Tuesday, August 07, 2007

Human Skin To Replace Animal Tests

From time to time you hear about a technological breaktrhough that blows your mind. Other times you wonder why it took so long.

For me, this is the latter. Not because I expect anyone to show concern for animals, but for the sake of accurate results I would have thought they'd accomplish this earlier.

From New Scientist Magazine.

Stretched taut across the top of a vial, the thin cream-coloured material feels almost like rubber.

Barely 1 centimetre in diameter, this is a sample of Episkin - a reconstructed human skin which has been approved for testing if cosmetics are likely to irritate the skin. It is the first complete replacement for animal testing.

Although cosmetics and skincare giant L'Oréal has been developing reconstructed skin since the 1980s, the search for animal alternatives became urgent in recent months with the introduction of two pieces of legislation. In December 2006, the European Union introduced REACH, which calls for more than 10,000 chemicals used in cosmetics to be tested for skin irritancy by 2019. At the same time, the EU's cosmetics directive bans the use of animals in such tests from 2009.


Tessonneaud's team grows the skin layers on collagen, using skin cells called keratinocytes left-over from breast surgery (see Diagram). The team can test the safety of cosmetics by simply smothering the skin in the product. They can then check the proportion of cells that have been killed off by adding a yellow chemical called MTT which turns blue in the presence of living tissue...Independent tests showed that in some cases Episkin was able to predict more accurately how a person would react to products than animal tests, she says.

Episkin improves on animal testing in other ways too. For example, it can be adapted to resemble older skin by exposing it to high concentrations of UV light. Adding melanocytes also results in skin that can tan, and by using donor cells from women of different ethnicities, the team has created a spectrum of skin colours which they are using to measure the efficiency of sunblock for different skin tones.

"This is a great advance - not just for animals but for people, who will finally have a safety test that is relevant to them," says Kathy Archibald of the anti-vivisection group Europeans for Medical Progress, London. She says animal skin often differs dramatically from human skin in terms of sensitivity.

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