Mussel-inspired surface modification of titania nanotubes as a novel drug delivery system.

Titania nanotubes (TNT) have attracted considerable attention for the development of new devices for local drug delivery applications. In this study TNT were synthesized by hydrothermal method from titania nanoparticles and then the surface of TNT were functionalized by in situ polymerization of bioinspired polydopamine (PDA). The proposed strategies emphasized on remarkable properties of these materials and their unique combination to design local drug delivery system with advanced performance. The samples were characterized using Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscope (FESEM), X-ray diffraction pattern (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and surface area analysis (BET). The results showed that the specific surface area significantly is increased by creating tubular nanostructure. TGA results indicated Surface functionalization of TNT with PDA (TNT-PDA) about 19.3% that led to increase biocompatibility and bioactivity of TNT as well as improve drug loading and release properties. It is attributed to the effect of NH groups which immobilize drug molecules on the TNT. According to the obtained release profiles for the samples, the release profiles followed from a Hill model. Thus, PDA modified TNT can be excellent candidate as specific drug delivery systems.