Figure 2. Improved cardiomyocyte contractility in net-shaped hPSC-CMs. (A-F) Immunostaining of sheet-shaped hiPSC-CMs 15 days after cardiac differentiation. (A and B) Images of cTnT (green) and DAPI (blue) staining. (C and D) NkX2.5-GFP and bright field images; (E and F) MitoTracker images (red) (G) cTnT fluorescence intensity; (H) TNNT2 mRNA expression. (I, J, and K) Cell area, cell perimeter, circularity index (n=51 in net-d15 and n=45 in sheet-d15). (L) Average MitoTracker density; All data were normalized to the sheet-day 15 group and are expressed as means±S.E.M. * Statistically significant differences between individual groups (n≥3; *P<0.05, **P<0.01, ***P<0.001). Scale bar: 50 μm.