Optimisation of the corrosion rate of iron-based alloys for bioresorbable stent applications by surface acidification

Reuter, Sarah [UCL] Georges, Cédric Duportal, Malo Mercier, Dimitri Oudriss, Abdelali Savall, Catherine Jacques, Pascal [UCL] et al.[show all]

Bioresorbable stents could prevent late complications such as late thrombosis [1]. Stents need to be mechanically strong, making steel a good candidate. But steel does not corrode sufficiently fast. Furthermore, during corrosion in the blood environment, different layers form on top of the metal. This hinders the oxygen diffusion towards the metal, slowing down the corrosion [2]. Therefore, a way to increase the corrosion rate needs to be found. The pH of the environment greatly influences the presence of these layers; an acidic pH favours their dissolution [2,3,4], which could help in activating the corrosion. However, the blood environment needs to keep a pH close to physiological pH (7.4) and thus only the near stent surface can undergo an acidification. The present work investigates the influence of hydrogen on the Fe-based alloy surface evolution.