Titania nanopores with dual micro-/nano-topography for selective cellular bioactivity

This letter describes a simple surface modification strategy based on a single-step electrochemical anodization towards generating dual micro- and nano-rough horizontally-aligned TiO₂ nanopores on the surface of clinically utilized micro-grooved titanium implants. Primary macrophages, osteoblasts and fibroblasts were cultured on the nano-engineered implants, and it was demonstrated that the modified surfaces selectively reduced the proliferation of macrophages (immunomodulation), while augmenting the activity of osteoblasts (osseo-integration) and fibroblasts (soft-tissue integration). Additionally, the mechanically robust nanopores also stimulated osteoblast and fibroblast adhesion, attachment and alignment along the direction of the pores/grooves, while macrophages remained oval-shaped and sparsely distributed. This study for the first time reports the use of cost-effectively prepared nano-engineered titanium surface via anodization, with aligned multi-scale micro/nano features for selective cellular bioactivity, without the use of any therapeutics.