TiO2 nanotubes (TNTs) are attractive nanostructures for localized drug delivery. Owing to
their excellent biocompatibility and physicochemical properties, numerous functionalizations of TNTs
have been attempted for their use as therapeutic agent delivery platforms. In this review, we discuss the
current advances in the applications of TNT-based delivery systems with an emphasis on the various
functionalizations of TNTs for enhancing osteogenesis at the bone-implant interface and for preventing
implant-related infection. Innovation of therapies for enhancing osteogenesis still represents a critical
challenge in regeneration of bone defects. The overall concept focuses on the use of osteoconductive
materials in combination with the use of osteoinductive or osteopromotive factors. In this context, we
highlight the strategies for improving the functionality of TNTs, using five classes of bioactive agents:
growth factors (GFs), statins, plant derived molecules, inorganic therapeutic ions/nanoparticles (NPs)
and antimicrobial compounds.