The effects of Ag and Mn co-doping on the bioactivity, biocompatibility and antibacterial performance of sol-gel derived bioactive glasses

Abstract

In this study, silver (Ag) and manganese (Mn) doped bioactive glasses (BGs) based on the SiO2-Na2O-CaO-P2O5 system were synthesized via the sol-gel method. The chemical compositions of the synthesized BGs were confirmed by X-ray fluorescence (XRF) analysis. In vitro bioactivity was assessed by immersing the samples in simulated body fluid (SBF) for determined periods. Surface reactivity and apatite-forming ability were investigated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The formation of a crystalline hydroxyapatite (HA) on the glass surfaces confirmed the bioactive behavior of both undoped and metal-doped BGs. Ion release profiles obtained by inductively coupled plasma-optical emission spectroscopy (ICP-OES) further supported these findings. Antibacterial activity tests revealed that Ag and Mn doped BGs exhibited enhanced antibacterial efficacy against Escherichia coli (E. coli), indicating a synergistic effect between Ag and Mn, whereas Ag-doped BGs demonstrated superior antibacterial performance against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In vitro cell viability assays showed that all synthesized BGs maintained cell viability levels above 70 %, confirming their cytocompatibility. Overall, the results suggest that Ag and Mn doped BGs combine bioactivity, cytocompatibility, and antibacterial performance, highlighting their potential as multifunctional graft materials for bone tissue engineering application.