Engineered Cardiac Tissue Contractility

The contractility of the engineered cardiac tissues was assessed using the “heart-on-a-chip” platform, as previously described.^{32 (link)} Briefly, the chips were placed in the Normal Tyrode solution, the films were cut out, and the experiments performed at 35–37 °C. The dynamics of the films were recorded using a stereoscope (no. SZX-ILLB2, Olympus America, Center Valley, PA) while the tissues were either allowed to contract spontaneously or were paced using a MyoPacer Field Stimulator (IonOptix, Milton, MA) at 0.5, 1, 1.5, and 2 Hz. The resultant movies were analyzed with custom software to extract diastolic stress, systolic stress, active stress, and beating frequency.^{23 (link),32 (link)} The whole dataset is made available through Dryad https://doi.org/10.7280/D10H40.