FIGURE 1.

The wound healing process. The four temporally overlapping stages of wound healing mainly include hemostasis, inflammation, proliferation, and tissue remodeling, which involves multiple cells, such as fibroblasts, keratinocytes (KCs), endothelial cells (ECs), and immune cells. Initially, fibrinogens and platelets combine to form the thrombus to stop bleeding, and provide fibrin matrix for infiltrating cells. In the inflammation stage, immune cells, represented by neutrophils and macrophages, are recruited to clear invading pathogens and debris. During the proliferative phase, activated fibroblasts synthesize new ECM and form granulation tissue. KCs migrate to close the wound gap, and ECs migrate to build new blood vessels. Finally, new blood vessels regress, and granulation tissues are remodeled into scar tissues. keratinocytes (KCs), endothelial cells (ECs).