Structure, dissolution behavior, cytocompatibility, and antibacterial activity of silver-containing calcium phosphate invert glasses.

Novel CaO-P O -Nb O -Ag O invert glasses with substitution Ag O for Nb O were successfully prepared using a melt-quenching method. Ag O in the glasses act as a network modifier oxide, playing the same role as Na O, which breaks the phosphate chains. Analysis of the ultraviolet-visible absorption spectra of the glasses showed that the glass matrix contained ionic silver species and silver nanoparticles. Approximately 0.05 mM of Nb ions released from the glasses, which would be expected to stimulate osteoblast differentiation. A glass containing 1 mol % Ag O showed a linear increase in the releasing amount of Ag ions with increasing soaking time, whereas glasses containing 3-5 mol % Ag O showed Ag ion concentrations of around 13 μM at day 3, and then maintained similar values until day 7. When the solution was replaced with fresh solution every 2 days, the Ag ion dissolution amounts indicated almost constantly 13 μM due to AgCl formation. There were no differences in the numbers of primary osteoblast cells on silver-free and silver-containing glasses after cultivation for 1-7 days. The silver-containing calcium phosphate invert glasses showed cytocompatibility with simultaneous antibacterial activity to Escherichia coli and Staphylococcus aureus. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3127-3135, 2017.