Degradation behavior of biodegradable Fe35Mn alloy stents

J Biomed Mater Res B Appl Biomater. 2015 Apr;103(3):572-7. doi: 10.1002/jbm.b.33242. Epub 2014 Jun 21.

Abstract

This article reports a degradation study that was done on stent prototypes made of biodegradable Fe35Mn alloy in a simulated human coronary arterial condition. The stent degradation was observed for a short-term period from 0.5 to 168 h, which simulates the early period of stenting procedure. Potentiodynamic polarization and electrochemical impedance spectroscopy were used to quantify degradation rate and surface property of the stents. Results showed that signs of degradation were visible on both crimped and expanded stents after 1 h of test, mostly located on the stent's curvatures. The degradation rate of stent was higher compared to that of the original alloy, indicating the surface altering effect of stent fabrication processing to degradation. A single oxide layer was formed and detected as a porous structure with capacitive behavior. Expanded stents exhibited lower polarization resistance compared to the nonexpanded ones, indicating the cold work effect of expansion procedure to degradation.

Keywords: biodegradable metals; biodegradation; electrochemical impedance spectroscopy; stents.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorbable Implants*
  • Alloys / chemistry*
  • Calcium / analysis
  • Chemical Precipitation
  • Dielectric Spectroscopy
  • Electric Capacitance
  • In Vitro Techniques
  • Materials Testing
  • Oxides / analysis
  • Phosphorus / analysis
  • Porosity
  • Potentiometry
  • Rheology
  • Shear Strength
  • Solutions
  • Stents*
  • Surface Properties

Substances

  • Alloys
  • Fe-35Mn alloy
  • Oxides
  • Solutions
  • Phosphorus
  • Calcium