Fig. 2
From: Regulatory T cells in skin regeneration and wound healing
Wound healing stages. Wound healing is a biological process consisting of four overlapping phases (hemostasis, inflammation, proliferation and remodeling). Immediately after the injury, platelets migrate to the wound site. The release of chemical signaling reagents triggers the activation and polymerization of fibrin leading to the adhesion of platelets. Thus, fibrin (fibrin clot) and coagulated blood accumulate in the wound site. During the inflammation phase, monocytes migrate into the wound tissue, differentiate into tissue macrophages, and subsequently phagocytose the blood coagulum. Growth factors are released into the wound site, stimulating cells to proliferate. As a result, by secreting collagen and fibronectin, fibroblasts form a provisional extracellular matrix. Simultaneously, the squamous epithelium of the skin is renewed via the ingrowth of new epithelial cells from the wound edges (epithelialization). Finally, the final scar tissue is formed, which lacks hair follicles as well as sebaceous and sweat glands. Mφ macrophage