Multifunctional cardiac microphysiological system based on transparent ITO electrodes for simultaneous optical measurement and electrical signal monitoring

Drug-induced cardiotoxicity is a significant contributor to drug recalls, primarily attributed to limitations in existing drug screening platforms. Traditional heart-on-a-chip platforms often employ metallic electrodes to record cardiomyocyte electrical signals. However, this approach hinders direct cardiomyocyte morphology observation and typically yields limited functionality. Consequently, this limitation may lead to an incomplete understanding of cardiomyocyte characteristics. To address these challenges, we introduce a multifunctional cardiac microphysiological system featuring transparent indium tin oxide electrodes. This innovative design aims to overcome the limitations of conventional heart-on-a-chip systems where metal electrodes interfere with the observation of cells and increase the difficulty of subsequent image processing of cell images. In addition to facilitating optical measurement combined with image processing capabilities, this system integrates a range of electrodes with diverse functionalities. These electrodes can realize cellular electrical stimulation, field potential monitoring, and impedance change tracking, enabling a comprehensive investigation of various cardiomyocyte traits. To demonstrate its versatility, we investigate the effects of four cardiac drugs with distinct pharmacological profiles on cardiomyocytes using this system. This platform provides a means for quantitatively and predictively assessing cardiac toxicity, which could be applied to conduct a comprehensive evaluation during the drug discovery process. We developed a multifunctional cardiac microphysiological system on transparent electrodes, enabling simultaneous electrical signal monitoring and optical observations of cardiac tissue, holding promise for applications in cardiac drug development.