Ultraviolet Light-Based Micropattern Printing on Titanium Surfaces to Promote Early Osseointegration

Patterned interfaces are widely used for surface modification of biomaterials because of a morphological unit similar to that of native tissue. However, engineering fast and cost-effective high-resolution micropatterns directly onto titanium surfaces remains a grand challenge. Herein, a simply designed ultraviolet (UV) light-based micropattern printing to obtain geometrical patterns on implant interfaces is fabricated by utilizing customized photomasks and titanium dioxide (TiO₂ ) nanorods as a photo-responsive platform. The technique manipulates the cytoskeleton of micropatterning cells on the surface of TiO₂ nanorods. The linear pattern surface shows the elongated morphology and parallel linear arrangements of human mesenchymal stem cells (hMSCs), significantly enhancing their osteogenic differentiation. In addition to the upregulated expression of key osteo-specific function genes in vitro, the accelerated osseointegration between the implant and the host bone is obtained in vivo. Further investigation indicates that the developed linear pattern surface has an outstanding effect on the cytoskeletal system, and finally activates Yes-Associated Protein (YAP)-mediated mechanotransduction pathways, initiating hMSCs osteogenic differentiation. This study not only offers a microfabrication method that can be extended to fabricate various shape- and size-controlled micropatterns on titanium surfaces, but also provides insight into the surface structure design for enhanced bone regeneration.