Fig. 2

Micrographs of cells stained with toluidine blue, sirius red and immunohistochemistry. The control cells showed almost no cytoplasm staining for toluidine blue, sirius red and Col I (a), while the experimental cells indicated obvious cytoplasmic staining (b–d). The staining became gradually stronger as the tensile strength increased. However, the staining of Col II was stronger in the control cells (a), and then it became lighter with greater tensile strength (b–d). Scale bars: 100 μm