Esophageal stent based on silk fibroin double-layer drug-loaded film

Abstract

The utility model provides a kind of based on silk fibroin double-layer drug-loading film esophageal stent.The esophageal stent based on silk fibroin double-layer drug-loading film includes: nickel-titanium alloy stent body;Passage, the passage equidistantly is opened in the outer surface of nickel-titanium alloy stent body, the nickel-titanium alloy stent body includes support stent and two expansion stents, two the expansion stent is located at the both ends of support stent;Drug-loading film, the drug-loading film is arranged on the outer surface of nickel-titanium alloy stent body.The esophageal stent based on silk fibroin double-layer drug-loading film provided by the utility model, by the design, outer film porous silk fibroin film fast release hemostatic analgesic drug ≤48 hours, inner film dense crosslinking silk fibroin film sustained-release triamcinolone acetonide ≥15 days, combine PLGA microsphere controlled-release technology, realize the time sequence release of drug, the stent has mechanical support, anti-adhesion and long-term anti-inflammatory function, applicable to esophageal large-area ESD postoperative stenosis prevention and postoperative repair.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to an esophageal stent based on a silk fibroin double-layer drug-loaded membrane. Background Technology

[0002] Esophageal stents are made of nickel-titanium shape memory alloy. Some stents are also covered with a silicone rubber film, which seals the mesh of the bare stent. Proliferative lesions cannot pass through the mesh into the lumen and will not cause restenosis.

[0003] An esophageal stent is a tubular support placed inside the esophagus. It mainly solves problems such as esophageal stenosis and obstruction through mechanical support. It can relieve esophageal stenosis and obstruction and prevent the occurrence and development of esophageal fistula.

[0004] Traditional esophageal stents have a single drug release mechanism, which can only release anti-inflammatory drugs in the short term and cannot meet the dual needs of hemostasis, analgesia and long-term anti-fibrosis. The local drug concentration is insufficient, and the degradation rate of traditional materials such as silicone and polyurethane is uncontrollable, which can easily lead to sudden drug release or premature failure. They also have poor biocompatibility, and the covering material is prone to adhesion or rejection reaction with esophageal tissue.

[0005] Therefore, it is necessary to provide an esophageal stent based on a silk fibroin bilayer drug-loaded membrane to solve the above-mentioned technical problems. Utility Model Content

[0006] This invention provides an esophageal stent based on a silk fibroin double-layer drug-loaded membrane, which solves the problem that traditional esophageal stents can only release anti-inflammatory drugs in a short period of time and cannot meet the dual needs of hemostasis, analgesia and long-term anti-fibrosis.

[0007] To solve the above-mentioned technical problems, the esophageal stent based on silk fibroin double-layer drug-loaded membrane provided by this utility model includes: a nickel-titanium alloy stent body;

[0008] The through-holes are equally spaced on the outer surface of the nickel-titanium alloy bracket body, which includes a support bracket and two extension brackets located at both ends of the support bracket.

[0009] A drug-loaded coating is disposed on the outer surface of a nickel-titanium alloy scaffold body. The drug-loaded coating includes an outer coating, a transition layer, an inner coating, and a silicone waterproof layer. The transition layer is used to connect the outer coating and the inner coating.

[0010] The extended scaffold is slightly larger than the supporting scaffold. The outer coating is made of a mixture of 6% silk fibroin and 2% gelatin, while the inner coating is made of 12% silk fibroin mixed with triamcinolone acetonide-PLGA75 / 25 microspheres. In vitro drug release of the coating: In pH 6.8 buffer, the outer coating requires 48 hours to achieve a release rate of 86.2%, and the inner coating requires 15 days to achieve a cumulative release rate of 62.5%. Mechanical testing: The radial support force of the scaffold reaches 162N, and there is no detachment of the coating after fatigue testing. Silk fibroin solution is used as an adhesive to form a transition layer with a thickness of 10-20μm between the outer and inner coatings.

[0011] Preferably, both ends of the nickel-titanium alloy stent body and the drug-loaded coating are provided with shrink bands, and both ends of the shrink bands are provided with tightening components.

[0012] Preferably, the tightening assembly includes a tightening band and a tightening head, wherein the tightening head is used to limit the tightening band.

[0013] The tightening head has a structure similar to a belt clamp, which can lock the tightening belt and shrink belt to the same length. The tightening head can also be manually knotted, connecting the two ends of the tightening belt and shrink belt.

[0014] Preferably, the outer surface of the support bracket has two rows of anti-deformation openings;

[0015] The anti-deformation opening ensures that the inner surface of the nickel-titanium alloy support body will not deform when the body is bent.

[0016] Preferably, the inner surface of the nickel-titanium alloy bracket body is integrally formed with retaining rings at both ends, and one end of the retaining ring protrudes from both ends of the nickel-titanium alloy bracket body.

[0017] Preferably, both ends of the drug-loaded coating are fixedly connected to docking rings, and each of the two docking rings has a docking groove at one of its adjacent ends;

[0018] The mating groove and the retaining ring are positioned correspondingly.

[0019] Compared with related technologies, the esophageal stent based on a silk fibroin bilayer drug-loaded membrane provided by this utility model has the following beneficial effects:

[0020] This invention provides an esophageal stent based on a silk fibroin double-layer drug-loaded membrane. To achieve synergistic treatment of hemostasis, analgesia, and long-term anti-inflammatory and anti-fibrotic effects, the drug-loaded membrane is first fitted inside the nickel-titanium alloy stent body. The drug-loaded membrane consists of an inner membrane and an outer membrane, connected by a transition layer to increase the bonding force between the two layers. The outer membrane is a fast-release layer containing hemostatic and analgesic drugs, a gelatin composite porous membrane with a porosity of 60%-70%. The inner membrane... The scaffold is a dense cross-linked silk fibroin membrane with a porosity of <30% containing triamcinolone acetonide and loaded with PLGA microspheres. This design allows for the rapid release of hemostatic and analgesic drugs within ≤48 hours using the outer porous silk fibroin membrane and the sustained release of triamcinolone acetonide within ≥15 days using the inner dense cross-linked silk fibroin membrane. Combined with PLGA microsphere controlled-release technology, it achieves timed drug release. This scaffold combines mechanical support, anti-adhesion, and long-term anti-inflammatory functions, making it suitable for the prevention and repair of stenosis after large-area esophageal ESD surgery. Attached Figure Description

[0021] Figure 1 A schematic diagram of the structure of the first embodiment of the esophageal stent based on a silk fibroin double-layer drug-loaded membrane provided by this utility model;

[0022] Figure 2 A schematic diagram of the structure of the nickel-titanium alloy support body is provided for this utility model;

[0023] Figure 3 Provided for this utility model Figure 2 An enlarged view of point A shown;

[0024] Figure 4 A schematic diagram of the inner layer coating structure is provided for this utility model;

[0025] Figure 5 A schematic diagram of the second embodiment of the esophageal stent based on a silk fibroin double-layer drug-loaded membrane provided by this utility model;

[0026] Figure 6 A schematic diagram of the docking ring is provided for this utility model;

[0027] Figure 7 Provided for this utility model Figure 6 A magnified view of point B shown.

[0028] The following are the labeling elements in the diagram: 1. Nickel-titanium alloy support body; 101. Extension support; 102. Support support; 2. Through-hole; 3. Shrink band; 4. Tightening assembly; 401. Tightening band; 402. Tightening head; 5. Drug-loaded coating; 501. Outer coating; 502. Transition layer; 503. Inner coating; 504. Silicone waterproof layer; 6. Deformation-resistant opening; 7. Docking ring; 8. Docking groove; 9. Snap ring. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] First Embodiment

[0031] Please refer to the following: Figure 1 , Figure 2 , Figure 3 , Figure 4 ,in, Figure 1 A schematic diagram of the structure of the first embodiment of the esophageal stent based on a silk fibroin double-layer drug-loaded membrane provided by this utility model; Figure 2 A schematic diagram of the structure of the nickel-titanium alloy support body is provided for this utility model; Figure 3 Provided for this utility model Figure 2 An enlarged view of point A shown; Figure 4 This invention provides a structural schematic diagram of the inner layer coating. The esophageal stent based on a silk fibroin double-layer drug-loaded coating includes: a nickel-titanium alloy stent body 1;

[0032] The through-holes 2 are equally spaced on the outer surface of the nickel-titanium alloy bracket body 1. The nickel-titanium alloy bracket body 1 includes a support bracket 102 and two extension brackets 101, with the two extension brackets 101 located at both ends of the support bracket 102.

[0033] Drug-loaded coating 5 is disposed on the outer surface of nickel-titanium alloy support body 1. The drug-loaded coating 5 includes an outer coating 501, a transition layer 502, an inner coating 503, and a silicone waterproof layer 504. The transition layer 502 is used to connect the outer coating 501 and the inner coating 503.

[0034] The extended scaffold 101 is slightly larger than the supporting scaffold 102. The outer coating 501 is made by mixing 6% silk fibroin with 2% gelatin, and the inner coating 503 is made by mixing 12% silk fibroin with triamcinolone acetonide-PLGA75 / 25 microspheres. In vitro release of the drug-loaded coating 5: In pH 6.8 buffer, the outer coating 501 requires 48 hours to achieve a release rate of 86.2%, and the inner coating 503 requires 15 days to achieve a cumulative release rate of 62.5%. The silicone waterproof layer 504 does not... (The sentence is incomplete and requires more context to translate accurately.) The drug dissolution was facilitated, and mechanical testing showed that the radial support force of the scaffold reached 162N. No detachment occurred after the coating fatigue test. A silk fibroin solution was used as an adhesive to form a transition layer 502 with a thickness of 10-20μm between the outer coating 501 and the inner coating 503. The molecular weight of the silk fibroin in the transition layer 502 was distributed in a gradient, with a lower molecular weight of about 10-30kDa near the inner layer and a higher molecular weight of about 50-100kDa near the outer layer, in order to enhance the bonding force between the two layers.

[0035] Both ends of the nickel-titanium alloy stent body 1 and the drug-loaded coating 5 are provided with shrink bands 3, and both ends of the shrink bands 3 are provided with tightening components 4.

[0036] The tightening component 4, together with the shrink band 3, can tighten both ends of the nickel-titanium alloy support body 1 and the drug-loaded coating 5.

[0037] The tightening component 4 includes a tightening band 401 and a tightening head 402, wherein the tightening head 402 is used to limit the tightening band 401.

[0038] The tightening head 402 has a structure similar to a belt clamp, which can lock the tightening belt 401 and the shrink belt 3 to the corresponding lengths. The tightening head 402 can also be manually knotted, and the two ends of the tightening belt 401 and the shrink belt 3 are connected.

[0039] The outer surface of the support bracket 102 is provided with two rows of anti-deformation openings 6;

[0040] The anti-deformation port 6 can ensure that the inner surface of the nickel-titanium alloy bracket body 1 will not deform when the nickel-titanium alloy bracket body 1 is bent.

[0041] The working principle of the esophageal stent based on a silk fibroin double-layer drug-loaded membrane provided by this utility model is as follows:

[0042] First, the drug-loaded membrane 5 is fitted inside the nickel-titanium alloy scaffold body 1. The drug-loaded membrane 5 is divided into an inner membrane 503 and an outer membrane 501. At the same time, the inner membrane 503 and the outer membrane 501 are connected by a transition layer 502 to increase the bonding force between the two layers. The outer membrane 501 is a fast-release layer containing hemostatic and analgesic drugs, a gelatin composite porous membrane with a porosity of 60%-70%. The inner membrane 503 is a sustained-release layer containing triamcinolone acetonide, a cross-linked dense membrane of silk fibroin with a porosity of <30%, and is loaded with PLGA microspheres.

[0043] Compared with related technologies, the esophageal stent based on a silk fibroin bilayer drug-loaded membrane provided by this utility model has the following beneficial effects:

[0044] To achieve synergistic treatment of hemostasis, analgesia, and long-term anti-inflammatory and anti-fibrotic effects, a drug-loaded membrane 5 is first placed inside the nickel-titanium alloy scaffold body 1. The drug-loaded membrane 5 consists of an inner membrane 503 and an outer membrane 501, connected by a transition layer 502 to increase the bonding force between the two layers. The outer membrane 501 is a fast-release layer containing hemostatic and analgesic drugs, a gelatin composite porous membrane with a porosity of 60%-70%, and the inner membrane 503 is a sustained-release layer. The stent is a dense cross-linked silk fibroin membrane containing triamcinolone acetonide with a porosity of <30%, loaded with PLGA microspheres. This design allows for the rapid release of hemostatic and analgesic drugs within ≤48 hours using the outer 501 porous silk fibroin membrane, and the sustained release of triamcinolone acetonide within ≥15 days using the inner 503 dense cross-linked silk fibroin membrane. Combined with PLGA microsphere controlled-release technology, it achieves time-sequential drug release. This stent has mechanical support, anti-adhesion, and long-term anti-inflammatory functions, and is suitable for the prevention and repair of stenosis after large-area esophageal ESD.

[0045] Second Embodiment

[0046] Please refer to the following: Figures 5-6 - Figure 7 , Figure 5 A schematic diagram of the second embodiment of the esophageal stent based on a silk fibroin double-layer drug-loaded membrane provided by this utility model; Figure 6 A schematic diagram of the docking ring is provided for this utility model; Figure 7 Provided for this utility model Figure 6 The enlarged view at point B shows an esophageal stent based on a silk fibroin double-layer drug-loaded membrane, as provided in the first embodiment of this application. The second embodiment of this application proposes another esophageal stent based on a silk fibroin double-layer drug-loaded membrane. The second embodiment is merely a preferred embodiment of the first embodiment, and its implementation will not affect the independent implementation of the first embodiment.

[0047] Specifically, the esophageal stent based on a silk fibroin double-layer drug-loaded membrane provided in the second embodiment of this application is different in that the inner surface of the nickel-titanium alloy stent body 1 is integrally formed with retaining rings 9 at both ends, and one end of the retaining ring 9 protrudes from both ends of the nickel-titanium alloy stent body 1.

[0048] The retaining ring 9 and the nickel-titanium alloy bracket body 1 are made of the same material.

[0049] Both ends of the drug-loaded coating 5 are fixedly connected to docking rings 7, and docking grooves 8 are opened at the adjacent ends of the two docking rings 7.

[0050] The docking groove 8 and the retaining ring 9 are positioned in a corresponding manner to prevent the two ends of the drug-loaded coating 5 from curling up.

[0051] Compared with related technologies, the esophageal stent based on a silk fibroin bilayer drug-loaded membrane provided by this utility model has the following beneficial effects:

[0052] To increase the stability of the connection between the drug-loaded membrane 5 and the nickel-titanium alloy stent body 1, a retaining ring 9 is integrally formed at both ends on the inner surface of the nickel-titanium alloy stent body 1. At the same time, a docking ring 7 with a docking groove 8 is integrally formed at both ends of the drug-loaded membrane 5. After the drug-loaded membrane 5 is fitted onto the outer surface of the nickel-titanium alloy stent body 1, the retaining ring 9 is inserted into the docking groove 8. This design prevents the ends of the drug-loaded membrane 5 from curling by inserting the retaining ring 9 into the docking groove 8.

[0053] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An esophageal stent based on a silk fibroin bilayer drug-loaded membrane, characterized in that, include: Nickel-titanium alloy support body; The through-holes are equally spaced on the outer surface of the nickel-titanium alloy bracket body, which includes a support bracket and two extension brackets located at both ends of the support bracket. The drug-loaded coating is disposed on the outer surface of the nickel-titanium alloy scaffold body. The drug-loaded coating includes an outer coating, a transition layer, an inner coating, and a silicone waterproof layer. The transition layer is used to connect the outer coating and the inner coating.

2. The esophageal stent based on a silk fibroin bilayer drug-loaded membrane according to claim 1, characterized in that, Both ends of the nickel-titanium alloy stent body and the drug-loaded coating are provided with shrink bands, and both ends of the shrink bands are provided with tightening components.

3. The esophageal stent based on a silk fibroin bilayer drug-loaded membrane according to claim 2, characterized in that, The tightening assembly includes a tightening band and a tightening head, the tightening head being used to limit the tightening band.

4. The esophageal stent based on a silk fibroin bilayer drug-loaded membrane according to claim 1, characterized in that, The outer surface of the support bracket has two rows of anti-deformation openings.

5. The esophageal stent based on a silk fibroin bilayer drug-loaded membrane according to claim 1, characterized in that, The inner surface of the nickel-titanium alloy bracket body is integrally formed with retaining rings at both ends, and one end of the retaining ring protrudes from both ends of the nickel-titanium alloy bracket body.

6. The esophageal stent based on a silk fibroin bilayer drug-loaded membrane according to claim 1, characterized in that, Both ends of the drug-loaded coating are fixedly connected to docking rings, and each of the two docking rings has a docking groove at one of its adjacent ends.

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