Generation and Maturation of Human iPSC-derived 3D Organotypic Cardiac Microtissues in Long-Term Culture

We have established a scaffold-free protocol to generate multicellular, beating and self-organized human organotypic cardiac microtissues (hOCMTs) in vitro from human induced pluripotent stem cells (hiPSCs) that can be cultured for long term. This is achieved by differentiation of hiPSC in 2D monolayer culture towards cardiovascular lineage, followed by further aggregation on low-attachment culture dishes in 3D. The generated hOCMTs containing multiple cell types that physiologically compose the heart, gradually self-organize and beat without external stimuli for more than 50 days. We have shown that 3D hOCMTs display improved cardiac specification, survival and maturation as compared to standard monolayer cardiac differentiation in 2D. We also confirmed the functionality of hOCMTs by metabolic flux analysis and their response to cardioactive and cardiotoxic drugs in long term culture. This study could help to develop more physiologically-relevant cardiac tissue models, and represent a powerful platform for future translational research in cardiovascular biology. Cross-comparison of bulk RNA-seq for hiPSC-derived 3D organotypic cardiac microtissues/organoids on Day 30 and Day 50 time points, vs 2D monolayer iPSC-derived cardiac differentiation on Day 30 and Day 50 timepoints