Diameter selective behavior of human nasal epithelial cell on Ag-coated TiO₂ nanotubes

Titanium oxide (TiO₂), a light, strong, corrosion resistant, biocompatible and non-toxic metal, is widely used as dental or orthopedic implants, but is rarely used in nasal applications. There are three potential clinical applications for titanium in nasal surgery, including nasal septal perforation repairment, nasal reconstruction or rhinoplasty, and cerebral spinal fluid (CSF) rhinorrhea repairment. Nasal cavity is a contaminated cavity, thus to develop a nasal implant with antibacterial activity has its importance. We have developed self-organized TiO₂ nanotubes with different diameters by utilizing an electrochemical anodization method and further decorated the TiO₂ nanotubes with silver (Ag) layer by electron-beam deposition. The human nasal epithelial cells (HNEpCs) was used for evaluating the cytocompatibility of TiO₂ nanotubes with or without Ag decoration, including cell adhesion, cell proliferation assay for analyzing cell growth condition, and scanning electronic microscopy (SEM) for observing cell morphology. Furthermore, Pseudomonus aeruginosa was used for assessing the antibacterial activity of titanium implants. Our results showed that 25-nm-diameter Ag-coated TiO₂ nanotubes possess both good cytocompatibility with cultured HNEpCs and antibacterial activity against P. aeruginosa, as compared to 100-nm-diameter nanotubes. In conclusion, the small-diameter Ag-decorated TiO₂ nanotubes have high biocompatibility and good antibacterial activity, and there is potential of its usage for future clinical applications as novel nasal implants.