epithelializing

Epithelializing, or epithelizing, is the process by which epithelial tissue forms a continuous surface or covers a wound. It is central to tissue repair and to the development of barrier surfaces in both skin and mucosal linings. In wound healing, keratinocytes at the wound margin migrate over the wound bed, proliferate, and reorganize to re-establish a stratified epithelial layer. Re-epithelialization begins after hemostasis and inflammation, with epithelial cells moving from the edges (and, when available, residual structures such as hair follicles or sweat glands) to close the defect. The newly formed epithelium is initially provisional and later remodels to restore normal structure and barrier function, including the reformation of the basement membrane and establishment of proper junctions.

Several factors influence the speed and quality of epithelializing. A moist wound environment, minimal infection, and adequate perfusion promote faster re-epithelialization. Nutritional status and systemic factors—such as protein intake and vitamins A and C—are important, as are local growth factors (for example, epidermal growth factor and transforming growth factor-beta). Poor epithelialization can contribute to chronic wounds or recurrent breakdown, while excessive or abnormal epithelial growth is less common but can occur in certain conditions. Beyond wound repair, epithelializing also describes the establishment of epithelium during embryonic development and in the regeneration of mucosal surfaces, reflecting the broader role of epithelial tissues in forming protective barriers.