Molecular markers of adhesion, maturation and immune activation of human osteoblast-like MG 63 cells on nanocrystalline diamond films

Abstract

A semi-quantitative evaluation was made of the concentration of α v- and β 1-integrins, integrin-associated proteins talin and vinculin, cytoskeletal protein β-actin, differentiation markers osteocalcin and osteopontin, and immunoglobulin adhesion molecule ICAM-1 (CD 54), using an enzyme-linked immunosorbent assay (ELISA), in human osteoblast-like MG 63 cells in 5-day-old cultures on hydrophilic oxygen-terminated nanocrystalline diamond (NCD) films with either nanoscale surface roughness (nano-NCD, RMS of 8.2 nm) or hierarchically organized submicron- and nanoscale roughness ( RMS of 301.0 nm and 7.6 nm, respectively). The concentration of talin was significantly higher in cells on submicron-nano-NCD (by 36.0 ± 6.2% compared to the value on the polystyrene dishes). In addition, the concentration of vinculin increased on both nano-NCD and submicron-nano-NCD (by 19.8 ± 3.4% and 26.0 ± 6.1%, respectively). The concentration of integrins α v and β 1, β-actin, osteocalcin, osteopontin and ICAM-1 were similar in the cells on both the NCD films and the control polystyrene surfaces. These results suggest that nanocrystalline diamond films give good support for colonization with osteogenic cells and could be used for surface modification of bone implants in order to improve their integration with the surrounding bone tissue, or for biosensor technology, where firm cell–substrate adhesion is also required.