Abstract 188: Manipulation of Excitation-contraction Coupling in Cardiomyocytes Using Conductive Polyaniline Scaffolds

The application of tissue engineered patches made of conductive polymer scaffolds combined with cardiomyocytes (CMs) could provide a dual method of improving the damaged myocardium after an infarction: firstly by introducing functional CMs to the area; secondly the conductive polymer could modulate electrical transmission across the scar tissue. Polyaniline (PANI) scaffolds are one such example, however, the consequences of growing CMs on conductive PANI scaffolds with regards to CM electrophysiology are unknown. In this study we assess the hypothesis that conductive PANI scaffolds affect CM calcium transients and action potential morphology in culture. Neonatal rat ventricular myocytes (NRVMs) and neonatal rat fibroblasts were co-cultured on conductive and non-conductive (sodium hydroxide treated) PANI scaffolds and remained viable after four days of culture, covering the surface of the construct. Compared to those cultured on non-conductive PANI scaffolds, NRVM cultured on conductive PANI scaffolds show faster calcium transients, measured using Fluo-4AM and field stimulated at 1 Hz, with a decrease in the time to peak (t p non-conductive=105±6 ms, t p conductive= 85±5 ms, p50 non-conductive=212±12 ms, t 50 conductive= 116±7 ms, p90 non-conductive=404±24 ms, t 90 conductive= 266±15 ms, p