Inkjet-Printed Graphene Multielectrode Arrays: An Accessible Platform for <i>In Vitro</i> Cardiac Electrophysiology

<i>In vitro</i> models have now become a realistic alternative to animal models for cardiotoxicity assessment. However, the cost and expertise required to implement <i>in vitro</i> electrophysiology systems to study cardiac cells pose a strong obstacle to their widespread use. This study presents a cost-effective approach for<i>in vitro</i> cardiac electrophysiology using fully printed graphene-based microelectrode arrays (pGMEAs) coupled to an open-source signal acquisition system. We characterized the pGMEAs' electrical properties and biocompatibility, observing low impedance values and cell viability. We demonstrated the platform's capability to record spontaneous electrophysiological activity from HL-1 cell cultures, and we monitored and quantified their responses to chemical stimulation with noradrenaline. This study demonstrates the feasibility of producing fully printed graphene-based devices for <i>in vitro</i> electrophysiology. The accessible and versatile platform we present here represents a step further in the development of alternative methods for cardiac safety screening.