Lab-Grown Human Skin Could Be the End of Animal Testing

What would we want lab-engineered skin for? Well, for one, it might help end animal testing.

Following a slew of recent groundbreaking stem cell breakthroughs, scientists at Kings College London and the San Francisco Veteran Affairs Medical Center have made the first ever lab-grown epidermis. The researchers created the skin layer out of human pluripotent cells—the kind that can be developed into any other kind of cell to make essential body parts like blood, lungs, livers, and here, the outermost layer of skin.

As with all these stem cell developments, what results is real human skin cells, grown in a petri dish rather than on a body. The most obvious application of this lab-engineered skin is to eliminate the need for animal testing of drugs and other skin products, such as cosmetics. Rather than trying out a new treatment on animals, scientists and companies could test it on actual human skin cells—without the need for an actual human.

The researchers published their work in the journal Stem Cell Reports, where they explained that the main goal was to create a skin model that acted the same as the epidermal barrier—the permeable layer that keeps good things (water, crucial body parts) inside, and bad things (like microbes and toxins) out. In a phone call, Dr. Dusko Ilic from Kings College London told me the layer is "like the roof on a building" in terms of function.

In their paper, the team acknowledged that previous “human epidermal equivalents” had been created, but that “their utility for addressing the mechanisms of various skin disorders, or for drug development and testing, has been limited by the fact that previously engineered HEEs do not form a fully developed epidermal barrier.” Ilic said his model "is the closest to human skin that we have so far."

Earlier attempts only yielded small samples, whereas the method they Ilic used would allow them to make “an unlimited number of genetically identical units,” he said in a statement. “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.”

Because they can make the skin layer in large quantities, it could offer a cost-effective method for testing products. That’s particularly interesting in relation to cosmetics, as the idea of animal testing for the development of luxury lotions and potions has always been less justifiable than animal testing in the pursuit of medical progress. In fact, as the researchers pointed out in their paper, the EU recently banned the sale of cosmetics containing ingredients tested on animals.

"Since then, we use ingredients that we know are safe but there is no way we can test new ones," Ilic said.

Cosmetics companies are obviously keen to have a model that allows them to test new ingredients and make sure they’re safe for human use, and an infinite supply of lab-grown skin could just be the perfect alternative. There’s the added benefit, of course, that human skin, even lab-grown, is a much closer match to our own bodies than that of animals.

There are also potential applications in the understanding and treatment of skin conditions like ichthyosis or atopic dermatitis, as scientists could take stem cells from people with the conditions to make lab-grown skin samples as test studies.

Ilic said that they've only produced the skin layer on a small scale so far, but estimated that they'd be able to start mass-production within a year if there is demand. Looks like we might one day be seeing skin factories next to our blood factories.