In vitro evaluation of the biocompatibility and bioactivity of plasma electrolyte oxidized titania/calcium phosphate nanocoatings on Ti

Abstract

In this study, monolayer and two-layer composite coatings of titania and calcium phosphate were fabricated via plasma electrolyte oxidation technique on titanium substrates. The calcium phosphate layers were produced by using an electrolyte containing calcium acetate and β-glycerophosphate. In order to study and compare their biocompatibility and bioactivity properties MTT, cell adhesion, and soaking in SBF solution tests were performed on both coatings. According to the XPS and AFM analysis results, two-layer coatings have a higher Ca/P proportion on their surface and rougher surface. Higher cell proliferation rate was observed on two-layer specimen’s surface. An appropriate cell adhesion was observed in both coatings. Higher amount of hydroxyapatite (HAp) nanocrystals were observed on coatings with two-layer in comparison with monolayer after being soaked in SBF solution for 28 days. Besides, the proportion of HAp to calcium triphosphate after soaking in SBF solution was higher in two-layer coating.