Nanoborate bioactive glass, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of preparation of biomedical materials. Disclosed are nanoborate bioactive glass, and a preparation method therefor and a use thereof. The method comprises: adding a surfactant into an aqueous dispersion of ethyl acetate to form a microemulsion system and adjusting the pH to alkaline to obtain an alkaline microemulsion system; sequentially adding a boron source, a calcium source, and a phosphorus source into the alkaline microemulsion system for reaction to obtain a precursor solution; and after precipitation, collecting, washing, and drying a precipitate and then calcining the dried precipitate to obtain the nanoborate bioactive glass. The present invention does not require high temperatures, has mild and controllable process conditions, can ensure that the prepared monodisperse borate bioactive glass has stable properties, and overcomes the problems that existing high-temperature melting methods cannot realize preparation of nanoborate bioactive glass and existing sol-gel methods have low synthesis efficiency and safety, poor particle dispersion, and poor size controllability, leading to difficulties in nanoscale research and applications.

Description

A nano-borate bioactive glass, its preparation method and application Technical Field

[0001] This invention belongs to the field of biomedical material preparation technology, specifically relating to a nano-borate bioactive glass, its preparation method, and its application. Background Technology

[0002] Bioactive glasses (BG) are a class of materials capable of repairing, replacing, and regenerating the body, and forming bonds between tissues and materials. Composed of silicate glasses such as SiO2, P2O5, Na2O, and CaO, these glasses degrade in vivo at a rate matching bone formation, and their degradation products regulate cell proliferation and differentiation as well as promote the expression of osteogenic genes, making them widely used in tissue repair and regenerative medicine.

[0003] Silicate bioactive glasses (SBG) possess a unique network structure that allows them to simultaneously incorporate multiple elements essential for human metabolism, such as boron. Boron, a trace element in the human body, not only promotes the binding of calcium to bones, joints, and cartilage but also, as part of bone metabolism, synergistically exerts anti-inflammatory and antioxidant functions with vitamin D, calcium, and magnesium. Typically, boron is introduced to partially or completely replace the silicon-oxygen network, forming borosilicate or borate bioactive glasses. Due to the difference between boron's trivalent electron structure and silicon's tetravalent structure, borate glasses differ significantly from traditional silicon-based glasses in structure, thermodynamic properties, and in vitro and in vivo biological behavior, attracting widespread research interest. Borate bioactive glasses (BBG) are generally prepared via a melt-melting method, where boron-containing compounds are mixed with compounds containing calcium, phosphorus, etc., in a specific ratio, then melted in a noble metal or ceramic crucible at a high temperature of 1200℃~1500℃. Quenching then inhibits crystallization to obtain amorphous glass. This method is not only costly and energy-intensive, but also carries certain risks. The presence of volatile components during the melting process, coupled with the uneven distribution of these components, makes controlling the glass composition challenging. Furthermore, glass prepared by the melt method is typically in block form and requires high-energy grinding and sieving before further use. The particles obtained from grinding are mostly micrometer-sized, exhibiting significant size variations and low bioactivity, which limits its research and application in the field of nanomedicine.

[0004] In recent years, researchers have explored the use of sol-gel processes to prepare nano-borate bioactive glasses. The sol-gel method utilizes liquid precursors to gel the glass network through hydrolysis and condensation reactions. Subsequently, the gel is dried and calcined to densify the amorphous glass and remove any organic products. However, the low network connectivity of borate glasses makes gelation difficult. To date, only a few studies have reported on the sol-gel processing of borate bioactive glasses, and these studies generally suffer from low synthesis efficiency, easy particle aggregation, and poor controllability of particle size, hindering their subsequent applications in the biomedical field. Technical issues

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a nano-borate bioactive glass, its preparation method and application, so as to solve the technical problems of complex preparation process, high energy consumption, low synthesis efficiency, easy agglomeration of glass products, poor size controllability, and difficulty in achieving good dispersibility in nano-sized preparation. Technical solutions

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] To achieve the above-mentioned objective, in a first aspect, the present invention provides a method for preparing monodisperse nano-borate bioactive glass, comprising the following steps:

[0008] 1) At a certain temperature, a surfactant is added to an aqueous dispersion of ethyl acetate to form a stable microemulsion system. The pH value is then adjusted to alkaline to obtain an alkaline microemulsion system.

[0009] 2) The boron source, calcium source and phosphorus source used to form borate bioactive glass are added sequentially to the above alkaline microemulsion to react and obtain a precursor solution;

[0010] 3) After the precursor solution has reacted and precipitated completely, collect the precipitate and wash and dry it.

[0011] 4) The dried and collected precipitate is calcined to obtain nano-borate bioactive glass.

[0012] Preferably, in step 1), the volume ratio of ethyl acetate to water in the aqueous dispersion of ethyl acetate is 1:(1~4).

[0013] More preferably, ethyl acetate is used as the oil phase of the reaction solvent, with the aim of forming a water-in-oil microemulsion reaction system with water, and the volume ratio of ethyl acetate to water in the aqueous dispersion of ethyl acetate is 1:(1.5~3).

[0014] Preferably, organic solvents such as cyclohexane that can form good microemulsion systems with water can be used as the oil phase in the reaction, but different water-in-oil systems involve different reaction conditions such as oil-water ratio.

[0015] Preferably, in step 1), the pH value is adjusted to alkaline using an alkali; the pH value range is 7.5~10.5;

[0016] More preferably, the pH value ranges from 7.5 to 9.5;

[0017] More preferably, the alkali includes at least one of inorganic alkali and organic alkali.

[0018] More preferably, the inorganic base is ammonia, sodium hydroxide, or potassium hydroxide, etc.; the organic base is triethanolamine, trimethylamine, or triethylamine, etc. Theoretically, as long as the pH value is within a suitable range, it is acceptable regardless of the type of alkaline reagent selected. However, further consideration should be given to avoid introducing other impurity ions during use.

[0019] Preferably, in step 1), the surfactant includes at least one of cationic surfactants such as dodecylamine, polyethylene glycol, or dodecyltrimethylammonium.

[0020] Preferably, in step 2), the boron source includes tributyl borate; the phosphorus source includes triethyl phosphate; and the calcium source includes calcium nitrate.

[0021] Preferably, the mass ratio of the boron source, phosphorus source, calcium source and surfactant is (20~90):(1~15):(10~65):(3~25);

[0022] More preferably, the mass ratio of the boron source, phosphorus source, calcium source and surfactant is (30~80):(2~10):(20~60):(5~20).

[0023] Preferably, in step 1), the certain temperature range is 20~80℃;

[0024] More preferably, the temperature range is 30~60℃.

[0025] Preferably, in step 4), the calcination temperature is 400~800 ℃; the sintering regime during the calcination process is: starting from room temperature, the temperature is increased at a rate of 3-15℃ / min.

[0026] More preferably, the calcination temperature is 500~700℃.

[0027] More preferably, the calcination treatment is carried out at a heating rate of 5-10℃ / min.

[0028] Secondly, the present invention provides a monodisperse nano-borate bioactive glass. The borate bioactive glass has the chemical composition aXO·bB2O3·cP2O5, where a, b, and c are mole fractions, a is 3-50, b is 40-96, c is 1-10, and X is Ca; alternatively, one or more of Mg and Sr may be selected.

[0029] The chemical composition of the nano-borosilicate bioactive glass is 3CaO·96B2O3·1P2O5, 12CaO·85B2O3·3P2O5, 25CaO·70B2O3·5P2O5, 30CaO·66B2O3·4P2O5, 42CaO·54B2O3·8P2O5, or 54CaO·42B2O3·4P2O5.

[0030] Preferably, the particle size of the nano-borosilicate bioactive glass is 20~800 nm.

[0031] More preferably, the particle size of the nano-borosilicate bioactive glass is 100~500 nm.

[0032] Thirdly, the present invention also discloses the application of the above-mentioned nano-borate bioactive glass in the preparation of biomedical materials.

[0033] Preferably, the biomedical material includes materials that promote tissue repair and regeneration. Beneficial effects

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] This invention selects ethyl acetate as the oil phase of the reaction solvent to form a water-in-oil microemulsion reaction system. A microemulsion-assisted sol-gel method is used to prepare borate bioactive glass, resulting in borate bioactive glass particles with a large specific surface area, controllable and uniform size, regular spherical shape, good dispersibility, and nanoscale particle size. Therefore, these particles exhibit high reactivity, high bioactivity, and rapid in vitro and in vivo degradation rates, allowing for direct use without subsequent grinding. The surface of the monodisperse borate bioactive glass is rich in active hydroxyl groups, providing a foundation for subsequent modification and applications. Furthermore, this invention does not require high temperatures, and the process conditions are mild and controllable, effectively ensuring the stable performance of the prepared monodisperse borate bioactive glass. It also significantly improves preparation efficiency and reduces costs, overcoming the limitations of existing high-temperature melting methods for preparing nano-borate bioactive glass, as well as the shortcomings of existing sol-gel methods, such as low synthesis efficiency and safety, poor particle dispersibility, and poor size control, making it difficult to obtain glass suitable for nanoscale research and applications.

[0036] Furthermore, the pH was adjusted to alkaline because tributyl borate hydrolyzes rapidly under acidic or even neutral conditions to form boric acid and butanol. If the hydrolysis rate is too fast, it cannot participate in the reaction at a rate matching the formation of bioactive glass, resulting in a significant loss of the boron source during the reaction. An alkaline / weakly alkaline emulsion system inhibits the hydrolysis of tributyl borate to some extent, allowing the boron source to be retained in the oil phase after its addition. When a calcium source is added, calcium ions continuously consume the boric acid formed from the hydrolysis of tributyl borate, further promoting the hydrolysis reaction of tributyl borate in the forward direction and continuously combining with calcium ions to form bioactive glass precursors. The boron source can then undergo hydrolysis at a rate matching that of bioactive glass. Attached Figure Description

[0037] Figure 1 is a schematic diagram of the process flow for preparing the nano-borate bioactive glass of the present invention;

[0038] Figure 2 is a scanning electron microscope image of the nano-borate bioactive glass of Example 1 of the present invention; wherein, the left image is a SEM image magnified 20,000 times, and the right image is a SEM image magnified 100,000 times.

[0039] Figure 3 is a scanning electron microscope image of the nano-borate bioactive glass of Example 2 of the present invention; wherein, the left image is a SEM image magnified 20,000 times, and the right image is a SEM image magnified 100,000 times.

[0040] Figure 4 is a scanning electron microscope image of the nano-borate bioactive glass of Example 3 of the present invention; wherein, the left image is a SEM image magnified 20,000 times, and the right image is a SEM image magnified 100,000 times.

[0041] Figure 5 shows a transmission electron microscope image and mapping diagram of the nano-borate bioactive glass of Example 3 of the present invention.

[0042] Figure 6 is a scanning electron microscope (SEM) image of the borate bioactive glass prepared by the melting method in Comparative Example 1 of this invention; wherein, the left image is a SEM image magnified 20,000 times, and the right image is a SEM image magnified 100,000 times.

[0043] Figure 7 is a scanning electron microscope (SEM) image of the borate bioactive glass prepared by the sol-gel method in Comparative Example 2 of this invention; the left image is a SEM image magnified 20,000 times, and the right image is a SEM image magnified 100,000 times. Embodiments of the present invention

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0046] The mass of each component mentioned in the specification of this invention can refer not only to the specific content of each component, but also to the proportional relationship between the masses of the components. Therefore, any scaling up or down of the content of each component according to the specification of this invention is within the scope disclosed in the specification of this invention. Specifically, the mass mentioned in the specification of this invention can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0047] The present invention will now be described in further detail with reference to the accompanying drawings:

[0048] This invention provides a method for preparing nano-borate bioactive glass. The preparation process of the nano-borate bioactive glass is shown in Figure 1, and includes the following steps:

[0049] S01: A stable microemulsion system is formed by adding a surfactant to an aqueous dispersion of ethyl acetate;

[0050] S02: The boron source, calcium source and phosphorus source used to form borate bioactive glass are added sequentially to the above microemulsion at a certain temperature and stirred thoroughly to obtain a precursor solution;

[0051] S03: After the precursor solution has reacted and precipitated completely, collect the precipitate and wash and dry it.

[0052] S04: The collected and dried precipitate is calcined.

[0053] Specifically, in step S01, ethyl acetate is dispersed in an aqueous solution to form an oil-in-water microemulsion to induce the shape and size of the particles. The template agent has both a structure guiding effect and is used to maintain the stability of the microemulsion droplets.

[0054] Furthermore, surfactants such as CTAB (hexadecyltrimethylammonium bromide) were selected as template agents. On the one hand, CTAB can stabilize the oil-water interface and maintain the stability of the microemulsion, making the microemulsion droplets stable spherical shapes, resulting in more regular morphology and more uniform size of the nanoparticles prepared subsequently. On the other hand, the removal of CTAB during the subsequent calcination process is expected to improve the pore structure of the nanoparticles.

[0055] Preferably, in a specific embodiment, the stable microemulsion system described in step S01 is preferably prepared according to the following method:

[0056] S011: Add a certain amount of deionized water to a beaker and preheat it to the specified temperature in a water bath;

[0057] S012: Add a certain amount of ethyl acetate to preheated deionized water and mix to obtain the first mixed system;

[0058] S013: Add a surfactant to the first mixture and add an alkali to adjust the pH value to obtain the second mixture, namely the stable microemulsion system;

[0059] In step S011, the temperature range is 20℃~60℃.

[0060] In step S012, during the process of mixing to obtain the first mixed system, ethyl acetate and water should be fully mixed, such as by means of magnetic stirring to accelerate the mixing process; the volume ratio of ethyl acetate to water is 1:(1~4), preferably 1:(1.5~3).

[0061] In step S013, the surfactant should be fully dissolved during the addition process. This can be achieved by using methods such as magnetic stirring or heating to accelerate the dissolution. The surfactant may include at least one cationic surfactant such as dodecylamine, polyethylene glycol, or dodecyltrimethylammonium, with a mass fraction ranging from 5% to 20%. The addition of an alkali to adjust the pH value includes inorganic alkalis such as ammonia and organic alkalis such as triethanolamine. The pH value is further preferably in the range of 7.8 to 9.6.

[0062] Specifically, in step S02, the precursor solution is preferably prepared according to the following method:

[0063] S021: The boron source is added to the second mixing system for mixing treatment to obtain a third mixing system;

[0064] S022: The phosphorus source is added to the third mixing system for mixing treatment to obtain the fourth mixing system;

[0065] S023: The calcium source is added to the fourth mixing system for mixing to obtain the precursor solution;

[0066] In step S021, the boron source is preferably added to the second mixing system in multiple batches, i.e., slowly. During the addition process, stirring and heating are preferably maintained, with water bath heating being the preferred heating method. After the addition is complete, stirring continues for at least 30 minutes. In one embodiment, the boron source is preferably tributyl borate.

[0067] In step S022, the phosphorus source is preferably added to the third mixing system in multiple batches, i.e., slowly. During the addition process, stirring and heating are preferably maintained, with water bath heating being the preferred heating method. After the addition is complete, stirring continues for at least 30 minutes. In one embodiment, the phosphorus source is preferably triethyl phosphate.

[0068] In step S023, the calcium source is preferably added to the fourth mixing system in multiple batches, i.e., slowly. During the addition process, stirring and heating are preferably maintained, with water bath heating being the preferred heating method. After the addition is complete, stirring continues for at least 30 minutes. In one embodiment, the calcium source is preferably calcium nitrate.

[0069] The reason for considering adding the nanoparticles in batches is that adding them simultaneously would cause severe agglomeration of the nanoparticles, affecting the product performance.

[0070] The amount of boron source, phosphorus source and calcium source added to form borate bioactive glass can be added according to the proportion of borate bioactive glass. For example, in one embodiment, the molar ratio of the boron source, phosphorus source and calcium source is controlled to be (30~80):(2~10):(20~60).

[0071] Therefore, by controlling and optimizing the preparation method of the mixed system in step S02 and further controlling and optimizing the proportion of each component, a stable sol-gel system can be effectively prepared, thereby further increasing the specific surface area of ​​borate bioactive glass particles, improving their size uniformity, making their particle size nanoscale, and improving their bioactivity.

[0072] In step S03, after the precursor solution has fully undergone the precipitation reaction, solid-liquid separation is performed, and the precipitate is collected, such as by centrifugation. Washing the precipitate removes impurities such as residual solvent and reactants that have not undergone precipitation. In one embodiment, the precipitate can be washed with water or alcohol. In a specific embodiment, after washing three times alternately with deionized water and ethanol, the resulting white precipitate is placed in a vacuum drying oven and dried for 12 hours.

[0073] In step S04, the precipitate is calcined to generate nano-borate bioactive glass, wherein the template agent and other components are removed.

[0074] In one embodiment, the calcination temperature is 400-800 °C, preferably 500-700 °C, and more specifically, 500 °C. The calcination time should be sufficient, such as 2-4 h, preferably 3 h. The heating rate of the calcination treatment ranges from 5 to 10 °C / min, preferably, as in one embodiment, the heating rate is 10 °C / min to the calcination temperature. This calcination temperature can effectively ensure the formation of nano-borate bioactive glass and the removal of impurities, and also improves the regularity of the nanoparticle morphology and the uniformity of the size.

[0075] As described above, the preparation method of the nano-borate bioactive glass employs a microemulsion-assisted sol-gel method, resulting in borate bioactive glass particles with large specific surface area, uniform size, nanoscale particle size, safety, and high bioactivity. Furthermore, the preparation method features mild and easily controllable process conditions and low energy consumption, effectively ensuring the stable performance of the prepared borate bioactive glass. Moreover, it requires no post-processing such as grinding and can be used directly, thus effectively improving preparation efficiency and reducing production costs.

[0076] Furthermore, the preparation method of the aforementioned nano-borate bioactive glass endows the prepared borate bioactive glass with properties such as large specific surface area, uniform size, nanoscale particle size, safety, and high bioactivity. It can be further used as a raw material for various forms of bioactive glass materials, including films, coatings, fibers, and scaffolds. In addition, the extremely small size of the 100-300 nm nano-borate bioactive glass allows for endocytosis by cells, enabling the direct release of bioactive ions such as boron, calcium, and phosphorus into cells to stimulate and induce cell growth. This allows for the regulation of cell proliferation, differentiation, and gene expression at the nanoscale, demonstrating broad research and application value.

[0077] The following examples illustrate the preparation method of nano-borate bioactive glass according to the present invention through several specific embodiments and comparative examples.

[0078] Example 1

[0079] This embodiment provides a method for preparing nano-borate bioactive glass, the steps of which are as follows:

[0080] 1) Accurately measure 80 mL of water using a graduated cylinder, preheat a water bath at 40 ℃ for 5 min, then accurately weigh 1.4 g of cetyltrimethylammonium bromide, slowly add it to the water under magnetic stirring, stir for 15 min, and wait until the solution becomes clear and transparent to obtain a mixed solution.

[0081] 2) Accurately measure 40 mL of ethyl acetate and add it to the above mixed solution, then stir for 30 min;

[0082] 3) After a stable microemulsion is formed, accurately measure 8.87 mL of tributyl borate and slowly add it to the reaction system in step 2), and continue stirring for 30 min;

[0083] 4) Accurately measure 0.17 mL of triethyl phosphate and slowly add it dropwise to the reaction system in step 3). After the addition is complete, continue stirring for 30 min.

[0084] 5) Accurately weigh 1.42 g of calcium nitrate tetrahydrate and add it to the reaction system in step 4). After the calcium nitrate tetrahydrate is completely dissolved, continue stirring for 3 hours.

[0085] 6) Centrifuge the reaction system of step 5), discard the supernatant to obtain a white precipitate, wash it three times alternately with deionized water and ethanol, and then place the obtained white precipitate in a vacuum drying oven and dry it for 12 hours.

[0086] 7) The dried white precipitate was placed in a muffle furnace and heated to 500℃ (10℃ / min) from room temperature for 3 hours, then allowed to cool naturally to obtain a white powder, i.e., nano-sized borate bioactive glass. The molar ratio of the components in the bioactive glass prepared in this example is 66B2O3, 30CaO, and 4P2O5.

[0087] The white powder obtained in Example 1, which is the nano-borate bioactive glass, was sputter-coated with gold and observed under a scanning electron microscope (SEM). The results are shown in Figure 2. The synthesized borate bioactive glass consists of spherical particles with a uniform particle size distribution and a diameter between 100-300 nm.

[0088] Example 2

[0089] This embodiment provides a method for preparing nano-borate bioactive glass, the steps of which are as follows:

[0090] 1) Accurately measure 80 mL of water using a graduated cylinder, preheat a water bath at 40 ℃ for 5 min, then accurately weigh 1.4 g of cetyltrimethylammonium bromide, slowly add it to the water under magnetic stirring, stir for 15 min until the solution becomes clear and transparent to obtain a mixed solution;

[0091] 2) Accurately measure 40 mL of ethyl acetate and add it to the above mixed solution, then stir for 30 min;

[0092] 3) After a stable microemulsion is formed, accurately measure 7.26 mL of tributyl borate and slowly add it to the microemulsion, and continue stirring for 30 min.

[0093] 4) Accurately measure 0.17 mL of triethyl phosphate and slowly add it dropwise to the reaction system in step 3). After the addition is complete, continue stirring for 30 min.

[0094] 5) Accurately weigh 2.48 g of calcium nitrate tetrahydrate and add it to the reaction system in step 4). After the calcium nitrate tetrahydrate is completely dissolved, continue stirring for 3 hours.

[0095] 6) Centrifuge the reaction system obtained in step 5), discard the supernatant to obtain a white precipitate, wash it three times alternately with deionized water and ethanol, and then place the obtained white precipitate in a vacuum drying oven and dry it for 12 hours.

[0096] 7) The dried white precipitate was placed in a muffle furnace and heated to 500℃ (10℃ / min) from room temperature for 3 hours, followed by natural cooling to obtain a white powder, i.e., nano-sized borate bioactive glass. The molar ratio of the components in the bioactive glass prepared in this example is 5:4B₂O₃, 4:2CaO, and 4P₂O₅.

[0097] The white powder obtained in this embodiment, namely nano-borate bioactive glass, was sputter-coated with gold and observed under a scanning electron microscope (SEM). The results are shown in Figure 3. The synthesized borate bioactive glass consists of spherical particles with a uniform particle size distribution and a diameter between 100-300 nm.

[0098] Example 3

[0099] This embodiment provides a method for preparing nano-borate bioactive glass, the steps of which are as follows:

[0100] 1) Accurately measure 80 mL of water using a graduated cylinder, preheat a water bath at 40 ℃ for 5 min, then accurately weigh 1.4 g of cetyltrimethylammonium bromide, slowly add it to the water under magnetic stirring, stir for 15 min until the solution becomes clear and transparent, and obtain a mixed solution.

[0101] 2) Accurately measure 40 mL of ethyl acetate and add it to the above mixed solution, then stir for 30 min;

[0102] 3) After a stable microemulsion is formed, accurately measure 5.65 mL of tributyl borate and slowly add it to the microemulsion, and continue stirring for 30 min;

[0103] 4) Accurately measure 0.17 mL of triethyl phosphate and slowly add it dropwise to the reaction system in step 3). After the addition is complete, continue stirring for 30 min.

[0104] 5) Accurately weigh 3.19 g of calcium nitrate tetrahydrate and add it to the reaction system in step 4). After the calcium nitrate tetrahydrate is completely dissolved, continue stirring for 3 hours.

[0105] 6) After stirring for 3 hours, centrifuge the reaction system, discard the supernatant to obtain a white precipitate, wash it three times with deionized water and ethanol alternately, and then place the obtained white precipitate in a vacuum drying oven and dry it for 12 hours.

[0106] 7) The dried white precipitate was placed in a muffle furnace and heated to 500℃ (10℃ / min) from room temperature for 3 hours, then allowed to cool naturally to obtain a white powder, which is the nano-sized borate bioactive glass. The molar ratio of the components in the bioactive glass prepared in this example is 42B2O3, 54CaO and 4P2O5.

[0107] The white powder obtained in this embodiment, namely nano-borate bioactive glass, was sputter-coated with gold and observed under a scanning electron microscope (SEM). The results are shown in Figure 4. The synthesized borate bioactive glass consists of spherical particles with a uniform particle size distribution and a particle diameter between 100-300 nm.

[0108] To better demonstrate the microstructure and elemental distribution of the nano-borate bioactive glass, transmission electron microscopy (TEM) was used to measure the sample. Figure 5 shows the TEM image, high-angle annular dark-field image (HAADF), and EDX energy dispersive spectroscopy image of the sample's elemental composition and distribution. It can be clearly observed that the prepared nano-borate bioactive glass exhibits uniform spherical shape and a consistent particle size distribution, with particle diameters ranging from 100 to 300 nm. Boron, calcium, and phosphorus elements are evenly distributed, highlighting the advantages of this nano-borate bioactive glass preparation method.

[0109] Comparative Example 1:

[0110] This comparative example prepared a borate bioactive glass (BBG). The difference between this comparative example and the previous example is that a melting method was used. Simply put, the required boron source, calcium source, and phosphorus source were uniformly mixed and melted at 1200°C. After quenching, a glass block was formed, which was then crushed, ground, and sieved through a stainless steel sieve to obtain BBG particles (white powder) with a diameter of 40µm or smaller.

[0111] The white powder prepared in Comparative Example 1 was sputter-coated with gold and observed under SEM. The results are shown in Figure 6. The borate bioactive glass synthesized by the melt method has an irregular shape, poor particle dispersion and size uniformity, and the particle size can only reach the micrometer level, making it difficult to use for nanoscale research and application.

[0112] Comparative Example 2:

[0113] This comparative example prepared a borate bioactive glass (BBG). The difference between this comparative example and the previous example is that the sol-gel method reported in the literature was used. In simple terms, the required boron, calcium, and phosphorus sources were added in an orderly manner to a solution of nitric acid, water, and anhydrous ethanol, and stirred to obtain a transparent solution. This transparent solution was aged in a sealed bottle for 1 day, and then the solvent was evaporated by heating to obtain a transparent gel. After drying, the white precipitate was collected, calcined at high temperature, ground, and sieved until the particle size was less than 40 μm, thus obtaining the borate bioactive glass.

[0114] The white powder prepared in Comparative Example 2 was sputter-coated with gold and observed under SEM. The results are shown in Figure 7. The borate bioactive glass synthesized by the traditional sol-gel method has irregular shape, poor size controllability, and the particles are prone to agglomeration, making it difficult to use for nanoscale research and application.

[0115] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing nano-borate bioactive glass, characterized in that, include: At a certain temperature, a surfactant is added to an aqueous dispersion of ethyl acetate to form a microemulsion system, and the pH value is adjusted to alkaline to obtain an alkaline microemulsion system. Boron source, calcium source and phosphorus source were added sequentially to an alkaline microemulsion system to react and obtain a precursor solution; After the precursor solution reacts and precipitates, the precipitate is collected, washed, dried, and then calcined to obtain nano-borate bioactive glass.

2. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The surfactant used is a cationic surfactant; Preferably, the cationic surfactant includes at least one of dodecylamine, polyethylene glycol, and dodecyltrimethylammonium.

3. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The volume ratio of ethyl acetate to water in the aqueous dispersion of ethyl acetate is 1:(1~4).

4. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The pH value was adjusted to 7.5-10.5 using alkali. Preferably, an inorganic base or an organic base is used; More preferably, the inorganic base is ammonia, sodium hydroxide, or potassium hydroxide; the organic base is triethanolamine, trimethylamine, or triethylamine.

5. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The mass ratio of boron source, phosphorus source, calcium source and surfactant is (20~90):(1~15):(10~65):(3~25).

6. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The boron source includes tributyl borate; the phosphorus source includes triethyl phosphate; and the calcium source includes calcium nitrate.

7. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The specified temperature is 20~80℃; Preferably, the temperature is 30~60℃.

8. The method for preparing nano-borate bioactive glass according to claim 1, characterized in that, The calcination temperature is 400~800 ℃, and the treatment time is 2~4h; the sintering regime during the calcination process is: starting from room temperature, the temperature is increased at a rate of 3~15℃ / min. Preferably, the calcination temperature is 500~700℃ and the treatment time is 3h; the sintering regime during the calcination process is: starting from room temperature, the temperature is increased at a rate of 5~10℃ / min.

9. A nano-borate bioactive glass prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The chemical composition of the nano-borate bioactive glass is aXO·bB2O3·cP2O5, where a, b, and c are mole fractions, a is 3-50, b is 40-96, c is 1-10, and X is one or more of Ca, Mg, and Sr.

10. The nano-borate bioactive glass according to claim 9, characterized in that, The nano-borate bioactive glass is monodisperse, has a regular spherical shape, and a particle size of 20~800 nm. Preferably, the particle size is 100~500 nm.

11. The nano-borate bioactive glass according to claim 9, characterized in that, The chemical composition of the nano-borosilicate bioactive glass includes one or more of the following: 3CaO·96B2O3·1P2O5; 12CaO·85B2O3·3P2O5; 25CaO·70B2O3·5P2O5; 30CaO·66B2O3·4P2O5; 42CaO·54B2O3·4P2O5; 54CaO·42B2O3·4P2O5.

12. The application of the nano-borate bioactive glass according to any one of claims 9 to 11 in the preparation of biomedical materials.

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