Figure 3. Histological sections of the tissue engineered skin constructs in vivo.

Skin constructs were implanted in dorsal skin fold chambers in mice for 11 days. Sections were stained with Masson’s trichrome (A–D) or analyzed with fluorescence microscopy (E), respectively. (A) illustrates an overview with the junction between the inserted skin construct (m = Matriderm®) and native mouse skin (n) at the wound edge after 11 days in the dorsal skin fold chamber in mice. The intact mouse skin opposite of the skin construct can be seen in the lower part of the picture (n) (see also Figure 1). The skin construct and the intact skin part in the sandwiched skin are separated by the panniculus carnosus (pc). Both in native mouse skin (B) and the printed skin construct (C) a dense epidermis (empty asterisks) and a corneal layer can be observed. In case of the skin construct, the epidermis is formed by the printed keratinocytes (E). This can clearly be seen by the green fluorescence emitted by the used HaCaT-eGFP cells. The fibroblasts (NIH3T3-mCherry) partly migrated into the Matriderm® (yellowish fibres). The fibroblasts, which stayed on top of the Matriderm®, display an outstretched morphology (C), being accompanied by collagen deposition (filled asterisks). Blood vessels (arrows) can be detected in the skin constructs (D). Scale bars depict 200 µm (A, D, E) and 100 µm (B, C).