First lab-grown epidermis points to animal testing alternatives

Scientists from both sides of the Atlantic say they have successfully developed the first fully functioning lab-grown skin epidermis, pointing the way to a replacement for animal testing of cosmetics products.

The teams, located at both the King’s College London and the San Francisco Veteran Affairs Medical Center (SFVAMC), state that the lab grown alternative has a fully functional permeability barrier, which bears a likeness to real skin.

Grown from human pluripotent stem cells, the alternative is also said to be a cost-effective alternative lab model that will be appropriate for testing a vast range of skin care, colour cosmetic and other personal care products.

Growing an epidermis alternative has proved a challenge

Growing the epidermis has proven to be highly challenging because of its complex structures, which includes a protective barrier between the body and the external environment that help prevent dehydration, as well as microbes and toxins entering the body.

Tissue engineers say the biggest challenge to growing the epidermis in the lab is the fact that the number of cells that can be grown at any one time from a single skin biopsy sample has traditionally been limited.

The scientists’ study, published in the peer-reviewed journal Stem Cell Reports, describes how pluripotent stem cells (iPSC) can be harnessed to produce pure keratinocytes, which is the major component to the outer skin layer.

Lab created sample proves to be almost identical

These keratinocytes were then used to create 3D epidermal equivalents with a functional permeability barrier, which is essential for moisture retention, as well as preventing the entry of both microbes and toxins into the body.

This lab created a skin sample that was then tested against human skin and shown to have no significant structural or functional difference.

"Our 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,” said Dr Dusko Ilic, leader of the team at King's College London.

“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."

Newcastle University researchers tap into immune cells alternative

Last October, researchers at Newcastle University said they had come up with a skin testing alternative that promised a faster and more accurate alternative to animal testing for cosmetics.

The test is named Skimune and uses human skin and immune cells to detect reactions to chemicals and drugs such as blistering or allergic reactions and toxicology testing.

Its creators claim that it has a quicker turnaround time than most similar tests and therefore allows companies to reduce their expense and time to market. The alternative is still in the testing phase.