Fig. 4: In vitro biomineralization and ionic release of IMBSs following immersion in PBS.

a Surface biomineralization (as indicated by the yellow circles) of IMBSs after immersion periods of 7 and 14 days as detection by SEM (scale bar = 10 μm). b XRD patterns of IMBSs following immersion in PBS of 14 days. c–e Cumulative concentration of BO33-, Ca2+ and Zn2+ in PBS. f pH curves of PBS following IMBSs immersed until 28 days. g, h Dynamic release profiles of BO33- and Ca2+ after IMBSs immersed in PBS for 28 days, with PBS being changed daily. Data in c-h are presented as means ± SD, n = 3 independent experiments.