CN104860538A - Method for preparing biological activity glass microspheres by macroporous carbon template - Google Patents

Abstract

The invention discloses a method for preparing biological activity glass microspheres by a macroporous carbon template and relates to the technical field of biomedical materials. A silicon source, a phosphorus source and a calcium source are used as raw materials, and three-dimensional ordered macroporous carbon is used as a template to synthesize several submicron-sized biological activity glass microspheres. The obtained biological activity glass microspheres have the advantages that the biological activity and the biological degradability are good, components are adjustable, the grain diameter is uniform, the dispersibility is good, and the like.

Description

Method for preparing bioactive glass microspheres with macroporous carbon template

technical field

The invention relates to the technical field of biomedical materials, in particular to a preparation method of submicron bioactive glass microspheres.

Background technique

Sub-micron biomaterials are an important part and development direction of research in the field of materials and medicine today, and sub-micron materials may become the core of biomedical materials in the 21st century. Bioactive glasses (Bioglasses, BGs) are the second generation of biodegradable biomaterials invented by Professor Larry L. Hench of the University of Florida in the early 1970s. They found that the components were divided into SiO ₂ -Na ₂ O - After the CaO-P ₂ O ₅ glass material is implanted in the organism, the components in the glass material can exchange or react with the components in the organism to form a strong chemical bond, and finally generate a material that is compatible with the organism itself. Substance that forms part of newborn bones and teeth. This kind of bioactive glass is not conventional glass, the mass percentage of SiO ₂ is only 45%, and the mass content of other components CaO, P ₂ O ₅ and Na ₂ O are 24.5%, 6% and 24.5% respectively That is, SiO ₂ (45)-Na ₂ O(24.5)-CaO(24.5)-P ₂ O ₅ (6) (wt%), which is now called commercial bioactive glass Bioglass ^® 45S5. As an important class of hard tissue repair materials, bioactive glass has excellent bioactivity and biocompatibility. The latest research also shows that bioactive glass also has cell and gene activation, which is critical for its hard tissue repair function. Since then, bioactive glass, as an important part of bioactive materials, has attracted more and more attention from the international biomaterials community.

Bioactive glass has good biological activity and can form a strong chemical bond with bone. It has attracted great attention from the international biomaterials community as soon as it came out. The types of bioactive glass mainly include: fusion bioactive glass, bioactive glass-ceramic and sol-gel bioactive glass. At present, bioglass used clinically is prepared by high-temperature melting method. Due to high-temperature volatilization and crucible materials, it is easy to cause fluctuations in the composition of bioglass, doping of harmful impurities, and uneven composition, making it difficult to control the structure and properties of the glass. In addition, the degradation performance of the material is poor. In recent years, due to the mild preparation conditions, the material composition and structure can be designed, the bioglass prepared by the sol-gel technology has high specific surface area, nanoporous structure, high biological activity, and adjustable degradation performance, making it highly Its research and application value is expected to become an important category of third-generation biomaterials. However, the biggest problem of sol-gel bioglass is that the particles are difficult to disperse, and its micro-nano structure, shape, and particle size are difficult to control, so that the micro-nano effect of the material is difficult to exert. Therefore, it is very necessary to find a method for preparing bioactive glass particles with high dispersion and controllable micro/nano structure, morphology and particle size.

Contents of the invention

The purpose of the present invention is to provide a method for preparing bioactive glass particles with high dispersibility, micro-nano structure, and controllable morphology and particle size.

The technical solution of the present invention is: firstly soak the macroporous carbon template with a pore diameter of 180-470nm in a mixed solution composed of silicon source, calcium source, inorganic acid, absolute ethanol and distilled water, and then place it in an oven at 60°C to dry. The composite of carbon template and glass xerogel is obtained; the composite of carbon template and glass xerogel is calcined at 600° C., ground and ultrasonically dispersed to obtain bioactive glass microsphere powder.

The microspheres prepared by using the three-dimensional ordered macroporous carbon template of the present invention have complete spherical structure, good dispersibility, uniform particle size, particle size deviation less than 5%, and the particle size can be controlled at 100-400nm, and have good biological activity. It can be degraded within 7-60 days in a body fluid environment or a simulated body fluid environment, and induces the formation of hydroxyapatite on the surface of the microsphere. The pore size of the carbon template is determined by the preparation method. In the present invention, the macroporous carbon template with a pore diameter of 180-470 nm can achieve better inventive effects.

When preparing the mixed solution, the present invention first mixes the silicon source, inorganic acid, distilled water and absolute ethanol to obtain a clear mixed solution, and then adds the calcium source. Step-by-step mixing can ensure that each component is fully mixed and uniform, and prevents the content of each component in the template from being different after the carbon template is soaked, which affects the uniformity of the components of the bioglass.

When the silicon source, mineral acid, distilled water and absolute ethanol are mixed, the phosphorus source is added at the same time. Whether to add a phosphorus source is determined by the type of bioactive glass to be prepared. For example, 70S30C bioactive glass does not require a phosphorus source, while 68S, 58S and 45S5 require a phosphorus source.

Add the sodium source at the same time as the calcium source. Whether to add a sodium source is determined by the type of bioglass to be prepared. For example, 45S5 bioactive glass requires a sodium source, while 68S, 58S and 70S30C do not need a sodium source.

The silicon source is tetraethyl orthosilicate. Tetraethyl orthosilicate can fully undergo hydrolysis reaction under acidic conditions and form a uniform and transparent sol solution.

The calcium source is calcium nitrate tetrahydrate, and the use of other calcium salts such as calcium chloride will incorporate a large amount of chloride ions, which cannot be removed in the subsequent treatment and will affect the biological glass.

The inorganic acid is nitric acid, and other inorganic acids such as hydrochloric acid will be mixed with chloride ions, and sulfuric acid will be mixed with sulfur elements, which cannot be removed in the subsequent treatment process and will affect the biological glass.

The sodium source is sodium nitrate. Sodium nitrate can not mix other elements and ions under the condition of providing sodium source, and the nitrate can be well removed in the subsequent treatment process.

The phosphorus source is triethyl phosphate. Triethyl phosphate can be hydrolyzed under acidic conditions to provide a phosphorus source and form a stable, uniform and transparent sol solution.

Description of drawings

Figure 1 is the SEM image of 58S bioactive glass.

Figure 2 is the DLS diagram of 58S bioactive glass.

Figure 3 is the XRD pattern of 58S bioactive glass.

Figure 4 is the EDS diagram of 58S bioactive glass.

Fig. 5 is the time-varying curve of Si, Ca, P concentration in SBF.

Figure 6 is the SEM image of 58S soaked in SBF for 1 day.

Figure 7 is the XRD pattern of 58S soaked in SBF for 0, 1, 3, 7, and 14 days.

Detailed ways

The present invention will be further described below in conjunction with examples, but not limited to implementation cases.

1. Implementation case 1 (58S does not require sodium source)

1. Preparation of 58S bioactive glass microspheres with different particle sizes:

(1) Stir 9.375g tetraethyl orthosilicate, 1.0875g triethyl phosphate, 7.5g absolute ethanol, 0.3g nitric acid solution (2mol/L), and 0.75g distilled water in a 50mL beaker for 2h.

(2) Add 6.375g calcium nitrate tetrahydrate to the above mixture, stir until completely dissolved.

(3) Four copies of the above solution were prepared in parallel.

(4) Immerse three-dimensionally ordered macroporous carbon templates with pore diameters of 470 nm, 350 nm, 250 nm, and 180 nm, respectively, and soak overnight.

(5) Place the 4 samples in an oven at 60°C and gel for 3 days until completely dry.

(6) Remove excess gel on the surface of the template, calcinate in a high-temperature furnace at 600°C for 3 hours, grind and ultrasonically disperse to obtain 4 parts of 58S (58%SiO ₂ -33%CaO-9%P ₂ O ₅ , wt %) bioactive glass microsphere powder.

The following table is the element composition list of 58S bioactive glass.

This table shows that the composition of the bioglass prepared by the present invention is consistent with the theoretical value, which proves that the prepared is 58S bioactive glass.

2. Effect analysis:

The 58S bioactive glass microspheres prepared from the 470 nm three-dimensional ordered macroporous carbon template have a complete spherical structure, uniform particle size, and a particle size deviation of less than 5%, as shown in Figure 1.

The average particle size of the 58S bioactive glass microspheres prepared from the 470 nm three-dimensional ordered macroporous carbon template is 320 nm, the particle size distribution coefficient PDI=0.152, and has good dispersion, as shown in Figure 2.

It can be seen from Figure 3 that the prepared 58S bioactive glass microspheres are amorphous non-crystalline materials. It can be seen from Figure 4 and the above table that the component ratio of the prepared 58S bioactive glass is consistent with the theoretical value.

The test also proved that the bioactive wave microspheres prepared by three-dimensional ordered macroporous carbon templates with different pore sizes of 470 nm, 350 nm, 250 nm, and 180 nm all have the same performance, but the particle size is different, because the preparation method same.

3. Bioactivity experiment of 58S bioactive glass microspheres:

(1) Soak 10 mg of 58S in 10 mL of simulated body fluid SBF (Simulated Body Fluid, pH=7.4, c(PO ₄ ^3- ) =0.01 M, SBF contains the same ions and ion concentration as human blood).

(2) Place in a constant temperature oscillator in a water bath with a constant temperature of 37°C and a rotational speed of 170 rpm to study the degradation behavior of BGs. It can be seen from Figures 5, 6, and 7 that the material prepared by the present invention has good degradation performance and biological activity through in vitro degradation experiments, and can generate hydroxyapatite in a short period of time, which can be well combined with bone tissue engineering. requirements.

It can be seen that the obtained 58S bioactive glass microspheres can degrade within 7-60 days in a body fluid environment or a simulated body fluid environment, and induce hydroxyapatite to form on the surface of the microspheres.

The test also proves that the bioactive wave microspheres prepared by three-dimensional ordered macroporous carbon templates with different pore sizes of 470 nm, 350 nm, 250 nm, and 180 nm all have bioactive properties.

2. Implementation case 2 (68S does not require sodium source)

1. Preparation of 68S bioactive glass microspheres with different particle sizes:

(1) Stir 12.23g tetraethyl orthosilicate, 1.145g triethyl phosphate, 7.5g absolute ethanol, 0.3g nitric acid solution (2mol/L), and 0.75g distilled water in a 50mL beaker for 2h.

(2) Add 4.825g calcium nitrate tetrahydrate and stir until completely dissolved.

(3) Four copies of the above solution were prepared in parallel.

(4) Immerse three-dimensionally ordered macroporous carbon templates with pore diameters of 470 nm, 350 nm, 250 nm, and 180 nm, respectively, and soak overnight.

(5) Place in an oven at 60°C for 3 days to gel until completely dry.

(6) Remove excess gel on the surface of the template, calcinate in a high-temperature furnace at 600°C for 3 hours, grind and ultrasonically disperse to prepare 68S (68%SiO ₂ -23%CaO-9%P ₂ O ₅ , wt%) biological Active glass microsphere powder.

2. The biological activity experiment is the same as in Example 1.

3. Effect analysis:

The prepared 68S bioactive glass microspheres of different sizes have a complete spherical structure, uniform particle size, and a particle size deviation of less than 5%; the average particle sizes are 120nm, 170nm, 230nm, and 320nm, respectively. The prepared 68S bioactive glass microspheres of different sizes are all amorphous and non-crystalline materials, and can degrade and induce the formation of hydroxyapatite in a short period of time. They have good degradation performance and biological activity, and can be well Composite bone tissue engineering requirements.

3. Implementation Case 3

1. Preparation of 45S5 bioactive glass microspheres with different particle sizes:

(1) Stir 7.812g tetraethyl orthosilicate, 0.774g triethyl phosphate, 0.8g nitric acid solution (2mol/L), and 12.15g distilled water in a 50mL beaker for 2h.

(2) Add 5.0182g of calcium chloride and 3.4g of sodium nitrate, and stir until completely dissolved.

(3) Four copies of the above solution were prepared in parallel.

(4) Immerse three-dimensionally ordered macroporous carbon templates with pore diameters of 470 nm, 350 nm, 250 nm, and 180 nm, respectively, and soak overnight.

(5) Place in an oven at 60°C for 3 days to gel until completely dry.

(6) Remove excess gel on the surface of the template, calcinate in a high-temperature furnace at 600°C for 3 hours, grind and ultrasonically disperse to obtain 45S5 (46.1%SiO ₂ -26.9%CaO-24.4%Na ₂ O-2.6%P ₂ O ₅ , wt%) bioactive glass microsphere powder.

2. The biological activity experiment is the same as in Example 1.

3. Effect analysis:

The prepared 45S5 bioactive glass microspheres of different sizes have a complete spherical structure, uniform particle size, and a particle size deviation of less than 5%; the average particle sizes are 120nm, 170nm, 230nm, and 320nm, respectively. The prepared 45S5 bioactive glass microspheres of different sizes are all amorphous and non-crystalline materials, and can degrade and induce the formation of hydroxyapatite in a short period of time. They have good degradation performance and biological activity, and can be well Composite bone tissue engineering requirements.

4. Implementation Case 4 (70S30C does not require phosphorus and sodium sources)

1. Preparation of 70S30C bioactive glass microspheres with different particle sizes:

(1) Stir 8.383g tetraethyl orthosilicate, 7.5g absolute ethanol, 0.3g nitric acid solution (2mol/L), and 0.75g distilled water in a 50mL beaker for 2h.

(2) Add 4.197g of calcium chloride and stir until completely dissolved.

(3) Four copies of the above solution were prepared in parallel.

(4) Immerse three-dimensionally ordered macroporous carbon templates with pore diameters of 470 nm, 350 nm, 250 nm, and 180 nm, respectively, and soak overnight.

(5) Place in an oven at 60°C for 3 days to gel until completely dry.

(6) Remove excess gel on the surface of the template, calcinate in a high-temperature furnace at 600°C for 3 hours, grind and ultrasonically disperse to prepare 70S30C (70%SiO ₂ -30%CaO, wt%) bioactive glass microsphere powder.

2. The biological activity experiment is the same as in Example 1.

3. Effect analysis:

The prepared 70S30C bioactive glass microspheres of different sizes have a complete spherical structure, uniform particle size, and a particle size deviation of less than 5%; the average particle sizes are 120nm, 170nm, 230nm, and 320nm, respectively. The prepared 70S30C bioactive glass microspheres of different sizes are all amorphous and non-crystalline materials, and can degrade and induce the formation of hydroxyapatite in a short period of time. They have good degradation performance and biological activity, and can be well Composite bone tissue engineering requirements.

The above examples illustrate that the bioactive glass microspheres prepared by the present invention have good bioactivity and can be used for the repair and regeneration of bone defects and tissue engineering scaffold materials.

Claims (9)

1. The method for preparing bioactive glass microspheres with a macroporous carbon template is characterized in that, first, the macroporous carbon template with a pore diameter of 180 to 470 nm is formed by a silicon source, a calcium source, an inorganic acid, dehydrated alcohol and distilled water After dipping in the mixed solution, dry it in an oven at 60°C to obtain the composite of carbon template and glass xerogel; then calcinate the composite of carbon template and glass xerogel at 600°C, grind and ultrasonically disperse to obtain Bioactive glass microsphere powder. 2. The method according to claim 1, wherein the silicon source, inorganic acid, distilled water and absolute ethanol are mixed first to obtain a clear mixed solution, and then the calcium source is added. 3. The method according to claim 2, characterized in that, when the silicon source, inorganic acid, distilled water and dehydrated alcohol are mixed, the phosphorus source is added simultaneously. 4. The method according to claim 2 or 3, characterized in that the sodium source is added while the calcium source is added. 5. The method according to claim 1, characterized in that, the silicon source is tetraethylorthosilicate. 6. The method according to claim 1, wherein the calcium source is calcium nitrate tetrahydrate. 7. method according to claim 1, is characterized in that, described mineral acid is nitric acid. 8. The method according to claim 2, wherein the sodium source is sodium nitrate. 9. The method according to claim 3, wherein the phosphorus source is triethyl phosphate.