FIG. 4.

Histological observation of artificial skeletal muscle tissue constructs on day 7. (A) Morphology of a representative artificial skeletal muscle tissue construct. The muscle bundle was anchored at each end with minuten pins. (B, C) Representative fluorescence images of the surface of C2C12/Bcl-2 (Dox−) (B) and C2C12/Bcl-2 (Dox+) (C) muscle bundles. Green, green fluorescent protein; blue, 4′,6-diamidino-2-phenylindole. (D, E) Typical hematoxylin and eosin staining images of cross-sections of C2C12/Bcl-2 (Dox−) (D) and C2C12/Bcl-2 (Dox+) (E) muscle bundles. The middle part of skeletal muscle tissue constructs between the pins was sliced to prepare the sections. (F, G) Bright-field micrographs of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining of C2C12/Bcl-2 (Dox–) (F) and C2C12/Bcl-2 (Dox+) (G) muscle bundles. Locations of sections (F) and (G) in the muscle bundles are indicated in (D) and (E), respectively. Blue, magnetite nanoparticles; brown, TUNEL-positive nuclei; purple, TUNEL-negative nuclei. Arrows indicate TUNEL-positive nuclei. Color images available online at www.liebertpub.com/tea