Researchers from King’s College in London and the San Francisco Veteran Affairs Medical Center (SFVAM C) have reportedly developed the first ever lab-grown epidermis—the outermost layer of skin—with a functioning permeability barrier similar to human skin. While other scientists have apparently been able to grow certain parts of the skin from embryonic skin cells, until now, none could produce the outermost layer responsible for keeping moisture in the body and toxins out. The researchers say that 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.”

Published in Stem Cell Reports, the study observes that researchers were able to produce a conceivably unending supply of keratinocytes—the major cell type in the epidermal layer—from human pluripotent stem cells and subsequently produce a three-dimensional, fully functional epidermis equivalent. Using this method, scientists believe they could produce an infinite line of skin cells from a single biopsy, allowing them to more easily research specific skin conditions.

“The ability to obtain an unlimited number of genetically identical units can be used to study a range of conditions where the skin’s barrier is defective due to mutations in genes involved in skin barrier formation, such as ichthyosis (dry, flaky skin) or atopic dermatitis,” said lead SFVAM C researcher Theodora Mauro. “We can use this model to study how the skin barrier develops normally, how the barrier is impaired in different diseases and how we can stimulate its repair and recovery.”

The new method would also provide cosmetic companies access to a relatively inexpensive supply of human skin that would be easier and more humane to work with than the animals currently used for testing, said the researchers, noting that lab-grown epidermal layers would provide “more reliable feedback on how human skin would react to cosmetic products.”

According to King’s College lead researcher Dusko Ilic, the new method can be used to grow “much greater quantities of lab-grown human epidermal equivalents, and thus could be scaled up for commercial testing of drugs and cosmetics. Human epidermal equivalents representing different types of skin could also be grown, depending on the source of the stem cells used, and could thus be tailored to study a range of skin conditions and sensitivities in different populations.” See King’s College London News Release, April 24, 2014.