Figure 6.

Vascularization of engineered myocardial tissue following epicardial implantation onto injured rat myocardium. (A) Representative hematoxylin and eosin staining (H&E) of transverse cross sections of the ventricles showing the location of the transplanted engineered myocardial tissue (denoted by *, with black line showing the boundaries of the engineered myocardial tissue) at 28 days after transplantation. Transverse tissue sections of explanted engineered myocardial tissue were immunofluorescently stained for murine-reactive antibodies against CD31 for endothelial cells (green) and smooth muscle α-actin (SMA, red). (B) Quantification of arteriole density within the explanted engineered myocardial tissues derived from aligned or randomly oriented scaffolds and cultured with iCM, iCM+iEC, or no cells (Acell). The microvessel density was calculated as the density of CD31⁺/SMA⁺ vessels per mm (n ≥ 3). *Denotes statistically significant relationship (P < 0.05). Scale bar: 1 mm (H&E); 100 μm (CD31/SMA).