Human skin cells used in animal-free cosmetic tests

XCellR8 uses scaffolds of cells from human skin donated by plastic surgery patients, which they say are ideally suited to testing cosmetic products.

“For skin irritation testing the cells are isolated from human skin that has been donated by people who have had plastic surgery and they’ve said that they’re quite happy for the tissue to be used for research purposes. So human skins cells are isolated from those skin samples and they’re grown in the laboratory,” explained XCellR8 founder Dr. Carol Treasure.

Skin cells are the first cells to be exposed to cosmetics and can provide a model for damage to other sites of the body. Many cosmetic ingredients are absorbed into the bloodstream, passing then to the organs, so it is vital any harmful effects are assessed. Treasure said their methods provide a test bed to accurately determine any health implications.

“What you end up with is an artificial piece of skin in the laboratory where if you cut a cross section through it is almost identical to real skin on the body. It even has a skin barrier so you can apply full cosmetic formulations to the surface. And what we do is then incubate those skin models with samples of cosmetic products or ingredients and then we can look at how much damage is being done to the skin over a period of time,” Treasure told Reuters.

A number of cosmetic companies have sent their ingredients to XCellR8 to test at their lab in Cheshire, north-west England, including ethical cosmetics company Lush.

Other versions of a human cell-based alternative to the traditional animal tests have been available for some years. But Treasure said the standard methods still use animal components, such as rat liver extract and bovine and horse serum.

“In many cases the culture of human cells still requires the use of animal components such as blood-derived components or liver extract which mean that ultimately animals have still been sacrificed for that work. One of the unique things about XCellR8 is that we’ve eradicated all of those components and so we have a truly animal free testing laboratory,” Treasure told Reuters.

For the industry-standard human skin sensitivity test, XCellR8 has replaced the bovine serum normally used with a human serum, and have shown that the test still works to an equivalent standard for regulatory purposes.

They’ve also adapted a test that evaluates if an ingredient is genotoxic – destructive to a cell’s genetic material – which replaces horse serum and rat liver extract with human serum and human liver extract. This test does not yet have full regulatory approval – a process that takes many years to achieve – but it provides extremely useful data to cosmetic companies and ingredient suppliers, helping them to develop safer products.

XCellR8 was one of the first winners of the Lush Prize – an annual £250,000 (approx. 365,000 USD) prize fund awarding those making significant contributions to removing animals from testing.

Dr Katy Taylor, Director of Science at Cruelty Free International, said the ongoing research at XCellR8 could make animal testing in the cosmetic industry completely redundant.

“XCellR8 are pioneers in providing humane testing solutions. They are leading the way in ensuring more and more new test methods that are completely cruelty free are available to ethical companies,” said Taylor.

The European Union banned animal-tested ingredients for the cosmetics industry in 2013.

However, animal testing is legal in more than 80 percent of the world, including the United States. But China is the only country that has mandatory laws requiring cosmetic products be tested on animals before they come to market, according to animal protection campaigner Cruelty Free International.

Regulations require all cosmetics to go through a lengthy approval process that includes animal testing, reducing the variety of products available for sale.

XCellR8 is now working to convince governments around the world that their research delivers a viable human-based approach to cosmetic testing. According to Treasure, their methods provide a much more scientific approach than the current animal tests.

“Our goal now is to increase the applicability of these tests around the world and to work alongside governments and industry to help them to understand that these tests provide a scientific advancement; that they are actually better at predicting human safety compared with traditional animal tests,” she said.