Construction of surface HA/TiO₂ coating on porous titanium scaffolds and its preliminary biological evaluation

A simple approach to fabricating hydroxyxapatite/titanium dioxide (HA/TiO₂) coating on porous titanium (Ti) scaffolds was developed in the present study. Surface TiO₂ layer was firstly formed on porous Ti scaffolds with multi-scale pores by acid-alkali (AA) treatment. The outer HA layer was then formed on the TiO₂ layer by subsequent pulse electrochemical deposition (ED) technique. All the three main process parameters, i.e. deposition times, current density and mass transfer mode affected the properties of the HA coating notably. Under the conditions of 90 deposition cycles, -10mA/cm² of pulse current density and stirring, a thin layer of homogeneous and nanorod-like HA sediments was formed on the substrate surface of porous Ti scaffolds. The results of protein adsorption and cellular experiments showed that compared to the single TiO₂ surface, the HA/TiO₂ surface allowed more adsorption of serum proteins and further enhanced the alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts.