Stratum corneum as polymer sheet: concept and cornification processes

The skin barrier protects our body from external insults and water loss through a specialized layer, the stratum corneum. The stratum corneum, an accumulation of dead keratinocytes (corneocytes), comprises lipids and supporting cell bodies. We propose a framework of lipid-filled polymer sheet of corneocytes, a unique structure that achieves flexibility and robustness, updating the rigid image of the historical bricks-and-mortar model. The polymerization of polymer sheet (cornification) by cell death of keratinocytes (corneoptosis) is delicately and dynamically controlled by cytoplasmic calcium ion and pH. Understanding the structure and formation of the stratum corneum can lead to better treatments for skin diseases and a better understanding of the evolution of the stratum corneum.

Automated summary

The skin barrier protects the body from external insults and water loss through the stratum corneum, which is composed of dead keratinocytes, lipids, and supporting cell bodies. The structure of the stratum corneum is a lipid-filled polymer sheet of corneocytes, providing flexibility and robustness. The formation of the stratum corneum is regulated by cytoplasmic calcium ion and pH.