Integrated Microphysiological Heart-On-A-Chip Platform with Real-Time ECG and Metabolic Sensors.

Mohammad Ghosheh ¹ Muneef Ayyash ^1,3,4 Avner Ehrlich ^1,2 Idit Goldfracht ⁵ Orian Leitersdof ¹ Merav Cohen ^1,2 Lior Gepstein ^5,6 Yaakov Nahmias ^1,2,3,4

¹Alexander Grass Center for Bioengineering, Benin School of Computer Science and Engineering, Jerusalem 91904, Israel, The Hebrew University of Jerusalem, Israel
²Department of Cell and Developmental Biology, Silberman Institute of Life Sciences, Jerusalem 91904, Israel, The Hebrew University of Jerusalem, Israel
³Tissue Dynamics, Jerusalem 91904, Israel, The Hebrew University of Jerusalem, Israel
⁴The Rachel and Selim Benin School of Computer Science and Engineering, the Hebrew University of Jerusalem, Jerusalem, Israel, The Hebrew University of Jerusalem, Israel
⁵Sohnis Research Laboratory for Cardiac Electrophysiology and Regenerative Medicine, the Rappaport Faculty of Medicine and Research Institute, Technion- Israel Institute of Technology, Haifa, Israel, Technion- Israel Institute of Technology, Israel
⁶Cardiolology Department, Rambam Health Care Campus, Haliya Hashniya St 8, Haifa 3109601, Israel, Haliya Hashniya

Over the past several years, efforts have been made to establish in-vitro environments of human-like organs that imitate normal physiology. The human heart is an important organ to emulate, due to the prevalence of cardiac disease and the high incidence of drug-induced cardiac toxicity. Here, we present a heart-on-chip platform capable of maintaining human tissue for over three months in vitro under physiological conditions, and tracking its function in real-time using tissue embedded microsensors. Induced Pluripotent Stem Cell-Derived Cardiomyocytes (hiPSC-CMs) were co-cultured with cardiac endothelial cells and self-assembled into hollow vascularized organoids, with structural and functional properties similar to a mature heart. Basal heart rate ranges from 60 to 80 beats per minute, achieving spontaneous, synchronized and steady beating. Organoids showed accurate response to heart stimuli (epinephrine) and inhibition (amiodarone) in terms of heart rate and contractility.

Mitochondrial respiration was monitored in real-time using two-frequency phase modulation of tissue-embedded phosphorescent microprobes. Metabolic fluxes were measured by a microfluidic electrochemical sensor unit, measuring glucose, glutamine, glutamate, and lactate, providing real-time analysis of minute shifts in key metabolic fluxes. Electrophysiological activity was simultaneously measured by extracellular field potentials, recorded using an on-chip nano-fabricated multi-electrode arrays (MEAs) system. We combine the data to provide elaborate real-time assessment of the organoid`s activity and health, allowing us to investigate the response for the prediction of drug-induced cardiotoxicity and ischemia-reperfusion injuries. Our microfluidic platform reveals the dynamics and strategies of cellular adaptation to cardiac damage, a unique advantage of our organ-on-chip technology.