Influence of the electrosynthesis conditions on the spontaneous release of anti-inflammatory salicylate during degradation of polypyrrole coated iron for biodegradable cardiovascular stent

Abstract

In this work, the spontaneous release of anti-inflammatory salicylate from polypyrrole (PPy) coated iron has been studied during degradation of the material in phosphate buffer saline at 37 °C. The sodium salicylate was incorporated into PPy in a one-step electropolymerization process. The influence of the synthesis conditions such as sodium salicylate concentration, pyrrole concentration and deposition charge on drug release profile has been investigated. The morphology, surface roughness and redox properties of PPy/Fe have been also studied. The drug release was studied by UV–Vis spectrophotometer with flow cuvette connected to the electrochemical cell, which provided continuous study of the released dopant. As a result, reliable and quantitative study of salicylate release from PPy coated iron was attained. Depending on the synthesis conditions the concentration of the salicylate released was in the range of 83–183 μM cm−2 after 21 h of immersion. The rate of drug release of 10–11 μM h−1 was the highest at the beginning after immersion (1–2 h), then it gradually decreased and finally it reached the lowest value of approximately 0.3 μM h−1 at the end of the process.”