Abstract 502: Reversible Cardiac Action Potential Recordings to Track Cellular Electrophysiology Over Days

Abstract

Long-term action potential (AP) studies from the same cell site over days in multicellular preparations are currently lacking, thus limiting our understanding of cardiac physiology in development and disease. We recently reported a novel high-throughput platform for label-free AP measurements using multielectrode array (MEA) technology to gain intracellular access by way of electroporation. We hypothesized that multiple reversible electroporations of the same cell site will allow high-resolution recordings of AP waveforms without detrimental effects to the cell membrane. A total of 19 hiPSC-CM constructs on multiwell MEAs were simultaneously electroporated by employing a train of low voltage pulses (1 V, 1 ms, 1 Hz) for 30 s to elicit a transient transformation of field potentials (FPs) to APs. Waveforms were recorded from 12 electrodes per construct for electrophysiological characterization of the network. Recurrent electroporations of the same cell site at 0, 24, 48, 72 and 96 h enabled tracking of the electrophysiological evolution of the AP waveforms (see figure). We analyzed millivolt AP signals 10 s following the end of electroporation before APs reverted to FP signals strongly suggesting cell membrane recovery and network integrity for subsequent recordings. This methodology allows for screening transmembrane APs from cardiomyocyte networks over days. Overall, we present a spatio-temporal model capable of tracking FPs and APs in a non-invasive approach for cardiomyocyte functional maturation, developmental and pharmacological studies.