MTF chip performance assessment.

<p>Results from this study were used to compare the MTF chip based model to <i>in vivo/ex vivo</i> and other <i>in vitro</i> tissue model studies. Many models only examine certain features of pathology, this MTF chip based model mimics ventricular tissue architecture and generates multiscale readouts and can be used to compare healthy and diseased tissues.</p

ANG II treatment leads to decreased contractile function.

<p>(A,) MTF Chip. (A,i) Photograph of experimental setup (Scale bar: 1 cm). (A ii-iii) Schematic of the MTF chip in diastole (ii) and systole positions (iii). Microcontact printing was used to pattern cells to resemble the structure of heart tissue architecture mimicked on the MTF chip (Scale bar: 20 μm). (A,iv) Fibronectin patterns on surface of thin film drive tissue architecture (Scale bar: 20 μm). (A,v) Brightfield image of engineered cardiac tissues on the MTF. (B-D) (i) Diastole and (ii) peak systole of muscular thin films. Blue outline represents the original film length, red line represents the x-projection of the radius of curvature of the film (Scale bar: 500 μm). (E) Representative stress traces generated from x-projections of films (F) ANG II treatment leads to a decrease in contractile stress generation. Control n = 85 tissues, 5 nM n = 15 tissues, 100 nM n = 69 tissues, 3 harvests. Tissues were paced at 2Hz (mean ± SEM, * indicates p < 0.05 vs control, # indicates p < 0.05 vs. 100 nM).</p

ANG II increases the occurrence of early after depolarizations (EADs) and arrhythmias.

<p>(A) Normalized fluorescence intensity of Rohd 2 dye (top panel) over time (<i>x</i>-axis) along a line crossing the 2D field of view (<i>y</i>-axis). Average fluorescence intensity traces (Bottom), red markers indicate the applied electrical pacing at 2Hz (Scale bar: 500 ms). Traces were normalized relative to the maximum peak intensity, F_N<b>=</b> F_{instantaneous}/ F_max. (B) Percentage EAD events relative to total paced events. (C) Percentage of EADs which evolved into sustained arrhythmia. (D) Time to peak for each condition. Control n = 8 tissues, 5 nM n = 8 tissues, 100 nM n = 10 tissues (mean ± SEM; * indicates p < 0.05 vs. control).</p