Synthesis of bio-functionalized three-dimensional titania nanofibrous structures using femtosecond laser ablation.

The primary objective of current tissue regeneration research is to synthesize nano-based platforms that can induce guided, controlled, and rapid healing. Titanium nanotubes have been extensively considered as a new biomaterial for biosensors, implants, cell growth, tissue engineering, and drug delivery systems. However, due to their one-dimensional structure and chemical inertness, cell adhesion to nanotubes is poor. Therefore, further surface modification is required to enhance nanotube-cell interaction. Although there have been a considerable number of studies on growing titanium nanotubes, synthesizing a three-dimensional (3-D) nano-architecture which can act as a growth support platform for bone and stem cells has not been reported so far. Therefore, we present a novel technique to synthesize and grow 3-D titania interwoven nanofibrous structures on a titanium substrate using femtosecond laser irradiation under ambient conditions. This surface architecture incorporate the functions of 3-D nano-scaled topography and modified chemical properties to improve osseointegration while at the same time leaving space to deliver other functional agents. The results indicate that laser pulse repetition can control the density and pore size of engineered nanofibrous structures. In vitro experiments reveal that the titania nanofibrous architecture possesses excellent bioactivity and can induce rapid, uniform, and controllable bone-like apatite precipitation once immersed in simulated body fluid (SBF). This approach to synthesizing 3-D titania nanofibrous structures suggests considerable promise for the promotion of Ti interfacial properties to develop new functional biomaterials for various biomedical applications.