Enhanced antibacterial and osteogenic properties of titanium by sputtering a nanostructured fluoride-doped tantalum oxide coating

Abstract

Infections and poor osseointegration are the main challenges for titanium implants in clinical practice. Herein, we proposed fabricating a novel fluoride-doped tantalum oxide (F-TaOx) coating on titanium by one-step reactive sputtering deposition to endow implants with superior antibacterial and osteogenic ability. By altering the fluorine and oxygen loading amount, the coating’s physicochemical properties, corrosion resistance, antibacterial and osteogenic activities are tuned simultaneously. All coatings exhibit nano-morphology, superhydrophilicity and improved surface hardness. Despite containing fluoride, the F-TaOx coating produced with fluorine and oxygen dual-deposition still shows enhanced corrosion resistance due to the protection of existing metal oxidizes. The antibacterial test reveals that the F-TaOx coating exhibits long-lasting and superior antibacterial properties. The microenvironment acidification by F-, the excessive ROS generation and the disruption of ATP by F-, TiF3 and Ta2O5, and the repulsive force by superhydrophilic surface synergistically result in bacterial death. The cell experiments indicate that the F-TaOx coating shows good cytocompatibility, promote cell spread and osteogenic differentiation by enhancing ALP activities and ECM mineralization. This work provides a promising strategy for the surface functionalization of metallic implants to produce dual anti-infection and osteogenesis effects for orthopedic and dental applications.