Targeting multifunctionality in S53P4 silica-based bioactive glass by multi-ion substitution: Synthesis and characterization

In this study, S53P4-based bioactive glasses (BGs) co-substituted with boron (B) and cobalt (Co) were synthesized by glass melting to tailor their structural, biological, and antibacterial properties. Structural changes induced by ionic substitution were analyzed using XRD, FTIR, Raman spectroscopy, XPS, and UV-Vis-NIR diffuse reflectance spectroscopy. The co-substitution of B and Co increased the glass stability factor, enhancing their suitability for sintering in additively manufactured scaffolds. At 10% (w/v) BG extract, dissolution products were cytotoxic to MG‑63, while MC3T3‑E1 showed higher viability than controls at the same concentration. In MC3T3‑E1 cells, LDH activity was consistent with viability data, and VEGF-A secretion remained comparable to controls. The co-substituted BGs exhibited improved in-vitro bioactivity and strong antibacterial activity against S. aureus and E. coli , with bactericidal efficacy increasing with substitution level. These findings demonstrate that ionic co-substitution might be an effective strategy to achieve multifunctional S53P4 BGs with synergistic regenerative and antibacterial capabilities.