Tag Archives: toxicology

Laboratory lungs are go

Almost exactly a year back, we mentioned that biologists were looking into the possibility of growing simulated lungs to use instead of rats for toxicology testing procedures. Today, The Guardian reports that working prototypes of these cheap and ethical lung analogues are well in hand. (Warning: article includes use of the colloquial “[x]-on-a-chip” buzzphrase which, if you’re anything like me, makes you want to punch kittens and cuss at nice old ladies.)

The work at Harvard will be used mainly for studying the workings of living lung tissue without having to open up people or animals. It could also be used to test the effects of environmental toxins or new drugs.

The lung-on-a-chip could predict how human lungs absorb airborne nanoparticles and mimic the inflammatory response triggered by pathogens, said Donald Ingber, the vascular biologist who led the work at Harvard University’s Wyss Institute.[…] The device was able to replicate many of the natural responses of lung tissue, such as detecting pathogens and speeding up blood flow so that immune cells can deal with the invaders.

And in the rather select category of “news also involving biology, lungs and rats”, a team at Yale has grown new rat lungs and patched them into test subjects, who are reportedly breathing just fine [via SlashDot]:

The team started with decellularized adult rat lungs, which retain the organs’ branching airways and blood vessel network, and added a mixture of lung cells from newborn rats. Niklason says that the crucial step was nurturing the would-be lungs in a bioreactor that circulates fluid—simulating what would happen during fetal development—or air through them. The cells stuck to the scaffold in the right locations and multiplied. After up to 8 days in the bioreactor, they had coalesced into what the researchers’ tests indicated was functional lung tissue.

How long until we can buy off-the-shelf replacement organs? Will they ever be cheaper (or more reliable) than back-street “donor” options sourced from underprivileged populations?

Laboratory lungs to replace rats

Got lungs?Briefly overcoming my kneejerk hatred of articles with the phrase “[x]-on-a-chip” in their headline, here’s a New Scientist article about a new development that could eradicate the need for lab rats in toxicology experiments. The basic idea: grow little spheres of lung tissue on a silicon substrate, enabling you to run multiple tests at once.

While the ethics of animal testing are a contributing factor here, there’s also a significant element of practicality:

… the European Union’s REACH regulations require about 30,000 chemicals to be tested for toxicity over the next decade. Yet testing the effects of inhaling a single dose of a particular chemical typically requires more than 200 rats, while testing the chronic effects of breathing it in over time can take more than 3000. Meanwhile the EU Cosmetics Directive – which covers items from deodorants and perfume to air-fresheners – seeks to ban all tests of cosmetics on animals by 2013.

The obvious alternative is to test chemicals on human cells grown in the lab. The difficulty, however, lies in enticing those cells to form complex tissue that responds as our organs do.

That difficulty hasn’t yet been overcome, but this project and others like it suggest that it’s far from insurmountable. Given the collosal advances in computer modelling in recent years, though, I wonder whether these artificial test organs will be in use for long before being superceded by software – which would not only be ethically sound but presumably much faster as well. [image by bbaunach]