This study investigated the effects of a calcium magnesium silicate bioceramic (akermanite) for bone
regeneration in vitro and in vivo, with b-tricalcium phosphate (b-TCP) as a control. In vitro, the human
bone marrow-derived mesenchymal stromal cells (hBMSCs) were cultured in an osteogenic medium
supplemented with a certain concentration of two bioceramics’ extracts for 20 days. An MTT assay
showed that akermanite extract promoted proliferation of hBMSC significantly more than did b-TCP
extract. The results of alkaline phosphatase (ALP) activity test and the expression of osteogenic marker
genes such as ALP, osteopontin (OPN), osteocalcin (OCN) and bone sialoprotein (BSP) demonstrated that
the osteogenic differentiation of hBMSC was enhanced more by akermanite extract than by b-TCP extract.
In vivo, a histomorphology analysis and histomorphometry of the two porous bioceramics implants in
rabbit femur defect models indicated that both in early- and late-stage implantations, akermanite
promoted more osteogenesis and biodegradation than did b-TCP; and in late-stage implantations, the
rate of new bone formation was faster in akermanite than in b-TCP. These results suggest that akermanite
might be a potential and attractive bioceramic for tissue engineering.