User-Friendly and Parallelized Generation of Human Induced Pluripotent Stem Cell-Derived Microtissues in a Centrifugal Heart-on-a-Chip

Abstract

The persistence of cardiovascular diseases as leading global causes of death has spurred attempts to develop microphysiological systems integrating engineered cardiac tissue. These novel platforms enable investigation of mechanisms underlying myocardial pathology as well as in vitro screening of candidate drugs for possible cardiotoxicity. However, most of the developed systems rely on manual cell injection protocols, resulting in nonstandardized tissue creation and requiring excessive amounts of cells. To address these issues, we present a novel integrated device enabling the parallelized generation of cardiac microtissues based on human induced pluripotent stem cells as well as rat primary cardiomyocytes in an especially designed multichamber system that provides a precisely controlled physiological environment. The next-generation device utilizes a centrifugally assisted cell loading procedure, which enables robust generation of tissues devoid of air bubbles. It requires solely a minimal amount of cells to create uniaxially aligned cardiac muscle fibers, displaying well-aligned collections of sarcomeres. The viability and functionality of myocardial tissues can be maintained for long time periods, while detailed spatial and temporal beating kinetics can be examined by optical means. As proof of concept, the applicability of the system for drug testing was demonstrated, highlighting the potential of this user-friendly and economical centrifugal heart-on-a-chip for future applications in pharmaceutical industry and mechanistic research. With the ultimate goal in tissue engineering of approaching in vivo functionality as closely as possible, organ-on-a-chip (OoC) systems provide unprecedented game-changing opportunities by enabling creation of perfused three-dimensional tissues. Most of the recently developed OoC systems, however, require complex handling steps. Hence, a large gap still exists between technology development and collection of valuable biological data in a standardized medium- or high-throughput manner. The system presented here bridges this gap by providing a user-friendly framework for the parallelized creation of multiple physiologically relevant tissues, which could be applicable in every laboratory without additional equipment.