In vitro biocompatibility of titanium oxide for prosthetic devices nanostructured by low pressure metal-organic chemical vapor deposition

Metal-Organic Chemical Vapor Deposition (MOCVD) has recently been proposed to coat orthopedic and dental prostheses with metal nanostructured oxide films through the decomposition of oxygenated compounds (single-source precursors) or the reaction of oxygen-free metal compounds with oxygenating agents. The present study was carried out to assess the in vitro biocompatibility in terms of cell proliferation and activation, of commercially pure Ti (control material: TI/MA) coated with nanostructured TiO2 film by MOCVD (Ti/MOCVD) using osteoblast-like cell cultures (MG-63). Evaluations were performed at 3, 7 and 14 days. Cell proliferation showed a similar trend for Ti/MA and TiIMOCVD compared to polystyrene; cell number increased with time from seeding to day 7 (p < 0.005), and then decreased progressively until day 14 (ranging from -14% to -47%). The ALP level and OC production showed no significant differences between TiIMOCVD and Ti/MA at each experimental time. Significantly higher ALP levels were found in Ti/MA at 3 days and in Ti/MOCVD at 7 and 14 days when compared to the polystyrene group. OC production decreased over time and the highest values were observed at 3 days, when it was significantly higher in the Ti/MA than in the polystyrene group (50%, p < 0.05). CICP synthesis was positively affected by the presence of TiIMOCVD and was higher in TiIMOCVD than in the polystyrene group. No significant differences were found between TiIMOCVD and Ti/MA in terms of IL-6 and TGF-beta1 synthesis at any experimental time. In conclusion, the current findings demonstrate that the nanostructured TiO2 coating positively affects the osteoblast-like cell behavior in terms of cell proliferation and activity, thus confirming its high level of in vitro biocompatibility in accordance with expectations.