Biological Applications of Anodized TiO₂ Nanostructures: A Review from Orthopedic to Stent Applications

Biomedical applications of nanotechnology represent a growing international trend, offering the opportunity to control material properties to improve electrical conductivity, optical properties, catalysis, mechanical strength, and most importantly, desirable tissue growth. Nanotechnology offers the ability to create biologically-inspired surface parameters including roughness, wettability, and topography to promote certain cell functions while inhibiting others. Anodization of titanium (Ti) is one such technology that can be used to quickly and inexpensively yield an array of titanium nanotubes on currently implanted Ti devices. Because of their ease of fabrication and improved biocompatibility properties, Ti nanotubes are finding applications ranging from controlling stem cell differentiation, increasing bone growth, decreasing bacterial functions, and improving bladder and vascular stent performance. This review will comprehensively examine the numerous biomedical uses of Ti nanotube arrays produced by anodization highlighting the challenges that remain ahead for the commercialization of this exciting technology.