Yesterday was a good day for bunnies: Scientific American reported that researchers now have a new way of testing toxicity that doesn’t involve adorable, helpless (and scientifically useful) animals. Instead, it involves lab-grown human skin.
It sounds like something out of science fiction—but at the same time it seems kind of weird that it hasn’t been done yet, mainly because it has the potential to be very, very useful. We come into contact all day with things—from personal care products to household cleaners—and we don’t know nearly enough as we need to about their safety. One of the big problems with toxicological testing has always been the fact that there’s no ethical way to test chemicals on human subjects—and so scientists have relied on animal data.
But even if you set aside the moral concerns with using rats and rabbits, the fact is that they’re not the same as us, which makes testing on them an inexact way of assessing the safety of a given chemical. (And boy are some of those chemicals unsafe.) What is perfectly okay on a rat may be an irritant in humans, and what may burn a rabbit may be benign to our skin because it’s thicker.
As for the lab skin? Reports SciAm:
[It comes] from normal human skin cells, which are cultured in specialized media to form a three-dimensional reconstruction of the real thing … [that] closely resembles intact human skin both structurally and biochemically. It consists of multiple layers of cells and has a stratum corneum, the dead layer of cells on the surface that provides a protective barrier. These properties make it amenable for use in toxicity testing.
Isn’t that something? Of course, when it comes to testing the safety of chemicals, skin reactions are just a small part of it. Many chemicals, we now know, can penetrate the skin. Some, if they are small enough, can even get into cells and alter DNA.
So while this is a step in the right direction, it’s not the end of the story. When chemicals are migrating to organs and accumulating in the body, we need much more than skin testing to know what’s safe and what isn’t.
As I joked on Twitter earlier—can they now figure out how to grow livers, brains, and entire endocrine systems too? Please? Thanks.
