A preliminary investigation into the structure, solubility and biocompatibility of solgel SiO₂–CaO–Ga₂O₃ glass-ceramics

The proposed study aims to synthesize gallium (Ga³⁺) containing glass-ceramics via the solgel method and determine their solubility and biocompatibility. Three solgel derived glass-ceramics, two containing Ga³⁺ were synthesized by substituting 5 mol% Ga³⁺ for both Ca²⁺ (Si-65) and Si⁴⁺ (Si-70) and were compared to a Ga³⁺ free control (control). Glass transition temperatures (T_g) ranged from 641 to 660 °C for all materials with particle sizes ranging between 1.5 and 2.5 μm. Surface area analysis ranged from 45 to 55 m² g⁻¹ and any changes in pH were determined over 0–14 days. Ga³⁺ ion release from Si-65 peaked at 433 mg L⁻¹ after 7 days, and Si-70 peaked at 601 mg L⁻¹ after 1 day. Both calcium (Ca²⁺) and silica (Si⁴⁺) were also released from each material. Antibacterial testing against E. coli and S. epidermidis revealed both bactericidal (maximum inhibition zone of 2.5 ± 0.3 mm) and bacteriostatic effects. The control material exhibited inhibition zones in both bacteria while bacteriostatic properties were found predominantly against E. coli with Si-65 and Si-70. Cytocompatibility testing was conducted in L929 mouse fibroblasts and determined no significant reduction in cell viability with respect to the control, with minimal, non-significant reductions for Si-65 and Si-70. - Highlights: • A solgel derived glass-ceramic series was synthesized with 5 mol% Ga₂O₃ doped for the SiO₂ and CaO. • Characterization included X-ray diffraction, thermal analysis and particle analysis methods. • Materials released gallium (Ga), calcium (Ca), silica (Si) and caused an increase in pH over time. • Antibacterial effects were observed when tested in E. coli and S. epidermidis. • No significant reduction in cell viability was observed with material ionic dissolution species