Effect of fluorination/oxidation level of nano-structured titanium on the behaviors of bacteria and osteoblasts

Abstract

Biomaterials with enhanced antibacterial property and osteogenic activity are highly desirable for the prevention of implant associated infection and promotion of osseointegration. Titanium surface modified by fluorine and oxygen dual-deposition has shown better antibacterial property and corrosion resistance than mono-deposition. Herein, fluorine and oxygen dual-deposited coatings (FO-DDCs) on titanium with different fluorine and oxygen percentage were fabricated to explore the effect of fluorination/oxidation level on the behaviors of bacteria and osteoblasts. Antibacterial test shows that titanium surface with the content ratio of fluoride to oxides greater than 0.22 exhibits excellent a stable and broad spectra antibacterial ability. The FO-DDCs can effectively restrain the biofilm formation of S. aureus through acidifying microenvironment, inactivating ATP synthesis and producing oxidative stress by released fluoride ion and existed titanium-fluoride complexes. Meanwhile, the cell viability and osteogenic activity tests show that the FO-DDCs does not introduce cytotoxicity to osteoblasts, but promote cell adhesion and spreading, enhance ALP activities and ECM mineralization, up-regulate osteogenesis related gene expressions of osteoblasts. In conclusion, optimizing an appropriate fluorination/oxidation level by plasma-related technology can endow titanium surface with antibacterial and osteogenic properties, which is an attracting strategy to design multifunctional biomaterials for dental or orthopedic applications.