The enhanced characteristics of osteoblast adhesion to porous Zinc–TiO2 coating prepared by plasma electrolytic oxidation

Abstract

Zinc-incorporated TiO2 coating (Zn–TiO2) was prepared on titanium (Ti) plate by plasma electrolytic oxidation (PEO) technique in the Ca, P, Zn-containing electrolyte. The surface topography, phase and element composition of the coatings were characterized by scanning electron microscopy, X-ray diffraction and energy dispersive spectrometer, respectively. Osteoblast-like MC3T3-E1 cell adhesion on Ti, TiO2 and Zn–TiO2 surfaces was evaluated and its possible signal transduction pathway involved was confirmed by the sequential gene expressions of integrin β1, α1, α3 and α5, focal adhesion kinase (FAK), and extracellular regulated kinases (ERK, including ERK1 and ERK2). The obtained results showed that Zn was successfully incorporated into the porous TiO2 coating, which did not alter apparently its surface topography and phase composition. The adhesion of MC3T3-E1 cells on Zn-incorporated TiO2 coating was significantly enhanced compared with that on the Zn-free TiO2 coating and pure Ti plate. In addition, the enhanced cell adhesion on Zn–TiO2 coating may be mediated by integrin (subunits β1 and α5) binding and subsequent signal transduction pathway (involving FAK and ERK1). The present work suggests that the Zn-incorporated porous TiO2 coating produced by PEO technique is promising as a candidate for orthopedic implant applications.