Fig. 4
From: Vocal fold restoration after scarring: biocompatibility and efficacy of an MSC-based bioequivalent
Heterotopic (subcutaneous) implantation of the bioequivalent to rats (days 3 and 7 after the surgery). Left: implants before excision (absence of reactive changes). Center: light microscopy, H&E stain, × 100; PEG-GEL 3 DAYS: a cell-less mass of an implant, surrounded by adipose tissue; PEG-GEL 7 DAYS: the marginal region of an implant is divided into strands, separated from each other by accumulations of cell elements; PEG-GEL + MSC 3 DAYS: regions of marginal resorption in the implant’s peripheral zone; PEG-GEL + MSC 7 DAYS: integral structure of an implant outside the muscle tissue, cells of the central and peripheral zones are seen, marginal resorption over the whole implant surface. Right: phase-contrast microscopy, H&E stain, × 400; PEG-GEL 3 DAYS: longitudinally extended fibrin fibers; PEG-GEL 7 DAYS: fibrous structure of the implant’s tissue, looser on day 7, the ingrowth of thin-walled capillaries is seen; PEG-GEL + MSC 3 DAYS: parallel orientation and compact packing of fibrin fibers; PEG-GEL + MSC 7 DAYS: fibrin fibers. Marginal regions (*) were infiltrated with lymphocytes (small oval mononuclear cells with a diameter of 8 µm) and macrophages (larger cells with U-shaped nucleus). Deeper tissues included groups of MSC (green arrows)