Biological activities of osteoblasts on poly(methyl methacrylate)/silica hybrid containing calcium salt.

The biological activity of osteoblasts on the newly developed bioactive poly(methyl methacrylate) (PMMA)/silica hybrid containing calcium salt was investigated. The attachment, proliferation, and differentiation of primary cultured mouse calvarial osteoblasts were evaluated by hexosaminase, MTT, and alkaline phosphatase activity assays, respectively. The PMMA/silica hybrid showed higher biological activities than those of pure PMMA with regard to all three parameters. Besides, the calcium phosphate layer, determined by scanning electron microscopy with energy dispersive spectroscopy, occurred only on the PMMA/silica hybrid. Better biological activities on the PMMA/silica hybrid than those on the PMMA were explained by the role of calcium phosphate layer formed on the PMMA/silica hybrid and the released calcium and silicon ions from it during the cell culture. These results suggest that the PMMA/silica hybrid might be useful as a bone substitute or filler.