Nanostructured sol-gel bioactive glass 60S: In vitro study of bioactivity and antibacterial properties in combination with vancomycin

Nanostructured samples of bioactive glass 60S (BG 60S) with a composition (mol %) of 60% SiO₂, 36% CaO, 4% P₂O₅ were synthesized by the sol-gel method in this research. The bioactivity of the synthesized material was evaluated by in vitro assays. The dynamics of the formation of hydroxyapatite (HA), contributing to the formation of effective bonds with bones and soft tissues during immersion in a simulated body fluid (SBF Kokubo), was evaluated using FTIR, XRD, and SEM-EDX. Changes of the specific surface values, particle size and zeta potential for soaked samples in SBF were also investigated. Determination of the antibacterial activity of BG 60S/vancomycin composites was carried out on test cultures of gram-positive microorganisms being one of the most frequent etiological factors of infectious complications in injuries – Staphylococcus aureus. The effectiveness of the release of the antibiotic was confirmed by determining the zone of inhibition of the test culture using the modified Kirby–Bauer disk diffusion method. It is shown that BG 60S/vancomycin composites are characterized by the preservation of antibacterial properties of vancomycin with its prolonged release, and osteoconductive properties, which are inherent in bioactive sol-gel glass and are promising for practical use in the surgical treatment of bone diseases. Based on the foundings, it is possible to suggest a positive effect of the joint application of BG 60S and vancomycin as part of composites with an effective combination of the functions of bone tissue restoration, treatment and prevention of postoperative infectious complications.