Structural dermis remodeling in a skin expansion rat model

Abstract

Introduction. Skin expansion is known to be the most effective way to obtain skin for alloplastic closing of large defects, and it has proven to be successfully used in various fields of surgery, cosmetology, and traumatology. At the same time, the issues of skin flap restructuring when it is stretched and possible range of its application are still relevant. In this regard, the aim was to study the adaptive skin rearrangements of the fibrous skeleton in a murine skin expansion model. Materials and methods. We used the skin of mature male Wistar rats (N=30) after a 2-week stretching. We utilized a complex morphological light and electron microscopy approach as well as an immunohistochemi-cal method to determine the types of collagen and to study the alterations in skin samples. Results. We revealed pronounced reactive changes in the skin structural components in the skin expansion area. On day 14, we observed a decrease in the epidermal cell layer thickness as well as stretching, partial disorganization, and damage of dermal fibrous structure. At the same time, cellular mechanisms of regen-eration and activation of collagen synthesis were launched, the morphological substrate of which was (1) a significant 2.7-fold increase in the number density of fibroblasts, which produce substances for building fibrous structures, (2) a five-fold increase in macrophages, which are a catalyst for the fibroblast functional activity and (3) a collagen fiber types’ redistribution s with Type III collagen structures’ predominance. Conclusion. The results indicate, first of all, the restructuring of the dermal fibrous component, which im-plies reparative and restorative processes. These must be taken into account in clinical practice to achieve not only an esthetic effect but also the subsequent adequate functioning and vital activity of the skin flap. Keywords: skin expansion, fibrous dermis, remodeling, skin, hyperextension