Biological evaluation of highly ordered TiO2 nanotubes produced on Ti6Al4V alloys manufactured via electron beam powder bed fusion (EB-PBF)

This experimental work evaluates the biological activity of highly ordered TiO 2 nanotubes produced on Ti6Al4V samples manufactured via electron beam powder bed fusion (EB-PBF) in longitudinal and cross orientation. The in vitro cytotoxicity assay shows that TiO 2 nanotubes produced on EB-PBF in longitudinal and cross orientation showed non-cytotoxic activity with viability percentages exceeding 85% in L929 and MG-63 cell lines. Additionally, moderate ROS and NO production from RAW 264.7 murine macrophages confirm TiO 2 nanotubes cytocompatibility. In cell adhesion assays, active living MG-63 cells with a strong green fluorescence signal, lamellipodia structures and mitotic rounded-cells, were seen in both TiO 2 nanotubes produced on EB-PBF in longitudinal and cross orientation. From the results of our experimental work, there are no significant differences in the cellular behavior of TiO 2 nanotubes produced on Ti6Al4V samples manufactured via electron beam powder bed fusion (EB-PBF) in longitudinal or cross orientation. The significance of this work lies in clarifying how an important processing variable in additive manufacturing build orientation impacts the biological performance of nanostructured implant surfaces.