A Comparative Study Between NiTi and a New Flash Treated Superelastic Ti‐Zr‐Nb‐Sn Alloy for Cardiovascular Stents

ABSTRACT Nowadays, for applications such as coronary stents, the most widely used materials are Nitinol or NiTi alloys, thanks to their unique superelastic properties, which make them the most suitable out of all metallic biomaterials for this type of application. The major problem with Nitinol in a physiological environment is the release of Ni ions through corrosion, which is allergenic and toxic, so its presence should be avoided. In this study, a new β‐metastable Ni‐free titanium alloy, Ti‐22Zr‐11Nb‐2Sn (at.%), was synthesized as an alternative to Nitinol. The new alloy was characterized structurally and tested mechanically, and its superelasticity, in vitro cytocompatibility using HPMEC cells, and corrosion resistance were studied; all the results were compared with those of Nitinol tested under the same conditions. Our results indicate that the newly developed Ni‐free alloy has good superelasticity, better biocompatibility, and corrosion resistance than Nitinol. These results are encouraging for the future use of this alloy as an alternative to Nitinol in the manufacture of coronary stents and other devices requiring good superelasticity for use in cardiac and vascular surgery.