Figure 2.

Enhanced Maturation of Cardiac Tissue-like Constructs

(A) Immunostaining images of β-MHC (red), and α-actinin and cTnT (green). Cardiomyocytes (CMs) were cultured on different substrates: aligned nanofibers (ANFs), random nanofibers (RNFs), and gelatin-coated flat substrate (Flat); nanofibers were fabricated with green or red dyes added before cell seeding. Scale bar, 50 μm.

(B) Fourier component analysis (FFT) of nuclei, nanofibers, and cTnT-positive thin filaments according to the positioning density on ANFs (upper panel), RNFs (middle panel), and Flat (bottom panel).

(C) qPCR analysis of gene expression in CMs, relative to day 0: ACTN2 (α-actinin), TNNT2 (cTnT), TNNI3 (troponin I), MYH7 (myosin heavy chain beta, β-MHC), MYL2 (ventricular myosin light chain-2), HAND2 (heart- and neural crest derivative-expressed protein 2), PLN (phospholamban), and RYR2 (ryanodine receptor 2). The CMs were cultured for 14 days. Heatmap of Z score values shows genes expressed in different groups. The FPKM (fragments per kilobase of exon per million fragments mapped) value of each gene is normalized using Z scores. Data are represented as means ±SD, n = 3 independent experiments. ^∗p < 0.05, ^∗∗p < 0.01, and ^∗∗∗p < 0.001 by one-way ANOVA followed by Tukey's post hoc test.

See also Figure S2.