Biocompability evaluation of micro textures coated with zinc oxide on Ti-6Al-4V treated by nanosecond laser

Abstract

Surface morphology of implants plays an important role in enhancing cell response at the interface. Zinc ions (Zn 2+ ) have a promising potential for osseointegration by stimulating osteoblast cell multiplication and differentiation. In this study, regular micro grooves coated with zinc oxide (ZnO) were successfully manufactured on Ti-6Al-4V surface by two-step nanosecond laser treatment to investigate the synergetic effects of micro/nano structures and Zn 2+ on the cell adhesion, proliferation and differentiation. Surface characteristics including surface morphology, roughness, wettability and phase composition were characterized. Results showed that the roughness and hydrophilicity of laser-processing surface were significantly improved compared with those of the acid etching surface. Moreover, XRD results indicated that the ZnO diffraction peak appeared on the surface. The biocompatibility of different samples was investigated by cell experiment in vitro. The spreading morphology of cells along grooves, cell multiplication rate, and activity of alkaline phosphatase and osteocalcin indicated that the micro grooves coated with ZnO on Ti-6Al-4V surface had great potential to promote the adhesion, multiplication and differentiation of MC3T3 cells. This study provides a new and effective method for surface modification of Ti-6Al-4V implants. • A micro textured surface coated with zinc oxide was fabricated on surface of Ti-6Al-4V by two-step nanosecond laser treatment, the precise control of surface morphology and close combination of bioactive coating are realized. • Micro textured surface coated with zinc oxide displayed increased roughness and enhanced hydrophilicity comparing with acid etching surface. • The cell adhesion, proliferation and differentiation of MC3T3s was improved obviously by the synergistic effects of micro grooves and zinc ions released.