FIG. 4.

Histological assessment of human SMC tubes. H&E-stained tissue tubes comprised rings precultured for 3 (A–C), 5 (D–F), or 7 (G–I) days before fusion. Low magnification longitudinal sections shown in (A, D, G). Higher magnification views show one fusion point at the outer surfaces (solid box; B, E, H) and at the inner surfaces (dashed box; C, F, I) of the tissue tubes. Lumen on bottom, scale bars = 250 μm (low magnification) or 100 μm (high magnification). Images representative from n = 3 samples/group. Sectioning schematic shown in lower right. Color images available online at www.liebertpub.com/tea