Nanopatterned titanium implants accelerate bone formation in vivo.

Accelerated de novo formation of bone is a highly desirable aim of implants targeting musculoskeletal injuries. To date this has primarily been addressed by biologic factors. However, there is an unmet need for robust, highly reproducible yet economic alternative strategies that strongly induce osteogenic cell response. Here we present a surface engineering method using a titanium-based sol-gel whereby metal implants can be engineered to induce osteoinduction both in vitro and in vivo. We show that controlled disordered nanotopographies presented as pillars with 20 nm height and 100 nm diameter on titanium dioxide effectively induces osteogenesis when seeded with STRO-1 enriched human skeletal stem cells in vivo subcutaneous implantation in mice. After 28 days samples were retrieved, which showed 20-fold increase in osteogenic gene induction of nanopatterned substrates. Nanopatterned titanium dioxide offers a promising route for translation to future clinical orthopaedic implants.