Tailoring the electrochemical degradation of iron protected with polypyrrole films for biodegradable cardiovascular stents

- The degradation of PPy/Fe is studied in PBS at 37 °C by odd random phase EIS.
- Anti-inflammatory salicylates are incorporated in the PPy coating.
- A reliable and quantitative evaluation of the PPy/Fe degradation is attained.
- The degradation of iron can be tailored by tuning properties of the PPy.
- PPy deposited under certain conditions can either inhibit or enhance Fe degradation.

The degradation of polypyrrole (PPy) coated iron is studied in phosphate buffer saline solution at 37 °C by odd random phase multisine electrochemical impedance spectroscopy (ORP-EIS). PPy is electropolymerized with anti-inflammatory salicylates incorporated in the film, as a drug release system. The modelling of EIS over time provides the quantitative description of the corrosion behaviour of the material. Thus, the reliable analysis of the degradation stages of PPy coated iron is attained. The outcome of the present study shows that the degradation of iron can be tailored by tuning the properties of the PPy coating for possible medical applications.