Ultrasonic response anisotropic electrostatic spinning patch and preparation method thereof

Abstract

The invention discloses an anisotropic electrostatic spinning patch with ultrasonic response and a preparation method thereof, a fiber membrane with a controllable anisotropic structure is constructed by a biodegradable polymer, antibacterial nanoparticles and a photoinitiator system through a step-by-step directional electrostatic spinning process, so that the mechanical matching property of the fiber membrane is improved; cell growth can be directionally guided and tissue regeneration can be accelerated by combining the piezoelectric material characteristics of the introduced biodegradable polymer with piezoelectric characteristics and electric field stimulation induced by the fiber topological structure; meanwhile, a zwitterionic coating is generated on the surface of the fiber membrane in situ by utilizing a single-sided photocuring technology, and an anti-adhesion function is realized on the single side of the fiber membrane. Furthermore, the soft tissue repair patch which has multiple functions of adjustable mechanical property, infection resistance, adhesion resistance and the like and has better structural mechanical suitability, function integration and tissue regeneration guiding capability is prepared by adopting the anisotropic electrostatic spinning patch with ultrasonic response.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical materials, and particularly relates to an ultrasonic response anisotropic electrospun patch and a preparation method thereof. BACKGROUND

[0002] In the field of soft tissue repair, various soft tissues in the human body, such as tendons, perineurium, muscles, skin and spinal dura, exhibit obvious anisotropic characteristics in structure, that is, different mechanical properties and biological functions in different directions; for example, tendons and nerve tissues have high tensile strength along the fiber direction, but are relatively soft in the vertical direction, and abdominal wall tissues also exhibit significant mechanical response differences in different directions; the existence of such anisotropy is closely related to the physiological function of the tissue, and also poses greater challenges to the repair method after injury or defect. Traditional homogeneous or isotropic repair materials are difficult to match the structure and mechanical properties of the original tissue in multiple directions, often leading to disordered structure of the healing tissue, stress concentration or incomplete functional recovery. Especially in applications requiring guided cell migration, regulation of force transmission or simulation of the microenvironment of the natural tissue, it is of great significance to construct an anisotropic soft tissue repair patch with direction selectivity.

[0003] Generally, the development of anisotropic soft tissue repair patches faces the dual challenges of biomechanical compatibility and biological function adaptability, and in the prior art, certain explorations have been made on the use of compression and tensile force of anisotropic hydrogel patches, directional crystallization, ion diffusion and photolithography, and knitting and weaving technology of fabric patches to prepare anisotropic soft tissue repair patches, however, the anisotropy ratio of most soft tissue repair patches prepared based on such methods is limited to the range of 1-3, which cannot meet the anisotropy requirements of various soft tissues, such as the anisotropy ratio of abdominal wall tissue, which can be as high as 1-9, so that the existing soft tissue repair patches are affected by the anisotropy ratio limitation, affecting the integration of soft tissues. At the same time, the soft tissue repair patch also needs to realize the dual physiological functions of promoting cell proliferation and preventing tissue adhesion, and the commercially available PCO patch successfully realizes the asymmetric functions of promoting cell proliferation and preventing tissue adhesion by constructing a Janus structure, including a double layer of polyester and collagen, however, such double-layer design is prone to the risks of weak interfacial bonding force and mechanical mismatch, thereby leading to poor delamination, displacement and tissue integration, affecting the soft tissue repair effect.

[0004] Further, the repair of soft tissue injury is a complex biological process, which usually includes multiple stages such as inflammatory response, cell proliferation and migration, and tissue regeneration and remodeling. Most existing treatment strategies mainly rely on the passive healing process of the tissue, and less actively regulate the endogenous cell behavior to accelerate regeneration. In recent years, electrical stimulation therapy has shown significant advantages in accelerating tissue repair because it can simulate and enhance the natural electric field in the tissue injury area. Wireless electrical stimulation treatment, such as ultrasound, radio frequency and electromagnetic field, as a new treatment method with non-invasive, strong targeting and low risk of infection, has gradually attracted attention. Among them, ultrasound is particularly suitable for deep tissue repair because its energy can penetrate deep tissues and focus precisely on the target area. Piezoelectric materials have the ability to convert mechanical energy into electrical signals, providing key support for the construction of wireless and self-powered electrical stimulation systems. Materials such as polylactic acid (PLLA), polylactide-co-lactic acid (PLCL) and polyvinylidene fluoride (PVDF) not only have good piezoelectric properties, but also have excellent biocompatibility and processing adaptability, and have been widely used in the fields of nerve, skin, bone and soft tissue repair.

[0005] Therefore, it is urgent to develop a multifunctional anisotropic soft tissue repair patch with good biomechanical compatibility and biological function adaptability, which can generate piezoelectric electric field, promote cell migration and endogenous active repair by combining with ultrasound wireless activation technology. SUMMARY

[0006] The present application aims to overcome at least one of the deficiencies of the prior art, and provides a piezoelectric electrospun patch for preventing adhesion, resisting infection and promoting healing, as well as a preparation method and application thereof, to solve the problems of existing abdominal wall defect patches, such as easy infection, tissue adhesion and hernia recurrence, while realizing multiple functions such as mechanical matching, promoting cell proliferation and angiogenesis, and preventing adhesion of wound tissue.

[0007] The technical scheme adopted by the present application is to provide a preparation method of an ultrasound-responsive anisotropic electrospun patch, comprising the following steps: S1: blending and dissolving a biodegradable polymer with piezoelectric properties, antibacterial nanoparticles and a photoinitiator in an organic solvent to obtain a spinning precursor solution; S2: dividing the spinning precursor solution prepared in step S1 into two parts with different proportions: A solution and B solution. First, electrospun the A solution along the first direction to obtain a first direction fiber film. Then, rotate the collection substrate to an angle in the second direction, and electrospun the B solution along the second direction to form a second direction fiber film on the surface of the first direction fiber film, forming an electrospun fiber film. The second direction has an orientation difference with the first direction; S3: soaking the fiber membrane prepared in step S2 in a zwitterionic solution, and then performing single-side ultraviolet irradiation to form a coating layer in situ on one side of the fiber membrane; S4: vacuum drying the fiber membrane after ultraviolet irradiation treatment to obtain the ultrasonic-responsive anisotropic electrospun patch.

[0008] In the technical solution, an ultrasonic-responsive anisotropic electrospun patch is prepared by multiple electrospinning and in-situ photopolymerization technology of a biodegradable polymer with piezoelectric properties, antibacterial nanoparticles and a photoinitiator system. The anisotropic structure with controllable fiber arrangement direction is constructed by a step-by-step directional electrospinning process. Thus, the mechanical matching of the ultrasonic-responsive anisotropic electrospun patch is improved, and the piezoelectric material properties of the biodegradable polymer with piezoelectric properties are introduced to combine the electric field stimulation induced by the fiber topological structure to directionally guide cell growth and accelerate tissue regeneration. At the same time, the zwitterionic coating layer is generated in situ on the surface of the fiber membrane by single-side photopolymerization technology, realizing the anti-adhesion function on one side of the ultrasonic-responsive anisotropic electrospun patch. Moreover, the fiber membrane is only soaked in a zwitterionic solution on one side and cured by ultraviolet irradiation, and the coating layer grows in situ on one side of the fiber surface, further enhancing the directionality of the fiber membrane in functional expression and realizing the anisotropic regulation of mechanics and interface behavior, so that the prepared ultrasonic-responsive anisotropic electrospun patch is suitable for use as a soft tissue repair patch. Further, the preparation method only needs to use electrospinning and in-situ photopolymerization technology to construct a multi-level composite structure, which has high process integration and is easy to scale up and clinically translate.

[0009] Specifically, when the prepared ultrasonic-responsive anisotropic electrospun patch is used as a soft tissue repair patch, the soft tissue repair patch integrates the triple functions of anti-adhesion, anti-infection and pro-healing. The biodegradable polymer with piezoelectric properties can generate a piezoelectric electric field in combination with ultrasonic wireless activation technology, thereby effectively promoting the migration and proliferation of fibroblasts along the electric field direction and accelerating the active repair of tissue defects. Secondly, the prepared ultrasonic-responsive anisotropic electrospun patch has a wide anisotropic regulation range by regulating the fiber diameter based on the gradient electrospinning process, so that the anisotropy ratio of the prepared ultrasonic-responsive anisotropic electrospun patch can be optimized by mechanical simulation, the mechanical requirements of different soft tissue repair areas can be accurately matched, and the problem of poor tissue healing caused by stress shielding of traditional patches is solved. Further, the zwitterionic coating layer formed by single-side photopolymerization endows the prepared ultrasonic-responsive anisotropic electrospun patch with a super-hydrophilic interface, reducing the risk of adhesion of the wound. Further, the incorporation of antibacterial nanoparticles in the ultrasonic-responsive anisotropic electrospun patch provides broad-spectrum antibacterial effect. The piezoelectric effect combined with the electric field stimulation induced by the fiber topological structure can directionally guide cell growth and accelerate tissue regeneration.

[0010] Further, in the step S1, the mass concentration of the biodegradable polymer in the organic solvent is 8%-25%, the addition amount of the antibacterial nanoparticles is 1%-15% of the mass of the biodegradable polymer, and the addition amount of the photoinitiator is 0.1%-10% of the mass of the biodegradable polymer.

[0011] In the technical solution, the proportion of the antibacterial nanoparticles directly determines the antibacterial ability of the patch. When the proportion is low, the bacteriostatic effect is not obvious, and when the proportion is high, the fiber forming and mechanical properties may be affected. The proportion of the photoinitiator affects the subsequent ultraviolet curing efficiency and the bonding degree of the coating and the fiber substrate. If the proportion is too low, the coating may not be polymerized sufficiently, and if the proportion is too high, free radical side reactions may occur, affecting the structural stability. By controlling the matching parameters between the antibacterial nanoparticles, the photoinitiator, and the biodegradable polymer with piezoelectric properties, the structural stability, the functional layer adhesion effect, and the antibacterial performance of the ultrasonic-responsive anisotropic electrospun patch when used as a soft tissue repair patch can be optimized.

[0012] Preferably, the mass concentration of the biodegradable polymer with piezoelectric properties in the organic solvent is preferably 10%, and the addition amount of the photoinitiator is 1% of the mass of the biodegradable polymer. When the mass ratio of the photoinitiator is 1%, after ultraviolet irradiation treatment, a relatively uniform, stable, and well-adhesive coating structure can be obtained in cooperation with the zwitterionic solution.

[0013] Preferably, in the step S1, the biodegradable polymer includes one or more combinations of polylactic-co-poly-caprolactone (PLCL), poly-L-lactic acid (PLLA), poly-lactic-co-glycolic acid (PLGA), poly-caprolactone (PCL), or polyethylene glycol (PEG) modified gelatin.

[0014] Preferably, in the step S1, the antibacterial nanoparticles are nano-zinc oxide particles.

[0015] Further, in the step S2, the anisotropy ratio of the ultrasonic-responsive anisotropic electrospun patch is adjusted by adjusting the stacking ratio of the first direction fiber film and the second direction fiber film. The stacking ratio of the first direction fiber film and the second direction fiber film is 10:1 to 1:1, the anisotropy ratio of the obtained ultrasonic-responsive anisotropic electrospun patch is 1:1 to 14:1, and the orientation angle difference between the first direction and the second direction is 0°-90°. Preferably, in the first direction, the drum collection direction is consistent with the spinning orientation direction, and the orientation angle difference between the first direction and the second direction is preferably 90°.

[0016] In the technical solution, the anisotropy ratio of the ultrasonic response anisotropic electrospun patch is adjusted by controlling the stacking ratio of the first direction fiber film and the second direction fiber film, preferably, in the electrospinning process, a first layer of oriented fiber film is prepared along the first direction, and then the collecting substrate is rotated to the second direction to spin the second layer of fiber, by accurately controlling the stacking ratio of the two layers of fiber 10:1 to 1:1, the anisotropy ratio of the patch is flexibly adjusted in the range of 1:1 to 14:1, through the design of the multi-level oriented structure, the patch can accurately match the anisotropy characteristics of the target tissue by adjusting the proportion of the dominant fiber layer according to the tissue repair needs, such as the mechanical difference of different areas of the abdominal wall, so as to improve the mechanical compatibility and reduce the stress shielding risk.

[0017] Further, in the step S2, the parameters of electrospinning are set as follows: the receiver rotating speed is 100-2000 rpm, the spinning voltage is 15-30 kV, the receiving distance is 10-25 cm, and the environmental humidity is controlled to be not more than 40%.

[0018] Further, in the step S3, the zwitterionic solution includes one or more combinations of 2-methacryloyloxyethyl phosphorylcholine, sulfobetaine methacrylate or carboxybetaine methacrylate.

[0019] Another object of the present application is to provide an ultrasonic response anisotropic electrospun patch prepared by the above-mentioned preparation method for use in soft tissue repair patches. Specifically, the wound surface of the soft tissue repair patch can be located in the soft tissue area of the abdominal wall, tendon, nerve bundle membrane, skin, spinal dura mater, etc.

[0020] Preferably, the soft tissue repair patch is one or more of an abdominal wall hernia repair patch, a traumatic tissue defect repair patch or a joint cartilage repair patch.

[0021] Compared with the prior art, the present application has the following advantages: 1. A preparation method of an ultrasonic-responsive anisotropic electrospun patch, an ultrasonic-responsive anisotropic electrospun patch is prepared by multiple electrospinning and in-situ photopolymerization technology of biodegradable polymers with piezoelectric properties, antibacterial nanoparticles and photoinitiator system, and an anisotropic structure with controllable fiber arrangement direction is constructed by a step-by-step directional electrospinning process; thereby improving the mechanical matching of the ultrasonic-responsive anisotropic electrospun patch, and through the piezoelectric material properties of the biodegradable polymers with piezoelectric properties introduced, combined with the electric field stimulation induced by the fiber topological structure, the cell growth can be directed and the tissue regeneration can be accelerated; at the same time, a zwitterionic coating is generated in-situ on the surface of the fiber membrane by using single-sided photopolymerization technology, and the anti-adhesion function is realized on one side of the ultrasonic-responsive anisotropic electrospun patch, and the fiber membrane is only soaked in zwitterionic solution on one side and cured by ultraviolet light, and the coating grows in-situ on one side of the fiber surface, thereby further enhancing the directionality of the fiber membrane in functional expression, realizing the anisotropic regulation of mechanics and interface behavior, so that the prepared ultrasonic-responsive anisotropic electrospun patch is suitable for use as a soft tissue repair patch. Further, this preparation method only needs to use electrospinning and in-situ photopolymerization technology to construct a multi-level composite structure, and the process integration degree is high, which is easy to scale up and clinically translate.

[0022] 2. The application of an ultrasonic-responsive anisotropic electrospun patch as a soft tissue repair patch, the formed soft tissue repair patch integrates the functions of anti-adhesion, anti-infection and healing promotion: specifically, the biodegradable polymers in the soft tissue repair patch can generate a piezoelectric electric field in combination with ultrasonic wireless activation technology, thereby effectively promoting the migration and proliferation of fibroblasts along the electric field direction and accelerating the active repair of tissue defects; secondly, the prepared ultrasonic-responsive anisotropic electrospun patch has a wide anisotropic regulation range based on the gradient electrospinning process to regulate the fiber diameter, thereby the anisotropy ratio of the prepared ultrasonic-responsive anisotropic electrospun patch can be optimized by mechanical simulation, the mechanical requirements of different soft tissue repair areas can be accurately matched, and the problem of poor tissue healing caused by stress shielding of traditional patches is solved; further, the zwitterionic coating formed by single-sided photopolymerization endows the prepared ultrasonic-responsive anisotropic electrospun patch with a super-hydrophilic interface, reducing the risk of adhesion of the wound surface. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Fluorescence microscope images of the coated side (a) and the uncoated side (b) of the JPLCL / ZnO patch prepared in Example 1.

[0024] Figure 2The output voltage curves of the JPLCL / ZnO patch prepared in Example 1 and the JPLCL patch prepared in Example 6 under the condition of the ultrasonic intensity fixed at 0.5 W / cm2and the pulse duty cycle set at 10%, 20%, 50% and 100%, respectively.

[0025] Figure 3 The output voltage curves of the JPLCL / ZnO patch prepared in Example 1 under the condition of the pulse duty cycle fixed at 50% and the ultrasonic intensity set at 0.1 W / cm2, 0.2 W / cm2, 0.3 W / cm2, 0.4 W / cm2and 0.5 W / cm2, respectively.

[0026] Figure 4 The scanning electron microscope (SEM) surface morphology and fiber diameter distribution of the coated and uncoated surfaces of the JPLCL patch prepared in Example 6.

[0027] Figure 5 The scanning electron microscope (SEM) surface morphology and fiber diameter distribution of the coated and uncoated surfaces of the JPLCL / ZnO patch prepared in Example 1.

[0028] Figure 6 The stress-strain curves of the JPLCL / ZnO patch prepared in Example 1 and the JPLCL patch prepared in Example 6, in which the loading direction is parallel or perpendicular to the fiber orientation direction, respectively.

[0029] Figure 7 The antibacterial performance test results of the JPLCL / ZnO patch prepared in Example 1.

[0030] Figure 8 The stress-strain curves of the JPLCL / ZnO patches prepared in Examples 1-4 with different orientation stacking structures. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed description is merely exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0032] It is also important to note that the terms "comprises", "comprising", "includes", "including", "contains", "containing" or variations thereof herein, do not specify an exhaustive or complete list of components or features as used by those skilled in the art.

[0033] The application will be further described in conjunction with specific examples. The following examples are only intended to explain the application, but not to limit the application. The test samples and test procedures used in the following examples include the following (if the specific conditions of the experiments are not specified in the examples, the general conditions are used or the conditions recommended by the reagent company; the reagents, consumables, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0034] Example 1 The present embodiment provides a preparation method of an ultrasonic-responsive anisotropic electrospun patch, comprising the following steps: S1: 8 g, 10% (w / v) of PLCL, 0.08 g, 1% (w / w) of I-2959 and 0.4 g, 5% (w / w) of ZnO nanoparticles are added into HFIP solvent, and stirred until completely dissolved to prepare a spinning precursor solution; S2: the spinning precursor solution prepared in step S1 is divided into two parts with a ratio of 10:1, i.e. A solution and B solution. The A solution is first spun in the 0° direction under the condition that the rotating speed of the drum is 1000 rpm, and a first layer of PLCL / ZnO fiber membrane is collected in a certain volume; then the aluminum foil is rotated by 90°, and the B solution is used to continue electrospinning in the 90° direction to obtain a PLCL / ZnO bidirectional oriented fiber membrane; S3: the bidirectional oriented fiber membrane prepared in step S2 is placed in a 25°C vacuum drying box for drying for 24 hours to remove residual solvent; then a 10% (w / v) 2-methacryloyloxyethyl phosphorylcholine (MPC) aqueous solution is prepared, the dried bidirectional oriented fiber membrane is completely immersed in the MPC solution on one side, and is irradiated under a UV curing lamp with a power of 48 W for 20 min to form an amphoteric ion coating on the surface of the bidirectional oriented fiber membrane in situ; S4: the bidirectional oriented fiber membrane with the amphoteric ion coating on one side is washed with deionized water for 5 times, and is dried again in a 25°C vacuum drying box to obtain a final ultrasonic-responsive anisotropic electrospun patch, i.e. a JPLCL / ZnO patch.

[0035] Example 2 The present embodiment provides a preparation method of an ultrasonic-responsive anisotropic electrospun patch, comprising the following steps: S1: 8 g, 10% (w / v) of PLCL, 0.08 g, 1% (w / w) of I-2959 and 0.4 g, 5% (w / w) of ZnO nanoparticles are added into HFIP solvent, and stirred until completely dissolved to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 is divided into two parts in a ratio of 5:1, A solution and B solution. The A solution is first spun in the 0° direction under the condition that the roller rotates at 1000 rpm, and a certain volume is collected to form a first layer of PLCL / ZnO fiber membrane. Then the aluminum foil is rotated by 90°, and the B solution is used to continue electrospinning in the 90° direction to obtain a PLCL / ZnO bidirectional oriented fiber membrane; S3: The bidirectional oriented fiber membrane prepared in step S2 is placed in a 25°C vacuum drying oven for 24 hours to remove residual solvent; then a 10% (w / v) 2-methacryloyloxyethyl phosphorylcholine (MPC) aqueous solution is prepared, and the dried bidirectional oriented fiber membrane is completely immersed in the MPC solution on one side, and is irradiated under a UV curing lamp with a power of 48 W for 20 min to form an amphoteric ion coating on the surface of one side of the bidirectional oriented fiber membrane in situ photocuring; S4: The bidirectional oriented fiber membrane with amphoteric ion coating on one side is washed with deionized water for 5 times, and is dried again in a 25°C vacuum drying oven to obtain the final ultrasound-responsive anisotropic electrospun patch, i.e. JPLCL / ZnO patch.

[0036] Example 3 The present embodiment provides a preparation method of an ultrasound-responsive anisotropic electrospun patch, comprising the following steps: S1: 8 g, 10% (w / v) of PLCL, 0.08 g, 1% (w / w) of I-2959 and 0.4 g, 5% (w / w) of ZnO nanoparticles are added into HFIP solvent, and stirring is performed until complete dissolution to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 is divided into two parts in a ratio of 3:1, A solution and B solution. The A solution is first spun in the 0° direction under the condition that the roller rotates at 1000 rpm, and a certain volume is collected to form a first layer of PLCL / ZnO fiber membrane. Then the aluminum foil is rotated by 90°, and the B solution is used to continue electrospinning in the 90° direction to obtain a PLCL / ZnO bidirectional oriented fiber membrane; S3: The bidirectional oriented fiber membrane prepared in step S2 is placed in a 25°C vacuum drying oven for 24 hours to remove residual solvent; then a 10% (w / v) 2-methacryloyloxyethyl phosphorylcholine (MPC) aqueous solution is prepared, and the dried bidirectional oriented fiber membrane is completely immersed in the MPC solution on one side, and is irradiated under a UV curing lamp with a power of 48 W for 20 min to form an amphoteric ion coating on the surface of one side of the bidirectional oriented fiber membrane in situ photocuring; S4: The bidirectional oriented fiber membrane with the zwitterionic coating on one side surface was washed with deionized water for 5 times and dried again in a vacuum drying oven at 25°C to obtain the final ultrasonic-responsive anisotropic electrospun patch, i.e. the JPLCL / ZnO patch.

[0037] Example 4 The present example provides a method for preparing an ultrasonic-responsive anisotropic electrospun patch, comprising the following steps: S1: 8 g of 10% (w / v) PLCL, 0.08 g of 1% (w / w) I-2959 and 0.4 g of 5% (w / w) ZnO nanoparticles were added into HFIP solvent and stirred until completely dissolved to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 was divided into two parts in a ratio of 1:1, i.e. solution A and solution B. Solution A was first spun in a 0° direction at a drum rotation speed of 1000 rpm, and a certain volume of the first layer of PLCL / ZnO fiber membrane was collected. Then the aluminum foil was rotated by 90°, and electrospinning was continued in a 90° direction using solution B to obtain a PLCL / ZnO bidirectional oriented fiber membrane; S3: The bidirectional oriented fiber membrane prepared in step S2 was dried in a vacuum drying oven at 25°C for 24 hours to remove residual solvent. Then a 10% (w / v) 2-methacryloyloxyethyl phosphorylcholine (MPC) aqueous solution was prepared, and the dried bidirectional oriented fiber membrane was completely immersed in the MPC solution on one side, and was irradiated under a UV curing lamp with a power of 48 W for 20 min to form a zwitterionic coating on the side surface of the bidirectional oriented fiber membrane in situ by photo-curing; S4: The bidirectional oriented fiber membrane with the zwitterionic coating on one side surface was washed with deionized water for 5 times and dried again in a vacuum drying oven at 25°C to obtain the final ultrasonic-responsive anisotropic electrospun patch, i.e. the JPLCL / ZnO patch.

[0038] Example 5 The present example provides a method for preparing a JBPLCL patch, comprising the following steps: S1: 8 g of 10% (w / v) PLCL was added into HFIP solvent and stirred until completely dissolved to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 was electrospun under a drum at a speed of 500 rpm, and the obtained PLCL fiber membrane was dried in a vacuum oven at 25°C; S3: 10% (w / v) benzophenone was weighed and dissolved in absolute ethanol to prepare a photoinitiating solution; the solution was poured into a culture dish to completely immerse the PLCL fiber membrane prepared in S2, and then placed under a UV curing lamp with a power of 48 W for irradiation for 20 min; after photocuring, the fiber membrane was washed with deionized water for at least 5 times; S4: The fiber membrane washed in S3 was dried in a vacuum oven at 25°C to obtain a JBPLCL patch.

[0039] Example 6 The present example provides a preparation method of a JPLCL patch, comprising the following steps: S1: 8 g, 10% (w / v) of PLCL and 0.08 g, 1% (w / w) of I-2959 were added into a HFIP solvent, and stirred until completely dissolved to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 was electrospun under a roller at 1500 rpm, and the obtained JPLCL fiber membrane was dried in a vacuum oven at 25°C; S3: A 10% (w / v) 2-methacryloyloxyethyl phosphorylcholine (MPC) aqueous solution was prepared, and the dried JPLCL fiber membrane was completely immersed in the MPC solution and placed under a UV curing lamp with a power of 48 W for irradiation for 20 min; after photocuring, the fiber membrane was washed with deionized water for at least 5 times; S4: The fiber membrane washed in S3 was dried in a vacuum oven at 25°C to obtain a JPLCL patch.

[0040] Example 7 The present example provides a preparation method of a JBPLCL / ZnO patch, comprising the following steps: S1: 8 g, 10% (w / v) of PLCL and 0.4 g, 5% (w / w) of ZnO nanoparticles were added into a HFIP solvent, and stirred until completely dissolved to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 was electrospun under a roller at 2000 rpm, and the obtained PLCL / ZnO fiber membrane was dried in a vacuum oven at 25°C; S3: 10% (w / v) benzophenone was weighed and dissolved in absolute ethanol to prepare a photoinitiating solution; the solution was poured into a culture dish to completely immerse the PLCL / ZnO fiber membrane prepared in S2, and then placed under a UV curing lamp with a power of 48 W for irradiation for 20 min; after photocuring, the fiber membrane was washed with deionized water for at least 5 times; S4: The fiber membrane washed in S3 was dried in a vacuum oven at 25°C to obtain a JBPLCL / ZnO patch.

[0041] Example 8 The present example provides a method for preparing a JPLCL / ZnO patch, comprising the following steps: S1: 8 g, 10% (w / v) of PLCL and 0.08 g, 1% (w / w) of I-2959 and 0.4 g, 5% (w / w) of ZnO nanoparticles are added into HFIP solvent, stirred until completely dissolved, to prepare a spinning precursor solution; S2: The spinning precursor solution prepared in step S1 is electrospun under a roller at 1000 rpm, and the obtained PLCL / ZnO fiber membrane is dried in a vacuum oven at 25°C; S3: A 10% (w / v) aqueous solution of 2-methacryloyloxyethyl phosphorylcholine (MPC) is prepared, and the dried PLCL / ZnO fiber membrane is completely immersed in the MPC solution and irradiated under a UV curing lamp with a power of 48 W for 20 min; after photocuring, the fiber membrane is washed with sufficient deionized water for at least 5 times; S4: The fiber membrane washed in S3 is dried in a vacuum oven at 25°C to obtain a PLCL / ZnO patch.

[0042] Effect Example 1 The present effect example uses a fluorescence microscope to observe the JPLCL / ZnO patch prepared in Example 1, to visualize the spatial relationship between the fibers and the coating.

[0043] The specific test method is as follows: the sample of Example 1 is subjected to fluorescent dyeing treatment, in which Nile red is used to dye the fiber skeleton, and fluorescein sodium is used to dye the PMPC coating, and then observed under a fluorescence microscope. The observation results are shown in Figure 1 As shown in FIG. 1, on the top surface of Example 1, the red-dyed fiber skeleton and the green-dyed coating can be clearly observed, and the green-dyed coating closely adheres to the red-dyed fiber skeleton (a), indicating that the PMPC coating is successfully attached to the surface of the single fiber. In contrast, only the red-dyed fiber skeleton is observed on the bottom surface (b), further confirming the Janus structure of Example 1. Figure 1 Figure 1

[0044] Effect Example 2 The present effect example uses a Rigol DS1102E oscilloscope to test the output voltage of the JPLCL / ZnO patch prepared in Example 1 and the JPLCL patch prepared in Example 6 under ultrasonic stimulation, to characterize their electrical output performance.

[0045] ​​The specific test method is as follows: the sample of the JPLCL / ZnO patch prepared in Example 1 and the sample of the JPLCL patch prepared in Example 6 are respectively cut into a circle with a diameter of 10 mm, clamped between a pair of copper electrodes, and sealed with Ecoflex to assemble a test device. The assembled patch device is placed under an ultrasonic transducer, and an ultrasonic stimulation is generated using a Mettler Sonicator® 740 digital therapeutic ultrasound system, with a frequency of 1 MHz, a pulse duty cycle set to 50%, and an ultrasonic intensity of 0.5 W / cm². The output voltage is measured in real time by a Rigol DS1102E oscilloscope. The test results are shown in Figure 2 Figure 6b, and the output voltage of the JPLCL / ZnO patch prepared in Example 1 is higher than that of the JPLCL patch prepared in Example 6.

[0046] Effect Example 3 In this effect example, the output voltage of the JPLCL / ZnO patch prepared in Example 1 under ultrasonic stimulation in the rat model in the in vivo experiment is tested using an oscilloscope to characterize its electrical output performance.

[0047] The specific test method is as follows: first, the rats are anesthetized by intraperitoneal injection of 3% sodium pentobarbital. Subsequently, the JPLCL / ZnO patch prepared in Example 1 is implanted in the abdominal wall defect of the rat, and exposed to ultrasonic waves. The output voltage is recorded in real time using an oscilloscope (Figure 6a). Figure 3 a). The conditions of ultrasonic stimulation are an ultrasonic intensity of 0.5 W / cm². The test results are shown in Figure 3 b, and under these conditions, the JPLCL / ZnO patch prepared in Example 1 can generate an output voltage of 231 mV, confirming the feasibility of providing electrical stimulation to the defect area under ultrasonic therapy.

[0048] Effect Example 4 In this effect example, the morphology of the JPLCL patch prepared in Example 6 is characterized using a scanning electron microscope.

[0049] The specific test method is as follows: the morphology is analyzed using a field emission scanning electron microscope at an acceleration voltage of 5 kV. The average fiber diameter in the SEM image is analyzed using Image J software, in which the diameters of 50 fibers are randomly measured. The test results are shown in Figure 4 Figure 7b, and the JPLCL patch prepared in Example 6 exhibits a fibrous morphology. After the PMPC coating is formed by photocuring, the fiber diameter of the top coating surface (a, c) is larger than that of the bottom non-coating surface (b, d). Figure 4 a, c). Figure 4(b) and (d) show an increase, and this increase in fiber diameter is beneficial for improving the hydrophilicity of the patch surface and tissue adhesion. Simultaneously, the patch fibers exhibit a highly oriented structure, with orientation angles concentrated between -20° and 20°, indicating good fiber orientation. This helps enhance the mechanical properties of the patch and promotes cell growth along the fiber direction, thereby promoting orderly tissue repair and demonstrating the beneficial effects of this patch in tissue repair.

[0050] Example 5 In this example, the morphology of the JPLCL / ZnO patch prepared in Example 1 was characterized using scanning electron microscopy.

[0051] The specific testing method is as follows: Morphology was analyzed using field emission scanning electron microscopy at an accelerating voltage of 5 kV. ImageJ software was used to analyze the average fiber diameter in the SEM images, with the diameter of 50 fibers randomly measured. The test results are as follows: Figure 5 As shown, the JPLCL / ZnO patch prepared in Example 1 exhibits a fibrous morphology. After photocuring to form a PMPC coating, its top surface has a coating ( Figure 5 The fiber diameters of a, c) compared to the uncoated surface at the bottom ( Figure 5 (b) and (d) are increased, which helps to improve surface hydrophilicity and cell adhesion; at the same time, the patch fibers exhibit a highly oriented structure, with orientation angles concentrated between -20° and 20°, indicating that the fiber structure still maintains good orientation. This orientation structure is beneficial to enhance the mechanical properties of the patch and promote the orderly growth of cells along the fiber direction, thereby improving the tissue repair effect.

[0052] Example 6 This example demonstrates tensile testing of the JPLCL / ZnO patch prepared in Example 1 and the JPLCL patch prepared in Example 6 using a WD-5A universal testing machine at a tensile speed of 5 mm / min. All samples were cut into rectangular strips (20 mm × 10 mm), with the loading direction parallel or perpendicular to the fiber orientation of the sample. Results are as follows: Figure 6 As shown, the JPLCL patch prepared in Example 6 ( Figure 6 a) and the JPLCL / ZnO patch prepared in Example 1 ( Figure 6b) both show significant mechanical anisotropy, in which the tensile strength and elastic modulus in the parallel direction are significantly higher than in the vertical direction; at the same time, due to the use of two times of electrospinning with staggered orientation to construct the fibers of the sample, the tensile strength of the JPLCL / ZnO patch prepared in Example 1 in the parallel direction is significantly improved compared with the JPLCL patch prepared in Example 6 which is made by only one time of electrospinning, so that the JPLCL / ZnO patch can be precisely matched for application in soft tissue repair areas with higher mechanical requirements, solving the problem of poor tissue healing caused by stress shielding of traditional patches, and improving the use function and application range of the JPLCL / ZnO patch in the field of soft tissue repair.

[0053] Effect Example 7 In this effect example, the agar plate colony counting method is used to evaluate the antibacterial performance of the JPLCL / ZnO patch prepared in Example 1.

[0054] As shown in Figure 8 Compared with the blank control group, the JPLCL / ZnO patch showed obvious bacteriostatic effect on Escherichia coli and Staphylococcus aureus. Further, under the condition of ultrasonic stimulation (JPLCL / ZnO+US group), the number of colonies was further reduced, indicating that the antibacterial performance of the patch was enhanced under physical stimulation. The statistical results showed that the bacteriostatic rates of the JPLCL / ZnO patch on Escherichia coli and Staphylococcus aureus were 88% and 86%, respectively; after ultrasonic treatment, the bacteriostatic rates increased to 94% and 93%, respectively. The results showed that the JPLCL / ZnO patch prepared in Example 1 had good antibacterial activity in the conventional state, and the antibacterial effect was further enhanced under external ultrasonic stimulation, which was suitable for application scenarios with antibacterial requirements in the field of wound infection control and soft tissue repair.

[0055] Effect Example 8 In this effect example, the WD-5A type universal mechanical testing machine is used to test the tensile strength of the JPLCL / ZnO patch prepared in Examples 1-4.

[0056] The test tensile speed was set to 5 mm / min, and all samples were cut into rectangular strips with a size of 20 mm × 10 mm. During the test, the loading direction was parallel or perpendicular to the main fiber orientation direction in the patch, respectively, to evaluate its anisotropic mechanical properties. As shown in Figure 8As shown, each group of JPLCL / ZnO patch presents different stress-strain behavior in different orientation directions, embodying good structural anisotropy regulation ability. The tensile strength and elastic modulus of the patch change with the change of the orientation ratio. When the stacking ratio is 10:1, it shows higher tensile strength and stiffness in the main orientation direction; for the JPLCL / ZnO patch prepared in Example 4, when the stacking ratio is 1:1, it shows higher ductility and lower modulus. Further calculation shows that the structural anisotropy ratio of the prepared JPLCL / ZnO patch can be adjusted between 1:1 and 14:1, and the tensile strength and elastic modulus of the JPLCL / ZnO patch prepared in Examples 1-4 in the main orientation direction all reach or exceed the baseline requirements required for tissue repair (tensile strength ≥0.08 MPa, elastic modulus ≥0.04 MPa). At the same time, the anisotropy range of the prepared ultrasonic response anisotropic electrospun patch can be regulated by adjusting the stacking ratio of the fibers in the two electrospinning processes, thereby optimizing the anisotropy ratio of the prepared PLCL / ZnO patch and directionally optimizing the tensile strength of the PLCL / ZnO patch, so that it can be suitable for the mechanical adaptation repair requirements of different regional abdominal wall defects, and solves the problem of poor tissue healing caused by stress shielding of traditional patches.

[0057] Obviously, the above examples of the present application are only examples for clearly illustrating the technical solutions of the present application, and are not a limitation on the specific embodiments of the present application. Any modification, equivalent replacement and improvement made within the spirit and principles of the claims of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method of preparing an ultrasonic-responsive anisotropic electrospun patch, characterized by, The method comprises the following steps: S1: blending and dissolving a biodegradable polymer with piezoelectric properties, antibacterial nanoparticles and a photoinitiator in an organic solvent to prepare a spinning precursor solution; S2: dividing the spinning precursor solution prepared in step S1 into two portions with different proportions: solution A and solution B, first electrospinning solution A along a first direction to obtain a first direction fiber film; then rotating the collection substrate to an angle of a second direction, electrospinning solution B along the second direction to form a second direction fiber film on the surface of the first direction fiber film, and forming an electrospun fiber film; the second direction has an orientation difference with the first direction; S3: soaking the fiber film prepared in step S2 in a zwitterionic solution, and then performing single-side ultraviolet irradiation to grow a coating on one side of the fiber film in situ; S4: vacuum drying the fiber film after ultraviolet irradiation treatment to prepare an ultrasonic response anisotropic electrospun patch.

2. The production method according to claim 1, characterized by, In the step S1, the mass concentration of the biodegradable polymer in the organic solvent is 8%-25%, the addition amount of the antibacterial nanoparticles is 1%-15% of the mass of the biodegradable polymer, and the addition amount of the photoinitiator is 0.1%-10% of the mass of the biodegradable polymer.

3. The preparation method according to claim 1, characterized in that, In the step S1, the biodegradable polymer comprises one or more combinations of polylactic acid-polycaprolactone (PLCL), poly-L-lactic acid (PLLA), polylactic acid-glycolic acid copolymer (PLGA), polycaprolactone (PCL) or polyethylene glycol (PEG) modified gelatin.

4. The method of claim 1, wherein, In the step S1, the antibacterial nanoparticles are nano-zinc oxide particles.

5. The preparation method according to claim 1, characterized in that, In the step S2, the anisotropy ratio of the ultrasonic response anisotropic electrospun patch is regulated by adjusting the stacking ratio of the first direction fiber film and the second direction fiber film; the stacking ratio of the first direction fiber film and the second direction fiber film is 10:1 to 1:1, the anisotropy ratio of the obtained ultrasonic response anisotropic electrospun patch is 1:1 to 14:1, and the orientation angle difference between the first direction and the second direction is 0°-90°.

6. The production method according to claim 5, wherein In the step S2, in the first direction, the drum collection direction is consistent with the spinning orientation direction; and the orientation angle difference between the first direction and the second direction is preferably 90°.

7. The preparation method according to claim 1, characterized in that, In the step S2, the parameters of electrospinning are set as follows: the receiver rotation speed is 100-2000 rpm, the spinning voltage is 15-30 kV, the receiving distance is 10-25 cm, and the environmental humidity is controlled to be not more than 40%.

8. The method of claim 1, wherein, In the step S3, the zwitterionic solution comprises one or more combinations of 2-methacryloyloxyethyl phosphorylcholine, sulfobetaine methacrylate or carboxybetaine methacrylate.

9. The use of the ultrasonic response anisotropic electrospun patch prepared by the preparation method of any one of claims 1-8 in a soft tissue repair patch.

10. Use according to claim 9 in a soft tissue repair patch, which is one or more of an abdominal wall hernia repair patch, a traumatic tissue defect repair patch or a joint cartilage repair patch.

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