Influence of SeO2 on in vitro bioactivity and antibacterial activity of CaF2–CaO–B2O3–P2O5–SrO glass system

Abstract

In vitro bioactivity studies (in SBF) and antibacterial activity studies (against S. aureus and E. coli bacteria) of SeO2 doped CaF2–CaO–B2O3–P2O5–SrO glasses were performed as a function of SeO2 content. X-ray diffraction and scanning electron microscopic studies indicated the formation of Se-HAp crystalline layer on the samples after immersing in SBF. Infrared and Raman spectral studies further established the deposition of hydroxyapatite layer on the surface of these samples. The thickness of HAp layer deposited on the samples is found to be dependent on the content of SeO2 dopant; this is assessed by measuring weight loss of the glasses due to dissolution in SBF and by measuring the variation of pH and the chemical analysis of the left-over fluid as functions of SeO2 content. The studies indicated the maximal content of hydroxyapatite is deposited on the surface the glasses doped with 4.0 mol% of SeO2. The studies on antibacterial effect against E. coli and S. aureus of the glasses indicated the maximal inhibition of bacteria in the samples doped with 4.0 mol%. This is ascribed to the presence of maximal concentration of [SeO3]2- ions (confirmed by IR and Raman studies) in this glass sample. Overall, the results of bioactivity of SeO2 doped bioglasses indicated that the presence of SeO2 not only enhanced bioactivity potential but also facilitated increase of antimicrobial activity.