Figure 2

Histological evaluation of pig and human ventricular tissue specimens showing preserved physiological morphology and structure. Representative photomicrographs of pig tissue block slices (A,E), pig transmural core biopsy slices (B,F), human papillary muscle slices (C,G) and human transmural core biopsy slices (D,H), stained with hematoxylin/eosin and imaged at 20 × magnification (upper panels) or stained with Masson’s trichrome and imaged at 63 × magnification (lower panels). The majority of fibers are longitudinally aligned, with elongated fibroblasts running among them. Note the presence of regular sarcoplasmic cross striations and of blood vessels surrounded by collagenous connective tissue (stained blue in the lower panels) as well the absence of signals of tissue damage like contraction bands or wavy fibers.