Evaluation of the effects of ag ion concentration on osteoblast activity

We reported the apatite-forming ability of 30CaO·70SiO₂ scaffolds with 0~100 ppm Ag ions by soaking in simulated body fluid (SBF). This study was to evaluate the effects of the concentrations of Ag ions in the 30CaO·70SiO₂ gels on in-vitro biocompatibility of osteoblasts (MC3T3). After seeding cells on the surface of Ag-30CaO·70SiO₂ gels scaffold, cellular behaviorswere evaluated by an assay of cell counting kit-8. Cytotoxicity of the scaffold samples was evaluated by employing the extract solutions of the scaffold samples by the assays of neutral red, MTT and BrdU. In addition, live & dead assay was performed by using a gel covering method, which the scaffolds have been directly contacted with the incubated cells on the well plate. According to the results of CCK-8 assay, the optical density value of the absorbance of the resulting solution decreased as the concentration of Ag ions in the scaffolds increased. Moreover, their cell viability was measured to be less than 50% at the Ag concentrations of 50 ppm or more, and dead cells were observed in the experiment results of both the cytotoxicity and gel covering tests. From these experimental results, we concluded that the Ag-30CaO·70SiO₂ scaffolds with less than 50 ppm Ag ion concentration were considered as biocompatible.