Effect of nanotubular-micro-roughened titanium surface on cell response in vitro and osseointegration in vivo

Abstract

This study was to evaluate wettability, cell response, and osseointegration of nanotubular titanium (Ti) surface by anodic oxidation. Commercially pure Ti discs were treated by polishing, sandblasting, and anodizing. These surfaces were characterized by scanning electron microscopy and contact angle measurement. MC3T3-E1 osteoblast cell was used to evaluate cell response in vitro. The cell morphology, cell viability, and alkaline phosphatase (ALP) specific activity were assessed. The Ti implants of 2.0 mm diameter and 5.0 mm long treated by anodizing and sandblasting/anodizing were inserted into the tibia of rats. After 3 weeks, the histology of the Ti–bone interface was examined. SEM observations showed that the anodizing and sandblasting/anodizing created the nanotubular surface and graded nanotubular-micro-roughened surfaces, respectively. The anodizing and sandblasting/anodizing significantly improved the hydrophilicity of Ti. The significant greatest cell spreading and ALP specific activity were observed on the graded nanotubular-micro-roughened surfaces treated by sandblasting/anodizing. The in vivo study shows that newly formed bone was intimately in contact with the nanotubular surfaces without adverse immune response. This study has suggested that the graded nanotubular-micro-roughened surface of Ti treated with sandblasting/anodizing is very promising in implantology due to improved hydrophilicity, favorable cell response, and excellent osseointegration.