Effects of a hydroxyapatite-coated nanotube surface of titanium on MC3T3-E1 cells: an in vitro study.

Abstract

To compare the biological behavior of mouse osteoblast-like cells (MC3T3-E1) on hydroxyapatite (HA)-coated nanotube surface of titanium and plasma-sprayed HA (HA-PS)-coated titanium surface. The HA-coated nanotube surface of titanium were fabricated by anodization coupled with alternative immersion method (AIM). MC3T3-E1 osteoblast cells cultured in vitro were seeded onto these different surfaces; their growth states were examined by a confocal laser scanning microscope; the proliferation behavior, alkaline phosphatase (ALP) activity, osteocalcin (OCN) secretion, and analysis of osteoblastic gene expressions were also compared in detail. Significant increases in ALP activity and OCN production on days 7 and 14 (P < 0.05) were observed for AIM-coated HA (HA-AIM) surfaces. However, cells cultured on HA-AIM-coated surfaces showed a delayed growth pattern. Real-time polymerase chain reaction analyses showed significantly higher relative mRNA expression levels of osteoblastic genes (runt-related protein 2, osterix, osteopontin, OCN) in cells cultured on the HA-AIM-coated nanotube surfaces as compared with cells cultured on the HA-PS and baer Ti surfaces. The current research showed that the HA-AIM-coated nanotubular Ti surfaces enhance osteoblast differentiation, which had the potential to further improve osseointegration.