Near-infrared controllable electroactive film and preparation method and application thereof

Abstract

This invention discloses a near-infrared controllable electroactive film, its preparation method, and its application, belonging to the field of biomedical technology. The near-infrared controllable electroactive film includes a base film and a bioactive coating attached to the surface of the base film. The raw materials for preparing the base film include piezoelectric polymers and polyurethane, while the raw materials for preparing the bioactive coating include dopamine, used for in-situ self-polymerization to form polydopamine on the surface of the base film. This near-infrared controllable electroactive film can solve the technical problems of uncontrolled potential, weakened potential, and poor long-term repair effects after implantation of current electroactive biomaterials. The method for preparing this near-infrared controllable electroactive film is simpler and more stable. It can be used to prepare or as a medical consumable for inducing regeneration of bone tissue defects.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and more specifically, to a near-infrared controllable electroactive thin film, its preparation method, and its application. Background Technology

[0002] Repairing bone defects, especially those in the maxillofacial region, has always been a challenging and hotly debated topic in clinical practice. While traditional techniques such as autologous bone grafting, allogeneic bone grafting, implantation of artificial substitutes, and bone lengthening have been applied clinically, further improvements are still needed. In recent years, a large number of bio-implant materials promoting in-situ bone regeneration and repairing bone defects have been developed. Using bio-implant materials to promote in-situ bone regeneration and repair bone defects has become an important clinical approach for the repair of bone defects, particularly those in the maxillofacial region.

[0003] Electrical properties are one of the important physiological characteristics of natural bone and a key regulatory factor in bone remodeling and healing. Numerous studies have confirmed that reconstructing the bone electrical microenvironment can significantly promote in-situ bone regeneration. Therefore, designing and constructing biomimetic bone electrical properties materials to reconstruct the electrical microenvironment for bone repair provides insights for developing new materials for the clinical repair and treatment of bone defects, especially those in the maxillofacial region.

[0004] Currently, biocompatible ferroelectric materials are the main system used to construct biomimetic bone electrical properties materials because they can provide surface potentials at physiological levels similar to bone tissue. In recent years, scholars at home and abroad have been exploring the use of physiological loads generated by daily biological activities to induce and regulate the surface potential of ferroelectric materials such as ceramics and polymers to promote the repair of bone defects.

[0005] However, existing biomimetic bone electrical properties materials still have at least the following shortcomings: they cannot solve the technical problems of uncontrolled potential, weakened potential, and poor long-term repair effect after implantation of current electroactive biomaterials, and they cannot achieve spatiotemporal dynamic regulation of the electrical properties of the material system according to physiological needs.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] One of the objectives of this invention is to provide a near-infrared controllable electroactive thin film to solve the above-mentioned technical problems.

[0008] The second objective of this invention is to provide a method for preparing the above-mentioned near-infrared controllable electroactive thin film.

[0009] A third objective of this invention is to provide an application of the aforementioned near-infrared controllable electroactive thin film.

[0010] This application can be implemented as follows:

[0011] In a first aspect, this application provides a near-infrared controllable electroactive thin film, which includes a base film and a bioactive coating attached to the surface of the base film;

[0012] The raw materials for preparing the base film include piezoelectric polymers and polyurethane, while the raw materials for preparing the bioactive coating include dopamine, which is used to form polydopamine in situ on the surface of the base film.

[0013] In an optional embodiment, the piezoelectric polymer is provided by a polyvinylidene fluoride-trifluoroethylene solution; and / or, the polyurethane is a phase change polyurethane; and / or, the dopamine is provided by a dopamine hydrochloride solution.

[0014] In an optional embodiment, the polyurethane is a solid-solid phase change polyurethane.

[0015] Secondly, this application provides a method for preparing a near-infrared controllable electroactive thin film as described in the foregoing embodiments, comprising the following steps: electrospinning a polyurethane solution with a piezoelectric polymer to obtain an electrospun thin film;

[0016] The electrospun film was annealed and then reacted with a dopamine donor in the presence of a buffer solution.

[0017] In an optional embodiment, the concentration of the polyvinylidene fluoride-trifluoroethylene solution is 1-3 g / mL;

[0018] And / or, the volume ratio of polyvinylidene fluoride-trifluoroethylene solution to polyurethane solution is 0.5-2:1.

[0019] In an optional embodiment, the electrospinning voltage is 10-20kV, the injection pump flow rate is 0.5-2ml / h, the receiver rotation speed is 50-200rpm, and the receiver distance is 10-30cm.

[0020] In an optional embodiment, the annealing temperature is 90-140°C, and / or the annealing time is 0.5-2 hours.

[0021] In an optional embodiment, the dopamine provider is a dopamine hydrochloride solution with a concentration of 0.5-4 mg / mL;

[0022] And / or, the buffer solution is a Tris solution with a pH of 8-9;

[0023] And / or, the reaction time of the annealed electrospun film with dopamine hydrochloride is 12-48 h.

[0024] In an optional embodiment, the polyurethane solution is prepared by reacting a polyhydroxy compound solution with a polyisocyanate and a chain extender under a protective atmosphere.

[0025] In an optional embodiment, the polyhydroxy compound includes at least one of polyethylene glycol and polytetrahydrofuran;

[0026] And / or, the solvent in the polyhydroxy compound solution includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and acetone;

[0027] And / or, the polyisocyanates include at least one of 4,4'-diphenylmethane diisocyanate, isoflurone diisocyanate, dicyclohexylmethane diisocyanate and 2,4-toluene diisocyanate;

[0028] And / or, the chain extender includes at least one of butanediol, N-methyldiethanolamine and 1,3-propanesulfonic acid lactone.

[0029] In an optional embodiment, the mass molar ratio of the polyhydroxy compound, the polyisocyanate, and the chain extender is 1:1-3:0.1-1.

[0030] In an optional embodiment, the reaction temperature of the polyhydroxy compound solution with the polyisocyanate and the chain extender is 50-80°C; and / or, the reaction time of the polyhydroxy compound solution with the polyisocyanate and the chain extender is 3-8 hours.

[0031] Thirdly, this application provides applications of the near-infrared controllable electroactive thin film as described above, for example, for use in the preparation or as a medical consumable for inducing regeneration of bone tissue defects.

[0032] The beneficial effects of this application include:

[0033] This application is the first to apply phase change polyurethane to a piezoelectric polymer substrate, and simultaneously prepares a polydopamine coating by in-situ self-polymerization of dopamine on the substrate surface. This preparation method is simple, easy to operate, readily applicable to industrial production, and low in cost.

[0034] The addition of the aforementioned phase change polyurethane and polydopamine endows the near-infrared controllable electroactive film with a responsive function that rapidly responds to near-infrared light stimulation, causing internal deformation, squeezing out piezoelectric components, and thus generating an electrical signal output. This gives the electroactive film material a good near-infrared-piezoelectric effect, and the electrical signal output effect of the film material can be controlled by near-infrared light.

[0035] Furthermore, this near-infrared controllable electroactive film material differs from traditional electroactive materials. By introducing polyurethane and polydopamine, it not only enhances the film's biocompatibility but also endows it with near-infrared piezoelectric capabilities. Under in vitro near-infrared light stimulation, the film can effectively regulate the release of electrical signals within the body, solving the problems of uncontrolled and weakened potential after long-term implantation of traditional electroactive materials. It demonstrates excellent therapeutic effects in bone defect repair and has the potential to become a favorable approach for future in vitro treatment of bone defects. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a physical image of the near-infrared controllable electroactive thin film material provided in Embodiment 1 of this application;

[0038] Figure 2 This is a scanning electron microscope image of the near-infrared controllable electroactive thin film material provided in Embodiment 1 of this application;

[0039] Figure 3 for Figure 2 Enlarged view of part of the image;

[0040] Figure 4 This refers to the piezoelectric output capability result corresponding to ① in the test example of this application;

[0041] Figure 5 This refers to the piezoelectric output capability result corresponding to test example ② in this application;

[0042] Figure 6 The photomicrograph corresponding to ④ in the experimental example of this application;

[0043] Figure 7 This is the micro-CT scan result corresponding to example ⑤ in this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0045] The near-infrared controllable electroactive thin film provided in this application, its preparation method, and its application are described in detail below.

[0046] This application proposes a near-infrared controllable electroactive thin film, which includes a base film and a bioactive coating attached to the surface of the base film.

[0047] The raw materials for preparing the base film include piezoelectric polymers and polyurethane, and the raw materials for preparing the bioactive coating include dopamine; moreover, dopamine undergoes in-situ self-polymerization on the surface of the base film to form polydopamine.

[0048] For reference, the thickness of the base film can be 50-70 μm. The thickness of the near-infrared controllable electroactive film can be 60-80 μm.

[0049] Preferably, the piezoelectric polymer can be provided by a polyvinylidene fluoride-trifluoroethylene solution. The polyurethane is a phase change polyurethane, preferably a solid-solid polyurethane. The dopamine is provided by a dopamine hydrochloride solution.

[0050] This application is the first to apply phase change polyurethane to a piezoelectric polymer substrate, and simultaneously prepares a polydopamine coating by in-situ self-polymerization of dopamine on the substrate surface. The addition of phase change polyurethane and polydopamine endows the near-infrared controllable electroactive film with a responsive function that rapidly responds to near-infrared light stimulation, causing internal deformation, squeezing out piezoelectric components, and thus generating an electrical signal output. This gives the electroactive film material a good near-infrared-piezoelectric effect, and the electrical signal output effect of the film material can be modulated by near-infrared light.

[0051] Furthermore, this near-infrared controllable electroactive film material differs from traditional electroactive materials. By introducing polyurethane and polydopamine, it not only enhances the film's biocompatibility but also endows it with near-infrared piezoelectric capabilities. Under in vitro near-infrared light stimulation, the film can effectively regulate the release of electrical signals within the body, solving the problems of uncontrolled and weakened potential after long-term implantation of traditional electroactive materials. It demonstrates excellent therapeutic effects in bone defect repair and has the potential to become a favorable approach for future in vitro treatment of bone defects.

[0052] Accordingly, this application also provides a method for preparing the above-mentioned near-infrared controllable electroactive thin film, comprising the following steps: electrospinning a polyurethane solution with a piezoelectric polymer to obtain an electrospun thin film; annealing the electrospun thin film, and then reacting it with a dopamine donor in the presence of a buffer solution.

[0053] For reference, the above polyurethane solution can be prepared by reacting a polyhydroxy compound solution with a polyisocyanate and a chain extender under a protective atmosphere.

[0054] Exemplarily, the polyhydroxy compound may include at least one of polyethylene glycol and polytetrahydrofuran. The solvent in the polyhydroxy compound solution may include at least one of N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and acetone. The polyisocyanate may include at least one of 4,4'-diphenylmethane diisocyanate (MDI), isoflurane diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), and 2,4-toluene diisocyanate (TDI). The chain extender may include at least one of butanediol (BDO), N-methyldiethanolamine (MDEA), and 1,3-propanesulfonic acid lactone (PS).

[0055] During the preparation process, the molar ratio of the polyhydroxy compound, polyisocyanate, and chain extender can be 1:1-3:0.1-1, such as 1:1:0.1, 1:1:0.5, 1:1:1, 1:1.5:0.1, 1:1.5:0.5, 1:1.5:1, 1:2:0.1, 1:2:0.5, 1:2:1, 1:2.5:0.1, 1:2.5:0.5, 1:2.5:1, 1:3:0.1, 1:3:0.5, or 1:3:1, or any other value within the range of 1:1-3:0.1-1.

[0056] The reaction temperature of the polyhydroxy compound solution with the polyisocyanate and chain extender can be 50-80℃, such as 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃, or any other value within the range of 50-80℃.

[0057] The reaction time of the polyhydroxy compound solution with the polyisocyanate and chain extender can be 3-8h, such as 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h or 8h, or any other value within the range of 3-8h.

[0058] The polyurethane prepared by the above method is a phase change polyurethane, specifically a solid-solid phase change polyurethane, whose volume can change with temperature.

[0059] For reference, the piezoelectric polymer is provided by a polyvinylidene fluoride-trifluoroethylene solution, the concentration of which can be 1-3 g / mL, such as 1 g / mL, 1.5 g / mL, 2 g / mL, 2.5 g / mL or 3 g / mL, or any other value within the range of 1-3 g / mL.

[0060] The volume ratio of polyvinylidene fluoride-trifluoroethylene solution to polyurethane solution can be 0.5-2:1, such as 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1, or any other value within the range of 0.5-2:1.

[0061] For example, the voltage for electrospinning can be 10-20kV, such as 10kV, 12kV, 15kV, 18kV or 20kV, or any other value within the range of 10-20kV.

[0062] The flow rate of the syringe pump can be 0.5-2 ml / h, such as 0.5 ml / h, 0.8 ml / h, 1 ml / h, 1.2 ml / h, 1.5 ml / h, 1.8 ml / h or 2 ml / h, or any other value within the range of 0.5-2 ml / h.

[0063] The receiver rotation speed can be 50-200 rpm, such as 50 rpm, 80 rpm, 100 rpm, 120 rpm, 150 rpm, 180 rpm or 200 rpm, or any other value within the range of 50-200 rpm.

[0064] The receiver distance can be 10-30cm, such as 10cm, 15cm, 20cm, 25cm or 30cm, or any value within the range of 10-30cm.

[0065] In the specific preparation process, the piezoelectric polymer is dissolved in an organic solvent, and a polyurethane solution is added in proportion. After stirring and dispersing evenly, a spinning solution is obtained. Then, the spinning solution is placed in a syringe, and the spinning parameters are adjusted according to the above parameter range. After electrospinning, the base film can be obtained.

[0066] By using piezoelectric polymers and phase change polyurethane as materials, the base film prepared by electrospinning is a piezoelectric film with high porosity (50%-80%). The base film has good material flexibility, which improves clinical operability.

[0067] Furthermore, the prepared base film is placed in a vacuum drying oven for annealing.

[0068] For example, the annealing temperature can be 90-140℃, such as 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃ or 140℃, or any other value within the range of 90-140℃.

[0069] The annealing time can be 0.5-2 hours, such as 0.5 hours, 0.8 hours, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours or 2 hours, or any other value within the range of 0.5-2 hours.

[0070] Based on the above electrospinning process and annealing treatment, the near-infrared controllable electroactive film has excellent electrical signal release capability and good electrical stability.

[0071] Preferably, the dopamine provided in this application is a dopamine hydrochloride solution, the concentration of which can be 0.5-4 mg / mL, such as 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, 3.5 mg / mL or 4 mg / mL, or any other value within the range of 0.5-4 mg / mL.

[0072] The buffer solution can be a Tris solution with a pH of 8-9.

[0073] The reaction time between the electrospun film after the above annealing treatment and dopamine hydrochloride can be 12-48h, such as 12h, 18h, 24h, 30h, 36h, 42h or 48h, or any other value within the range of 12-48h.

[0074] Through the above treatment, dopamine can be self-polymerized in situ on the surface of the base film to form a polydopamine layer, which gives the film material excellent biocompatibility and makes it more suitable for in vivo implantation.

[0075] The presence of phase change polyurethane and polydopamine endows the film with near-infrared volumetric deformation response, giving the electroactive thin film material a good near-infrared piezoelectric effect. The electrical signal output effect of the thin film material can be modulated by near-infrared light.

[0076] As mentioned above, the preparation method of the near-infrared controllable electroactive thin film provided in this application is simple, easy to operate, easy to industrialize, and low in cost.

[0077] In addition, this application also provides applications of the above-mentioned near-infrared controllable electroactive thin film, such as its use in the preparation or as a medical consumable for inducing regeneration of bone tissue defects, especially for the repair treatment of maxillofacial bone defects.

[0078] The aforementioned near-infrared controllable electroactive film possesses biomimetic biological tissue structure and can provide various electrochemical environments required for tissue repair. It can be placed at various bone defects, and the electrical signals generated by external forces such as muscle compression or stimulation by external near-infrared light induce continuous bone regeneration, effectively regulating and maintaining the release of electrical signals within the body. When applied to bone defect repair, this near-infrared controllable electroactive film material exhibits excellent and stable electrical properties with slow decay, controllable and adjustable electroactivity, and meets clinical needs.

[0079] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0080] Example 1

[0081] Step (1): Weigh 10g of polyethylene glycol and dissolve it in 50mL of N,N-dimethylformamide to obtain a polyethylene glycol solution. Under nitrogen protection, add 3g of 4,4'-diphenylmethane diisocyanate and 1g of 1,4-butanediol to the solution in sequence, and react at 60℃ for 6h to obtain a phase change polyurethane solution.

[0082] Step (2): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution, add polyurethane solution in a volume ratio of 1:1, and stir magnetically to obtain spinning solution.

[0083] Step (3): Take 5 mL of spinning solution into the electrospinning needle, put in the injection pump, turn on the electrospinning equipment, adjust the spinning voltage to 15 kV, the injection pump flow rate to 1 mL / h, the receiver rotation speed to 100 rpm, the receiver distance to 10 cm, and peel off the film after spinning. The film thickness is 50 μm.

[0084] Step (4): Place the film in a vacuum drying oven for annealing. Set the annealing temperature to 120℃ and the annealing time to 1 hour. Remove the film after annealing.

[0085] Step (5): Dissolve 1.2g of Tris in 100mL of deionized water and adjust the pH to 8.5. Immerse the membrane in the Tris solution and add 200mg of dopamine hydrochloride. Place the solution in a shaker at 37℃ and react for 24h. After drying, the near-infrared controllable electroactive thin film material is obtained.

[0086] A physical image of the near-infrared controllable electroactive thin film material is shown below. Figure 1 As shown, by Figure 1 It can be seen that the near-infrared controllable electroactive thin film material prepared in this embodiment is soft and tough overall.

[0087] The scanning electron microscope image of the near-infrared controllable electroactive thin film material is shown below. Figure 2 and Figure 3 As shown, by Figure 2 and Figure 3 As can be seen, the near-infrared controllable electroactive thin film material prepared in this embodiment shows a clear polyvinylidene fluoride-trifluoroethylene fiber structure and polydopamine nanoparticles adhered to the fiber surface under a scanning electron microscope. This indicates that dopamine has been successfully polymerized onto the fiber membrane surface, forming a polydopamine coating structure.

[0088] Example 2

[0089] The difference between this embodiment and Embodiment 1 is that:

[0090] Step (2): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution, add polyurethane solution at a volume ratio of 2:1, and stir magnetically to obtain spinning solution.

[0091] Example 3

[0092] The difference between this embodiment and Embodiment 1 is that:

[0093] Step (2): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution, add polyurethane solution at a volume ratio of 0.5:1, and stir magnetically to obtain spinning solution.

[0094] Example 4

[0095] Step (1): Weigh 10g of polyethylene glycol and dissolve it in 50mL of N,N-dimethylformamide to obtain a polyethylene glycol solution. Under nitrogen protection, add 3g of 4,4'-diphenylmethane diisocyanate and 1g of 1,4-butanediol to the solution in sequence, and react at 50℃ for 8h to obtain a phase change polyurethane solution.

[0096] Step (2): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution, add polyurethane solution at a volume ratio of 0.67:1, and stir magnetically to obtain spinning solution.

[0097] Step (3): Take 5 mL of spinning solution into the electrospinning needle, put in the injection pump, turn on the electrospinning equipment, adjust the spinning voltage to 10 kV, the injection pump flow rate to 0.5 mL / h, the receiver rotation speed to 50 rpm, the receiver distance to 20 cm, and peel off the film after spinning. The film thickness is 50 μm.

[0098] Step (4): Place the film in a vacuum drying oven for annealing. Set the annealing temperature to 90℃ and the annealing time to 2 hours. Remove the film after annealing.

[0099] Step (5): Dissolve 1.2g of Tris in 100mL of deionized water and adjust the pH to 8. Immerse the membrane in the Tris solution and add 50mg of dopamine hydrochloride. Place the solution in a shaker at 37℃ and react for 12h. After drying, the near-infrared controllable electroactive thin film material is obtained.

[0100] Example 5

[0101] Step (1): Weigh 10g of polyethylene glycol and dissolve it in 50mL of N,N-dimethylformamide to obtain a polyethylene glycol solution. Under nitrogen protection, add 3g of 4,4'-diphenylmethane diisocyanate and 1g of 1,4-butanediol to the solution in sequence, and react at 80℃ for 3h to obtain a phase change polyurethane solution.

[0102] Step (2): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution, add polyurethane solution at a volume ratio of 1.5:1, and stir magnetically to obtain spinning solution.

[0103] Step (3): Take 5 mL of spinning solution into the electrospinning needle, put in the injection pump, turn on the electrospinning equipment, adjust the spinning voltage to 20 kV, the injection pump flow rate to 2 mL / h, the receiver rotation speed to 200 rpm, the receiver distance to 30 cm, and peel off the film after spinning. The film thickness is 50 μm.

[0104] Step (4): Place the film in a vacuum drying oven for annealing. Set the annealing temperature to 140℃ and the annealing time to 0.5h. Remove the film after annealing.

[0105] Step (5): Dissolve 1.2g of Tris in 100mL of deionized water and adjust the pH to 9. Immerse the membrane in the Tris solution and add 400mg of dopamine hydrochloride. Place the solution in a shaker at 37℃ and react for 48h. After drying, the near-infrared controllable electroactive thin film material is obtained.

[0106] Comparative Example 1

[0107] The difference between this comparative example and Example 1 is that steps (1) and (5) in Example 1 are not included, and polyurethane solution is not added in step (2) of Example 1.

[0108] Specifically, the preparation method of this comparative example is as follows:

[0109] Step (1): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution and stir magnetically until homogeneous to obtain a spinning solution.

[0110] Step (2): Take 5 mL of spinning solution into the electrospinning needle, put in the injection pump, turn on the electrospinning equipment, adjust the spinning voltage to 15 kV, the injection pump flow rate to 1 mL / h, the receiver rotation speed to 100 rpm, the receiver distance to 10 cm, and peel off the film after spinning. The film thickness is 50 μm.

[0111] Step (3): Place the film in a vacuum drying oven for annealing. Set the annealing temperature to 120℃ and the annealing time to 1 hour. After annealing, remove the film to obtain a polyvinylidene fluoride-trifluoroethylene film.

[0112] Comparative Example 2

[0113] The difference between this comparative example and Example 1 is that step (5) is omitted, and the polyurethane added in step (2) of Example 1 is a non-phase change polyurethane solution.

[0114] Specifically, the preparation method of this comparative example is as follows:

[0115] Step (1): Dissolve 2g of polyvinylidene fluoride-trifluoroethylene in 10mL of N,N-dimethylformamide solution, add non-phase change polyurethane solution at a volume ratio of 1:1, and stir magnetically to obtain a spinning solution.

[0116] Step (2): Take 5 mL of spinning solution into the electrospinning needle, put in the injection pump, turn on the electrospinning equipment, adjust the spinning voltage to 15 kV, the injection pump flow rate to 1 mL / h, the receiver rotation speed to 100 rpm, the receiver distance to 10 cm, and peel off the film after spinning. The film thickness is 50 μm.

[0117] Step (3): Place the film in a vacuum drying oven for annealing. Set the annealing temperature to 120℃ and the annealing time to 1 hour. After annealing, remove the film to obtain a polyvinylidene fluoride-trifluoroethylene / polyurethane film.

[0118] Test case

[0119] ① Taking the near-infrared controllable electroactive thin film prepared in Example 1 as an example, its piezoelectric output performance was tested using the single-arm cantilever method. A linear motor was used to periodically impact the sample to provide a mechanical force of 10N. The electrical signal generated by the sample was connected to a signal acquisition system through wires and amplified by a low-noise current preamplifier to obtain the output voltage. The results are as follows: Figure 4 As shown.

[0120] Depend on Figure 4 It can be seen that the near-infrared controllable electroactive thin film material provided in Example 1 has better piezoelectric output capability.

[0121] ② Taking the near-infrared controllable electroactive thin film prepared in Example 1 as an example, the near-infrared-piezoelectric output performance of the thin film was tested by near-infrared periodic irradiation. An 808nm near-infrared light emitter was used to periodically irradiate the sample surface. The electrical signal generated by the sample was connected to a signal acquisition system via wires and amplified by a low-noise current preamplifier to obtain the output voltage. The results are as follows: Figure 5 As shown.

[0122] Depend on Figure 5 It can be seen that the near-infrared controllable electroactive thin film material provided in Example 1 has a good near-infrared-piezoelectric response effect and can output voltage under periodic near-infrared light modulation.

[0123] ③ The near-infrared controllable electroactive thin film materials prepared in Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests. The piezoelectric performance was tested according to the test standard GB / T 3389.2-1999 by the Materials Testing Center of Wuhan University of Technology. The piezoelectric output capability of the thin film was tested, and the test performance results are shown in Table 1.

[0124] Table 1 Performance test results of thin film materials

[0125]

[0126] As shown in Table 1, compared with Comparative Example 1 and Comparative Example 2, the piezoelectric output capability is still retained after polyurethane and polydopamine are combined in the embodiments of the present invention. At the same time, the near-infrared-piezoelectric effect of the thin film is also endowed, which can output a voltage of 0.2-0.4V under periodic near-infrared light modulation.

[0127] ④ Taking the near-infrared controllable electroactive film prepared in Example 1 as an example, after sterilizing the near-infrared controllable electroactive film material with cobalt-60, an inoculation density of 5×10⁻⁶ was applied to it. 4 Rat bone marrow mesenchymal stem cells were periodically irradiated with an 808nm near-infrared light emitter for 20 minutes every 24 hours. After 72 hours of culture, the cells were fixed, and their cytoskeleton and nuclei were stained. The results were then observed using a laser confocal microscope. Figure 6 As shown.

[0128] Depend on Figure 6 It can be seen that rat bone marrow mesenchymal stem cells grow well on the surface of an electroactive membrane stimulated by near-infrared and electrical signals, and the cytoskeleton is fully spread, suggesting that the controllable electrical stimulation generated by the electroactive membrane is beneficial to the function of cells.

[0129] ⑤ Taking the near-infrared controllable electroactive film prepared in Example 1 as an example, after sterilization with cobalt-60, the near-infrared controllable electroactive film material was cut into circular film sheets with a diameter of 7 mm and covered with a 5 mm diameter rat skull defect. The defect covered with the electroactive film material of Example 1 served as a control group. The rat skull defect was periodically irradiated with an 808 nm near-infrared light emitter for 20 minutes every 24 hours. The animals were sacrificed 4 weeks after the operation, and the film material was separated and analyzed by micro-CT scanning. The test results are shown in the appendix. Figure 7 As shown. The left side shows the micro-CT scan of the electroactive thin film material in Comparative Example 1, and the right side shows the micro-CT scan of the near-infrared controllable electroactive thin film material provided in Example 1.

[0130] Depend on Figure 7 It can be seen that under the stimulation of the near-infrared light source, the electroactive film can generate a continuous and stable electrical signal effect, which significantly accelerates the repair and regeneration rate of critical-sized skull bone defects in rats, suggesting that it plays a significant role in promoting bone tissue regeneration.

[0131] In summary, the near-infrared controllable electroactive film provided in this application is mainly composed of piezoelectric polymers polyvinylidene fluoride-trifluoroethylene, solid-solid phase change polyurethane, and a polydopamine coating, and is prepared through electrospinning. Unlike traditional electroactive materials, the near-infrared controllable electroactive film provided in this application, by introducing phase change polyurethane and polydopamine, not only improves the biocompatibility of the film but also endows it with near-infrared-piezoelectric capabilities. Under the stimulation of near-infrared light in vitro, the film can effectively regulate the release of electrical signals in vivo, solving the problems of uncontrolled potential and potential weakening after long-term implantation of traditional electroactive materials. It exhibits excellent therapeutic effects in the repair of bone defects and has the potential to become a favorable approach for future in vitro treatment of bone defects.

[0132] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A near-infrared controllable electroactive thin film, characterized in that, The near-infrared controllable electroactive film includes a base film and a bioactive coating attached to the surface of the base film; The raw materials for preparing the base film include piezoelectric polymers and polyurethane, and the raw materials for preparing the bioactive coating include dopamine used to form polydopamine in situ on the surface of the base film. The piezoelectric polymer is provided by a polyvinylidene fluoride-trifluoroethylene solution; the polyurethane is a solid-solid phase change polyurethane; and the dopamine is provided by a dopamine hydrochloride solution. The preparation of the near-infrared controllable electroactive film includes the following steps: electrospinning a polyurethane solution with a piezoelectric polymer to obtain an electrospun film; annealing the electrospun film, and then reacting it with a dopamine donor in the presence of a buffer solution. The polyurethane solution is prepared by reacting a polyhydroxy compound solution with a polyisocyanate and a chain extender under a protective atmosphere; the polyhydroxy compound includes at least one of polyethylene glycol and polytetrahydrofuran; the solvent in the polyhydroxy compound solution includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and acetone; the polyisocyanate includes at least one of 4,4'-diphenylmethane diisocyanate, isoflurone diisocyanate, dicyclohexylmethane diisocyanate, and 2,4-toluene diisocyanate; the chain extender includes at least one of butanediol, N-methyldiethanolamine, and 1,3-propanesulfonic acid lactone; the molar ratio of the polyhydroxy compound, the polyisocyanate, and the chain extender is 1:1-3:0.1-1. The near-infrared controllable electroactive film is used to prepare or as a medical consumable for inducing regeneration of bone tissue defects.

2. A method for preparing a near-infrared controllable electroactive thin film, characterized in that, The preparation method is used to prepare the near-infrared controllable electroactive thin film according to claim 1.

3. The preparation method according to claim 2, characterized in that, The concentration of the polyvinylidene fluoride-trifluoroethylene solution is 1-3 g / mL.

4. The preparation method according to claim 2, characterized in that, The volume ratio of polyvinylidene fluoride-trifluoroethylene solution to polyurethane solution is 0.5-2:

1.

5. The preparation method according to claim 2, characterized in that, The electrospinning voltage is 10-20kV, the injection pump flow rate is 0.5-2ml / h, the receiver rotation speed is 50-200rpm, and the receiver distance is 10-30cm.

6. The preparation method according to claim 2, characterized in that, Also includes: The annealing temperature is 90-140℃, and / or the annealing time is 0.5-2h.

7. The preparation method according to claim 2, characterized in that, The dopamine provider is a dopamine hydrochloride solution, and the concentration of the dopamine hydrochloride solution is 0.5-4 mg / mL; And / or, the buffer solution is a Tris solution with a pH of 8-9; And / or, the reaction time between the annealed electrospun film and the dopamine hydrochloride is 12-48 h.

8. The preparation method according to claim 2, characterized in that, The reaction temperature of the polyhydroxy compound solution with the polyisocyanate and chain extender is 50-80℃; and / or, the reaction time of the polyhydroxy compound solution with the polyisocyanate and chain extender is 3-8h.

9. An application of the near-infrared controllable electroactive thin film as described in claim 1, characterized in that, The near-infrared controllable electroactive film is used to prepare or as a medical consumable for inducing regeneration of bone tissue defects.

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