Human iPSC-Derived Cardiomyocyte Networks on Multiwell Micro-electrode Arrays for Recurrent Action Potential Recordings

Abstract

Cardiac safety screening is of paramount importance for drug discovery and therapeutics. Therefore, the development of novel high-throughput electrophysiological approaches for hiPSC-derived cardiomyocyte (hiPSC-CM) preparations is much needed for efficient drug testing. Although multielectrode arrays (MEAs) are frequently employed for field potential measurements of excitable cells, a recent publication by Joshi-Mukherjee and colleagues described and validated its application for recurrent action potential (AP) recordings from the same hiPSC-CM preparation over days. The aim here is to provide detailed step-by-step methods for seeding CMs and for measuring AP waveforms via electroporation with high precision and a temporal resolution of 1 µs. This approach addresses the lack of easy-to-use methodology to gain intracellular access for high-throughput AP measurements for reliable electrophysiological investigations. A detailed work flow and methods for plating of hiPSC-CMs on multiwell MEA plates are discussed emphasizing critical steps wherever relevant. In addition, a custom-built MATLAB script for rapid data handling, extraction and analysis is reported for comprehensive investigation of the waveform analysis to quantify subtle differences in morphology for various AP duration parameters implicated in arrhythmia and cardiotoxicity.

Automated Feature Extraction from Large Cardiac Electrophysiological Data Sets

“…High-purity iPSC-CM cultures were produced from human cardiac fibroblasts as described in (Zlochiver et al, 2019). hiPSCs cultures were differentiated using the feeder-free monolayer differentiation protocol.…”

“…Much like a medical electrocardiogram, FP recordings measure the potential change across the entire bulk of tissue and have been observed to be closely correlated to the underlying AP (Tertoolen et al, 2018). Recent work has shown the feasibility of multi-electrode arrays (MEA) (Meyer et al, 2012) in the large-scale efficient recording of both AP and FP readings (Edwards et al, 2018; Zlochiver et al, 2019; Hayes et al, 2019; Balafkan et al, 2020).…”

In Situ and Quantitative Monitoring of Cardiac Tissues Using Programmable Scanning Electrochemical Microscopy

“…Hence, in situ characterizations of oxygen consumption, extracellular H 2 O 2 level, and contraction frequency of cardiac tissues can evaluate their metabolic activity and electrophysiological property in real time and thus reflect their physiological functions. The traditional methods for characterizing these parameters, for example, Clark-type electrodes for oxygen concentration detection, fluorescent probes for H 2 O 2 concentration characterization, , microelectrode arrays, , and Ca 2+ -dependent fluorescent dyes , for measuring action potentials, are either performed at the cellular static state or in an invasive manner, which cannot meet the needs of in situ and noninvasive monitoring of living cells. Methods that can in situ and continuously monitor the dynamic changes in metabolic activity and contractile frequency of cardiac tissues in a label-free and noninvasive way are still needed.…”