Photoresponse self-shaping degradable paranasal sinus stent and preparation method thereof

Abstract

The invention belongs to the technical field of biomedical materials and medical instruments, and particularly relates to a photoresponse self-shaping degradable paranasal sinus stent and a preparation method thereof.The stent body of the degradable paranasal sinus stent is a grid stent, and grid gaps are filled with PLGA microspheres containing gold nanorods; the surface of the support body is provided with hemispherical or spherical protruding structures which are regularly distributed. According to the technical scheme, by means of near-infrared light thermal softening and ultraviolet light curing dual-mode shaping, a doctor can adjust the shape of the stent in real time during an operation, the stent perfectly fits the specific anatomical structure of a patient, and the occurrence rate of postoperative complications is reduced. After operation, local microenvironment pH adjustment is triggered through low-intensity NIR illumination, acidic by-products generated by PLA / PCL degradation are neutralized, and inflammatory response is delayed.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials and medical devices, and particularly relates to a light-responsive self-shaping degradable sinus stent and a preparation method thereof. Background Art

[0002] The sinus cavity has a complex morphology (such as the multi-septate structure of the ethmoid sinus and sphenoid sinus), and traditional silicone / metal stents cannot fit well, resulting in compressive necrosis. Non-degradable stents need to be removed after surgery, and the infection rate increases by 12-18%. The degradation rate of existing degradable stents (such as PLGA stents) does not match tissue regeneration, which can easily cause collapse or granulation hyperplasia. Summary of the Invention

[0003] The purpose of the present invention is to provide a light-responsive self-shaping degradable sinus stent and a preparation method thereof, which has the functions of real-time shaping during surgery, controllable degradation after surgery and sustained drug release, and is suitable for postoperative sinus repair and functional reconstruction to solve the problems existing in the above-mentioned background technology.

[0004] To achieve the above objectives, this application is implemented through the following technical solutions:

[0005] A light-responsive self-shaping biodegradable sinus stent, the stent body of which is a grid stent, with PLGA microspheres containing gold nanorods filled in the grid gaps; and regularly distributed hemispherical or spherical protrusion structures designed on the surface of the stent body.

[0006] Furthermore, the stent body is prepared using light-responsive smart material polylactic acid-caprolactone copolymer.

[0007] Furthermore, the porosity of the mesh scaffold is greater than or equal to 85%.

[0008] Furthermore, the PLGA microspheres are a composite system of near-infrared photothermal nanoparticles and ultraviolet light-cured hydrogel.

[0009] Furthermore, the PLGA microspheres contain 0.5% gold nanorods, and the aspect ratio of the gold nanorods is 4:1.

[0010] Furthermore, the particle size of the PLGA microspheres is 10-50 μm.

[0011] Furthermore, the diameter of the hemispherical or spherical protrusion structure is 0.5-2 mm, the height is 0.3-1 mm, and the spacing is 1-3 mm.

[0012] The method for preparing any of the above-mentioned light-responsive self-shaping degradable sinus stents comprises the following steps:

[0013] S1. Prepare a polylactic acid-caprolactone copolymer mesh scaffold using fused deposition modeling 3D printing technology, fill the mesh gaps of the mesh scaffold with PLGA microspheres containing gold nanorods, and design the surface of the mesh scaffold to have regularly distributed hemispherical or spherical protrusions to obtain a scaffold substrate;

[0014] S2, spraying methacrylated gelatin prepolymer solution on the surface of the stent substrate in step S1 to form a UV-cured layer, and then impregnating the PLGA nanofibers loaded with dexamethasone;

[0015] S3, using laser to soften the target area of the stent, and after the stent is shaped as needed, immediately curing the methacrylated gelatin layer with UV light to lock the shape;

[0016] S4. Perform NIR irradiation on the proximal end of the stent every week after surgery to trigger the PLGA microspheres to accelerate the release of alkaline buffer to neutralize the acidic degradation products of PLCL.

[0017] Furthermore, in step S2, the methacrylated gelatin prepolymer solution includes 0.1% Irgacure 2959 photoinitiator.

[0018] Furthermore, in step S2, the drug loading is 8% and the sustained-release period is 21 days.

[0019] The beneficial effects of the present invention compared with the prior art are:

[0020] ① Dynamic adaptability during surgery: Through near-infrared (NIR) photothermal softening + ultraviolet (UV) light curing dual-mode shaping, doctors can adjust the stent shape in real time during surgery (deformation rate ≥ 80%), perfectly fitting the patient's specific anatomical structure and reducing the incidence of postoperative complications (such as compression necrosis).

[0021] ② Gradient degradation design: The proximal end of the stent (contacting the nasal entrance) is preset with a faster degradation rate (twice as fast as the distal end) to match the timing requirements of mucosal regeneration from outside to inside.

[0022] ③ Light-controlled degradation regulation: After surgery, low-intensity NIR light is used to trigger local microenvironment pH regulation (such as releasing alkaline buffers), neutralize the acidic byproducts produced by PLA / PCL degradation, and delay the inflammatory response.

[0023] ④Surface microsphere protrusion array: The spherical protrusions improve the fit rate between the stent and the complex sinus cavity, forming multi-point anchoring and reducing the risk of stent displacement. The spherical structure converts traditional surface contact into point contact, reducing local pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of the degradable sinus stent of the present invention.

[0025] Description of reference numerals:

[0026] 1. Bracket body; 2. Grid gap; 3. Hemispherical or spherical protrusion structure. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is described in detail below with reference to the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, and cannot be interpreted as limiting the technical solution of the present invention.

[0028] This application's technical solution utilizes innovative photoresponsive materials, incorporating a composite system of near-infrared (NIR) photothermal nanoparticles and ultraviolet (UV) light-curable hydrogels to achieve dynamic control of "softening-shaping-curing." Simultaneously, light-triggered accelerated local degradation (e.g., photocatalytic hydrolysis) and targeted release of anti-inflammatory drugs address the vicious cycle of inflammation and degradation. Furthermore, an array of microsphere protrusions is added to the stent surface, creating regularly distributed hemispherical or spherical protrusions that can be embedded in sinus mucosal folds or bony depressions, creating multi-point anchoring and reducing the risk of stent migration.

[0029] like Figure 1 As shown, the present application provides a light-responsive, self-shaping, biodegradable sinus stent. The stent body 1 is a mesh stent. The specific shape of the stent body is the same as the shape of the user's sinus. The specific shape of the stent body may vary from user to user, requiring corresponding adjustments during surgery, but this does not change the overall structure of the stent body. The mesh gaps 2 are filled with PLGA microspheres containing gold nanorods; and the surface of the stent body is designed with regularly distributed hemispherical or spherical protrusions 3.

[0030] In the present application, the stent body is prepared using the light-responsive smart material polylactic acid-caprolactone copolymer.

[0031] In the present application, the porosity of the mesh scaffold is greater than or equal to 85%.

[0032] In the present application, PLGA microspheres are a composite system of near-infrared photothermal nanoparticles and ultraviolet light-cured hydrogel.

[0033] In the present application, the PLGA microspheres contain 0.5% by weight of gold nanorods, and the aspect ratio of the gold nanorods is 4:1.

[0034] In the present application, the particle size of the PLGA microspheres is 10-50 μm.

[0035] In the present application, the diameter of the hemispherical or spherical protrusion structure is 0.5-2 mm, the height is 0.3-1 mm, and the spacing is 1-3 mm.

[0036] The present application also includes a method for preparing any of the above-mentioned light-responsive self-shaping degradable sinus stents, which comprises the following steps:

[0037] S1. Substrate forming:

[0038] A polylactic acid-caprolactone copolymer (PLCL) mesh scaffold with a porosity of ≥85% and a 200 μm diameter copolymer filament was fabricated using fused deposition modeling (FDM) 3D printing technology. The mesh gaps were filled with PLGA microspheres (10-50 μm in diameter) containing 0.5% gold nanorods by weight and an aspect ratio of 4:1. The scaffold surface was designed with regularly distributed hemispherical or spherical protrusions with diameters of 0.5-2 mm, heights of 0.3-1 mm, and spacing of 1-3 mm, forming the scaffold substrate.

[0039] S2. Functional modification:

[0040] A methacrylated gelatin (GelMA) prepolymer solution containing 0.1% by weight of Irgacure 2959 photoinitiator was sprayed on the surface of the stent substrate to form a UV-cured layer with a thickness of 50 μm.

[0041] Drug loading treatment: The stent substrate forming the UV-cured layer was impregnated with PLGA nanofibers loaded with dexamethasone, with a drug loading of 8% and a sustained release period of 21 days.

[0042] S3, light control operation process:

[0043] During the surgery, an 808nm laser (power density 1.5W / cm², irradiation for 15 seconds) was used to soften the target area (temperature raised to 60°C, below the melting point of PLCL, 65°C). After manually adjusting the stent shape, the GelMA layer was immediately cured with 365nm UV light (intensity 10mW / cm²) for 30 seconds, locking the shape.

[0044] Degradation regulation: After surgery, the proximal end of the stent is irradiated with NIR (0.8W / cm², 30 seconds / time) every week to trigger the PLGA microspheres to accelerate the release of alkaline buffer (NaHCO3) to neutralize the acidic degradation products of PLCL.

[0045] The above description is merely an embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, it is not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A light-responsive self-shaping degradable sinus stent, characterized in that: The stent body is a grid stent, and PLGA microspheres containing gold nanorods are filled in the grid gaps; regularly distributed hemispherical or spherical protrusion structures are designed on the surface of the stent body.

2. The light-responsive self-shaping degradable sinus stent according to claim 1, characterized in that: The bracket body is prepared by using the light-responsive intelligent material polylactic acid-caprolactone copolymer.

3. The light-responsive self-shaping degradable sinus stent according to claim 1, characterized in that: The porosity of the mesh scaffold is greater than or equal to 85%.

4. The light-responsive self-shaping degradable sinus stent according to claim 1, characterized in that: PLGA microspheres are a composite system of near-infrared photothermal nanoparticles and UV-curable hydrogels.

5. The light-responsive self-shaping degradable sinus stent according to claim 4, characterized in that: The PLGA microspheres contain 0.5% gold nanorods, and the aspect ratio of the gold nanorods is 4:

1.

6. The light-responsive self-shaping degradable sinus stent according to claim 4, characterized in that: The particle size of PLGA microspheres is 10-50 μm.

7. The light-responsive self-shaping degradable sinus stent according to claim 1, characterized in that: The diameter of the hemispherical or spherical protrusion structure is 0.5-2 mm, the height is 0.3-1 mm, and the spacing is 1-3 mm.

8. The method for preparing the light-responsive self-shaping degradable sinus stent according to any one of claims 1 to 7, characterized in that: Use the following steps: S1. Prepare a polylactic acid-caprolactone copolymer mesh scaffold using fused deposition modeling 3D printing technology, fill the mesh gaps of the mesh scaffold with PLGA microspheres containing gold nanorods, and design the surface of the mesh scaffold to have regularly distributed hemispherical or spherical protrusions to obtain a scaffold substrate; S2, spraying methacrylated gelatin prepolymer solution on the surface of the stent substrate in step S1 to form a UV-cured layer, and then impregnating the PLGA nanofibers loaded with dexamethasone; S3, using laser to soften the target area of the stent, and after the stent is shaped as needed, immediately curing the methacrylated gelatin layer with UV light to lock the shape; S4. Perform NIR irradiation on the proximal end of the stent every week after surgery to trigger the PLGA microspheres to accelerate the release of alkaline buffer to neutralize the acidic degradation products of PLCL.

9. The method for preparing the light-responsive self-shaping degradable sinus stent according to claim 8, wherein: In step S2, the methacrylated gelatin prepolymer solution includes 0.1% Irgacure 2959 photoinitiator.

10. The method for preparing the light-responsive self-shaping degradable sinus stent according to claim 8, characterized in that: In step S2, the drug loading amount is 8% and the sustained-release period is 21 days.

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