A comparative study of the osteogenic performance between the hierarchical micro/submicro-textured 3D-printed Ti6Al4V surface and the SLA surface

Three-dimensional (3D) printed titanium and its alloys have broad application prospect in the field of biomedical implant materials, although the biological performance of the original surface should be improved. Learning from the development experience of conventional titanium implants, to construct a hierarchical hybrid topological surface is the future direction of efforts. Since the original 3D-printed (3D hereafter) Ti6Al4V surface inherently has micron-scale features, in the present study, we introduced submicron-scale pits on the original surface by acid etching to obtain a hierarchical micro/submicro-textured surface. The characteristic and biological performance of the 3D-printed and acid-etched (3DA hereafter) surface were evaluated in vitro and in vivo, compared with the conventional sandblasted, large-grit, acid-etched (SLA hereafter) surface. Our results suggested the adhesion, proliferation and osteogenic differentiation of bone marrow derived mesenchymal stromal cells (BMSCs), as well as the in vivo osseointegration on 3DA surfaces were significantly improved. However, the overall osteogenic performance of the 3DA surface was not as good as the conventional SLA surface.