Figure 1: (a) Model system of 3D engineered muscle tissue culture. MDSCs undergo cellular aggregation prior to EMT construction. EMT is formed by mixing MDSC aggregates with collagen/ECM in a Flexcell Tissue Train Culture System. MDSC aggregates are cultured as EMT under low-serum conditions to induce differentiation. In an analogous manner, iPS-EMT is constructed by mixing dissociated iPS cardiac cells with collagen/ECM. (b) Composite phase contrast image of EMT. Cells in EMT aligned in the longitudinal direction and formed a muscle tissue during the 14-day culture period. Tissue morphology is maintained by anchors at each end of the tissue train plate. Individual sections of the EMT were imaged using a Leica light microscope at 2.5x magnification and merged using Adobe Photoshop.