WO2024016481A1 - Charged composite film material with high osteogenic activity, method for preparing same, and use thereof - Google Patents

Abstract

Disclosed is a charged composite film material with high osteogenic activity, a method for preparing same, and use thereof. The charged composite film with high osteogenic activity provided by the present invention consists of an inorganic filler and a high-molecular-weight polymer. The inorganic filler is titanium dioxide nanoparticles with particle size in the range of 50-150 nm. The doping amount of the inorganic filler is 1-10 wt%. The organic polymer is a polyvinylidene fluoride-based polymer. The composite film material provided by the present invention has high electrical polarization intensity and excellent piezoelectric properties, thus having good electrical activity, biological safety, and high osteogenic activity for promoting bone repair.

Description

A charged composite membrane material with high osteogenic activity and its preparation method and use Technical field

The invention relates to the field of bone tissue defect repair and bionic design of biomedical materials, and in particular to a charged composite membrane material with high osteogenic activity and its preparation method and use.

Background technique

Large-scale bone defects, bone nonunions, and delayed bone healing are difficult problems in clinical treatment. Guided bone tissue regeneration is an important technology to solve the above problems. Currently, guided bone tissue regeneration membranes are mainly used clinically as a physical barrier to promote bone tissue regeneration.

Chinese Patent Publication CN112999430 A discloses an oral repair film and a preparation method thereof. First, a polyhydroxyalkanoate (PHA) blend is prepared, and then the acellular matrix, gelatin microspheres and polyhydroxyalkanoate (PHA) are co-produced. The mixture was dissolved in a mixture of chloroform and acetone to prepare an electrospinning solution to prepare the barrier layer and cell scaffold layer. The pore size range of the barrier layer is 7-16 μm; the non-dense structure is just larger than the diameter of human red blood cells 7-7.6 μm, so that blood and tissue fluid can pass through the barrier layer to ensure nutrition and blood infiltration exchange in the bone defect area; and the surrounding Tissues such as connective cells and epithelial cells have a diameter of 20-65 μm and cannot pass through because they are larger than the pore size of the shielding layer. This can effectively prevent these surrounding tissues from entering the bone defect area and avoid competition between surrounding tissue cells and cells with bone production capacity to inhibit bone formation. Generate effects. The pore size of the tissue scaffold layer ranges from 50 to 300 μm, which faces the bone defect area and can effectively induce and provide a good scaffold for the migration, adhesion, proliferation and growth of fibroblasts. Although the oral repair membrane prepared by this invention can achieve good bone repair effect and also has good mechanical properties and degradation properties, the bone repair effect is limited and lacks osteoinductive activity. At the same time, the chemical properties are unstable and it cannot induce osteogenesis. precise control. In addition, the preparation method of this oral repair film is complex, the process is cumbersome, and it is not easy to promote.

Chinese Patent Publication CN110128679 A discloses a method for preparing a conductive double-layer hydrogel for electrically stimulating osteochondral integrated regeneration, which includes the following steps: Step 1: Disperse conductive particles and dopamine monomers in water to form a suspension, add Calcium hydroxide solution adjusts the suspension to be weakly alkaline, and fully reacts to generate calcium hydroxide solution A of dopamine-modified conductive particles; Step 2: Prepare polyvinyl alcohol solution B and add it to solution A to obtain mixed solution C; Step 3: Add phosphoric acid dropwise to the mixed solution C to react and form. After freeze-thaw cycles, the lower hydrogel can be obtained; Step 4: Dissolve polyvinyl alcohol, natural polymers and dopamine in water to form a mixed solution. Under weakly alkaline conditions After complete reaction, solution D is obtained; Step 5: Place solution D above the lower hydrogel, and the required double-layer hydrogel can be obtained after freeze-thaw cycles; the double-layer hydrogel obtained by the present invention has tissue adhesion and Good electrical stimulation response ability. However, the present invention is not a completely degradable material and is not easy to remove after inducing osteogenesis. At the same time, the network structure of the hydrogel is also easy to adhere to the newly formed bone tissue.

The information in the Background is merely illustrative of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes the prior art that is already known to those of ordinary skill in the art.

Contents of the invention

In order to solve at least part of the technical problems in the prior art, the present invention provides charged composite membrane materials with high osteogenic activity and their preparation methods and uses. Specifically, the present invention includes the following contents.

A first aspect of the present invention provides a charged composite membrane material with high osteogenic activity, which includes a membrane structure of a polyvinylidene fluoride-based polymer with a thickness of 20-50 μm and nano titanium dioxide particles dispersed therein or on its surface. , wherein the doping amount of the titanium dioxide particles is 1-10% based on the film weight.

In some embodiments, the charged composite membrane material with high osteogenic activity according to the present invention further includes a base body, wherein the film is coated on at least part of the surface of the base body.

In certain embodiments, according to the charged composite membrane material with high osteogenic activity of the present invention, the matrix is selected from the group consisting of glass, stainless steel, plastic and/or ceramic.

In some embodiments, according to the charged composite membrane material with high osteogenic activity of the present invention, the polyvinylidene fluoride-based polymer is selected from polyvinylidene fluoride PVDF (molecular weight 400,000-600,000), At least one of the group consisting of polyvinylidene fluoride-hexafluoropropylene PVDF-HFP (molecular weight 400,000-600,000) and polyvinylidene fluoride-trifluoroethylene P (VDF-TrFE) (molecular weight 400,000-600,000).

In certain embodiments, according to the charged composite membrane material with high osteogenic activity of the present invention, the particle size of the titanium dioxide is 50-150 nm.

A second aspect of the present invention provides the use of charged composite membrane materials with high osteogenic activity in preparing bone tissue defect repair materials or wound dressings.

A third aspect of the present invention provides a method for preparing a charged composite membrane material with high osteogenic activity, which includes the following steps:

(a) Mix an inorganic titanium source, a polyvinylidene fluoride-based polymer and an organic solvent to obtain a source solution;

(b) Coating and casting the source solution to obtain a membrane material system;

(c) Use annealing treatment to assist corona polarization to arrange the internal charges of the membrane material system in a certain direction to obtain the charged composite membrane material with high osteogenic activity.

In some embodiments, according to the method for preparing a charged composite membrane material with high osteogenic activity according to the present invention, the inorganic titanium source includes one of titanium dioxide, titanium tetrachloride and titanium trichloride or A variety of; or the polyvinylidene fluoride-based polymer includes polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene and polyvinylidene fluoride-trifluoroethylene.

In some embodiments, according to the method for preparing a charged composite membrane material with high osteogenic activity according to the present invention, the organic solvent includes N,N-dimethylformamide, toluene, chloroform, methanol and one or more of ethyl acetate, particularly preferably N,N-dimethylformamide or a mixed solvent thereof with other solvents.

In some embodiments, according to the preparation method of a charged composite membrane material with high osteogenic activity according to the present invention, the temperature of the annealing treatment is 105-145°C, and the annealing time is 15min-1h; corona electrode The polarization field strength is 0.1-3kV/mm, and the corona polarization time is 15-30 minutes.

The charged composite membrane material with high osteogenic activity of the present invention has anti-adhesion properties, and the dielectric constant of titanium dioxide is relatively high and has excellent electrical properties. It is also non-toxic, has the best opacity and stable chemical properties. Therefore, it can be used Titanium dioxide prepares charged composite membrane materials with high osteogenic activity, which can reach higher physiological potentials and maintain good electrical stability, and can be used as medical implant materials.

By comparing the mechanical properties, electrical properties, osteogenic gene expression levels and bone regeneration promotion effects of charged composite membrane materials with high osteogenic activity and barium titanate nanocomposite membranes, it is verified that the charged composite membrane materials with high osteogenic activity can be used as It is feasible and effective for medical implant materials to efficiently induce bone regeneration.

Description of drawings

Figure 1 is a scanning electron microscope photo of the surface and cross-sectional morphology of the highly osteogenic active charged composite membrane obtained in Example 1;

Figure 2 is an elemental analysis energy spectrum diagram of the highly osteogenic active charged composite membrane obtained in Example 1;

Figure 3 shows the elastic modulus of the highly osteogenic active charged composite membrane obtained in Example 1 (significantly higher than the comparative example, **p<0.01);

Figure 4 shows the electric polarization intensity (left) and piezoelectric constant d ₃₃ (right) of the highly osteogenic active charged composite film obtained in Example 1 (both significantly higher than the comparative example, ***p<0.001);

Figure 5 is an X-ray diffraction pattern of the highly osteogenic active charged composite membrane obtained in Example 1 (compared with the comparative example, it shows that the β phase that determines the electrical properties of the membrane material is significantly enhanced);

Figure 6 shows the expression of specific genes for osteogenic differentiation of bone marrow mesenchymal stem cells by the highly osteogenic active charged composite membrane obtained in Example 1 (all significantly higher than the comparative example, ***p<0.001);

Figure 7 shows micro-CT pictures, histological staining pictures and quantitative analysis results of bone volume and bone density (new bone formation amount and bone density) after 4 weeks of repairing critical size defects in rat skulls with the highly osteogenic active charged composite membrane obtained in Example 1. The density is significantly higher than that of the control example, *p＜0.05, **p＜0.01);

Figure 8 is a micro-CT picture of the critical size defect of rat skull repaired by the highly osteogenic active charged composite membrane obtained in Example 1 for 12 weeks (the bone healing effect is significantly better than that of the comparative example);

Figure 9 is a transmission electron microscope image of titanium dioxide particles coated with dopamine;

Figure 10 shows the piezoelectric constant d ₃₃ of the charged composite film with high osteogenic activity obtained in Example 1 and the charged composite film obtained in Comparative Example 2 (both are significantly higher than the Comparative Example, ***p<0.001);

Figure 11 is an SEM image of the nanoparticles in Comparative Example 2, in which the arrow indicates that titanium dioxide aggregates into larger particles;

Figure 12 shows the micro-CT pictures and histological staining pictures of the nanocomposite membrane obtained in Comparative Example 3 after repairing critical size defects in rat skulls for 4 weeks.

Detailed ways

Various exemplary embodiments of the invention will now be described in detail. This detailed description should not be construed as limitations of the invention, but rather as a more detailed description of certain aspects, features and embodiments of the invention.

It should be understood that the terms used in the present invention are only used to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges in the present invention, it should be understood that the upper and lower limits of the range and every intermediate value therebetween are specifically disclosed. Every smaller range between any stated value or value intermediate within a stated range and any other stated value or value intermediate within a stated range is also included within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded from the range.

Unless defined otherwise, 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 invention belongs. Although only the preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and/or materials in connection with which the documents relate. In the event of conflict with any incorporated document, the contents of this specification shall prevail. Unless otherwise stated, "%" is a percentage by weight.

As used herein, the term “composite membrane material” refers to a membrane material composed of inorganic titanium dioxide particles and organic polyvinylidene fluoride-based polymer. Among them, inorganic titanium dioxide particles are dispersed inside the organic polyvinylidene fluoride-based polymer or attached to its surface. The composite membrane material of the present invention is a white membrane material with high osteogenic activity and electrical charge, and also has the property of preventing tissue adhesion.

Composite membrane material

A first aspect of the present invention provides a charged composite membrane material with high osteogenic activity, sometimes referred to as "composite membrane material" herein, which includes a membrane structure and an optional matrix. The membrane structure is a necessary component of the composite membrane material, and the matrix is an optional component, that is, in some embodiments, the composite membrane material does not include a matrix, and in other embodiments, the composite membrane material includes a matrix, and the membrane structure covers the At least part of the surface of the substrate, preferably the entire surface.

In the present invention, the piezoelectric constant d ₃₃ of the composite membrane material is above 10 pC/N, preferably above 15 C/N, and even reaches 18 C/N or higher. Compared with the BTO film, the piezoelectric constant is higher and can effectively induce bone tissue repair and regeneration.

In the present invention, the membrane structure contains polyvinylidene fluoride-based polymer as an organic substance and nanometer titanium dioxide particles as an inorganic substance. The thickness of the membrane structure is not particularly limited, but is generally 20-60 μm, preferably 25-55 μm, and preferably 25-45 μm, such as 30 μm, 35 μm, 40 μm, etc.

In the present invention, a mixture of a specific amount of nano-titanium dioxide particles is used to prepare a charged composite membrane material with high osteogenic activity. Based on weight, the doping amount (or content) of nano-titanium dioxide particles is generally 1-10%, preferably 1-9%, more preferably 2-8%, further preferably 2-7%, and still preferably 3-6%. The present invention found that if the content of nano-titanium dioxide is too high, for example, higher than 10%, it tends to cause the charge capacity of the composite membrane material to decrease, and thus cannot induce the repair and regeneration of bone tissue efficiently. On the other hand, if the content of nano-titanium dioxide particles is too low, the charge will also decrease, and the whiteness of the resulting composite membrane material will decrease. When titanium dioxide is not doped (the material is transparent), the charge amount is much lower than that of doped titanium dioxide. The present invention achieves a higher charge by optimizing the doping amount of nano-titanium dioxide particles in order to induce efficient repair and regeneration of bone tissue.

In the present invention, the size of nano titanium dioxide particles is not particularly limited, as long as it is within the nanometer range, the preferred average particle size is 50-300 nm, preferably 50-200 nm, more preferably 60-150 nm, such as 70 nm, 80 nm, 90 nm, 100 nm, 120nm. If the particle size is too large, it will affect the strength of the composite membrane material, and if the particle size is too large, it will weaken the nano-effect and easily lead to a decrease in the electrical properties of the material. On the other hand, if the particle size is too small, the particles will easily agglomerate and have poor dispersion.

In the present invention, after annealing treatment, it can be seen that the β phase in the charged composite film with high osteogenic activity, which determines the electrical properties of the film material, is significantly enhanced. At the same time, the present invention found that the charge amount of the composite membrane increased, and thus had higher osteogenic induction activity.

The titanium dioxide of the present invention also preferably has surface modification to improve the miniaturization of nanoparticles. Such surface modifications include poly(dopamine) modification, gamma-methacryloxypropyl trimethoxysilane (KH570), isocyanatopropyltriethoxysilane ( ICTOS). The present invention finds that the above modification can effectively prevent agglomeration, uniformly disperse the nanoparticles, and improve the interfacial compatibility between the particles and the polymer matrix. At the same time, the inventor found that the above surface modification may cause the modified substance to covalently bond with the organic matrix, improve the surface defects caused by doping inorganic particles, and further affect the charging performance of the material.

In the present invention, examples of polyvinylidene fluoride-based polymers include, but are not limited to, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, and polyvinylidene fluoride-trifluoroethylene. One or more of the above substances may be used in the present invention. When a mixture of two or more types is used, the ratio of each component is not particularly limited and can be any ratio. In the present invention, the molecular weight of the polymer is generally controlled between 400,000 and 600,000, preferably between 450,000 and 580,000, and still more preferably between 450,000 and 550,000.

In the present invention, the substrate is not particularly limited and can be any substrate in the field. The material of the substrate includes but is not limited to glass, stainless steel, plastic or ceramic, or a combination of two or more.

Preparation

A second aspect of the present invention provides a method for preparing a charged composite membrane material with high osteogenic activity (herein sometimes referred to as the "method of the present invention"). The method of the present invention generally includes the following steps:

(a) Mix an inorganic titanium source, a polyvinylidene fluoride-based polymer and an organic solvent to obtain a source solution;

(b) Coating and casting the source solution to obtain a membrane material system;

(c) Use annealing treatment to assist corona polarization to arrange the internal charges of the membrane material system in a certain direction to obtain the charged composite membrane material with high osteogenic activity.

Wherein, in step (a), the organic solvent includes one or more of N,N-dimethylformamide, toluene, chloroform, methanol and ethyl acetate. Preferred is N,N-dimethylformamide or a mixed solvent thereof and other solvents. N,N-dimethylformamide is particularly suitable for blending titanium dioxide. The reason may be that the positively charged end of N,N-dimethylformamide is surrounded by methyl groups, forming a steric hindrance that prevents negative ions from approaching and only associates positive ions. In the present invention, the amount of organic solvent is generally suitable to dissolve the inorganic titanium source and the polyvinylidene fluoride-based polymer. In certain embodiments, when the mass ratio of titanium dioxide is 5 wt%, the amount of N,N-dimethylformamide or a mixed solvent thereof and other solvents is 50 ml.

In the present invention, the mixing method of the inorganic titanium source, polyvinylidene fluoride-based polymer and organic solvent is not limited. This can be done by means such as magnetic stirring and ultrasound. In some embodiments, the present invention uses magnetic stirring for mixing, and the rotation speed of the magnetic stirring can be controlled at 500-1500 rpm, preferably 500-1000 rpm. The stirring time is generally controlled to be 2-5h, and more preferably 2.5-3.5h. In some embodiments, the present invention uses ultrasonic mixing, the mixing temperature is generally controlled at 0-25°C, and the mixing time is generally 1-30 min, preferably 20-30 min.

In the present invention, the preparation of the membrane material system is generally carried out in a constant temperature heating platform; the heating temperature of the constant temperature heating platform is preferably 40-60°C, such as 45-55°C. The working time is generally 2.5-6.5h, preferably 3.5-5.5h. In the present invention, tape casting can transform the source solution into a large-area membrane material system.

In the present invention, after obtaining the membrane material system, annealing treatment is further used to assist corona polarization to charge the surface of the membrane material system, thereby obtaining a charged composite membrane material with high osteogenic activity. The charge amount of the nano-titanium dioxide composite film in the present invention is due to the annealing/corona polarization treatment, and the increase in charge amount is because the polyvinylidene fluoride-based polymer and titanium dioxide forming the source solution are mixed to form an optimal mass percentage. . The annealing treatment-assisted corona polarization of the present invention includes the following parameters: the annealing temperature is further preferably 105-145°C; the annealing time is further preferably 15min-1h; the field strength of the corona polarization is preferably 0.1-3kV/mm, It is preferably 0.5-2.5kV/mm, more preferably 0.5-2.0kV/mm; the corona polarization time is further preferably 15-30min. In the present invention, the annealing treatment-assisted corona polarization is preferably performed in devices such as a constant temperature heating platform and a corona polarizer.

In the present invention, optionally, the substrate is pretreated before coating with the source solution. Exemplary pretreatment includes the following steps: wiping, washing, and drying the base material in sequence. In the present invention, the wiping reagent is preferably absolute ethanol, and the specific wiping process is: wiping with lens cleaning paper dipped in absolute ethanol. Washing preferably includes acetone washing, first deionized water washing, absolute ethanol washing and second deionized water washing in sequence. In the present invention, the first deionized water washing, the absolute ethanol washing and the second deionized water washing are preferred. The present invention does not limit the specific dosage of each washing reagent in the above washing process. In the present invention, the drying method is preferably vacuum drying oven drying and hair dryer drying. The drying parameters are not specifically limited, as long as the washed substrate surface is free of any solvent and impurities.

Example 1

This embodiment is an exemplary preparation method of a charged composite membrane material with high osteogenic activity, which includes the following steps:

1) First wipe the substrate with lens paper dipped in absolute ethanol, then clean it with the first deionized water, absolute ethanol and the second deionized water in sequence, dry it and set aside.

2) Disperse titanium dioxide (particle size 100nm) and polyvinylidene fluoride-trifluoroethylene (500,000) in N,N-dimethylformamide with magnetic stirring to obtain a mass percentage of titanium dioxide of 5wt% and polyvinylidene fluoride. The mass percentage of ethylene-trifluoroethylene is 9.5wt%. After ultrasonic mixing, the source solution is obtained; the source solution is coated and casted onto the substrate to obtain a membrane material system; a constant temperature heating platform is set up to heat up at a constant rate to achieve the reaction After the temperature is reached, the membrane material system is placed. The reaction time of the heating platform is 30 minutes. After the annealing treatment is completed, the heating switch is turned off, and the sample is taken out after cooling down.

3) The annealed membrane material system is then placed in a corona polarizer for corona polarization. The polarization time is 30 minutes, and finally a charged composite membrane material with high osteogenic activity is obtained.

The surface and cross-section of the obtained charged composite membrane material with high osteogenic activity were observed using a HITACHIS-4800 field emission scanning electron microscope. The results are shown in Figure 1. It can be seen from Figure 1 that scattered nanoscale titanium dioxide particles can be seen on the surface and cross section of the obtained charged composite membrane material with high osteogenic activity, and the nanoparticles show good dispersion.

Scanning electron microscopy energy spectroscopy was used to conduct elemental analysis of the obtained charged composite membrane material with high osteogenic activity. The results are shown in Figure 2. As can be seen from Figure 2, the weight percentage of titanium in the obtained charged composite membrane material with high osteogenic activity is 2.64%.

Barium titanate nanocomposite membrane (BTO/P(VDF-TrFE)) was used as a control, and the elastic modulus of the charged composite membrane material with high osteogenic activity was tested using the INSTRON-1121 universal mechanical testing machine. The results are shown in Figure 3. The results show that the elastic modulus of the obtained charged composite membrane material with high osteogenic activity is significantly higher than that of the barium titanate nanocomposite membrane, indicating that the charged composite membrane material with high osteogenic activity has greater stiffness.

The hysteresis loop of the charged composite membrane material with high osteogenic activity was tested using a TF1000 ferroelectric analyzer. The results are shown in Figure 4. The results show the maximum polarization and residual polarization of the charged composite membrane material with high osteogenic activity. are higher than those of barium titanate nanocomposite films.

The piezoelectric constant of the charged composite membrane material with high osteogenic activity was tested using the ZJ-3AN quasi-static _d33 tester. The results are shown in Figure 4. The results show that the piezoelectric constant of the charged composite membrane material with high osteogenic activity is significantly Higher than the barium titanate nanocomposite film, the piezoelectric constant reaches 18pC/N.

The crystal phase of the charged composite membrane material with high osteogenic activity was measured using an X-ray diffraction spectrometer. The results are shown in Figure 5. The results show that the β phase that determines the electrical properties of the membrane material is significantly enhanced in the obtained charged composite membrane material with high osteogenic activity. .

qPCR was used to demonstrate the gene expression levels after 3 days of osteogenic differentiation of bone marrow mesenchymal stem cells by charged composite membrane materials with high osteogenic activity. The results are shown in Figure 6. The results show that the gene expression levels of the osteogenic transcription factor RUNX2, bone morphogenetic protein BMP2 and alkaline phosphatase ALP in the obtained charged composite membrane with high osteogenic activity were significantly higher than those in the barium titanate nanocomposite membrane.

Micro CT images, H-E staining images, Masson staining images and quantitative analysis images were used to demonstrate the effect of charged composite membrane materials with high osteogenic activity in inducing bone regeneration in rat skulls after 4 weeks. The results are shown in Figure 7. The results show that the obtained charged composite membrane material with high osteogenic activity has a better repair effect in promoting bone tissue regeneration.

The lateral and medial views of Micro CT images were used to demonstrate the effect of the charged composite membrane material with high osteogenic activity in promoting bone regeneration after 12 weeks. The results are shown in Figure 8. The results show that the obtained charged composite membrane material with high osteogenic activity has Better repair effect by promoting bone tissue regeneration.

Example 2

The only difference from Example 1 is that the mass fraction of titanium dioxide is 10 wt%.

The elemental analysis energy spectrum shows that the weight percentage of titanium in the white film doped with titanium dioxide is 5.33%.

The surface of the obtained doped titanium dioxide white film was observed using a HITACHIS-4800 field emission scanning electron microscope. The results show that the surface of the obtained doped titanium dioxide white film is composed of nanoscale titanium dioxide particles, and the particle density increases.

The piezoelectric coefficient of the obtained doped titanium dioxide white film was tested according to the testing method of Example 1, and the result was about 13 pC/N.

Example 3

The only difference from Example 1 lies in the modification of the surface of titanium dioxide nanoparticles.

Prepare a dopamine aqueous solution with a concentration of 0.01 mol/L, weigh a certain mass of titanium dioxide nanoparticles and ultrasonically vibrate for 30 minutes, disperse in the dopamine aqueous solution, stir in a 40-80°C water bath for 10-14 hours, wash 3 times and dry to obtain Dopamine-coated titanium dioxide particles.

Observation using high-resolution transmission electron microscopy shows that the titanium dioxide particles have been coated with a layer of dopamine, and the thickness of the coating layer is about 1-2nm, see Figure 9.

Comparative example 1

The difference from Example 1 is that nanometer barium titanate particles, organic polyvinylidene fluoride-based polymer and organic solvent are mixed in a beaker to prepare a source solution to obtain a membrane material system.

The elastic modulus was measured using a universal mechanical testing machine (INSTRON-1121), and the results are shown in Figure 3. At the same time, a ferroelectric analyzer (TF1000) and a piezoelectric coefficient meter (ZJ-3AN) were used to test the ferroelectricity and piezoelectric coefficient of the obtained barium titanate nanocomposite film. The results are shown in Figure 4. It can be seen from Figure 4 that the maximum polarization, residual polarization and piezoelectric coefficient of the charged composite membrane material with high osteogenic activity obtained in Example 1 are significantly better than those of the barium titanate nanocomposite membrane. Relative mRNA levels were tested, and the results are shown in Figure 6. It can be seen from Figure 6 that the relative mRNA levels of RUNX2, BMP2 and ALP in the charged composite membrane material with high osteogenic activity obtained in Example 1 are significantly higher than those in the barium titanate nanocomposite membrane. Micro CT, H-E staining and Masson staining were used to observe the bone tissue regeneration effect. The results are shown in Figure 7. It can be seen from Figure 7 that the charged composite membrane material with high osteogenic activity obtained in Example 1 has a repair effect that better promotes bone tissue regeneration. As can be seen from the results in Figure 8, the lateral and medial views show that the obtained charged composite membrane material with high osteogenic activity has a better repair effect in promoting bone tissue regeneration.

Comparative example 2

The difference from Example 1 is that titanium dioxide and polyvinylidene fluoride-trifluoroethylene are dispersed in N,N-dimethylformamide with magnetic stirring. The mass fraction of titanium dioxide is 15 wt%, and the mass fraction of polyvinylidene fluoride-trifluoroethylene is 15 wt%. The mass percentage is 8.5wt%. After ultrasonic mixing, the source solution is obtained; the source solution is coated and casted onto the substrate to obtain a membrane material system; a constant temperature heating platform is set up to raise the temperature at a constant rate. After reaching the reaction temperature, the membrane material system is After placement, the reaction time of the heating platform is 30 minutes. After the annealing process is completed, turn off the heating switch and take out the sample after cooling down. Afterwards, the annealed membrane material system was placed in a corona polarizer for corona polarization. The polarization time was 30 minutes, and finally a charged composite membrane material was obtained.

The piezoelectric constant of the charged composite membrane material was tested using the ZJ-3AN quasi-static _d33 tester. The results are shown in Figure 10. The results show that the piezoelectric constant of the obtained charged composite membrane material is lower than that of the charged composite membrane material with high osteogenic activity. Membrane material, piezoelectric constant is 5pC/N. At this mass volume fraction, it can be seen that the nanoparticles aggregate into larger particles, further indicating that the particle size effect is poor. Figure 11 is the corresponding SEM image.

Comparative example 3

The difference from Example 1 is that titanium dioxide and polyvinylidene fluoride-trifluoroethylene are magnetically stirred and dispersed in N,N-dimethylformamide. The mass fraction of titanium dioxide is 5wt%, and mixed after ultrasonic to obtain a source solution; The solution is coated and casted onto the substrate, and finally a nanocomposite membrane material is obtained.

Micro CT images, H-E staining images, Masson staining images and quantitative analysis images were used to demonstrate the effect of nanocomposite membrane materials on inducing bone regeneration in rat skulls for 4 weeks. The results are shown in Figure 12. The results show that the obtained nanocomposite membrane materials It does not have the repairing effect of promoting bone tissue regeneration.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Various modifications or changes may be made to the exemplary embodiments described herein without departing from the scope or spirit of the invention. The scope of the claims should be given the broadest interpretation to cover all modifications and equivalent structures and functions.

Claims (10)

1. A charged composite membrane material with high osteogenic activity, characterized by comprising a membrane structure of a polyvinylidene fluoride-based polymer with a thickness of 20-50 μm and nanometer titanium dioxide particles dispersed therein or on the surface, wherein, based on the membrane weight , the doping amount of the titanium dioxide particles is 1-10%.
2. The charged composite membrane material with high osteogenic activity according to claim 1, further comprising a base body, wherein the film is coated on at least part of the surface of the base body.
3. The charged composite membrane material with high osteogenic activity according to claim 2, wherein the matrix is selected from the group consisting of glass, stainless steel, plastic and/or ceramic.
4. The charged composite membrane material with high osteogenic activity according to claim 1, wherein the polyvinylidene fluoride-based polymer is selected from the group consisting of polyvinylidene fluoride PVDF, polyvinylidene fluoride-hexafluoropropylene PVDF-HFP and polyvinylidene fluoride-based PVDF. At least one of the group consisting of vinylidene fluoride-trifluoroethylene P (VDF-TrFE).
5. The charged composite membrane material with high osteogenic activity according to claim 1, wherein the particle size of the titanium dioxide is 50-150 nm.
6. Use of the charged composite membrane material with high osteogenic activity according to any one of claims 1 to 5 in the preparation of bone tissue defect repair materials or trauma dressings.
7. A method for preparing a charged composite membrane material with high osteogenic activity, which is characterized by including the following steps:

   (a) Mix an inorganic titanium source, a polyvinylidene fluoride-based polymer and an organic solvent to obtain a source solution;

   (b) Coating and casting the source solution to obtain a membrane material system;

   (c) Use annealing treatment to assist corona polarization to arrange the internal charges of the membrane material system in a certain direction to obtain the charged composite membrane material with high osteogenic activity.
8. The method for preparing a charged composite membrane material with high osteogenic activity according to claim 7, wherein the inorganic titanium source includes one or more of titanium dioxide, titanium tetrachloride and titanium trichloride;

   The polyvinylidene fluoride-based polymer includes one or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, and polyvinylidene fluoride-trifluoroethylene.
9. The method for preparing a charged composite membrane material with high osteogenic activity according to claim 7, wherein the organic solvent includes N,N-dimethylformamide, toluene, chloroform, methanol and ethyl acetate. one or more.
10. The method for preparing a charged composite membrane material with high osteogenic activity according to claim 7, wherein the temperature of the annealing treatment is 105-145°C, the annealing time is 15min-1h; the field strength of the corona polarization is 0.1 -3kV/mm, corona polarization time is 15-30min.

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