Biovalve coating and method of forming coating on a biovalve

Abstract

The embodiment of the invention relates to the technical field of medical coating materials, in particular to a bioprosthetic valve coating and a method for forming the coating on a bioprosthetic valve. The bioprosthetic valve coating provided by the embodiment of the invention comprises a polylactic acid-glycolic acid copolymer loaded with curcumin and curcumin nanoparticles, a platelet inhibitor, a piezoelectric nanofiber membrane and hydrogel of methylacryloyl gelatin-methylacryloyl heparin (GelMA-HepMA). According to the bioprosthetic valve coating provided by the embodiment of the invention, the bioprosthetic valve can have the comprehensive performance of resisting thrombus in the early stage of implantation, resisting inflammation and oxidation in the middle stage and delaying calcification and degeneration of valve leaflets in the long term, meanwhile, endothelialization of the bioprosthetic valve is promoted, and the long-term functional stability and biocompatibility of the bioprosthetic valve are improved.

Description

Technical Field

[0001] Embodiments of this application relate to the technical field of medical covering materials, and more specifically to a bioprosthetic valve coating and a method for forming a coating on a bioprosthetic valve. Background Technology

[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.

[0003] For patients with severe valvular stenosis or regurgitation, clinical treatment primarily employs surgical valve replacement and transcatheter aortic / mitral valve replacement. Bioprosthetic valves are widely used due to their superior hemodynamic performance, relatively low thrombotic risk, and theoretically lower dependence on long-term strong anticoagulation. However, after implantation of a bioprosthetic valve, three main issues remain: early thrombosis, persistent inflammation and oxidative stress in the immediate post-implantation period, and the risk of calcification and degeneration of the valve leaflets in the long term, potentially leading to valvular regurgitation or stenosis recurrence and requiring further surgical intervention.

[0004] Specifically, from the perspective of blood compatibility mechanisms, after implantation of bioprosthetic valves, protein adsorption and conformational changes easily occur on the blood-contact surfaces, triggering platelet adhesion, aggregation, and activation, and further activating the coagulation cascade. This is especially true in applications such as transcatheter valve replacement or valve-in-valve replacement, where the valve leaflets are in a complex blood flow shear and eddy environment, and local stagnant and low-shear areas are more prone to thrombosis. From the perspective of inflammation and immune response, bioprosthetic valve tissue usually undergoes fixation, cross-linking, or other chemical treatments to reduce immunogenicity and improve mechanical stability. However, such treatments may introduce residual reactive groups or alter the tissue microstructure, leading to persistent local inflammation. In addition, residual cellular components, phospholipids, and micro-damage introduced during processing may induce macrophage infiltration, inflammatory factor release, and oxidative stress accumulation. Furthermore, inflammation and oxidative stress not only exacerbate the tendency to form thrombi but also promote the transformation of valve leaflet interstitial cells and surrounding cells into osteoblastic phenotypes, driving calcification deposition. Summary of the Invention

[0005] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] In a first aspect, embodiments of this application provide a bioprosthetic valve coating comprising polylactic acid-glycolic acid copolymer@curcumin nanoparticles loaded with curcumin, a platelet inhibitor, a piezoelectric nanofiber membrane, and a hydrogel of methacryloyl gelatin-heparyl methacrylamide (GelMA-HepMA).

[0007] The bioprosthetic valve coating provided in this application utilizes a methacryloyl gelatin-methacrylated heparin hydrogel to provide a stable anticoagulant and biomimetic extracellular matrix microenvironment. Combined with platelet inhibitors, it can reduce platelet adhesion activation and coagulation cascade reactions triggered by protein adsorption in the early stages of bioprosthetic valve implantation, thus achieving a rapid antithrombotic effect. By introducing curcumin-loaded polylactic-co-glycolic acid copolymer@curcumin nanoparticles, the anti-inflammatory and antioxidant active ingredient curcumin is protected and released sustainably by the polylactic-co-glycolic acid copolymer, reducing local reactive oxygen species (ROS) accumulation, regulating the inflammatory cascade reaction, and weakening the driving factors promoting valve leaflet calcification from the source, thereby delaying valve leaflet calcification. Thickening and structural degeneration are addressed by introducing a piezoelectric nanofiber membrane. This membrane generates micro-electrical signals beneficial to endothelialization under the periodic mechanical loads generated by valve opening and closing or non-invasive stimulation such as external ultrasound. Without altering the valve structure, this membrane, in conjunction with the biomimetic extracellular matrix microenvironment provided by the methacryloyl gelatin-methacrylated heparin hydrogel, promotes endothelial cell adhesion, migration, and functionalization, improving the continuity and stability of endothelial coverage. Consequently, the bioprosthetic valve possesses comprehensive properties, including early antithrombotic effects, mid-term anti-inflammatory and antioxidant effects, and long-term delay in leaflet calcification and degeneration. It also promotes endothelialization of the bioprosthetic valve, thereby enhancing its long-term functional stability and biocompatibility.

[0008] Secondly, embodiments of this application provide a method for forming a coating on a bioprosthetic valve, the method comprising the following steps: S10: preparing polylactic acid-glycolic acid copolymer@curcumin nanoparticles loaded with curcumin; S20: adding the polylactic acid-glycolic acid copolymer@curcumin nanoparticles prepared in step S10 to a biodegradable polymer material polylactic acid (PLLA), and adding it into an electrospinning machine to prepare an oriented piezoelectric nanofiber membrane; S30: preparing a hydrogel solution of methacrylamide gelatin-methacrylamide heparin; S40: adding a platelet inhibitor to the hydrogel solution of methacrylamide gelatin-methacrylamide heparin prepared in step S30; S50: setting the piezoelectric nanofiber membrane prepared in step S20 on the blood contact surface of the bioprosthetic valve, and coating the mixture obtained in step S40 onto the piezoelectric nanofiber membrane; S60: performing photocrosslinking treatment on the mixture to form a coating on the blood contact surface of the bioprosthetic valve.

[0009] The method for forming a coating on a bioprosthetic valve provided in this application involves adding prepared polylactic acid-glycolic acid copolymer@curcumin nanoparticles to a biodegradable polymer material, polylactic acid (PLLA), and preparing an oriented piezoelectric nanofiber membrane using an electrospinning machine to achieve a stable bond between the nanoparticles and fibers through co-spinning. The piezoelectric nanofiber membrane is then placed on the blood contact surface of the bioprosthetic valve, and a hydrogel solution containing a platelet inhibitor, methacrylamide gelatin-heparin methacrylamide, is coated onto the piezoelectric nanofiber membrane and photocrosslinked to form a stable layered composite coating. This improves the integrity and adhesion stability of the coating under dynamic shear and bending loads. Furthermore, compared to traditional surface treatment processes, it reduces the impact of the coating on the mechanical properties and long-term safety of the valve leaflets. This helps ensure that the bioprosthetic valve possesses comprehensive properties, including early antithrombotic effects, mid-term anti-inflammatory and antioxidant effects, and long-term delay in leaflet calcification and degeneration. It also promotes endothelialization of the bioprosthetic valve and improves its long-term functional stability and biocompatibility. Attached Figure Description

[0010] Other objects and advantages of this application will become apparent from the following description of embodiments of this application with reference to the accompanying drawings, and will help to provide a comprehensive understanding of this application.

[0011] Figure 1 This is a particle size distribution diagram of polylactic acid-glycolic acid copolymer@curcumin nanoparticles according to an embodiment of this application; Figure 2 This is a transmission electron microscope image of polylactic acid-glycolic acid copolymer@curcumin nanoparticles according to an embodiment of this application; Figure 3 This is a scanning electron microscope image of an oriented fiber membrane according to an embodiment of this application; Figure 4 This is a piezoelectric microscopy image of an oriented fiber membrane according to an embodiment of this application; Figure 5 This is a scanning electron microscope image of a piezoelectric nanofiber membrane with directional alignment according to an embodiment of this application; Figure 6 This is a piezoelectric microscopy image of an oriented piezoelectric nanofiber membrane according to an embodiment of this application; Figure 7 This is a frontal view of a hydrogel of methacrylamide gelatin-methacrylamide heparin according to an embodiment of this application; Figure 8 This is a frontal view of a hydrogel of methacrylamide gelatin-heparylamide according to an embodiment of this application after photocrosslinking treatment; Figure 9This is a scanning electron microscope image of an uncoated biological valve according to an embodiment of this application; Figure 10 This is a scanning electron microscope image of a coated bioprosthetic valve according to an embodiment of this application; Figure 11 These are Fourier transform infrared spectra of the bioprosthetic valve before and after coating formation according to embodiments of this application; Figure 12 This is a schematic diagram of a contact angle test of an uncoated bioprosthetic valve according to an embodiment of this application; Figure 13 This is a schematic diagram of a contact angle test of a coated bioprosthetic valve according to an embodiment of this application.

[0012] Explanation of reference numerals in the attached figures: 10. Bioprosthetic valve; 20. Coating.

[0013] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding. Detailed Implementation

[0014] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0015] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0016] In related technologies, various methods have been proposed to improve the biochemical properties of the bioprosthetic valve surface in order to address the problems that arise after bioprosthetic valve implantation in the heart. For example, forming a heparinized hydrophilic polymer coating on the bioprosthetic valve surface can introduce anticoagulant groups, fix anticoagulant proteins and peptides, etc., to inhibit the formation of thrombi in the early stage of implantation; loading glucocorticoids, nonsteroidal anti-inflammatory drugs or natural antioxidant molecules can scavenge reactive oxygen species (ROS) and reduce the inflammatory cascade reaction in the middle stage of implantation; and reducing the risk of calcification of the valve leaflets in the long term of implantation can be achieved through techniques such as phospholipid extraction, aldehyde blocking, introduction of metal ion chelating agents or anti-calcification molecules.

[0017] However, the inventors of this application have found that most existing technical means only target the improvement of single-level biochemical properties, which can often only reduce the risk at a certain stage and are difficult to take into account multiple modification directions at the same time, so as to achieve a comprehensive consideration of the performance requirements of bioprosthetic valve implantation at all stages. This makes the bioprosthetic valve have the comprehensive performance of early antithrombosis, mid-term anti-inflammatory and antioxidant, and long-term delay of leaflet calcification and degeneration, which is not conducive to improving the long-term functional stability and biocompatibility of bioprosthetic valves.

[0018] Based on this, embodiments of this application provide a biological valve coating, the coating comprising polylactic acid-glycolic acid copolymer@curcumin nanoparticles loaded with curcumin, platelet inhibitors, piezoelectric nanofiber membranes, and a hydrogel of methacryloyl gelatin-heparyl methacrylamide (GelMA-HepMA).

[0019] The bioprosthetic valve coating provided in this application utilizes a methacryloyl gelatin-methacrylated heparin hydrogel to provide a stable anticoagulant and biomimetic extracellular matrix microenvironment. Combined with platelet inhibitors, it can reduce platelet adhesion activation and coagulation cascade reactions triggered by protein adsorption in the early stages of bioprosthetic valve implantation, thus achieving a rapid antithrombotic effect. By introducing curcumin-loaded polylactic-co-glycolic acid copolymer@curcumin nanoparticles, the anti-inflammatory and antioxidant active ingredient curcumin is protected and released sustainably by the polylactic-co-glycolic acid copolymer, reducing local reactive oxygen species (ROS) accumulation, regulating the inflammatory cascade reaction, and weakening the driving factors promoting valve leaflet calcification from the source, thereby delaying valve leaflet calcification. Thickening and structural degeneration are addressed by introducing a piezoelectric nanofiber membrane. This membrane generates micro-electrical signals beneficial to endothelialization under the periodic mechanical loads generated by valve opening and closing or non-invasive stimulation such as external ultrasound. Without altering the valve structure, this membrane, in conjunction with the biomimetic extracellular matrix microenvironment provided by the methacryloyl gelatin-methacrylated heparin hydrogel, promotes endothelial cell adhesion, migration, and functionalization, improving the continuity and stability of endothelial coverage. Consequently, the bioprosthetic valve possesses comprehensive properties, including early antithrombotic effects, mid-term anti-inflammatory and antioxidant effects, and long-term delay in leaflet calcification and degeneration. It also promotes endothelialization of the bioprosthetic valve, thereby enhancing its long-term functional stability and biocompatibility.

[0020] In some embodiments, the mass ratio of nanoparticles, platelet inhibitors, piezoelectric nanofiber membranes, and hydrogels is 20:1:20:225. Coatings prepared with such mass ratios can achieve optimal comprehensive performance of bioprosthetic valves in early antithrombosis, mid-term anti-inflammatory and antioxidant effects, and long-term delay of leaflet calcification and degeneration, and are more conducive to promoting endothelialization.

[0021] In related technologies, when modifying the surface of bioprosthetic valves, some drugs or active molecules are loaded only through physical adsorption or simple encapsulation. This can easily lead to initial burst release, activity decay, or loss under blood flow, resulting in insufficient adhesion stability and durability, thus causing insufficient effective window of action. While using partial covalent binding of macromolecular proteins can improve adhesion stability, the surface treatment process used may damage the bioprosthetic valve tissue or introduce potential cytotoxic residues, affecting the mechanical properties and long-term safety of the valve leaflets.

[0022] To address the aforementioned technical problems, embodiments of this application also provide a method for forming a coating on a biological valve, the method comprising the following steps: S10: Preparation of polylactic acid-glycolic acid copolymer@curcumin nanoparticles loaded with curcumin.

[0023] S20: The polylactic acid-hydroxyacetic acid copolymer@curcumin nanoparticles prepared in step S10 are added to the biodegradable polymer material polylactic acid (PLLA) and then added to an electrospinning machine to prepare a directionally aligned piezoelectric nanofiber membrane.

[0024] S30: Preparation of a hydrogel solution of methacrylated gelatin-methacrylated heparin.

[0025] S40: Add platelet inhibitors to the hydrogel solution of methacrylamide gelatin-methacrylamide heparin prepared in step S30.

[0026] S50: The piezoelectric nanofiber membrane prepared in step S20 is placed on the blood contact surface of the bioprosthetic valve, and the mixture obtained in step S40 is coated onto the piezoelectric nanofiber membrane.

[0027] S60: The mixture is photocrosslinked to form a coating on the blood-contact surface of the bioprosthetic valve.

[0028] The method for forming a coating on a bioprosthetic valve provided in this application involves adding prepared polylactic acid-glycolic acid copolymer@curcumin nanoparticles to a biodegradable polymer material, polylactic acid (PLLA), and preparing an oriented piezoelectric nanofiber membrane using an electrospinning machine to achieve a stable bond between the nanoparticles and fibers through co-spinning. The piezoelectric nanofiber membrane is then placed on the blood contact surface of the bioprosthetic valve, and a hydrogel solution containing a platelet inhibitor, methacrylamide gelatin-heparin methacrylamide, is coated onto the piezoelectric nanofiber membrane and photocrosslinked to form a stable layered composite coating. This improves the integrity and adhesion stability of the coating under dynamic shear and bending loads. Furthermore, compared to traditional surface treatment processes, it reduces the impact of the coating on the mechanical properties and long-term safety of the valve leaflets. This helps ensure that the bioprosthetic valve possesses comprehensive properties, including early antithrombotic effects, mid-term anti-inflammatory and antioxidant effects, and long-term delay in leaflet calcification and degeneration. It also promotes endothelialization of the bioprosthetic valve and improves its long-term functional stability and biocompatibility.

[0029] In some embodiments, step S10 may further include the following steps: S11: Place a predetermined amount of polylactic acid-glycolic acid copolymer (PLGA) in a predetermined amount of chloroform and stir in an ice-water bath to dissolve the polylactic acid-glycolic acid copolymer.

[0030] S12: Disperse a predetermined amount of curcumin (Cur) in the mixed solution obtained in step S11.

[0031] S13: Prepare a carrier solution by dissolving the carrier solution in the mixed solution obtained in step S12 and performing a membrane emulsification treatment to generate an emulsified aqueous suspension.

[0032] S14: Stir the emulsified aqueous suspension in a vacuum environment to remove chloroform and generate a polylactic acid-hydroxyacetic acid copolymer@curcumin nanoparticle aqueous dispersion.

[0033] S15: Remove excess ions from the polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion and resuspend it in deionized water to obtain polylactic acid-glycolic acid copolymer@curcumin nanoparticles.

[0034] This embodiment, through the above steps, facilitates the preparation of polylactic acid-glycolic acid copolymer@curcumin nanoparticles that meet the requirements, forming a nano-delivery platform loaded with anti-inflammatory and antioxidant active ingredients. This allows the polylactic acid-glycolic acid copolymer to protect and sustain the release of the anti-inflammatory and antioxidant active ingredient curcumin, so that after the bioprosthetic valve is implanted in the heart, it can effectively reduce the accumulation of local reactive oxygen species (ROS), regulate the inflammatory cascade reaction, weaken the driving factors that promote valve leaflet calcification from the source, and delay valve leaflet calcification, thickening, and structural degeneration.

[0035] In some embodiments, in step S11, 50-200 mg of polylactic-co-glycolic acid copolymer (PLGA) can be placed in 5-20 mL of chloroform and stirred in an ice-water bath to dissolve the PLGA. For example, placing 80 mg of PLGA in 8 mL of chloroform facilitates obtaining PLGA@curcumin nanoparticles with uniform particle size.

[0036] In some embodiments, in step S12, 100-500 mg of curcumin (Cur) can be uniformly dispersed in the mixed solution obtained in step S11 using ultrasonic vortexing to obtain a homogeneous mixed solution.

[0037] In some embodiments, step S13 may further include the step of preparing a 1% (w / v) polyvinyl alcohol (PVA) solution and adding sodium chloride to the PVA solution to a molar concentration of 0.05 to obtain a carrier solution. In this embodiment, by configuring the carrier solution as described above, it acts as an emulsifying stabilizer, effectively preventing the aggregation of microspheres in the mixed solution obtained in step S12 by reducing surface tension. Based on this, the product of the carrier solution and the mixed solution is subjected to a membrane emulsification treatment to generate an emulsified aqueous suspension, thereby facilitating the formation of polylactic acid-glycolic acid copolymer microspheres with uniform particle size and distribution, and obtaining polylactic acid-glycolic acid copolymer@curcumin nanoparticles with uniform particle size.

[0038] In some embodiments, in step S13, an SPG membrane emulsification device can be used for membrane emulsification. The SPG pipeline temperature is set to 35°C, the membrane pressure is set to 0.1 MPa, and nitrogen gas is used as the pressurized gas. The membrane is passed through twice at a rate of 0.5 mL / s. Under these conditions, polylactic acid-glycolic acid copolymer@curcumin nanoparticles with the highest yield and uniform particle size can be obtained.

[0039] In some embodiments, in step S14, a rotary evaporator can be used to stir the emulsified aqueous suspension in a vacuum environment at 35°C to remove chloroform and obtain an aqueous dispersion of polylactic acid-glycolic acid copolymer@curcumin nanoparticles.

[0040] In some embodiments, in step S15, excess ions in the polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion can be removed by centrifugation and washing, and then resuspended in deionized water and freeze-dried to obtain polylactic acid-glycolic acid copolymer@curcumin nanoparticles.

[0041] like Figure 1 As shown, Figure 1 The diagram shows the particle size distribution of polylactic acid-glycolic acid copolymer@curcumin nanoparticles according to embodiments of this application. Figure 2 Transmission electron microscopy (TEM) images of polylactic acid-glycolic acid copolymer@curcumin nanoparticles according to embodiments of this application are shown. Figure 1 and Figure 2 It is known that the polylactic acid-glycolic acid copolymer@curcumin nanoparticles prepared by the method provided in the embodiments of this application have similar nanoscale sizes, about 294-295 nm, and have good dispersion stability, which is beneficial for drug delivery.

[0042] In some embodiments, step S20 may further include the following steps: S21: Dissolve polylactic acid (PLLA) of a predetermined molecular weight in hexafluoroisopropanol (HFIP) to generate an electrospinning solution of a predetermined concentration.

[0043] S22: The polylactic acid-hydroxyacetic acid copolymer@curcumin nanoparticles prepared in step S10 are added to the electrospinning solution and then added to the electrospinning machine to generate an oriented fiber membrane.

[0044] S23: Hold the oriented fiber membrane at a predetermined temperature for a predetermined time and allow it to cool naturally to generate an oriented piezoelectric nanofiber membrane.

[0045] In this embodiment, an electrospinning solution was prepared, and the prepared polylactic acid-glycolic acid copolymer@curcumin nanoparticles were added to the electrospinning solution and then fed into an electrospinning machine. Through electrostatic interaction, hydrogen bonds were formed between the two, achieving a stable combination of the nanoparticles and fibers through co-spinning. This allows the oriented piezoelectric nanofiber membrane to generate piezoelectric signals that are beneficial to endothelialization under the periodic mechanical load generated by valve opening and closing or under the action of external ultrasound. Thus, without changing the valve structure, it can synergistically promote the adhesion, migration, and functionalization of endothelial cells with the biomimetic extracellular matrix microenvironment provided by the methacryloyl gelatin-methacrylated heparin hydrogel, improve the continuity and stability of endothelial coverage, and promote the endothelialization of biological valves.

[0046] In some embodiments, in step S21, polylactic acid (PLLA) may also be replaced by a polylactic acid copolymer or a blend containing polylactic acid.

[0047] In some embodiments, in step S21, polylactic acid (PLLA) with a molecular weight of 300,000 is obtained, and it is dissolved in hexafluoroisopropanol (HFIP) by stirring for 2 hours to generate a homogeneous electrospinning solution with a concentration of 10% (w / v).

[0048] In some embodiments, in step S23, the oriented fiber membrane can be kept at 120°C for 4 hours and allowed to cool naturally to complete the annealing process, which is beneficial to improve the crystal phase orientation and piezoelectric properties of polylactic acid (PLLA) and generate an oriented piezoelectric nanofiber membrane.

[0049] In some embodiments, step S20 may further include the following steps: S21': Dissolve polylactic acid (PLLA) of a predetermined molecular weight in hexafluoroisopropanol (HFIP) to generate an electrospinning solution of a predetermined concentration.

[0050] S22': Use the polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion prepared in step S14 as an electrostatic spray solution.

[0051] S23': Electrospinning solution and electrospraying solution are added to the electrospinning machine, and electrospinning and electrospraying are carried out simultaneously under predetermined temperature and humidity conditions to generate an oriented fiber membrane.

[0052] S24': The oriented fiber membrane is held at a predetermined temperature for a predetermined time and then naturally cooled to generate an oriented piezoelectric nanofiber membrane.

[0053] In this embodiment, an electrospinning solution was prepared, and the polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion prepared in step S14 was used as an electrospinning solution to simultaneously perform electrospinning and electrospinning, thereby achieving composite deposition of fibers and nanoparticles. Compared with the method of combining nanoparticles with fibers through co-spinning, the yield of piezoelectric nanofiber membranes is higher, and the nanoparticles can be more uniformly attached to polylactic acid (PLLA). As a result, the oriented piezoelectric nanofiber membrane can generate piezoelectric signals that are more conducive to endothelialization under the periodic mechanical load generated by valve opening and closing or the action of external ultrasound. This is beneficial to further promote the adhesion, migration and functionalization of endothelial cells, improve the continuity and stability of endothelial coverage, and promote the endothelialization of biological valves.

[0054] In some embodiments, in step S21', polylactic acid (PLLA) may also be replaced by a polylactic acid copolymer or a blend containing polylactic acid.

[0055] In some embodiments, in step S21', polylactic acid (PLLA) with a molecular weight of 300,000 is obtained and dissolved in hexafluoroisopropanol (HFIP) by stirring for 2 hours to generate a homogeneous electrospinning solution with a concentration of 10% (w / v).

[0056] In some embodiments, in step S23', the electrospinning solution and the electrospraying solution are added to the electrospinning machine. Electrospinning and electrospraying are performed simultaneously under the conditions of an ambient temperature of about 24°C and a relative humidity of 35%. Both electrospinning and electrospraying use 22G needles. The electrospraying voltage is set to 8kV and the receiving distance is set to 8cm. The electrospinning voltage is set to 12kV and the receiving distance is set to 10cm. The flow rate is set to about 1mL / h and the collector rotation speed is about 2500r / min to form an oriented fiber membrane.

[0057] In some embodiments, in step S24', the oriented fiber membrane can be kept at 120°C for 4 hours and allowed to cool naturally to complete the annealing process. This process is beneficial for improving the crystal phase orientation and piezoelectric properties of polylactic acid (PLLA) and for allowing the polylactic acid-glycolic acid copolymer@curcumin nanoparticles to be more firmly bonded to the surface of polylactic acid (PLLA), thereby generating a stable oriented piezoelectric nanofiber membrane.

[0058] like Figures 3-6 As shown, Figure 3 This document shows a scanning electron microscope (SEM) image of an oriented fiber membrane according to an embodiment of this application. Figure 4 This image shows a piezoelectric microscopy image of an oriented fiber membrane according to an embodiment of this application. Figure 5 This image shows a scanning electron microscope (SEM) image of an oriented piezoelectric nanofiber membrane according to an embodiment of this application. Figure 6 A piezoelectric microscopy image of an oriented piezoelectric nanofiber membrane according to an embodiment of this application is shown. Figures 3-6 It can be seen that after the annealing treatment of the oriented fiber membrane in step S23 or step S24', the resulting oriented piezoelectric nanofiber membrane is characterized by a darker and more uniform color, indicating that the piezoelectric properties of the material are significantly enhanced after annealing. At the same time, the polylactic acid-glycolic acid copolymer@curcumin nanoparticles are more firmly "anchored" to the surface of polylactic acid (PLLA) due to the relaxation and rearrangement of the polymer chains, forming a more stable composite interface.

[0059] In some embodiments, step S30 may further include the following steps: S31: At a predetermined temperature, a predetermined amount of methacryloyl gelatin (GelMA) is dissolved in a predetermined amount of buffer solution to obtain a methacryloyl gelatin solution.

[0060] S32: Dissolve a predetermined amount of heparin methacrylate (HepMA) in a methacryl gelatin solution.

[0061] S33: Add a predetermined amount of photoinitiator to the mixed solution prepared in step S32, stir in the dark until clear, and obtain a hydrogel solution of methacrylamide gelatin-methacrylamide heparin.

[0062] In this embodiment, the above steps facilitate the preparation of a hydrogel solution of methacrylamide gelatin-methacrylamide heparin that meets the requirements. This solution can provide a stable anticoagulant and biomimetic extracellular matrix microenvironment. Combined with platelet inhibitors, it can reduce platelet adhesion activation and coagulation cascade reactions triggered by protein adsorption in the early stage of bioprosthetic valve implantation, thus playing a rapid antithrombotic role. At the same time, in synergy with piezoelectric nanofiber membranes, it can promote the adhesion, migration and functionalization of endothelial cells, and improve the continuity and stability of endothelial coverage.

[0063] In some embodiments, in step S31, 1 g of methacryloyl gelatin (GelMA) can be dissolved in 10 mL of buffer solution at a temperature of 50°C and stirred for 20-30 min to obtain a methacryloyl gelatin solution.

[0064] In some embodiments, in step S32, 100 mg of heparan methacrylate (HepMA) may be added to the methacryloyl gelatin solution and stirred continuously until it is dissolved evenly.

[0065] In some embodiments, in step S33, 25 mg of a photoinitiator, such as lithium acyl phosphate (LAP), can be added to the mixed solution prepared in step S32, and stirred in the dark until clear to obtain a hydrogel solution of methacrylated gelatin-methacrylated heparin.

[0066] In some embodiments, in step S40, the platelet inhibitor may be selected from one or more of aspirin, tirofiban, clopidogrel, or prasugrel.

[0067] In some embodiments, step S50 may further include the step of: mildly activating the blood contact surface of the bioprosthetic valve, such as plasma treatment, hydrophilication treatment, and introducing reactive groups, to increase the hydrophilicity of the blood contact surface of the bioprosthetic valve, thereby enhancing the adhesion of the coating and improving the integrity and adhesion stability of the coating under dynamic shear and bending loads. For example, the bioprosthetic valve may be plasma treated for 30-60 seconds.

[0068] In some embodiments, step S50 may further include the following steps: S51: Determine the blood flushing area in the blood contact surface of the bioprosthetic valve.

[0069] S52: The piezoelectric nanofiber membrane prepared in step S20 is placed on the blood contact surface of the bioprosthetic valve, so that the piezoelectric nanofiber membrane covers the blood flushing area.

[0070] S53: Fixed piezoelectric nanofiber membrane.

[0071] S54: Coat the mixture obtained in step S40 onto a piezoelectric nanofiber membrane.

[0072] In this embodiment, the above steps help to improve the bonding strength between the coating and the bioprosthetic valve, achieving full coverage of the blood flushing area on the blood contact surface of the bioprosthetic valve. This helps to ensure the stability of the bioprosthetic valve's performance and achieve a multi-target integrated synergistic effect of antithrombosis, anti-inflammation, anti-calcification, and endothelialization after implantation in the heart.

[0073] In some embodiments, in step S53, the piezoelectric nanofiber membrane can be fixed by edge limiting, dotted holding, or pre-wetting to effectively prevent its displacement.

[0074] In some embodiments, in step S54, the bioprosthetic valve with the piezoelectric nanofiber membrane fixed thereon can be immersed in the mixture obtained in step S40 and removed at a predetermined speed, such as 0.5-10 mm / s. Alternatively, the mixture obtained in step S40 can be coated onto the surface and / or pores of the piezoelectric nanofiber membrane by means of drop coating, brush coating, scraping coating, spraying, etc., and the excess mixture can be removed after coating to control the thickness and uniformity of the coating.

[0075] In some embodiments, in step S60, an intensity of 35 mw / can be used. The bioprosthetic valve was irradiated with 405nm visible light for 60 seconds to facilitate the formation of a stable coating on the blood-contact surface of the bioprosthetic valve.

[0076] In some embodiments, the bioprosthetic valve may be made of biological or non-biological materials, such as valve materials or pericardial materials from animal tissues, or bioprosthetic valve materials that have undergone one or more of the following treatments: cross-linking treatment, decellularization treatment, and dephospholipid treatment.

[0077] like Figure 7 and Figure 8 As shown, Figure 7 A frontal view of a hydrogel containing methacrylamide gelatin and methacrylamide heparin, according to an embodiment of this application, is shown. Figure 8A frontal view showing a hydrogel of methacrylamide gelatin-heparin methacrylamide, an embodiment of this application, after photocrosslinking treatment. According to... Figure 7 and Figure 8 It can be seen that after photocrosslinking treatment, the hydrogel of methacrylated gelatin-methacrylated heparin is transformed into a semi-solid phase, and its basic physicochemical properties meet the requirements.

[0078] like Figure 9 and Figure 10 As shown, Figure 9 The image shown is a scanning electron microscope image of an uncoated bioprosthetic valve according to an embodiment of this application. Figure 10 A scanning electron microscope image of a coated bioprosthetic valve according to an embodiment of this application is shown. Figure 9 and Figure 10 It can be seen that the original substrate structure of the bioprosthetic valve 10 is uniformly covered by a continuous and dense coating 20. The surface of the coating 20 exhibits a more uniform and smooth morphology, and the micro-roughness of the original substrate structure of the bioprosthetic valve 10 is significantly reduced. This indicates that the coating 20 has been successfully and completely deposited on the substrate of the bioprosthetic valve 10.

[0079] like Figure 11 As shown, Figure 11 The Fourier transform infrared (FTIR) spectra of the bioprosthetic valve before and after coating formation according to an embodiment of this application are shown. The FTIR results show that the curve trends are basically consistent, indicating that the coating does not significantly change the skeletal structure of the bioprosthetic valve. Furthermore, the bioprosthetic valve after coating formation exhibits typical biopolymer or biomolecular characteristics, including the presence of chemical bonds such as C–H, C=O, and O–H / N–H. Additionally, the coating shows enhancement in hydrophilic and polar functional groups, such as O–H and C=O, indicating that the surface properties of the bioprosthetic valve, such as wettability and biological activity, are significantly improved.

[0080] like Figure 12 and Figure 13 As shown, Figure 12 This diagram illustrates a contact angle test of an uncoated bioprosthetic valve according to an embodiment of this application. Figure 13 The diagram illustrates a contact angle test of a coated bioprosthetic valve according to an embodiment of this application. The average contact angle of the uncoated bioprosthetic valve is 60.007°, while the average contact angle of the coated bioprosthetic valve is 77.07°. A smaller contact angle indicates better hydrophilicity, demonstrating that the hydrophilicity of the bioprosthetic valve does not deteriorate after coating; its original hydrophilicity is preserved.

[0081] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0082] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A biological valve coating, characterized in that, The coating comprises curcumin-loaded polylactic acid-glycolic acid copolymer@curcumin nanoparticles, platelet inhibitors, piezoelectric nanofiber membranes, and a hydrogel of methacryloyl gelatin-heparin methacrylamide (GelMA-HepMA).

2. The bioprosthetic valve coating according to claim 1, characterized in that, The mass ratio of the polylactic acid-glycolic acid copolymer@curcumin nanoparticles, the platelet inhibitor, the piezoelectric nanofiber membrane, and the methacryloyl gelatin-heparin methacrylamide (GelMA-HepMA) hydrogel is 20:1:20:

225.

3. A method for forming a coating on a biological valve, characterized in that, Includes the following steps: S10: Preparation of polylactic acid-glycolic acid copolymer@curcumin nanoparticles loaded with curcumin; S20: The polylactic acid-glycolic acid copolymer@curcumin nanoparticles prepared in step S10 are added to the biodegradable polymer material polylactic acid (PLLA) and then added to an electrospinning machine to prepare a directionally aligned piezoelectric nanofiber membrane. S30: Preparation of a hydrogel solution of methacrylated gelatin-methacrylated heparin; S40: Add platelet inhibitors to the hydrogel solution of methacrylamide gelatin-methacrylamide heparin prepared in step S30; S50: The piezoelectric nanofiber membrane prepared in step S20 is placed on the blood contact surface of the bioprosthetic valve, and the mixture obtained in step S40 is coated on the piezoelectric nanofiber membrane; S60: The mixture is subjected to photocrosslinking treatment to form a coating on the blood contact surface of the bioprosthetic valve.

4. The method according to claim 3, characterized in that, Step S10 also includes the following steps: S11: Place a predetermined amount of polylactic acid-glycolic acid copolymer (PLGA) in a predetermined amount of chloroform and stir in an ice-water bath to dissolve the polylactic acid-glycolic acid copolymer; S12: Disperse a predetermined amount of curcumin (Cur) in the mixed solution obtained in step S11; S13: Prepare a carrier solution by dissolving the carrier solution in the mixed solution obtained in step S12 and performing a membrane emulsification treatment to generate an emulsified aqueous suspension. S14: Stir the emulsified aqueous suspension in a vacuum environment to remove chloroform and generate a polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion; S15: Remove excess ions from the polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion and resuspend it in deionized water to obtain the polylactic acid-glycolic acid copolymer@curcumin nanoparticles.

5. The method according to claim 4, characterized in that, Step S13 also includes the following steps: A polyvinyl alcohol (PVA) solution with a mass-volume ratio of 1% was prepared, and sodium chloride was added to the PVA solution to a molar concentration of 0.05 to obtain a carrier solution.

6. The method according to claim 4, characterized in that, In step S13, an SPG membrane emulsification device is used for membrane emulsification. The SPG pipeline temperature is set to 35℃, the membrane pressure is set to 0.1MPa, and nitrogen is used as the pressurized gas. The membrane is passed through twice at a rate of 0.5mL / s.

7. The method according to claim 3, characterized in that, Step S20 also includes the following steps: S21: Dissolve polylactic acid (PLLA) of a predetermined molecular weight in hexafluoroisopropanol (HFIP) to generate an electrospinning solution of a predetermined concentration; S22: The polylactic acid-glycolic acid copolymer@curcumin nanoparticles prepared in step S10 are added to the electrospinning solution and then added to the electrospinning machine to generate an oriented fiber membrane; S23: The oriented fiber membrane is kept at a predetermined temperature for a predetermined time and then naturally cooled to generate the oriented piezoelectric nanofiber membrane.

8. The method according to claim 4, characterized in that, Step S20 also includes the following steps: S21': Dissolve polylactic acid (PLLA) of a predetermined molecular weight in hexafluoroisopropanol (HFIP) to generate an electrospinning solution of a predetermined concentration; S22': Use the polylactic acid-glycolic acid copolymer@curcumin nanoparticle aqueous dispersion prepared in step S14 as an electrostatic spray solution; S23': The electrospinning solution and the electrospraying solution are added to the electrospinning machine, and electrospinning and electrospraying are carried out simultaneously under predetermined temperature and humidity conditions to generate an oriented fiber membrane; S24': The oriented fiber membrane is kept at a predetermined temperature for a predetermined time and then naturally cooled to generate the oriented piezoelectric nanofiber membrane.

9. The method according to claim 3, characterized in that, Step S30 also includes the following steps: S31: At a predetermined temperature, a predetermined amount of methacrylamide gelatin (GelMA) is dissolved in a predetermined amount of buffer solution to obtain a methacrylamide gelatin solution; S32: Dissolve a predetermined amount of heparin methacrylate (HepMA) in the methacryl gelatin solution; S33: Add a predetermined amount of photoinitiator to the mixed solution prepared in step S32, stir in the dark until clear, and obtain the hydrogel solution of methacrylamide gelatin-methacrylamide heparin.

10. The method according to claim 3, characterized in that, The S50 step also includes the following steps: S51: Determine the blood flushing area in the blood contact surface of the bioprosthetic valve; S52: The piezoelectric nanofiber membrane prepared in step S20 is disposed on the blood contact surface of the bioprosthetic valve, so that the piezoelectric nanofiber membrane covers the blood flushing area; S53: Fix the piezoelectric nanofiber membrane; S54: Coat the mixture obtained in step S40 onto the piezoelectric nanofiber membrane.

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