Preparation method, product and application of modified PVDF (Polyvinylidene Fluoride) film

Abstract

The invention discloses a preparation method, a product and application of a modified PVDF (Polyvinylidene Fluoride) film, belongs to the technical field of material modification, and aims to solve the problems of poor bone integration capability, low bone healing speed and insufficient effectiveness of the conventional PVDF film. The preparation method of the modified PVDF film comprises the following steps: placing a pretreated PVDF film on a glass slide coated with a conductive adhesive, sequentially installing elemental titanium and a low-oxygen hydroxyapatite target material in a direct-current target region of a magnetron sputtering chamber, then inversely placing the glass slide into the chamber, and carrying out magnetron sputtering on the glass slide to obtain the modified PVDF film. And depositing elemental titanium and low-oxygen hydroxyapatite on the surface of the PVDF film in an argon atmosphere to finally obtain the modified PVDF film. The modified PVDF film disclosed by the invention is suitable for the fields of tissue engineering, bone defect repair and the like, has excellent biocompatibility, antibacterial property and osteogenic induction capability, and expands the application scene of the modified PVDF film in an oral cavity and other parts.

Description

Technical Field

[0001] The invention belongs to the technical field of material modification, and in particular relates to a preparation method, a product and an application of a modified PVDF film. Background Art

[0002] Sputtering coating technology is a traditional method for preparing piezoelectric thin films. It usually uses discharge to ionize the gas. The positive ions bombard the cathode target at high speed under the action of the electric field, knocking out the atoms or molecules of the cathode target, causing them to fly to the surface of the substrate to be plated and deposit into a thin film. Magnetron sputtering coating technology is to establish a runway magnetic field on the cathode target surface, use it to control the movement of secondary electrons, prolong their residence time near the target surface, increase their collision probability with the gas, and thus increase the density of the plasma. Magnetron sputtering coating technology can significantly increase the sputtering rate of the target material, thereby increasing the coating rate.

[0003] PVDF (polyvinylidene fluoride polymer) film is a piezoelectric film. After being stretched and polarized, when subjected to external force in a certain direction, its polarization surface will generate a certain charge, that is, a piezoelectric effect occurs. PVDF film can generate electrical stimulation when mechanically deformed, thereby promoting the regeneration and repair of bone tissue. It has excellent piezoelectric properties and biocompatibility and is widely used in bone tissue engineering, bone repair, biosensors, drug delivery, etc. In recent years, titanium and low-oxygen hydroxyapatite nanomaterials have been proven to have good bioactivity and osteogenesis, which can promote bone repair and regeneration.

[0004] Although PVDF membranes have shown great potential, they still face some challenges and problems in practical applications, such as poor electrical signal stability, weak bone regeneration regulation ability, low anti-inflammatory effect, etc. Therefore, it is of great significance to develop a PVDF membrane with stronger osteogenesis ability and better anti-inflammatory effect. Summary of the invention

[0005] The purpose of the present invention is to address the problems existing in the prior art and provide a method for preparing a modified PVDF film, a product and an application thereof. The modified PVDF film prepared by the method has excellent biocompatibility, anti-inflammatory properties and osteogenic induction ability, effectively solving the problems of poor bone integration ability, slow bone healing speed and insufficient effectiveness of the existing PVDF film, and expanding its application scenarios in the oral cavity and other parts.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] The first aspect of the present invention provides a method for preparing a modified PVDF film, which is prepared by sputtering elemental titanium and low-oxygen hydroxyapatite on the surface of the PVDF film using a magnetron sputtering method.

[0008] Preferably, a method for preparing a modified PVDF film comprises the following steps:

[0009] Step S1: pre-treating the PVDF film;

[0010] Step S2: The surface of the PVDF film obtained in step S1 is sputtered with elemental titanium and low-oxygen hydroxyapatite by a magnetron sputtering method to obtain a modified PVDF film.

[0011] Furthermore, in step S2, the magnetron sputtering method for sputtering elemental titanium and low-oxygen hydroxyapatite specifically controls the sputtering distance between the PVDF film and the elemental titanium and low-oxygen hydroxyapatite, the sputtering power, the sputtering time, the substrate temperature, the reaction gas, the reaction gas flow rate and the gas pressure.

[0012] Preferably, the sputtering distance is 4-10 cm.

[0013] Preferably, the sputtering power is 10-100W.

[0014] Preferably, the sputtering time is 10-20 min.

[0015] Preferably, the substrate temperature is room temperature-300°C.

[0016] Preferably, the reaction gas is high-purity argon.

[0017] Preferably, the reaction gas flow rate is 5-80 sccm.

[0018] Preferably, the air pressure is 0.5-5Pa.

[0019] Preferably, in step S1, the pretreatment method is to clean the PVDF film, dry it and store it in a vacuum.

[0020] Preferably, the cleaning method is ultrasonic cleaning with anhydrous ethanol for 15 minutes.

[0021] Preferably, the drying method is drying with nitrogen.

[0022] Preferably, in step S2, the PVDF film is adhered to the conductive glue of the glass slide.

[0023] Preferably, in step S1, the area of ​​the PVDF film is (1-2) cm×(1-2) cm.

[0024] Preferably, the thickness of the PVDF film in step S1 is 28 μm.

[0025] The second invention of the present invention provides a modified PVDF film prepared by the above preparation method.

[0026] The third invention of the present invention provides an application of a modified PVDF film prepared by the above-mentioned preparation method, wherein the modified PVDF film is applied to prepare materials for bone defect repair or tissue engineering.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The existing PVDF film surface nanostructure cannot establish good adhesion with bone tissue. The present invention effectively modifies the PVDF film surface with elemental titanium and low-oxygen hydroxyapatite through magnetron sputtering technology, wherein the carbon content is 41.01wt%, the oxygen content is 2.18wt%, the fluorine content is 55.42wt%, the calcium content is 0.03wt%, and the titanium content is 1.36wt%.

[0029] 2. The existing PVDF film has poor anti-inflammatory effect. The modified PVDF film prepared by the present invention can effectively stimulate macrophages to express T lymphocyte activation antigen (CD86), interleukin 1β (IL-1β), interferon regulatory factor 3 (IRF3), TNF receptor-associated factor 6 (TRAF6) and nuclear factor receptor-κB (NF-κB), thereby exerting excellent anti-inflammatory activity.

[0030] 3. The existing PVDF film has poor bone binding and bone repair capabilities. The modified PVDF film prepared by the present invention can promote osteoblasts to express RUNX family transcription factor 2 (RUNX2), thereby exerting good osteogenic induction activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of a preparation method of a modified PVDF film in the present invention;

[0032] Figure 2 The whole image of the modified PVDF film prepared in Example 1 was obtained by using a scanning electron microscope at a magnification of 10,000 times;

[0033] Figure 3 is the energy spectrum of the surface elements of the modified PVDF film scanned by the energy spectrum scanning module in Example 1;

[0034] Figure 4 is the relative expression of CD86 mRNA after culturing macrophages RAW264.7 with the modified PVDF film in Example 1 and the PVDF film in Comparative Example 1;

[0035] Figure 5is the relative expression of IL-1β mRNA after culturing macrophage RAW264.7 with the modified PVDF film in Example 1 and the PVDF film in Comparative Example 1;

[0036] Figure 6 is the relative expression of IRF3 mRNA after culturing macrophage RAW264.7 cells with the modified PVDF film in Example 1 and the PVDF film in Comparative Example 1;

[0037] Figure 7 is the relative expression of TRAF6 mRNA after culturing macrophage RAW264.7 cells with the modified PVDF film in Example 1 and the PVDF film in Comparative Example 1;

[0038] Figure 8 is the relative expression of NF-κB mRNA after culturing macrophage RAW264.7 cells with the modified PVDF film in Example 1 and the PVDF film in Comparative Example 1;

[0039] Fig. 9 is the relative expression of TRAF6 mRNA after culturing macrophages RAW264.7 on the modified PVDF film in Example 1, the low oxygen hydroxyapatite doped PVDF film in Comparative Example 2, and the titanium doped PVDF film in Comparative Example 3;

[0040] Fig.10 is the relative expression of NF-κB mRNA after culturing macrophages RAW264.7 on the modified PVDF film in Example 1, the low-oxygen hydroxyapatite-doped PVDF film in Comparative Example 2, and the titanium-doped PVDF film in Comparative Example 3;

[0041] Fig.11 is the relative expression of MYD88 mRNA after culturing macrophages RAW264.7 on the modified PVDF film in Example 1, the low oxygen hydroxyapatite doped PVDF film in Comparative Example 2, and the titanium doped PVDF film in Comparative Example 3;

[0042] Fig.12 is the relative expression of RUNX2 mRNA after osteoblasts MT-3T3 were cultured on the modified PVDF film in Example 1 and the PVDF film in Comparative Example 1;

[0043] Fig.13 It is the relative expression amount of IL-6 mRNA after culturing macrophages RAW264.7 with the modified PVDF film in Example 1, the low oxygen hydroxyapatite doped PVDF film in Comparative Example 2, and the titanium doped PVDF film in Comparative Example 3. DETAILED DESCRIPTION

[0044] The following will be used in conjunction with examples to explain the implementation of the present invention in detail, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The present invention provides a preparation method, product and application of a modified PVDF film. The PVDF film modified by elemental titanium and low-oxygen hydroxyapatite has better anti-inflammatory performance and osteogenic ability, and has a wider application prospect in clinical practice, and is suitable for: (1) providing a scaffold and barrier with excellent biocompatibility for the repair of bone defects in tissue engineering applications; (2) providing better anti-inflammatory and antibacterial ability at the material implantation site; (3) providing better osteogenic activity at the bone grafting site.

[0046] The method for preparing the modified PVDF film of the present invention comprises the following steps:

[0047] Step S1: pre-treating the PVDF film;

[0048] Step S2: The surface of the PVDF film obtained in step S1 is sputtered with elemental titanium and low-oxygen hydroxyapatite by a magnetron sputtering method to obtain a modified PVDF film.

[0049] Preferably, in step S2, the magnetron sputtering method sputters elemental titanium and low-oxygen hydroxyapatite by controlling the sputtering distance between the PVDF film and the elemental titanium and low-oxygen hydroxyapatite to be 4-10 cm, the sputtering power to be 10-100 W, the sputtering time to be 10-20 min, the substrate temperature to be room temperature -300 ° C, the reaction gas to be high-purity argon, the reaction gas flow rate to be 5-80 sccm, and the gas pressure to be 0.5-5 Pa.

[0050] PVDF film, namely polyvinylidene fluoride film, was purchased from PolyK Company.

[0051] Low oxygen hydroxyapatite, with a surface oxygen content of 53.23%. Purchased from Muta New Materials Hebei Co., Ltd.

[0052] The reagents and instruments used in the following specific embodiments, unless otherwise specified, can all be purchased through conventional channels. The reagents or reaction raw materials used, unless otherwise specified, all use the initial concentration of each raw material in the purchased goods.

[0053] Example 1

[0054] A method for preparing a modified PVDF film comprises the following steps:

[0055] Step S1: Cut the PVDF film into a film with an area of ​​2 cm×2 cm, clean the film with anhydrous ethanol by ultrasonic for 15 minutes, blow dry with nitrogen and store in a vacuum.

[0056] Step S2: Adhere conductive glue to the glass slide, adhere the PVDF film treated in S1 to the conductive glue, and put the glass slide upside down into the magnetron sputtering chamber. Install elemental titanium and low-oxygen hydroxyapatite crystals in the DC target area of ​​magnetron sputtering. After closing the chamber, introduce high-purity argon gas to keep the gas pressure at 5 Pa, and deposit elemental titanium and low-oxygen hydroxyapatite on the PVDF film in an argon atmosphere, wherein the sputtering distance is 10 cm, the sputtering power is 100 W, the sputtering time is 20 min, the substrate temperature is 300 ° C, and the argon gas flow rate is 5 sccm, and finally a modified PVDF film is obtained.

[0057] The preparation method of a modified PVDF film described in this embodiment is as follows Figure 1 shown.

[0058] The modified PVDF film prepared in Example 1 was imaged as a whole using a scanning electron microscope at a magnification of 10,000 times. Figure 2 As shown, the surface of the modified PVDF film is smoother.

[0059] The surface elements of the modified PVDF film were scanned using the energy spectrum scanning module. The results are as follows Figure 3 As shown in Table 1, the modified PVDF film generates stable titanium and low-oxygen hydroxyapatite, wherein the carbon content is 41.01wt%, the oxygen content is 2.18wt%, the fluorine content is 55.42wt%, the calcium content is 0.03wt%, and the titanium content is 1.36wt%.

[0060] Table 1 Specific component results of energy spectrum scanning

[0061]

[0062] Example 2

[0063] A method for preparing a modified PVDF film comprises the following steps:

[0064] Step S1: Cut the PVDF film into a film with an area of ​​2 cm×2 cm, clean the film with anhydrous ethanol by ultrasonic for 15 min, blow dry with nitrogen and store in a vacuum.

[0065] Step S2: Adhere conductive glue to the glass slide, adhere the PVDF film treated in S1 to the conductive glue, and put the glass slide upside down into the magnetron sputtering chamber. Install elemental titanium and low-oxygen hydroxyapatite crystals in the DC target area of ​​magnetron sputtering. After closing the chamber, introduce high-purity argon gas to keep the gas pressure at 0.5 Pa, and deposit elemental titanium and low-oxygen hydroxyapatite on the PVDF film in an argon atmosphere, wherein the sputtering distance is 10 cm, the sputtering power is 100 W, the sputtering time is 15 min, the substrate temperature is room temperature, and the argon gas flow rate is 5 sccm, and finally a modified PVDF film is obtained.

[0066] Example 3

[0067] A method for preparing a modified PVDF film comprises the following steps:

[0068] Step S1: Cut the PVDF film into a film with an area of ​​2 cm×2 cm, clean the film with anhydrous ethanol by ultrasonic for 15 minutes, blow dry with nitrogen and store in a vacuum.

[0069] Step S2: Adhere conductive glue to the glass slide, adhere the PVDF film treated in S1 to the conductive glue, and put the glass slide upside down into the magnetron sputtering chamber. Install elemental titanium and low-oxygen hydroxyapatite crystals in the DC target area of ​​magnetron sputtering. After closing the chamber, introduce high-purity argon gas to keep the gas pressure at 0.5 Pa, and deposit elemental titanium and low-oxygen hydroxyapatite on the PVDF film in an argon atmosphere, wherein the sputtering distance is 5 cm, the sputtering power is 50 W, the substrate temperature is 200 ° C, the argon gas flow rate is 80 sccm, and the sputtering time is 20 min, and finally a modified PVDF film is obtained.

[0070] Comparative Example 1

[0071] The processing of the PVDF film in this comparative example is the same as step S1 in Example 1, except that the PVDF film obtained in this comparative example 1 is not modified by magnetron sputtering technology.

[0072] Comparative Example 2

[0073] A method for preparing a low-oxygen hydroxyapatite-doped PVDF film comprises the following steps:

[0074] Step S1: Cut the PVDF film into a film with an area of ​​2 cm×2 cm, clean the film with anhydrous ethanol by ultrasonic for 15 minutes, blow dry with nitrogen and store in a vacuum.

[0075] Step S2: Adhere conductive glue to the glass slide, adhere the PVDF film treated in S1 to the conductive glue, and put the glass slide upside down into the magnetron sputtering chamber. Install low-oxygen hydroxyapatite crystals in the DC target area of ​​magnetron sputtering. After closing the chamber, introduce high-purity argon gas to keep the gas pressure at 5 Pa, and deposit low-oxygen hydroxyapatite on the PVDF film in an argon atmosphere, wherein the sputtering distance is 10 cm, the sputtering power is 100 W, the sputtering time is 20 min, the substrate temperature is 300 ° C, and the argon gas flow rate is 5 sccm, and finally a low-oxygen hydroxyapatite-doped PVDF film is obtained.

[0076] Comparative Example 3

[0077] A method for preparing a titanium-doped PVDF film comprises the following steps:

[0078] Step S1: Cut the PVDF film into a film with an area of ​​2 cm×2 cm, clean the film with anhydrous ethanol by ultrasonic for 15 minutes, blow dry with nitrogen and store in a vacuum.

[0079] Step S2: Adhere conductive glue to the glass slide, adhere the PVDF film treated in S1 to the conductive glue, and put the glass slide upside down into the magnetron sputtering chamber. Install elemental titanium in the DC target area of ​​magnetron sputtering. After closing the chamber, introduce high-purity argon gas to keep the gas pressure at 5 Pa, and deposit elemental titanium on the PVDF film in an argon atmosphere, wherein the sputtering distance is 10 cm, the sputtering power is 100 W, the sputtering time is 20 min, the substrate temperature is 300 ° C, and the argon gas flow rate is 5 sccm, and finally a titanium-doped PVDF film is obtained.

[0080] Comparative Example 4

[0081] A method for preparing a titanium and low-oxygen hydroxyapatite doped PVDF film comprises the following steps:

[0082] Step S1: Cut the PVDF film into a film with an area of ​​2 cm×2 cm, clean the film with anhydrous ethanol by ultrasonic for 15 minutes, blow dry with nitrogen and store in a vacuum.

[0083] Step S2: Adhere conductive glue to the glass slide, adhere the PVDF film processed in S1 to the conductive glue, and put the glass slide upside down into the magnetron sputtering chamber. Install elemental titanium in the DC target area of ​​the magnetron sputtering, close the chamber, introduce high-purity argon gas, keep the gas pressure at 5 Pa, and deposit elemental titanium on the PVDF film in an argon atmosphere, wherein the sputtering distance is 10 cm, the sputtering power is 100 W, the sputtering time is 20 min, the substrate temperature is 300 ° C, and the argon gas flow rate is 5 sccm.

[0084] Then, low-oxygen hydroxyapatite crystals were installed in the DC target area of ​​magnetron sputtering, and high-purity argon gas was introduced into the chamber after closing to keep the gas pressure at 5 Pa. Low-oxygen hydroxyapatite was deposited on the PVDF film in an argon atmosphere, with a sputtering distance of 10 cm, a sputtering power of 100 W, a sputtering time of 20 min, a substrate temperature of 300 °C, and an argon gas flow rate of 5 sccm.

[0085] Finally, a PVDF film doped with titanium and low-oxygen hydroxyapatite was obtained.

[0086] Test example

[0087] (1) Anti-inflammatory activity detection

[0088] The PVDF films prepared in Example 1 and Comparative Example 1 were respectively soaked in alcohol and then fully sterilized by ultraviolet irradiation.

[0089] They were placed in a six-well cell culture plate and inoculated with 50% macrophage RAW264.7. Two days later, when the density increased to about 80%, the cells were collected for real-time fluorescence quantitative polynucleotide chain reaction (RT-qPCR) experiment to detect the expression of T lymphocyte activation antigen (CD86), interleukin 1β (IL-1β), interferon regulatory factor 3 (IRF3), TNF receptor-associated factor 6 (TRAF6) and nuclear factor receptor-κB (NF-κB). Statistical analysis and drawing were performed using GraphPad Prism8 software.

[0090] The results are as follows Figure 4-8 As shown, the modified PVDF film in Example 1 can promote the expression of inflammatory factors such as CD86, IL-1β, IRF3, TRAF6 and NF-κB in macrophages, indicating that it enhances the anti-inflammatory activity of macrophages.

[0091] In this test example, the same method was used to compare the expression of TNF receptor-associated factor 6 (TRAF6), nuclear factor receptor-κB (NF-κB) and myeloid differentiation factor 88 (MYD88) in Example 1, Comparative Example 2 and Comparative Example 3. The results are as follows: Figure 9-11 As shown, the anti-inflammatory activity of the PVDF films in Comparative Examples 2 and 3 is relatively low.

[0092] (2) Osteogenic activity detection

[0093] The PVDF films prepared in Example 1 and Comparative Example 1 were respectively soaked in alcohol and then fully sterilized by ultraviolet irradiation.

[0094] They were placed in six-well cell culture plates and inoculated with MT-3T3 osteoblasts at a density of 50%. Two days later, when the density increased to about 80%, the cells were collected for real-time fluorescence quantitative polynucleotide chain reaction (RT-qPCR) experiments to detect the expression of RUNX family transcription factor 2 (RUNX2). Statistical analysis and drawing were performed using GraphPad Prism8 software.

[0095] The results are as follows Fig.12 As shown, the modified PVDF film in Example 1 can upregulate the expression of RUNX2 transcription factor in osteoblasts, indicating that it has excellent osteogenic activity.

[0096] In this test example, the same method was used to compare the expression of interleukin 6 (IL-6) in Example 1, Comparative Example 2 and Comparative Example 3. The results are as follows: Fig.13 As shown, the osteogenic activity of the PVDF films in Comparative Examples 2 and 3 is relatively low.

[0097] The experimental steps of real-time quantitative polynucleotide chain reaction (RT-qPCR) in this test example are as follows:

[0098] (1) Inoculate 10 6 BMDM cells or osteoblasts MT3T3 were cultured in a constant temperature CO2 cell culture incubator at 37°C and 5% CO2. The culture medium used for cell culture was DMEM medium with a serum concentration of 10%.

[0099] (2) In a fume hood, use an enzyme-free pipette to remove the supernatant from the plate and rinse the plate with sterile PBS. Add 1 mL of RNA lysis buffer to each well and place the plate on ice for 1 min. Then, gently blow the RNA lysis buffer with an enzyme-free pipette and collect it in an enzyme-free EP tube.

[0100] (3) Add 300 μL of clean chloroform solution to the collected RNA lysate and gently invert the EP tube to mix the liquid thoroughly. After standing at room temperature for 15 min, centrifuge at 13,000 rpm for 15 min. After centrifugation, a layered liquid component with the protein component as the dividing line is obtained. Carefully collect the liquid above the protein layer and transfer it to a new clean enzyme-free EP tube.

[0101] (4) Add 750 μL of clean isopropanol to the EP tube, gently shake it upside down, let it stand at room temperature for 15 min, and then centrifuge it at 13,000 rpm for 10 min. After centrifugation, a white RNA precipitate is obtained at the bottom of the EP tube.

[0102] (5) Carefully remove the solution components in the EP tube with an enzyme-free pipette tip, leaving the white precipitate at the bottom of the tube. Add 1 mL of anhydrous ethanol, gently flick the EP tube to clean the white precipitate in the tube, and centrifuge at 13,000 rpm for 10 min.

[0103] (6) Add 1 mL of anhydrous ethanol again, gently flick the EP tube to clean the white precipitate in the tube, and centrifuge at 13,000 rpm for 10 min. Remove the supernatant and repeat this step once.

[0104] (7) Carefully remove the solution components in the EP tube with an enzyme-free pipette tip, open the EP tube and place it sideways in a fume hood. After the liquid in the tube evaporates, add 30 μL of enzyme-free water to the EP tube and use Nanodrop to test the RNA concentration.

[0105] After the RNA concentration is quantified, reverse transcription is performed according to the reverse transcription system in the reverse transcription kit instructions. The specific steps are as follows:

[0106] (8) Take a 200 μL enzyme-free EP tube and place it on an ice box. Prepare the reverse transcription solution reagent environment according to the reagent formula (1 μL of gDNA scavenger, 4 μL of 5× DNA scavenger solvent, and add enzyme-free water to 20 μL). The RNA content of each tube is set to 800 ng.

[0107] (9) Gently shake and mix, place the EP tube in a common PCR instrument, and the reverse transcription temperature change process is as follows: first, raise the temperature to 37 °C and keep it for 2 min. Then, raise the temperature to 55 °C and keep it for 15 min. Then, raise the temperature to 85 °C and keep it for 5 min. Finally, cool it down to 4 °C. After reverse transcription is completed, the changes in the mRNA expression levels of various cell indicators are detected by real-time fluorescence quantitative PCR.

[0108] (10) Place the EP tube on ice after the reverse transcription reaction is completed, and prepare the RT-qPCR solution reagent system according to the reagent recipe (Mix 10 μL, primer 0.8 μL, cDNA 4 μL, deionized water to 20 μL).

[0109] (11) Gently shake to mix, place the EP tube in a conventional PCR instrument, and perform qPCR amplification reaction.

[0110] (12) Analyze the above reaction results by real-time fluorescence quantitative PCR to detect the mRNA expression of primary cells.

[0111] Although the embodiments of the present invention have been shown and described, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for preparing a modified PVDF film, characterized in that: The method is prepared by sputtering elemental titanium and low-oxygen hydroxyapatite on the surface of a PVDF film using a magnetron sputtering method.

2. The method for preparing a modified PVDF film according to claim 1, characterized in that: The following steps are involved: Step S1: pre-treating the PVDF film; Step S2: The surface of the PVDF film obtained in step S1 is sputtered with elemental titanium and low-oxygen hydroxyapatite by a magnetron sputtering method to obtain a modified PVDF film.

3. The method for preparing a modified PVDF film according to claim 1, characterized in that: In step S2, the magnetron sputtering method sputters elemental titanium and low-oxygen hydroxyapatite by controlling the sputtering distance between the PVDF film and the elemental titanium and low-oxygen hydroxyapatite, the sputtering power, the sputtering time, the substrate temperature, the reaction gas, the reaction gas flow rate and the gas pressure.

4. The method for preparing a modified PVDF film according to claim 3, characterized in that: The sputtering distance is 4-10 cm, the sputtering power is 10-100 W, and the sputtering time is 10-20 min.

5. The method for preparing a modified PVDF film according to claim 3, characterized in that: The substrate temperature is room temperature-300° C., the reaction gas is high-purity argon, the reaction gas flow rate is 5-80 sccm, and the gas pressure is 0.5-5Pa.

6. The method for preparing a modified PVDF film according to claim 1, characterized in that: In the step S1, the pretreatment method is to clean the PVDF film, dry it and store it in a vacuum.

7. The method for preparing a modified PVDF film according to claim 1, characterized in that: In the step S2, the PVDF film is adhered to the conductive glue of the glass slide.

8. The method for preparing a modified PVDF film according to claim 1, characterized in that: In the step S1, the area of ​​the PVDF film is (1-2) cm×(1-2) cm, and the thickness is 28 μm.

9. A modified PVDF film prepared by the preparation method according to any one of claims 1 to 8.

10. Application of the modified PVDF film prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The modified PVDF film is used for preparing materials for bone defect repair or tissue engineering.

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