Biocompatibility of nanoporous TiO ₂ coating on NiTi alloy prepared via dealloying method

This paper investigated the biocompatibility of nanoporous TiO2 coating on NiTi shape-memory alloy (SMA) prepared via dealloying method. Our previous study shows that the dealloying treatment at low temperature leads to 130nm Ni-free surface titania surface layer, which possesses good bioactivity because of the combination of hydroxyl (OH ^-) group in the process of dealloying treatment simultaneously. In this paper, the biological compatibility of NiTi alloy before and after dealloying treatment was evaluated and compared by direct contact method with dermal mesenchymal stem cells (DMSCs) by the isolated culture way. The interrelation between the biological compatibility and surface change of material after modification was systematically analyzed. As a consequence, the dealloying treatment method at low temperature could be of interest for biomedical application, as it can avoid sensitization and allergies and improve biocompatibility of NiTi shape-memory alloys. Thus it laid the foundation of the clinical trials for surface modification of NiTi memory alloy.