Histological Evaluation of the Emerging Role of Adipose Stem Cells-Derived Exosomes in Cutaneous Wound Healing in Albino Rats

Prolonged healing and scar formation are two major challenges in treating wounds, resulting in physical, mental and socioeconomic burden to the affected subjects. Exosomes (Exos) are naturally secreted vesicles playing a vital role in the transfer of RNA to neighboring or distant recipient cells and there are numerous on-going studies on their role of in tissue regeneration and wound healing.Aim of the work: Evaluation of the efficiency of Exos derived from adipose stem cells on cutaneous wound healing in adult male albino rats.Materials and Methods: Thirty-four rats were divided into three groups; Group I: control. Group II: a dorsal cut wound (1.5 × 1.5 cm) was done to each rat. Group III: the same wound was done and rats were injected with 200μ PKH26-labeled Exos intravenously. Rats were sacrificed after 21 days. Skin sections were subjected to hematoxylin and eosin (HandE), Mallory's trichrome and orcein stains, alpha smooth muscle actin (α-SMA) and Ki67 immunohistochemical stains.Results: Skin sections from group II showed scar formation, lost epidermal layers and hair follicles. There was significant increase in collagen fibers and α-SMA immunoreaction, with significant decrease in elastic fibers and Ki67 immunoexpression compared to the control. In group III, the skin revealed almost normal histology, significant decrease in collagen fibers and α-SMA, with significant increase in elastic fibers and Ki67 immunoreaction compared to group II.Conclusion: Exos injection has demonstrated a beneficial effect on cutaneous wound healing and could prevent scar formation in adult male albino rats.