Characterization, in vitro bioactivity assessment, and antibacterial activity of a sol–gel-derived borosilicate-based glass

A borosilicate glass in the SiO 2 –B 2 O 3 –CaO system was synthesized by the sol–gel method for potential bone tissue engineering applications. X-ray diffraction (XRD) confirmed its amorphous nature, while Fourier-transform infrared spectroscopy (FTIR) identified Si–O–Si and B–O vibrational bands characteristic of a borosilicate network. Surface morphology and elemental composition were analyzed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS) before and after the in vitro bioactivity evaluation. Bioactivity was assessed by immersion in simulated body fluid (SBF), resulting in the formation of a calcium-phosphate-rich layer. Antibacterial activity against Escherichia coli and Staphylococcus aureus showed no inhibition zones under the tested conditions. These findings demonstrate the apatite-forming ability of the synthesized glass, while further compositional optimization is required to improve its antibacterial performance.