Abstract: In this study, the in vitro bioactivity and cytotoxicity of gamma-dicalcium silicate (γ-Ca₂SiO₄) ceramic were evaluated systematically. The surface physicochemical changes
of the ceramic soaked in a simulated physiological fluid (Kokubo’s SBF) for various periods were determined by means of XRD, FT-IR, SEM and EDS
analysis. The results indicated that the ceramic surface transformed to a carbonated hydroxyapatite (CHA) within 72h and a silica-rich layer occurred
between the CHA layer and ceramic matrix after 240h. In addition, the ionic products of the material dissolution had no cytotoxicity to fibroblasts
compared with the negative control. This ceramic supported the bone mesenchymal stem cells (BMSCs) adhesion and spreading, and the BMSCs established close
contacts with the ceramics after 24h of culture. This combination of properties indicates that the novel γ-Ca₂SiO₄ ceramic might be suitable for
potential application in the biomedical field, preferentially as materials for bone repair.

Key words: γ-dicalcium silicate, in vitro bioactivity, carbonated apatite, cytotoxicity, bioactive ceramics