Synthesis and Characterisation of Bioactive Glass 45S5 by Sol-gel Method and Evaluation of Biological Properties in vitro

Bone defects resulting from trauma or pathological events are among the most significant clinical, social, and economic problems. Bioactive glass (BG) is a possible alternative to inert graft materials. In this study, BG was fabricated from a SiO2–CaO–NaO–PO5 system using a new acid-catalyzed sol-gel method. Field emission scanning electron microscopy was used to analyze the morphology of 45S5 BG powders, and their microstructural properties were investigated in detail. The common distinctive peaks of hydroxyapatite (HA) formation were confirmed by X-ray diffraction (XRD) and Fourier transform-infrared (FTIR) spectroscopy. Bioactivity and degradation were evaluated by immersion in simulated body fluid (SBF) at 37 °C for 1, 7, 14, 21, and 28 days. After immersion, the pH increased with time, indicating HA formation on the disk surfaces, and BG weight loss also increased. Antimicrobial activity of 45S5 BG was evaluated against Gram-positive bacteria, Staphylococcus aureus and Streptococcus mutans, and Gram-negative bacteria, Klebsiella pneumoniae and Pseudomonas aeruginosa, using dilutions of 64–160 μg/mL. Results indicated strong antibacterial activity, which increased with concentration; 160 μg/mL was adopted. The highest inhibition zones were 22 mm for P. aeruginosa, 21.33 mm for S. aureus, 18.33 mm for K. pneumoniae, and 17.66 mm for S. mutans. MIC, MBC, antibiofilm activity, growth curves, and bacterial adhesion were also determined. These findings suggest that BG is a promising solution for treating bone infections and reconstructing bone defects.