The electroactivity and stability of conductive PPy/HE/PLLA membranes

Linli Zhang, Shiyun Meng, Ze Zhang Faculty of Medicine, Laval University; Saint-François d’Assise Hospital Research Center, CHUQ, Quebec, QC, Canada. Statement of Purpose: Polypyrrole (PPy) is an important intrinsically conducting polymer studied for tissue engineering and bioelectrical applications. Its composites with biodegradable polylactide (PLLA) can be used as substrate for electrically stimulated cell growth. Heparin (HE)-doped PPy/PLLA composite membranes (PPy/HE/PLLA) are developed in our lab for biomedical applications. We had hypothesized that the HE-doped PPy should have a superior electrical stability and proved it in a direct current stability experiment. But the stability of electroactivity, i.e., the ability of maintaining ion exchange during multiple redox cycling, has not been studied. The current work employed the cyclic voltammetry method to investigate the environment stability of electroactivity of the PPy/PLLA membranes with or without HE as dopant. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and scanning electron spectroscopy (SEM) were used to investigate these PPy/PLLA composites before and after the cyclic voltammetry experiment.