Effect of Polydopamine Coating on Ti6Al4V

Introduction Inspired by mussel-adhesion phenomena in nature can integrate inorganic hydroxyapatite crystals within versatile materials. This is a simple, aqueous, two-step functionalization approach, called polydopamine-assisted hydroxyapatite formation (pHAF), that consists of i) the chemical activation of material surfaces via polydopamine coating and ii) the growth of hydroxyapatite in a simulated body fluid (SBF). We presumed polydopamine coating on the surface of titanium alloy would improve the ability of cementless stems to osseointegrate. We therefore compared the in vitro ability of cells to adhere to polydopamine coated Ti alloy and machined Ti alloy. Method We performed energy-dispersive x-ray spectroscopy and scanned electron microscopy investigations to assess the structure and morphology of the surfaces. Biologic and morphologic responses to osteoblast cell lines (MC3T-E1) were then examined by measuring cell proliferation, cell differentiation (alkaline phosphatase activity), and avb3 integrin. Results Cell proliferation, alkaline phosphatase activity, migration, and adhesion were not increased in the polydopamine coated Ti alloy compared to other group. And, the polydopamine coated Ti alloy shows better apatite forming ability than the untreated one, as evidenced by apatite formation after SBF immersion for 14 days. Discussion The surface modifications we used (polydopamine coating) enhanced the apatite formation, but did not change the biocompatibility (proliferation and migration of osteoblastlike cells) of Ti alloy.