Anodized 3D-printed titanium implants with dual micro- and nano-scale topography promote interaction with human osteoblasts and osteocyte-like cells.

The success of implantation of materials into bone is governed by effective osseointegration, requiring biocompatibility of the material and the attachment and differentiation of osteoblastic cells. To enhance cellular function in response to the implant surface, micro- and nano-scale topography have been suggested as essential. In this study, we present bone implants based on 3D-printed titanium alloy (Ti6Al4V), with a unique dual topography composed of micron-sized spherical particles and vertically aligned titania nanotubes. The implants were prepared by combination of 3D-printing and anodization processes, which are scalable, simple and cost-effective. The osseointegration properties of fabricated implants, examined using human osteoblasts, showed enhanced adhesion of osteoblasts compared with titanium materials commonly used as orthopaedic implants. Gene expression studies at early (day 7) and late (day 21) stages of culture were consistent with the Ti substrates inducing an osteoblast phenotype conducive to effective osseointegration. These implants with the unique combination of micro- and nano-scale topography are proposed as the new generation of multi-functional bone implants, suitable for addressing many orthopaedic challenges, including implant rejection, poor osseointegration, inflammation, drug delivery and bone healing.