Digital Light Processing 3D Printing enables High Throughput Fabrication of Human Engineered Heart Tissues for Disease Modeling

3D in vitro engineered heart tissue (EHT) models recapitulate aspects of native cardiac physiology but are often limited by scalability, cost, and reproducibility. Here, we report a simple, one-step method for rapid (∼minutes) fabrication of molds using digital light processing (DLP)-based 3D printing that support the formation of EHTs by human induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) with high reproducibility (>95% efficiency) and varied designs (e.g., length, aspect ratio). Compared to 2D iPSC-CMs, 3D EHTs display enhanced maturity, including increased expression of β-oxidation genes, higher concentrations of sarcomeric myosins, improved sarcomere density and alignment, and enrichment of cardiac pathways (e.g., upregulation of sodium channels, action potentials, contraction). The technology is applied to model pathological cardiac hypertrophy in vitro , using either (i) acute adrenergic agonism or (ii) chronic culture within stiff hydrogel molds. Treated EHTs exhibit increased levels of pathology-associated gene expression and activation of signaling cascades involved in pathological remodeling compared to untreated controls or treated 2D iPSC-CMs. Thus, our method results in robust yet simpler, cheaper, and faster EHTs to study cardiac disease.