Fig. 4.
Drug dose-response and structural studies. (a) Epinephrine drug dose assay stress traces (PDMS layer = 28 μm). (b) The epinephrine dose-response summarized for a two film assay. (c) Bright field and fluorescent images of a “heart on a chip” tissue: (i) image of an 8-film chip; (ii) a stain of two of the films, actin (green), nuclei (blue); (iii) actin fibers (green), nuclei (blue); (iv) sarcomeres (α-actinin). (d)(i) Example stress traces; (ii) sarcomeres (α-actinin); (iii) sarcomere orientation histograms; (iv) summary of OOP, peak systole and diastole stresses. Scale bars = 2mm for (b), (c)(i)–(ii); 20μm for (d)(iii)–(iv), (e)(i); PDMS layer thickness: chip 1–20 μm, chip 2–15.6 μm.