Dual-wavelength UV photofunctionalization of 3D-printed Ti6Al4V porous bone implant enhances osseointegration via adhesion–cytoskeleton–nuclear mechanotransduction

Orthopedic implants can be modified with ultraviolet (UV) photofunctionalization to improve osseointegration via force-sensing mechanotransduction in the microenvironment. Meanwhile, few researches have elucidated how UV wavelengths affect the photon-functionalized efficiency to promote synergistic osseointegration. Therefore, three-dimensional (3D)-printed porous Ti6Al4V implants were photofunctionalized with UVC (270 nm; G270), UVA (365 nm; G365), or UV-AC (270 + 365 nm; GU) to investigate the influence of different UV wavelengths on synergistic osseointegration via mechanotransduction. The alkaline phosphatase activity, hydrophilicity, and cytocompatibility of the porous Ti6Al4V implants were considerably higher following UV-AC treatment than following UVA or UVC treatment. Increased bone-implant contact and mineralized (osteoid) bone ratios further showed that UV-AC therapy significantly improved the osteointegration of porous Ti6Al4V implants in an in vivo rabbit condyle defect model. These results suggested that synergistic osteogenic effect of UV-AC irradiation could successfully promote the osseointegration by osteogenic staining and Micro-CT. The surface modification of 3D-printed titanium alloys using multi-wavelength UV functionalization for osseointegration enhancement was supported through adhesion-cytoskeleton-nuclear coupling via force-sensing mechanotransduction in bone tissue microenvironment. This study may be helpful for understanding the photon-functionalized osseointegration of 3D-printed scaffolds via force-sensing mechanotransduction in bone microenvironment.