Surface modification of NiTi alloy and human platelet activation under static and flow conditions

Abstract

The effect of surface nickel species on NiTi alloy thrombogeneity was investigated by assessment of platelet activation and whether oxidative modification of the alloy would affect platelet response. Tests were conducted under static conditions and arterial levels of shear stress. Heat treatment of the alloy at 600 °C significantly reduced surface nickel species. Under both static and flow conditions platelet activation on the heat-treated alloy was comparable to that on pure titanium and was significantly lower than that on polished NiTi. This study demonstrates that the risk of thrombotic complications associated with NiTi in vivo can be reduced through heat modification of the alloy surface to reduce surface nickel.