Effects of hydrogenated TiO2 nanotube arrays on protein adsorption and compatibility with osteoblast‐like cells.

Background : Modified titanium substrates with titanium dioxide nanotubes have broad usage as implant surface treatment and drug delivery system. Their performance in most of these application is highly dependent on their morphology, nanotube dimension, and wettability. Aim/Hypothesis : To improve the drug-loading capacity and accelerate bone integration with titanium, in this study, we hydrogenated anodized titanium dioxide nanotubes (TNTs) by a thermal treatment. Material and Methods: Three groups were examined, namely- hydrogenated TNTs (H2-TNTs, test), unmodified TNTs (air- TNTs, control), and Ti substrates (Ti control). Results : Our results showed that oxygen vacancies were present in all the nanotubes. The quantity of -OH groups greatly increased after hydrogenation. Furthermore, the protein adsorption and loading capacity of the H2- TNTs were considerably enhanced as compared with the properties of the air-TNTs ( P < 0.05). Additionally, time-of-flight secondary ion mass spectrometry (TOF- SIMS) was used to investigate the interactions of TNTs with proteins. During the protein- loading process, the H2- TNTs not only enabled rapid protein adsorption, but also decreased the rate of protein elution compared with that of the air-TNTs. We found that the H2-TNTs exhibited better biocompatibility than the air-TNT and Ti groups. Both cell adhesion activity and alkaline phosphatase activity were significantly improved toward MG-63 human osteoblast-like cells as compared with the control groups (P < 0.05). Conclusions and Clinical Implications : Therefore, we conclude that hydrogenated TNTs can greatly improve the loading capacity of bioactive molecules and MG-63 cell proliferation. [ABSTRACT FROM AUTHOR]