Bioactivity and cytocompatibility of silicon wafers treated by water.

A range of bioactive ceramics can induce bone-like apatite to deposit on their surface in simulated body fluid (SBF). In this work, the silicon wafer was treated using deionized water to improve its bioactivity. The morphology and chemical composition of the treated silicon wafer was examined using Fourier transform infrared spectroscopy, atomic force microscopy and X-ray photoelectron spectroscopy. Field emission scanning electron microscopy was used to observe the surface morphologies of silicon wafers soaked in SBF. The results indicated that a hydrated sub-oxide film having Si--OH groups formed on the surface of the silicon wafer after the water treatment. The amount of Si--OH groups increased with raising the treatment temperature or prolonging the immersion time. Apatite was deposited on the surface of water-treated silicon wafers immersed in SBF. The apatite deposition was correlated with the amount of Si--OH groups. Human mesenchymal stem cells cultured on the surface of the water-treated silicon wafers showed good adhesion and spread, indicating that the cytocompatibility of silicon wafer was enhanced by this water treatment.