Title: Effect of surface treatment on surface roughness and Ni content of nitinol stents

Authors: Yongsug Tak; Byoung-Gu Lee; Jaemin Kim; Jang Yong Kim

Addresses: Department of Chemical Engineering, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon, 405-731, South Korea ' Department of Chemical Engineering, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon, 405-731, South Korea ' CoETEC Co. Ltd., 40-9 Baekjegobun-ro 27gil, Sonpa-gu, Seoul, South Korea ' Department of Surgery, Division of Vascular and Transplant Surgery, School of Medicine, The Catholic University of Korea, 222 Banpo-Daero, Seocho-Gu, Seoul 137-701, South Korea

Abstract: Nitinol (NiTi) is a biocompatible material with hyperelastic properties. It represents a well-established shape memory alloy metal, commonly adopted in medical devices such as vascular stents. Although its biocompatibility as a base metal is of crucial importance for implanting a NiTi stent (a short and narrow metal mesh tube) into an anatomical blood vessel, the surface roughness and Ni content of the stent also represent important factors to consider, because the surface smoothness affects the biocompatibility of the implant, and the Ni exposed on the material surface is known to be toxic to surrounding living tissues. The present research thus aims to identify an optimal way to control surface roughness and Ni content on the NiTi surface, by testing the effect of four carefully chosen surface treatments. The present results show that electropolishing combined with hydration represents the treatment with the best potential to achieve the above objectives.

Keywords: nickel; titanium; NiTi alloys; surface treatment; electropolishing; mechanical polishing; anodising; hydration; surface quality; surface roughness; nickel content; nitinol stents; biocompatible materials; hyperelasticity; shape memory alloys; SMA; medical devices; vascular stents; biomedical engineering; bioengineering; blood vessels.

DOI: 10.1504/IJSURFSE.2016.077541

International Journal of Surface Science and Engineering, 2016 Vol.10 No.4, pp.389 - 399

Available online: 05 Jul 2016

Full-text access for editors Access for subscribers Purchase this article Comment on this article