Open AccessEffects of TiO 2 nanotube layers on RAW 264.7 macrophage behaviour and bone morphogenetic protein‐2 expression
Author(s) -
Sun S. J.,
Yu W. Q.,
Zhang Y. L.,
Jiang X. Q.,
Zhang F. Q.
Publication year - 2013
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/cpr.12072
Subject(s) - nanotube , adhesion , bone morphogenetic protein 2 , materials science , cell adhesion , macrophage , viability assay , biophysics , morphology (biology) , microbiology and biotechnology , chemistry , nanotechnology , cell , in vitro , carbon nanotube , biology , biochemistry , composite material , genetics
Abstract Objectives To investigate behaviour and osteogenic cytokine expression of RAW 264.7 macrophages grown on TiO 2 nanotube layers. Materials and methods The murine macrophage cell line RAW 264.7 was cultured on TiO 2 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. Results 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 TiO 2 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. Conclusion These results demonstrate that nanoscale topography of TiO 2 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.