An international team led by King’s College London and the San Francisco Veteran Affairs Medical Center (SFVAMC) has developed the first lab-grown epidermis (the outermost skin layer) with a functional permeability barrier akin to real skin.
The new epidermis, grown from human pluripotent stem cells, offers a cost-effective alternative lab model for testing drugs and cosmetics, and could also help to develop new therapies for rare and common skin disorders.
The epidermis, the outermost layer of human skin, forms a protective interface between the body and its external environment, preventing water from escaping and microbes and toxins from entering.
Tissue engineers have been unable to grow epidermis with the functional barrier needed for drug testing or produce an in vitro (lab) model for large-scale drug screening. That’s because the number of cells that can be grown from a single skin biopsy sample has been limited.
The new study, published in the journal Stem Cell Reports (open access), describes the use of human induced pluripotent stem cells (iPSC) (stem cells that can develop into different types of body cells) to produce an unlimited supply of pure keratinocytes (the predominant cell type in the outermost layer of skin). These new keratinocytes closely match keratinocytes generated from other stem-cell types: human embryonic stem cells (hESC) and primary keratinocytes from skin biopsies.