Novel fast-setting calcium silicate bone cements with high bioactivity and enhanced osteogenesis in vitro

Novel calcium silicate cements (CSCs) consisting of sol-gel-derived calcium silicate powder as a solid phase and ammonium phosphate solution as a liquid phase were developed. The diametral tensile strength, morphology, and phase composition of various cements were evaluated before and after immersion in physiological solution, in addition to setting time. The proliferation and osteogenetic expression of human osteosarcoma cell line U2OS for the cement specimens were also analyzed. The results indicated that the simultaneous formation of apatite and calcium silicate hydrates (CaO-SiO(2)-H(2)O, C-S-H) may endow CSCs with unique properties after mixing with a phosphate buffer solution. These CSCs were not only fast-setting within 9 min, as well as highly bioactive, but they also enhanced proliferation and differentiation of U2OS cells. The development of fast-setting CSCs with high bioactivity may thus have numerous applications as biomaterials.