Work

Synergistic bactericidal and anticancer potential of rubidium and silver-containing phosphate-based bioglasses

Year: 2025

Type: article

Abstract: A new vitreous system, 44P 2 O 5 ·25CaO·21Na 2 O·5ZnO·5Ag 2 O, doped with 1–7 mol% Rb₂O, was synthesized by conventional melt quenching, and the structural and biological effects of rubidium incorporation were systematically investigated. The X-ray diffraction confirmed the amorphous nature of all compositions, while FTIR and Raman spectroscopy revealed that Rb + ions act as network modifiers, promoting progressive depolymerization of the phosphate network dominated by Q 2 and Q 1 units. X-ray photoelectron spectroscopy demonstrated the presence of all constituent elements at the glass surface, with silver detected in both ionic (Ag⁺) and metallic (Ag⁰) states; the Ag + /Ag 0 ratio varied slightly (0.62–0.65) with Rb₂O addition, indicating stable coexistence of ionic species and metallic nanoparticle clusters. Transmission electron microscopy corroborated the formation of Ag-containing nanoclusters dispersed within the vitreous matrix. Biological performance was evaluated through a comprehensive series of assays, including fibroblast viability (MTT), antimicrobial, antifungal, and anticancer tests. Human skin fibroblasts displayed a high proliferation rate at both 24 and 48 h, confirming the excellent cytocompatibility of the glass system in the 0–5 mol% Rb 2 O compositional range. In contrast, a pronounced cytotoxic effect was recorded against breast cancer cells for the composition containing 7 mol% Rb 2 O at a concentration of 0.78 mg mL –1 after 48 h. Antimicrobial testing revealed complete elimination of gram-negative bacteria within 1 h, attributed primarily to Ag⁺ release. A bacteriostatic effect against gram-positive strains at 2 h, as well as inhibition of fungal propagation at 4 h, was also observed and correlated with the surface concentration of silver and rubidium.

Source: Scientific Reports

DOI: 10.1038/s41598-025-21009-2