In vitro bioactivity and gene expression by cells cultured on titanium dioxide doped phosphate-based glasses

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• 作者：Ensanya Ali Abou Neel ; Toshihide Mizoguchi ; Michio Ito ; Malak Bitar ; Vehid Salih ; Jonathan Campbell Knowles
• 关键词：Phosphate glass ; Titanium doped ; Bioactivity ; Simulated body fluid
• 刊名：Biomaterials
• 出版年：2007
• 出版时间：July 2007
• 年：2007
• 卷：28
• 期：19
• 页码：2967-2977
• 全文大小：1055 K

文摘

In our previous study, glasses with 50 P₂O₅-(20–15) Na₂O-30 CaO-(0–5 mol % ) TiO₂ have been prepared by the conventional melt-quenching process. MG63 cell proliferation, gene expression, in vivo biocompatibility, and bioactivity of these glasses is the concern of this study. The results showed that addition of TiO₂ in small amounts up to 5 mol % enhanced the biocompatibility of these glasses. The cell metabolic activity was conspicuous, on 3 and 5 mol % TiO₂ compositions in particular, with no significant difference from Thermanox^® control over a period of 21 days. The findings from the gene expression study showed that, at day 1 and on 5 mol % TiO₂ glass, core binding protein factor alpha 1 (Cbfa1) and alkaline phosphatase (ALP) showed significantly lower transcription level; however, collagen type I alpha subunit I (COLIAI) and Osteonectin (Sparc) showed no significant differences compared to the control. At day 7, all these genes transcription levels were not significantly different form the control, but at day 14, they were significantly higher than the control. Moreover, there were no significant differences detected in these genes on both 3 and 5 mol % TiO₂ glasses up to 7 days. At day 14; however, 5 mol % TiO₂ glasses showed significantly higher level than 3 mol % TiO₂ composition. This was also correlated by the presence of new bone tissue at the bone–particles interface for 5 mol % TiO₂ composition after 5 weeks of implantation in rat calvarium. Regardless of this favourable cell response and gene up-regulation, these glasses showed no evidence of apatite layer formation after 14 days incubation in SBF.