Comprehensive promotion of iPSC-CM maturation by integrating metabolic medium, nanopatterning, and electrostimulation

Abstract

The immaturity of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) is a major limitation for their use in drug screening to identify pro-arrhythmogenic or cardiotoxic molecules, thus hindering their potential role in guiding personalised drug selection for patients. Here, we demonstrate an approach that combines lipid-enriched maturation medium, nanopatterning of culture surfaces and electrostimulation to generate iPSC-CMs with an advanced electrophysiological, structural and metabolic phenotype. Through a systematic, stepwise parallel testing of the three stimuli, electrostimulation emerged as the pivotal factor to enhance mitochondrial development and to improve the electrophysiological properties of iPSC-CMs. The combined approach brought a substantial modification in their current composition by increasing INa, Ito, IK1 and IKr but decreasing ICa−L, resulting in a significant change in their sensitivity to cardioactive drugs. Transcriptome analysis revealed that activation of HMCES and TFAM targets played a role in mitochondrial development, whereas the downregulation of MAPK/PI3K signalling pathways and SRF targets were associated with polyploidy of iPSC-CMs. Taken together, our study provides mechanistic insights into the maturation of iPSC-CMs with a more adult-like drug response.