In this study, the bone-like apatite-formation ability of akermanite ceramics (Ca2MgSi2O7) in simulated body fluid (SBF) and the effects of ionic products from akermanite dissolution on osteoblasts and mouse fibroblasts (cell line L929) were investigated. In addition, osteoblast morphology and proliferation on the ceramics were evaluated. The results showed that akermanite ceramics possessed bone-like apatite-formation ability comparable with bioactive wollastonite ceramics (CaSiO3) after 20 days of soaking in SBF and the mechanism of bone-like apatite formation on akermanite ceramics is similar to that of wollastonite ceramics. The Ca, Si, and Mg ions from akermanite dissolution at certain ranges of concentration significantly stimulated osteoblast and L929 cell proliferation. Furthermore, osteoblasts spread well on the surface of akermanite ceramics, and proliferated with increasing the culture time. The results showed that akermanite ceramics possess bone-like apatite-formation ability and can release soluble ionic products to stimulate cell proliferation, which indicated good bioactivity.

Calcium silicate ceramics have been proposed as new bone repair biomaterials, since they have proved to be bioactive, degradable, and biocompatible. ␤-tricalcium phosphate ceramic is a well-known degradable material for bone repair. This study compared the effects of CaSiO 3 (␣-, and ␤-CaSiO 3 ) and ␤-Ca 3 (PO 4 ) 2 (␤-TCP) ceramics on the early stages of rat osteoblast-like cell attachment, proliferation, and differentiation. Osteoblast-like cells were cultured directly on CaSiO 3 (␣-, and ␤-CaSiO 3 ) and ␤-TCP ceramics. Attachment of a greater number of cells was observed on CaSiO 3 (␣-, and ␤-CaSiO 3 ) ceramics compared with ␤-TCP ceramics after incubation for 6 h. SEM observations showed an intimate contact between cells and the substrates, significant cells adhesion, and that the cells spread and grew on the surfaces of all the materials. In addition, the proliferation rate and alkaline phosphatase (ALP) activity of the cells on the CaSiO 3 (␣-, and ␤-CaSiO 3 ) ceramics were improved when compared with the ␤-TCP ceramics. In the presence of CaSiO 3 , elevated levels of calcium and silicon in the culture medium were observed throughout the 7-day culture period. In conclusion, the results of the present study revealed that CaSiO 3 ceramics showed greater ability to support cell attachment, proliferation, and differentiation than ␤-TCP ceramic.

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