Bioactive glass microsphere with piezoelectric property as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of inorganic piezoelectric material preparation and medical application, and discloses a bioactive glass microsphere with piezoelectric property as well as a preparation method and application thereof, the bioactive glass microsphere with piezoelectric property takes a mesoporous bioactive glass microsphere as a framework, and a piezoelectric material is deposited in mesopores in situ. The preparation method comprises the following steps: firstly, preparing mesoporous bioactive glass microspheres by adopting a sol-gel template method, then depositing zinc ions with positive charges in the mesopores of the microspheres in situ in an alkaline environment, and carrying out heat treatment to obtain the bioactive glass microspheres with piezoelectric properties. The prepared bioactive glass microspheres with the piezoelectric property have good biocompatibility and piezoelectric property, the preparation process is simple, the zinc oxide loading capacity can be adjusted, the microspheres can generate potential difference through ultrasound, cells are electrically stimulated, and the piezoelectric property of the microspheres is improved. And the compound has the advantages of synergism with various active ions in bioactive glass to promote tooth formation and vascularization, and the like, and has important significance for expanding clinical application.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of inorganic piezoelectric materials and medical applications, and particularly relates to a bioactive glass microsphere with piezoelectric properties, a preparation method thereof, and an application thereof. Background Art

[0002] Bioactive glass is an important type of inorganic biomedical material with good biocompatibility. In recent years, it has been found through research that the dissolved ions of bioactive glass microspheres can promote the proliferation and differentiation of osteoblasts and odontoblasts. Therefore, as a good bone repair material and dental repair material, it is widely used in bone defect repair and dental pulp injury repair. Mesoporous bioactive glass microspheres have a large specific surface area and good biocompatibility, and are an ideal drug carrier material.

[0003] In the fields of bone repair materials and dental repair materials, the piezoelectric properties of materials have been proven to promote the proliferation and differentiation of cells and have good development potential. Currently, piezoelectric materials that have been studied more, such as zinc oxide, sodium potassium niobate, barium titanate, etc., have the following defects: zinc oxide degrades in the body and is likely to cause cytotoxicity; sodium potassium niobate and barium titanate cannot degrade in the body and will exist in the human body for a long time, which may pose potential biosafety problems and limit their actual clinical applications. The prior art (Mohankandhasamy Ramasamy, Minakshi Das, Seong Soo A An, Dong Kee Yi. Role of surface modification in zinc oxide nanoparticles and its toxicity assessment toward human dermal fibroblast cells, International Journal of Nanomedicine, 2014, 9, 3707 - 3718.) coated the surface of zinc oxide with a silica coating to reduce the cytotoxicity brought by zinc oxide. However, as the silica coating degrades, the zinc oxide core still exhibits cytotoxicity. Although the pores on the surface of bioactive glass microspheres can be loaded with components such as drugs and proteins to obtain better properties, bioactive glass microspheres with piezoelectric properties have not been reported. Therefore, it is of great significance to develop bioactive glass microspheres with piezoelectric properties. Summary of the Invention

[0004] In order to overcome the disadvantages and deficiencies of the prior art, the primary object of the present invention is to provide a bioactive glass microsphere with piezoelectric properties.

[0005] Another object of the present invention is to provide a method for preparing bioactive glass microspheres with piezoelectric properties. The entire preparation process is simple, low-cost and easy to synthesize in large quantities. The prepared bioactive glass microspheres loaded with zinc oxide having piezoelectric properties are uniform in size, have good biocompatibility, degradability and piezoelectric response performance, and the content of zinc oxide loaded in the microspheres can be regulated by changing the content of zinc nitrate hexahydrate in the formulation.

[0006] Another object of the present invention is to provide the application of the above-mentioned bioactive glass microspheres with piezoelectric properties.

[0007] To achieve the above object, the technical solutions provided by the present invention are as follows:

[0008] A kind of bioactive glass microspheres with piezoelectric properties, with mesoporous bioactive glass microspheres as the skeleton, and piezoelectric materials are in-situ deposited in the mesopores of the mesoporous bioactive glass microspheres.

[0009] Preferably, the mass fraction of the piezoelectric material is 5%-20%, preferably 5%-17.3%;

[0010] The piezoelectric material is ZnO.

[0011] Preferably, the composition of the mesoporous bioactive glass microspheres is SiO2 and CaO.

[0012] Preferably, the composition of the bioactive glass microspheres with piezoelectric properties is 82-94wt% SiO2-0.1-1wt% CaO-5-20% ZnO.

[0013] Preferably, the in-situ deposition is to make positively charged zinc ions in-situ deposit in the mesopores of the mesoporous bioactive glass microspheres under an alkaline environment.

[0014] Preferably, the particle size of the bioactive glass microspheres with piezoelectric properties is 80-100nm, and the pore diameter of the mesopores is 2-10nm.

[0015] A method for preparing bioactive glass microspheres with piezoelectric properties, comprising the following steps:

[0016] S1. Add a hydrolysis catalyst and a template agent to water in sequence to obtain a micelle solution, then add a silicon source and a calcium source, stir, and after dehydration condensation reaction, obtain amorphous structure bioactive glass microspheres, and after centrifugation, washing and drying, remove the template agent to obtain mesoporous bioactive glass microspheres;

[0017] S2. Disperse the mesoporous bioactive glass microspheres into an ethanol aqueous solution to obtain a uniformly dispersed suspension. Add a zinc source and stir. Under alkaline conditions, zinc hydroxide is in-situ deposited in the mesopores of the mesoporous bioactive glass microspheres, and after heat treatment, bioactive glass microspheres with piezoelectric properties are obtained.

[0018] Preferably, the hydrolysis catalyst in S1 is triethanolamine or ammonia water, and the template agent is cetyltrimethylammonium bromide;

[0019] When the hydrolysis catalyst in S1 is ammonia water, it is 37% ammonia water.

[0020] Preferably, the silicon source in S1 is tetraethyl orthosilicate; the calcium source is calcium nitrate tetrahydrate or calcium chloride or calcium acetate; the zinc source is zinc nitrate hexahydrate or zinc acetate.

[0021] The post-treatment in S1 includes centrifugation, washing and drying. The drying is freeze-drying, and the freeze-drying parameters are 0.37 mbar, -30 to -50 °C;

[0022] The removal of the template agent in S1 is to remove the template agent by heat treatment. The temperature of the heat treatment is 500 - 700 °C, and the time is 2 - 4 h.

[0023] Preferably, the pH value range of the alkaline condition in S2 is 10.2 - 11.0;

[0024] The heat treatment conditions in S2 are: heat treatment at 500 - 700 °C for 2 - 5 h.

[0025] Preferably, the volume ratio of ethanol / water in the ethanol aqueous solution in S2 is 3:1.

[0026] Application of the above-mentioned bioactive glass microspheres with piezoelectric properties in tissue engineering.

[0027] Application of the above-mentioned bioactive glass microspheres with piezoelectric properties in sonodynamic promotion of tissue regeneration and repair.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] 1. By combining the methods of sol-gel method, template method and heat treatment, the prepared bioactive glass microspheres loaded with zinc oxide have a particle size of 80 - 100 nm, and the particle size distribution range is narrow and uniform;

[0030] 2. Compared with other bioactive glass microspheres, while retaining good biocompatibility and biodegradability, the microspheres have good piezoelectric response performance. After ultrasonic treatment, they can generate electrical stimulation through the piezoelectric effect and act on cells, which is beneficial to the in vitro odontogenic differentiation of hDPSCs and the angiogenesis of HUVEC;

[0031] 3. The zinc oxide loading can be regulated by the content of zinc nitrate hexahydrate in the formulation. The higher the zinc oxide loading, the better the piezoelectric response performance.

[0032] 4. The mesoporous bioactive glass microspheres loaded with zinc oxide prepared by the present invention can slowly release zinc oxide and reduce the toxicity of zinc oxide.

[0033] 5. The method of the present invention has a simple process, low cost, and is easy to mass-produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a process flow chart for the preparation of piezoelectric bioactive glass microspheres loaded with zinc oxide.

[0035] Figure 2 It is a scanning electron microscope image of the piezoelectric bioactive glass microspheres loaded with zinc oxide obtained in Example 1 of the present invention.

[0036] Figure 3 It is a hysteresis loop diagram of the piezoelectric bioactive glass microspheres loaded with zinc oxide obtained in Example 1 of the present invention by piezoresponse force microscopy.

[0037] Figure 4 It is a butterfly curve diagram of the piezoelectric bioactive glass microspheres loaded with zinc oxide obtained in Example 1 of the present invention by piezoresponse force microscopy.

[0038] Figure 5 It is a scanning electron microscope image of the piezoelectric bioactive glass microspheres loaded with zinc oxide obtained in Example 2 of the present invention.

[0039] Figure 6 It is a hysteresis loop diagram of the piezoelectric bioactive glass microspheres loaded with zinc oxide obtained in Example 2 of the present invention by piezoresponse force microscopy.

[0040] Figure 7 It is a butterfly curve diagram of the piezoelectric bioactive glass microspheres loaded with zinc oxide obtained in Example 2 of the present invention by piezoresponse force microscopy.

[0041] Figure 8 It is a cell proliferation diagram obtained by the CCK-8 method for the co-culture of Example 1 of the present invention with hDPSC.

[0042] Figure 9 It is a cell proliferation diagram obtained by the CCK-8 method for the co-culture of Example 2 of the present invention with hDPSC.

[0043] Figure 10 It is a schematic diagram of the ultrasonic treatment for the co-culture of the piezoelectric bioactive glass microspheres loaded with zinc oxide and hDPSCs.

[0044] Figure 11It is the ALP activity staining map obtained by co-culturing Example 2 of the present invention with hDPSCs and subjecting the co-culture control blank group of Example 2 and hDPSCs to ultrasonic treatment.

[0045] Figure 12 It is the HUVEC angiogenesis test map obtained by co-culturing Example 2 of the present invention with HUVEC and subjecting the co-culture control blank group of Example 2 and HUVEC to ultrasonic treatment.

[0046] Figure 13 It is the MTT cell survival rate map obtained by co-culturing Example 2 of the present invention and nano-zinc oxide with L929 cells respectively. Detailed implementation manners

[0047] The following further describes the present invention in detail with reference to specific embodiments. However, the implementation manners of the present invention are not limited thereto. For process parameters not specifically noted, conventional techniques can be referred to.

[0048] The mass fraction of zinc oxide is determined by inductively coupled plasma testing (ICP testing).

[0049] The relevant tests for piezoelectric coefficient and piezoelectric properties are determined by piezoresponse force microscopy.

[0050] Example 1

[0051] The preparation method of the piezoelectric bioactive glass microspheres loaded with zinc oxide provided in this example is as follows: First, mesoporous bioactive glass microspheres are prepared by the sol-gel templating method. Then, using the mesopores on the surface of the microspheres, positively charged zinc ions are in-situ deposited in the mesopores of the microspheres under an alkaline environment, and bioactive glass microspheres loaded with zinc oxide with piezoelectric properties are obtained through heat treatment, specifically as follows:

[0052] (1) Dissolve 0.1331 g of the hydrolysis catalyst triethanolamine (TEAH3) in 30 ml of deionized water, stir for 10 min at a temperature of 30 °C to obtain a triethanolamine solution;

[0053] (2) Add 0.2 g of the mesoporous template cetyltrimethylammonium bromide (CTAB) to the system in step (1), stir for 30 min at a temperature of 30 °C to obtain a CTAB micelle solution;

[0054] (3) Add 2 ml of tetraethyl orthosilicate (TEOS) to the system in step (2), stir for 20 min to obtain a TEOS solution;

[0055] (4) Add 0.9 g of calcium nitrate tetrahydrate (CN) to the system in step (3), stir for 24 h to carry out a dehydration condensation reaction to form amorphous-structured bioactive glass microspheres of silicon dioxide and calcium oxide;

[0056] (5) Centrifuge the amorphous structured bioactive glass microspheres obtained in step (4), wash them three times with deionized water, and then freeze-dry for 24 h. The freeze-drying parameters are 0.37 mbar and -30 °C to obtain a white solid.

[0057] (6) Calcinate the white solid synthesized in step (5) at 600 °C for 3 h to remove the template agent. The calcination heating rate is 2 °C / min to obtain mesoporous bioactive glass microspheres composed of silicon dioxide and calcium oxide.

[0058] (7) Add 200 mg of the microspheres synthesized in step (6) to 20 ml of an ethanol aqueous solution, where the volume ratio of alcohol to water is 3:1. After ultrasonic dispersion and stirring for 10 min, a uniformly dispersed suspension is obtained.

[0059] (8) Dissolve 38.5 mg of zinc nitrate hexahydrate in 10 ml of deionized water and stir for 5 min to obtain a zinc nitrate solution.

[0060] (9) Add ammonia water with a mass concentration of 37% to the system in step (8) and adjust the pH to 10.2.

[0061] (10) Add the solution obtained in step (9) to the system in step (7), and add ammonia water with a mass concentration of 37% to the mixed suspension. Adjust the pH to 10.2 and stir for 24 h to in-situ deposit zinc hydroxide in the mesopores of the bioactive glass microspheres.

[0062] (11) Centrifuge the suspension obtained in step (10), take the white precipitate, wash it three times with deionized water, and then freeze-dry for 24 h. The freeze-drying parameters are 0.37 mbar and -30 °C to obtain a white solid.

[0063] (12) Calcinate the white solid synthesized in step (11) at 600 °C for 3 h. The calcination heating rate is 3 °C / min. Calcination converts zinc hydroxide to zinc oxide to obtain piezoelectric bioactive glass microspheres loaded with zinc oxide. The composition of the piezoelectric bioactive glass microspheres loaded with zinc oxide is 93.4 wt% SiO2 - 1 wt% CaO - 5.6 wt% ZnO.

[0064] The obtained piezoelectric bioactive glass microspheres loaded with zinc oxide have an average particle size of 87 nm, a mesopore diameter of 3.4 nm, a specific surface area of 274 m 2 / g, a pore volume of 0.515 cc / g, a zinc oxide mass fraction of 5.6%, and a piezoelectric coefficient of 0.53 pC / N.

[0065] Figure 2It is the scanning electron microscope image of the zinc oxide-loaded bioactive glass microspheres obtained in Example 1 of the present invention, indicating that the microspheres in Example 1 have uniform particle sizes, with an average particle size of 87 nm, a regular spherical morphology, and good dispersion.

[0066] Figure 3 It is the hysteresis loop diagram of the zinc oxide-loaded bioactive glass microspheres obtained in Example 1 of the present invention by piezoresponse force microscopy. The 180° phase conversion indicates that the microspheres in Example 1 possess piezoelectric properties.

[0067] Figure 4 It is the butterfly curve diagram of the zinc oxide-loaded bioactive glass microspheres obtained in Example 1 of the present invention by piezoresponse force microscopy. With the change of the external voltage, the obvious amplitude change shown by the microspheres further characterizes that the microspheres in Example 1 have piezoelectric properties.

[0068] Example 2

[0069] The preparation method of the mesoporous bioactive glass microspheres loaded with zinc oxide provided in this example is as follows:

[0070] (1) Dissolve 0.1331 g of triethanolamine (TEAH3) in 30 ml of deionized water, stir for 10 min at a temperature of 30 °C to obtain a triethanolamine solution;

[0071] (2) Add 0.2 g of cetyltrimethylammonium bromide (CTAB) to the system in step (1), stir for 30 min at a temperature of 30 °C to obtain a CTAB micelle solution;

[0072] (3) Add 2 ml of tetraethyl orthosilicate (TEOS) to the system in step (2), stir for 20 min to obtain a TEOS solution;

[0073] (4) Add 0.9 g of calcium nitrate tetrahydrate (CN) to the system in step (3), stir for 24 h to carry out a dehydration condensation reaction to form amorphous-structured bioactive glass microspheres of silicon dioxide and calcium oxide;

[0074] (5) Centrifuge the amorphous-structured bioactive glass microspheres in step (4), wash them 3 times with deionized water, and then freeze-dry for 24 h. The freeze-drying parameters are 0.37 mbar and -30 °C to obtain a white solid;

[0075] (6) Calcinate the white solid synthesized in step (5) at 600 °C for 3 h to remove the template agent. The calcination heating rate is 2 °C / min to obtain mesoporous bioactive glass microspheres composed of silicon dioxide and calcium oxide;

[0076] (7) Add 200 mg of the microspheres synthesized in step (6) to 20 ml of an ethanol aqueous solution, where the volume ratio of alcohol to water is 3:1. After ultrasonic dispersion and stirring for 10 min, a uniformly dispersed suspension is obtained;

[0077] (8) Dissolve 81.2 mg of zinc nitrate hexahydrate in 10 ml of deionized water and stir for 5 min;

[0078] (9) Add ammonia water with a mass concentration of 37% to the system in step (8) and adjust the pH to 10.2;

[0079] (10) Add the solution obtained in step (9) to the system in step (7), and add ammonia water with a mass concentration of 37% to the mixed suspension. Adjust the pH to 10.2 and stir for 24 h;

[0080] (11) Centrifuge the suspension obtained in step (10), take the white precipitate, wash it 3 times with deionized water, and then freeze-dry it for 24 h. The freeze-drying parameters are 0.37 mbar and -30 °C to obtain a white solid;

[0081] (12) Calcinate the white solid synthesized in step (11) at 600 °C for 3 h. The calcination heating rate is 3 °C / min. The calcination converts zinc hydroxide to zinc oxide to obtain piezoelectric bioactive glass microspheres loaded with zinc oxide. The composition of the piezoelectric bioactive glass microspheres loaded with zinc oxide is 87.8 wt% SiO2 - 1 wt% CaO - 11.2 wt% ZnO.

[0082] The obtained piezoelectric bioactive glass microspheres loaded with zinc oxide have an average particle size of 87 nm, a mesopore aperture of 3.0 nm, a specific surface area of 228 m 2 / g, a pore volume of 0.42 cc / g, a zinc oxide mass fraction of 11.2%, and a piezoelectric coefficient of 1.06 pC / N.

[0083] Figure 5 is the scanning electron microscope image of the bioactive glass microspheres loaded with zinc oxide obtained in Example 2 of the present invention, indicating that the microspheres in Example 2 have a uniform particle size, an average particle size of 87 nm, a regular spherical morphology, good dispersion, and the increase in the zinc oxide content does not change the average particle size of the microspheres, indicating that zinc oxide is mainly deposited in the mesopores of the microspheres.

[0084] Figure 6 is the hysteresis loop diagram obtained by piezoresponse force microscopy of the bioactive glass microspheres loaded with zinc oxide obtained in Example 2 of the present invention. The 180° phase conversion indicates that the microspheres in Example 2 have piezoelectric properties.

[0085] Figure 7This is the butterfly curve graph obtained by piezoresponse force microscopy for the zinc oxide-loaded bioactive glass microspheres obtained in Example 2 of the present invention. With the change of the external voltage, the microspheres exhibit more obvious amplitude changes than those in Example 1, further characterizing that the microspheres in Example 2 have better piezoelectric properties than those in Example 1.

[0086] Example 3

[0087] The preparation method of the mesoporous bioactive glass microspheres loaded with zinc oxide provided in this example is as follows:

[0088] (1) Dissolve 0.1331 g of triethanolamine (TEAH3) in 30 ml of deionized water, stir for 10 min at a temperature of 30 °C to obtain a triethanolamine solution;

[0089] (2) Add 0.2 g of cetyltrimethylammonium bromide (CTAB) to the system in step (1), stir for 30 min at a temperature of 30 °C to obtain a CTAB micelle solution;

[0090] (3) Add 2 ml of tetraethyl orthosilicate (TEOS) to the system in step (2), stir for 20 min to obtain a TEOS solution;

[0091] (4) Add 0.9 g of calcium nitrate tetrahydrate (CN) to the system in step (3), stir for 24 h to carry out a dehydration condensation reaction to form amorphous-structured bioactive glass microspheres of silicon dioxide and calcium oxide;

[0092] (5) Centrifuge the amorphous-structured bioactive glass microspheres in step (4), wash them 3 times with deionized water, and then freeze-dry them for 24 h. The freeze-drying parameters are 0.37 mbar and -30 °C to obtain a white solid;

[0093] (6) Calcinate the white solid synthesized in step (5) at 600 °C for 3 h to remove the template agent. The calcination heating rate is 2 °C / min to obtain mesoporous bioactive glass microspheres with a composition of silicon dioxide and calcium oxide;

[0094] (7) Add 200 mg of the microspheres synthesized in step (6) to 20 ml of an ethanol aqueous solution, where the volume ratio of alcohol to water is 3:1. After ultrasonic dispersion and stirring for 10 min, a uniformly dispersed suspension is obtained;

[0095] (8) Dissolve 129 mg of zinc nitrate hexahydrate in 10 ml of deionized water and stir for 20 min;

[0096] (9) Add ammonia water with a mass concentration of 37% to the system in step (8) and adjust the pH to 10.2;

[0097] (10) Add the solution obtained in step (9) to the system of step (7), add ammonia water with a mass concentration of 37% to the mixed suspension, adjust the pH to 10.2, stir for 24 h, and in-situ deposit zinc hydroxide in the mesopores of the bioactive glass microspheres;

[0098] (11) Centrifuge the suspension obtained in step (10), take the white precipitate, wash it 5 times with deionized water, and then freeze-dry it for 24 h. The freeze-drying parameters are 0.37 mbar and -30 °C to obtain a white solid;

[0099] (12) Calcinate the white solid synthesized in step (11) at 600 °C for 5 h. The calcination heating rate is 3 °C / min. The calcination converts zinc hydroxide into zinc oxide to obtain piezoelectric bioactive glass microspheres loaded with zinc oxide.

[0100] The obtained piezoelectric bioactive glass microspheres loaded with zinc oxide have an average particle size of 87 nm, a zinc oxide mass fraction of 17.3%, and the composition of the piezoelectric bioactive glass microspheres loaded with zinc oxide is 82.2 wt% SiO2 - 0.5 wt% CaO - 17.3 wt% ZnO.

[0101] Test Example 1 Cell Compatibility Test

[0102] Test method: Use the CCK-8 method to perform cell proliferation tests on hDPSCs (5×10 3 cells / well) co-cultured with the blank control and Example 1 and Example 2 for 1, 3, and 5 days. The CCK-8 reagent and the complete medium are configured into a working solution according to a volume ratio of 1:9. Remove the complete medium containing the material co-cultured with the cells for 1 d, 3 d, and 5 d respectively, add 200 μl of the CCK-8 working solution to each well, and continue to culture in the incubator for 1 h. Subsequently, aspirate 100 μl of the working solution from each well of the well plate and transfer it to a new 96-well plate, and use a microplate reader (Thermo3001, Thermo, USA) to measure the absorbance value (OD value) of the solution at 450 nm. 6 parallel samples are measured for each group.

[0103] The test results are as Figure 8 、 9 shown:

[0104] The results of CCK-8 show that the proliferation rate of hDPSCs on the piezoelectric bioactive glass microspheres loaded with zinc oxide prepared in Example 1 and Example 2 is relatively fast, indicating that the microspheres have good cell compatibility.

[0105] Test Example 2 Odontogenic Ability Test - Verification of the Sonodynamic Effect of Bioactive Glass Microspheres Loaded with Zinc Oxide at the Cellular Level

[0106] Test method: hDPSCs (1×10 5After co - culturing with the blank control group, Example 2, and the ultrasonic - treated Example 2 for 7 days and 14 days at a density of [[number of cells per well]], the alkaline phosphatase (ALP) activity secreted by hDPSCs was qualitatively detected using an ALP activity kit.

[0107] The ultrasonic treatment step was to apply ultrasonic coupling agent to the bottom of the well plate of the corresponding group, and place the ultrasonic probe directly facing the bottom of the well plate for ultrasonic treatment. The ultrasonic parameters of the ultrasonic treatment instrument were 1 MHz, 400 mW / cm 2 , and a 20% duty cycle.

[0108] The test results are as Figure 11 shown:

[0109] The hDPSCs in the ultrasonic - treated Example 2 had higher ALP activity compared to the blank control group and the non - ultrasonic group, indicating stronger odontogenic differentiation ability of the cells. It shows that in Example 2 of the present invention, after ultrasonic treatment, an electrical stimulation can be generated through the piezoelectric effect and act on the cells, and this electrical stimulation is beneficial to the in vitro odontogenic differentiation of hDPSCs.

[0110] Test Example 3 Angiogenic test - Verification of the sonodynamic effect of zinc - oxide - loaded bioactive glass microspheres at the cellular level

[0111] Test method: Three groups were set up, with five parallel samples in each group. The first group was the blank control group where HUVECs were normally cultured for 2 days. The second group co - cultured HUVECs with Example 2 for 2 days. The third group co - cultured HUVECs with Example 2 and performed ultrasonic treatment for 2 days. After digesting the cells, they were mixed with Matrigel at a density of 3×10 4 cells per well and cultured for 4 - 6 h to observe the formation of HUVEC tubular structures.

[0112] The results are as Figure 12 shown:

[0113] The more obvious the HUVEC tubular and reticular structures are, the better the angiogenic ability. The results show that after ultrasonic treatment, the HUVECs co - cultured with Example 2 showed better angiogenic ability. To further verify the sonodynamic effect of zinc - oxide - loaded bioactive glass microspheres at the cellular level, in Example 2 of the present invention, the electric potential generated after ultrasonic treatment can cause the cells to be electrically stimulated and promote cell angiogenesis.

[0114] Test Example 4 Sustained - release effect - MTT test

[0115] Test method: L929 cells were co - cultured with mesoporous bioactive glass microspheres, Example 1, and nano - zinc oxide (particle size 90 ± 10 nm). The zinc oxide content in the medium containing Example 1 and the medium containing nano - zinc oxide was kept the same, with a content of 5.6 μg / ml. The cell viability after 1 - day co - culture was detected using the MTT method.

[0116] The results are as Figure 13 shown below:

[0117] At the same zinc oxide concentration, the average cell survival rate of the nano-zinc oxide group was 59.8%, which was significantly lower than that of Example 2 group. The average cell survival rate of Example 2 group was 99.0%. Example 2 of the present invention has better cell compatibility compared with nano-zinc oxide. The piezoelectric bioactive glass microspheres of the present invention have a certain effect of slowly releasing zinc oxide and reducing the toxicity of zinc oxide.

[0118] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A bioactive glass microsphere with piezoelectric properties, characterized in that, The bioactive glass microspheres with piezoelectric properties use mesoporous bioactive glass microspheres as the framework, and the piezoelectric material is in-situ deposited in the mesopores of the mesoporous bioactive glass microspheres.

2. The bioactive glass microspheres with piezoelectric properties according to claim 1, characterized in that, The mass fraction of the piezoelectric material is 5-20%, and the piezoelectric material is ZnO.

3. The bioactive glass microspheres with piezoelectric properties according to claim 2, characterized in that, The composition of the mesoporous bioactive glass microspheres is SiO2 and CaO.

4. The bioactive glass microspheres with piezoelectric properties according to claim 3, characterized in that, The composition of the bioactive glass microspheres with piezoelectric properties is 82-94 wt% SiO2 - 0.1-1 wt% CaO - 5-20 wt% ZnO; The particle size of the bioactive glass microspheres with piezoelectric properties is 80-100 nm, and the pore diameter of the mesopores is 2-10 nm.

5. A method for preparing the bioactive glass microspheres with piezoelectric properties according to any one of claims 1 to 4, characterized in that, It includes the following steps: S1. Add a hydrolysis catalyst and a template agent to water in sequence to obtain a micellar solution, then add a silicon source and a calcium source in proportion and stir to carry out a dehydration condensation reaction to obtain amorphous-structured bioactive glass microspheres. After post-treatment to remove the template agent, mesoporous bioactive glass microspheres are obtained; S2. Disperse the mesoporous bioactive glass microspheres into an ethanol aqueous solution to obtain a uniformly dispersed suspension. Add a zinc source in proportion and stir. Under alkaline conditions, zinc hydroxide is in-situ deposited in the mesopores of the mesoporous bioactive glass microspheres. After heat treatment, bioactive glass microspheres with piezoelectric properties are obtained.

6. The preparation method of the bioactive glass microspheres with piezoelectric properties according to claim 5, characterized in that, The hydrolysis catalyst in S1 is triethanolamine or ammonia water; the template agent is cetyltrimethylammonium bromide.

7. The preparation method of the bioactive glass microspheres with piezoelectric properties according to claim 5, characterized in that, The silicon source in S1 is tetraethyl orthosilicate, the calcium source is calcium nitrate tetrahydrate or calcium chloride or calcium acetate, and the zinc source is zinc nitrate hexahydrate or zinc acetate; The post-treatment in S1 includes centrifugation, washing, and drying; The removal of the template agent in S1 is to remove the template agent by heat treatment. The temperature of the heat treatment is 500-700 °C, and the time is 2-4 h.

8. The preparation method of the bioactive glass microspheres with piezoelectric properties according to claim 5, characterized in that, The pH value range of the alkaline condition in S2 is 10.2-11.0; The heat treatment conditions in S2 are: heat treatment at 500-700 °C for 2-5 h.

9. The application of the bioactive glass microspheres with piezoelectric properties according to any one of claims 1-4 in tissue engineering.

10. The application of the bioactive glass microspheres with piezoelectric properties according to any one of claims 1-4 in sonodynamic promotion of tissue regeneration and repair.

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