Osseointegrative and immunomodulative 3D-Printing Ti6Al4V-based implants embedded with biogenic hydroxyapatite

Although titanium-based metal implants have become the game changers in dental and orthopedic therapies, they still have several problems, such as late osseointegration and immune response. We report a novel strategy for developing Ti6Al4V-based implants embedded with biogenic hydroxyapatite derived from equine bone to overcome the problems. In this study, a selective laser melting technique was employed for facile fabrication with flexible fusing feedstock and regular uniform equine bone distribution. After that, we conducted investigations on the physicochemical characteristics, cell attachment, proliferation, osteogenic differentiation, osseointegration, inflammatory response, and metabolomics of the developed Ti6Al4V/equine bone composite. The Ti6Al4V-based composite integrated with equine bone at a certain concentration has improved the crystalline structure (β-Ti) suitable for implantation and exhibited higher hydrophilicity and protein adsorption. They significantly promoted cell attachment, osteogenic differentiation, and anti-inflammatory effects in vitro. In vivo study confirmed the osseointegration and alleviated inflammatory responses. Furthermore, the Ti6Al4V-based implants integrated with equine bone significantly reduced metabolites associated with inflammatory responses both in vitro and in vivo. The observed reduction in inflammatory responses suggests a subsequent promotion of osteogenesis. These promising results position the Ti6Al4V-based implant integrated with equine bone as a potential candidate for replacing conventional dental and orthopedic implants.