Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, 200011, China.
Cell Prolif. 2013 Dec;46(6):685-94. doi: 10.1111/cpr.12072.
To investigate behaviour and osteogenic cytokine expression of RAW264.7 macrophages grown on TiO2 nanotube layers.
The murine macrophage cell line RAW 264.7 was cultured on TiO2 nanotubes of varying diameter; macrophage morphology was examined using scanning electron microscopy. Cell adhesion and viability were assessed with the aid of the MTT method and BMP-2 and TGF-β gene expression were examined by RT-PCR analysis. Levels of BMP-2, TGF-β1 and ICAM-1 proteins secreted into the supernatant were measured by ELISA assay.
Macrophages cultured on nanotube layers had spread out morphology, the largest (120 nm) nanotube layer eliciting an elongation by 24 h. Macrophages adhered significantly less to 120 nm TiO2 nanotubes than to control discs at 4 h after application; after 24 h incubation, macrophages were sufficiently viable (P < 0.05) on 30 and 70 nm nanotube layers. Increasing nanotube diameter led to increased BMP-2 protein secretion and increased BMP-2 mRNA expression.
These results demonstrate that nanoscale topography of TiO2 nanotube layers can affect macrophage morphology, adhesion, viability and BMP-2 expression. Macrophages grown on layers of large nanotubes had the highest potential to enhance bone formation during bone healing.
研究在 TiO2 纳米管层上生长的 RAW264.7 巨噬细胞的行为和成骨细胞因子表达。
将鼠源巨噬细胞系 RAW 264.7 培养在不同直径的 TiO2 纳米管上；使用扫描电子显微镜观察巨噬细胞形态。借助 MTT 法评估细胞黏附和活力，并通过 RT-PCR 分析检测 BMP-2 和 TGF-β 基因表达。通过 ELISA 测定上清液中分泌的 BMP-2、TGF-β1 和 ICAM-1 蛋白的水平。
在纳米管层上培养的巨噬细胞呈现出伸展的形态，最大（120nm）纳米管层在 24h 时引起细胞伸长。与对照组相比，应用 4h 后，巨噬细胞在 120nm TiO2 纳米管上的黏附性显著降低；24h 孵育后，30nm 和 70nm 纳米管层上的巨噬细胞具有足够的活力（P<0.05）。纳米管直径的增加导致 BMP-2 蛋白分泌增加和 BMP-2 mRNA 表达增加。
这些结果表明，TiO2 纳米管层的纳米级形貌可以影响巨噬细胞的形态、黏附、活力和 BMP-2 表达。在大纳米管层上生长的巨噬细胞在骨愈合过程中具有最强的增强骨形成的潜力。
