Sol-gel synthesis of nano-bioactive glass 60SiO2-36CaO-4P2O5 (mol.%) without using acid catalysts

• Published in: Journal of sol-gel science and technology 2024-06, Vol.110 (3), p.900-909
• Main Authors: Hoa, Bui Thi, Vuong, Bui Xuan
• Format: Article
• Language: English
• Subjects: Amorphous materials; Apatite; Biocompatibility; Bioglass; Biological activity; Biomedical materials; Body fluids; Calcium nitrate; Catalysts; Ceramics; Chemistry and Materials Science; Composites; Glass; Hydroxyapatite; In vitro methods and tests; Inorganic acids; Inorganic Chemistry; Materials Science; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper; Precursors; Sol-gel processes; Tetraethyl orthosilicate
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-024-06426-5

Nano-bioactive glass 60SiO 2 -36CaO-4P 2 O 5 (mol.%) was synthesized by using the sol-gel method without using acid catalysts. Two sol precursors, tetraethyl orthosilicate and triethyl phosphate, were tested for hydrolysis at different temperatures and times. Experimental observation shows that the precursors tetraethyl orthosilicate, triethyl phosphate, and calcium nitrate tetrahydrate were hydrolyzed in the solvent system H 2 O/C 2 H 5 OH (weight ratio of 1/8) at 80 °C. In a hydrothermal reactor, the resulting sol was transformed into a gel, and then the dried gel was transformed into a glass material by heating treatment. Physical-chemical methods such as TG-DSC, XRD, FTIR, BET, and SEM-TEM were used to evaluate synthesized glass. Additionally, the glass material was assessed for its bioactivity in SBF solution (Simulated Body Fluid), and biocompatibility with fibroblast cells (L-929) following the ISO10993-5 standard. Research results show that the glass 60SiO 2 -36CaO-4P 2 O 5 (mol.%) synthesized in this study is an amorphous material with particle size at the nanoscale, forming a mesoporous structure. The synthesized glass can be bioactive by forming an apatite mineral layer when soaked in SBF solution, and it is biocompatible with L-929 cells. Graphical Abstract Highlights The nano-bioactive glass 60SiO 2 -36Ca O-4P 2 O 5 (mol.%) was successfully synthesized by the sol-gel method without using toxic inorganic acids. The physical-chemical characterization confirmed that the synthetic glass has an amorphous and mesoporous structure containing nanoparticles with sizes ranging from 9 to 15 nm. In vitro experiment in SBF solution showed the bioactivity of glass material through the formation of hydroxyapatite (HA) bone mineral layer after 7 days of experiment. In vitro experiment with L-929 cells showed biocompatibility when the cell survival rates after exposure to glass extract at different concentrations reached over 80%.