Keratinization of epidermal cells

Keratinization is multi-step biological process resulting in the terminal differentiation of keratinocytes. The keratinizing epithelium is a specialized tissue type protecting terrestrial mammals from water loss and noxious physical, chemical and mechanical factors. The process of epidermal differentiation or keratinization is characterized by a series of morphological changes of keratinocytes. During terminal differentiation the epidermal keratinocytes form an approximately 15 mm thick layer called the cornified cell envelope (CE) assembling on the keratinocytes' inner surface. These envelopes are composed of several cross-linked molecules, including involucrin, loricrin, SPRs and hydroksyceramides attached to the proteins by ester bonds.