structural stability to facilitate wall adhesion.

[0082] To form a dense network structure conducive to tissue growth and drug release, the surface area porosity of the support component 10 is preferably 60% to 85%. Optionally, the surface area porosity is 60%, 70%, 72.5%, 75%, 80%, 82.5%, or 85%. Within this range, higher porosity helps reduce the overall mass of the scaffold, improves flexibility, and promotes tissue ingrowth and drug diffusion. If the porosity is below 60%, it may lead to excessive scaffold rigidity and insufficient drug loading capacity; if it is above 85%, it may significantly weaken its radial support strength, affecting effective support for the airway.

[0083] To balance drug loading, mechanical support, and structural flexibility, the linear braiding density of the support component 10 is preferably 8 to 16 stitches / cm. Within this range, a braiding density that is too low (<8 stitches / cm) will result in a larger mesh size, which will not only reduce the adhesion and uniformity of the drug coating, but may also weaken the initial radial support strength of the stent. Conversely, a density that is too high (>16 stitches / cm) will significantly reduce the flexibility and porosity of the stent, affecting its adhesion effect in curved airways and limiting the long-term sustained-release performance of the drug.

[0084] To balance support and flexibility, in one aspect, the axial mesh angle β of the support component 10 is preferably 60°~80°, such as... Figure 4 As shown. Optionally, the weaving mesh angle β is 60°, 70° or 80°. Within this angle range, the biodegradable airway stent 100 can simultaneously achieve excellent radial collapse resistance and good axial bending flexibility, thereby ensuring that it can effectively support narrow airway sections while conforming to the physiological curvature of the airway.

[0085] On the other hand, the number of weaving intersections in the circumferential direction of the support member 10 is preferably 12 to 36. This is because the number of intersections directly affects mechanical performance: too many intersections reduce structural flexibility, hindering the support from adhering to the wall; too few intersections weaken mechanical strength, resulting in insufficient radial support. This preferred range aims to achieve the optimal balance between flexibility and support force.

[0086] The axial length L1 of the support member 10 is preferably 20mm to 60mm. The diameter D1 of the support member 10 is preferably 12mm to 20mm. Here, the axial length and diameter refer to the dimensions of the support member 10 in its naturally unfolded state. This range of length and diameter can accommodate the lesion sizes of different patients in clinical practice.

[0087] In this embodiment, the first biodegradable polymer material is selected from at least one of the following materials: polylactic acid, L-polylactic acid, D-polylactic acid, polyglycolic acid, poly(ε-caprolactone), polyethylene glycol, polyphthalamide, polyethylene oxide, and polyvinyl alcohol, as well as copolymers formed from monomers used to prepare the above homopolymers, such as copolymers of polylactide-glycolic acid, polylactide-caprolactone, and polylactide-glycolic acid-caprolactone.

[0088] Similarly, the second biodegradable polymer material is selected from at least one of the following materials: polylactic acid, L-polylactic acid, D-polylactic acid, polyglycolic acid, poly(ε-caprolactone), polyethylene glycol, polyphthalamide, polyethylene oxide, and polyvinyl alcohol, as well as copolymers formed from monomers used to prepare the above homopolymers, such as copolymers of polylactide-glycolic acid, polylactide-caprolactone, and polylactide-glycolic acid-caprolactone.

[0089] The biodegradable polymer materials listed above possess both moderate mechanical strength and good flexibility. Those skilled in the art may also select other suitable biodegradable polymer materials according to actual needs.

[0090] It should be noted that the first and second biodegradable polymer materials can be selected from the same or different materials, as long as they have different tensile strengths and degradation times. "Same" materials mean that they have the same chemical structure (e.g., both are polylactic acid (PLA)). However, by giving them different weight-average molecular weights, their respective tensile strengths and in vivo degradation times can be effectively controlled, resulting in different tensile strengths and degradation times. Generally, under the same chemical structure, a larger weight-average molecular weight usually corresponds to higher tensile strength and a longer degradation period. Based on this principle, different molecular weights of the same polymer can be selected to meet the differentiated mechanical support and degradation rate requirements of different components in the device.

[0091] Optionally, both the first and second biodegradable polymer materials have a weight-average molecular weight of 100,000–300,000 g / mol and a degradation time of 6–18 months. Compared to metal biodegradable materials, the degradation rate of these biodegradable polymer materials is stable and controllable in the humid airway environment, and they are less prone to the problem of excessively rapid local degradation, which can solve the problem of premature stent breakage and failure.

[0092] The following section provides further details on the configuration of the reinforcing ring component 20.

[0093] Those skilled in the art should understand that the reinforcing ring component 20 primarily serves a fixing function, preventing the biodegradable airway stent 100 from shifting or falling off. Furthermore, the smooth, rounded design of the reinforcing ring component 20 avoids protrusion of the stent's free end, reducing irritation and damage to the airway mucosa. Because the reinforcing ring component 20 is made of a biodegradable polymer material with higher tensile strength and is fixed to both ends of the support component 10, it provides additional axial and radial resistance to deformation, particularly resisting external forces such as airway peristalsis and coughing, effectively preventing stent shifting and falling off.

[0094] The reinforcing ring component 20 is a C-shaped open ring, which can be a semi-circular arc, a major arc, or a minor arc.

[0095] In its natural state, the inner diameter D of the reinforcing ring component 20 can be greater than or equal to the gap d at the opening 13, such as... Figure 5 As shown. The benefits of the open annulus are: during stent compression and delivery, the opening 13 can be partially closed to reduce the outer diameter; after the stent is released, its elastic restoring force causes the annulus to expand, which helps it anchor to the airway wall at the target location.

[0096] The reinforcing ring component 20 is made of a rod-shaped structure. The cross-sectional shape of this rod-shaped structure can be circular or non-circular. If non-circular, the rod-shaped structure is non-damaging or low-damage, for example, with rounded or chamfered corners to soften its surface and reduce tissue irritation or damage. If the rod-shaped structure is non-circular, it can be elliptical or a rounded rectangle, especially a rectangular rod or a flattened ellipse, which helps increase the contact area with the airway wall, improves anchoring stability, and reduces the risk of pressure sores on the mucosa.

[0097] Optionally, the tensile strength of the rod-shaped structure should be greater than 70 MPa. Insufficient tensile strength may cause the scaffold to shift within the body due to external forces or tissue movement, thereby detaching it from the target treatment area and affecting the treatment outcome.

[0098] Optionally, the diameter or equivalent diameter of the rod-shaped structure is greater than or equal to the diameter or equivalent diameter of the grid rod in the support member 10 to ensure sufficient thickness and guarantee structural strength.

[0099] Optionally, the axial length L2 of the reinforcing ring component 20 is between 1 mm and 5 mm. This range ensures effective anchoring while avoiding a decrease in support performance due to excessive length, or an impact on the axial stability of the bracket due to insufficient length.

[0100] The diameter (outer diameter) of the reinforcing ring component 20 is set according to the gap d at the opening 13. Optionally, the diameter (outer diameter) of the reinforcing ring component 20 is 0.5mm to 1.5mm.

[0101] When optimizing the reinforcing ring component 20, its external dimensions (ring outer diameter) need to achieve a balance between conveying performance and support performance. In this embodiment, at any axial end of the support component 10, any two adjacent reinforcing ring components 20 are spaced apart by a given distance g (see [reference]). Figure 2 and Figure 6 The given distance g is set to be 0.1mm~0.5mm. If the given distance g is too small, the open rings (reinforcing ring component 20) are prone to stacking during transportation, affecting the overall passability and release stability of the support; if the given distance g is too large, it will weaken the synergistic reinforcement effect of the open rings on local support, reducing the support's anti-collapse ability. In short, the outer diameter design of the reinforcing ring component 20 should be based on the principle of avoiding mutual stacking and interference between adjacent arcs, ensuring that an appropriate gap is maintained between them.

[0102] It should also be understood that at any axial end of the support member 10, the diameter of the envelope circumference defined by all the reinforcing ring members 20 on the same circumference is D2, and the support member 10 is approximately a circular tube structure with a diameter (outer diameter) of D1, such as... Figure 6 As shown.

[0103] In some implementation schemes, such as Figures 1 to 3 As shown, at any axial end of the support member 10, the diameter D2 of the envelope circumference defined by all the reinforcing ring members 20 is equal to the diameter D1 of the support member 10. This is equivalent to the biodegradable airway support 100 having equal-diameter openings at both ends.

[0104] In other implementation schemes, such as Figure 6 As shown, at any axial end of the support member 10, the diameter D2 of the envelope circumference defined by all reinforcing ring members 20 is larger than the diameter D1 of the support member 10. That is, each reinforcing ring member 20 extends outward at an angle to form a flared structure. This enhances the anchoring effect at the end of the stent and improves its adherence to the airway. It should be understood that after implantation into the airway, the slightly larger reinforcing ring member 20 will generate a slight, radially outward elastic prestress, allowing it to gently embed into the airway mucosa, forming a mechanical interlock, thereby effectively resisting the axial displacement force caused by breathing, coughing, and airway peristalsis.

[0105] Optionally, at either end of the support member 10 along its axial direction, the diameter D2 of the envelope circumference defined by all reinforcing ring members 20 is 0.5 mm to 2.0 mm larger than the diameter D1 of the support member 10. This size range is sufficient to achieve anchoring, prevent displacement, and improve adhesion to the wall; while avoiding the risk of tissue damage due to overexpansion; and taking into account both transportability and adaptability to anatomical structures.

[0106] The present application does not limit the molding method of the reinforcing ring component 20. Optionally, the reinforcing ring component 20 is molded by extrusion molding, injection molding, or 3D printing.

[0107] The following describes in more detail the configuration of the biodegradable airway stent 100 through some specific embodiments.

[0108] Example 1:

[0109] The biodegradable airway stent 100 includes a support component 10 and a reinforcing ring component 20; wherein the support component 10 is a hollow tubular structure with a dense mesh woven from biodegradable fibers, and the reinforcing ring component 20 is an open circular ring structure. This structural design gives the biodegradable airway stent 100 good flexibility and adherence to the airway wall, while also providing good fixation within the airway. Thus, the biodegradable airway stent 100 can balance adherence to the airway wall with providing good mechanical support.

[0110] The support component 10 is woven from biodegradable polylactide-caprolactone (polymer) fibers with a diameter of 0.15 mm (weight average molecular weight of 250,000 g / mol and degradation period of 12 months); the axial length of the support component 10 is 50 mm and the diameter is 18 mm; the support component 10 has 20 weaving intersections in the circumferential direction and the weaving grid angle β is 70°; in addition, the outer surface of the support component 10 is coated with a drug coating, which uses polyglycolic acid as the drug carrier and contains silver nanoparticles.

[0111] Meanwhile, the reinforcing ring component 20 is injection molded and has a diameter (outer diameter of the ring) of 1.0 mm; the reinforcing ring component 20 is made of polylactide-hexylene rod (tensile strength 80 MPa, weight-average molecular weight 200,000 g / mol, degradation period 12 months); the reinforcing ring component 20 is bonded and fixed to the grid rods on both sides of the opening 13; the axial length of the reinforcing ring component 20 is 3 mm, and the enveloping circumference diameter D2 is 1.5 mm larger than the diameter D1 of the supporting component 10.

[0112] Subsequently, the biodegradable airway stent 100 provided in Example 1 was implanted into a simulated airway system, and phosphate-buffered saline (PBS) (pH=7.4±0.2) was selected as the simulated body fluid, with the ambient temperature set at 37°C. This in vitro degradation simulation experiment showed that, three months after implantation in the simulated airway environment, the stent maintained a compressive strength of 150 kPa, and no collapse, detachment, or displacement occurred.

[0113] Example 2:

[0114] The biodegradable airway stent 100 includes a support component 10 and a reinforcing ring component 20; wherein the support component 10 is a hollow tubular structure with a dense mesh woven from biodegradable fibers, and the reinforcing ring component 20 is an open circular ring structure. This structural design gives the biodegradable airway stent 100 good flexibility and adherence to the airway wall, while also providing good fixation within the airway. Thus, the biodegradable airway stent 100 can balance adherence to the airway wall with providing good mechanical support.

[0115] The support component 10 is woven from polyhydroxyacetic acid biodegradable fiber (weight average molecular weight of 300,000 g / mol, degradation period of 18 months) with a diameter of 0.20 mm; the axial length of the support component 10 is 60 mm and the diameter is 20 mm; the support component 10 has 36 weaving intersections in the circumferential direction and the weaving grid angle β is 80°; in addition, the outer surface of the support component 10 is coated with a drug coating, which uses polycarbonate as the drug carrier and contains sirolimus.

[0116] Meanwhile, the reinforcing ring component 20 is injection molded with a diameter (outer diameter of the ring) of 1.5 mm; the reinforcing ring component 20 is made of L-shaped polylactic acid rod (tensile strength 100 MPa, weight-average molecular weight 250,000 g / mol, degradation period 18 months); the reinforcing ring component 20 is bonded and fixed to the grid rods on both sides of the opening 13; the axial length of the reinforcing ring component 20 is 5 mm, and the enveloping circumference diameter D2 is 2 mm larger than the diameter D1 of the supporting component 10.

[0117] Therefore, the biodegradable airway stent 100 provided in Example 2 was implanted into a simulated airway system, and phosphate-buffered saline (PBS) (pH=7.4±0.2) was used as the simulated body fluid, with the ambient temperature set at 37°C. This in vitro degradation simulation experiment showed that, three months after implantation in the simulated airway environment, the stent maintained a compressive strength of 180 kPa, and no collapse, detachment, or displacement occurred.

[0118] Example 3:

[0119] The biodegradable airway stent 100 includes a support component 10 and a reinforcing ring component 20; wherein the support component 10 is a hollow tubular structure with a dense mesh woven from biodegradable fibers, and the reinforcing ring component 20 is an open circular ring structure. This structural design gives the biodegradable airway stent 100 good flexibility and adherence to the airway wall, while also providing good fixation within the airway. Thus, the biodegradable airway stent 100 can balance adherence to the airway wall with providing good mechanical support.

[0120] The support component 10 is woven from poly(lactic-co-glycolic acid)-caprolactone biodegradable fiber (weight-average molecular weight of 150,000 g / mol, degradation period of 6 months) with a diameter of 0.10 mm; the axial length of the support component 10 is 40 mm and the diameter is 16 mm; the support component 10 has 24 weaving intersections in the circumferential direction and the weaving grid angle β is 60°; in addition, the outer surface of the support component 10 is coated with a drug coating, which uses a copolymer of polylactic acid and polyglycolic acid as the drug carrier and contains paclitaxel.

[0121] Meanwhile, the reinforcing ring component 20 is injection molded with a diameter (outer diameter of the ring) of 1.25 mm; the reinforcing ring component 20 is made of right-handed polylactic acid rod (tensile strength 90 MPa, weight-average molecular weight 175,000 g / mol, degradation period of 6 months); the reinforcing ring component 20 is bonded and fixed to the grid rods on both sides of the opening 13; the axial length of the reinforcing ring component 20 is 2 mm, and the enveloping circumference diameter D2 is 1 mm larger than the diameter D1 of the supporting component 10.

[0122] Accordingly, the biodegradable airway stent 100 provided in Example 3 was implanted into a simulated airway system, and phosphate-buffered saline (PBS) (pH=7.4±0.2) was selected as the simulated body fluid, with the ambient temperature set at 37°C. This in vitro degradation simulation experiment showed that, three months after implantation in the simulated airway environment, the stent maintained a compressive strength of 120 kPa, and no collapse, detachment, or displacement occurred.

[0123] In summary, the biodegradable airway stent 100 provided in this application reduces, on the one hand, the complications such as respiratory tract infections, malignant tumors, and restenosis caused by granulation tissue proliferation resulting from silicone and metal airway stents; on the other hand, it improves the wall adhesion of the biodegradable airway stent; furthermore, it can prevent the dynamic collapse and displacement of the biodegradable airway stent, and at the same time, it can overcome the problem that the biodegradable airway stent may degrade too quickly in a moist airway environment, leading to breakage and failure.

[0124] The above description is only a description of the preferred embodiments of this application and is not intended to limit the scope of this application in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the technical solution of this application.

Claims

1. A biodegradable airway stent, characterized in that, include: A mesh-like support component, said support component being made of a first biodegradable polymer material; And multiple open annular reinforcing ring components, the reinforcing ring components being made of a second biodegradable polymer material, the second biodegradable polymer material having a tensile strength greater than that of the first biodegradable polymer material; The supporting component includes several annular support segments connected sequentially along the axial direction, and each annular support segment includes multiple grid units distributed along the circumferential direction. In the annular support sections at both axial ends of the support member, each of the grid cells has an opening at its axial protruding position; the grid rods on opposite sides of each opening are respectively connected to the two ends of a reinforcing ring member, so that the reinforcing ring member and the grid cell with the opening do not overlap axially.

2. The biodegradable airway stent according to claim 1, characterized in that, The support component is woven from biodegradable fibers and forms a dense mesh structure.

3. The biodegradable airway stent according to claim 2, characterized in that, The supporting component has at least one of the following structural features: The biodegradable fiber has a diameter of 0.05 mm to 0.20 mm; The biodegradable fiber has a breaking elongation greater than 30%; The linear knitting density of the support component is 8 stitches / cm to 16 stitches / cm; The woven mesh angle of the support component in the axial direction is 60°~80°; The number of weaving intersections in the circumferential direction of the support component is 12 to 36; The surface porosity of the support component is 60%~85%; The axial length of the support component is 20mm~60mm; The diameter of the support component is 12mm~20mm.

4. The biodegradable airway stent according to claim 1 or 2, characterized in that, The reinforcing ring component is a semi-circular arc, a major arc, or a minor arc; at any end of the axial direction of the support component, the diameter of the envelope circumference defined by all the reinforcing ring components is greater than or equal to the diameter of the support component.

5. The biodegradable airway stent according to claim 4, characterized in that, At any axial end of the support member, the diameter of the envelope circumference defined by all the reinforcing ring members is 0.5 mm to 2.0 mm larger than the diameter of the support member.

6. The biodegradable airway stent according to claim 1 or 2, characterized in that, At any axial end of the support component, any two adjacent reinforcing ring components are spaced apart by a given distance, the given distance being 0.1mm to 0.5mm.

7. The biodegradable airway stent according to claim 1 or 2, characterized in that, The reinforcing ring component is made of a rod-shaped structure, and the cross-sectional shape of the rod-shaped structure is circular or non-circular.

8. The biodegradable airway stent according to claim 7, characterized in that, The reinforcing ring component has at least one of the following structural features: The tensile strength of the rod-shaped structure is greater than 70 MPa; The axial length of the reinforcing ring component is 1mm to 5mm; The diameter of the reinforcing ring component is 0.5mm to 1.5mm.

9. The biodegradable airway stent according to claim 1 or 2, characterized in that, The first biodegradable polymer material is selected from at least one of the following materials: polylactic acid, L-polylactic acid, D-polylactic acid, polyglycolic acid, polycaprolactone, polyethylene glycol, polyphthalamide, polyethylene oxide, polyvinyl alcohol and its copolymers.

10. The biodegradable airway stent according to claim 1 or 2, characterized in that, The second biodegradable polymer material is selected from at least one of the following materials: polylactic acid, L-polylactic acid, D-polylactic acid, polyglycolic acid, polycaprolactone, polyethylene glycol, polyphthalamide, polyethylene oxide, polyvinyl alcohol and its copolymers.

11. The biodegradable airway stent according to claim 1 or 2, characterized in that, The weight-average molecular weight of both the first and second biodegradable polymer materials is 100,000 to 300,000 g / mol, and the degradation time is 6 to 18 months.

12. The biodegradable airway stent according to claim 1 or 2, characterized in that, Also includes: A drug coating is applied to the outer surface of the support component; The drug coating may consist solely of a drug, or it may consist of a drug and a biodegradable polymer carrier.

13. The biodegradable airway stent according to claim 1 or 2, characterized in that, The reinforcing ring component is connected to the grid bars on opposite sides of the opening by at least one of welding, bonding, and fitting.

14. The biodegradable airway stent according to claim 1 or 2, characterized in that, The reinforcing ring component is formed by extrusion molding, injection molding, or 3D printing.

15. A method for preparing a biodegradable airway stent, used to prepare the biodegradable airway stent as described in any one of claims 1-14, characterized in that, The preparation method includes: A mesh-like support component was prepared using a first biodegradable polymer material; An open-ring reinforcing component is prepared using a second biodegradable polymer material, and multiple such reinforcing ring components are prepared. The reinforcing ring components are respectively fixedly connected to the openings of each grid cell at both axial ends of the support component, and each reinforcing ring component and the corresponding grid cell do not overlap axially.

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