Objective:Micro-and nanostructures with sharp disordered and rounded ordered features were fabricated on titanium surfaces,respectively,and their osteogenic potential was evaluated both in vitro and in vivo.Methods:Sharp disordered titanium surfaces(SLA-Ti)and rounded ordered titanium surfaces(Laser-Ti)were prepared using sandblast acid etching and high-repeti-tion-rate femtosecond laser,respectively.Smooth titanium(Ti)was used as the control group,SLA-Ti and Laser-Ti were used as the experimental groups.Characterization was conducted using scanning electron microscopy coupled with hydrophilicity assess-ments.The adhesion,elongation,and osteogenic differentiation capabilities of osteoblasts in vitro were evaluated through cell mor-phology observations,cytoskeletal fluorescence staining,cell viability assays,and PCR experiments.Osteogenic potential in vivo of rabbits was assessed through Micro CT scans and histological staining(HE and Masson).Results:The surface of Laser-Ti exhibits a rounded,ordered,multi-scale micro-and nano-morphology with the best hydrophilicity(P＜0.01).In vitro,it promotes cell adhe-sion,extension,and osteogenic differentiation,while in vivo,it enhances bone regeneration around the implants.Overall,a trend of Laser-Ti＞SLA-Ti＞Ti is observed,with a higher bone volume fraction(BV/TV)(P＜0.05),greater trabecular thickness(Tb.Th)(P＜0.05),an increased number of trabeculae(Tb.N)(P＜0.05),and a larger area of bone around the implants(P＜0.05).Conclusion:The rounded ordered micro-and nano-structures fabricated using high-repetition-rate fem-tosecond laser demonstrate enhanced osteoinductive capac-ity both in vitro and in vivo.

Objective:Micro-and nanostructures with sharp disordered and rounded ordered features were fabricated on titanium surfaces,respectively,and their osteogenic potential was evaluated both in vitro and in vivo.Methods:Sharp disordered titanium surfaces(SLA-Ti)and rounded ordered titanium surfaces(Laser-Ti)were prepared using sandblast acid etching and high-repeti-tion-rate femtosecond laser,respectively.Smooth titanium(Ti)was used as the control group,SLA-Ti and Laser-Ti were used as the experimental groups.Characterization was conducted using scanning electron microscopy coupled with hydrophilicity assess-ments.The adhesion,elongation,and osteogenic differentiation capabilities of osteoblasts in vitro were evaluated through cell mor-phology observations,cytoskeletal fluorescence staining,cell viability assays,and PCR experiments.Osteogenic potential in vivo of rabbits was assessed through Micro CT scans and histological staining(HE and Masson).Results:The surface of Laser-Ti exhibits a rounded,ordered,multi-scale micro-and nano-morphology with the best hydrophilicity(P＜0.01).In vitro,it promotes cell adhe-sion,extension,and osteogenic differentiation,while in vivo,it enhances bone regeneration around the implants.Overall,a trend of Laser-Ti＞SLA-Ti＞Ti is observed,with a higher bone volume fraction(BV/TV)(P＜0.05),greater trabecular thickness(Tb.Th)(P＜0.05),an increased number of trabeculae(Tb.N)(P＜0.05),and a larger area of bone around the implants(P＜0.05).Conclusion:The rounded ordered micro-and nano-structures fabricated using high-repetition-rate fem-tosecond laser demonstrate enhanced osteoinductive capac-ity both in vitro and in vivo.