New chip improves drug safety, helps stop animal testing
Device speeds up testing and knocks out unnecessary toxic compounds, reducing the need to test on animals.
Sat, Jan 30, 2010 at 10:45 PM
Put away the frying pan and eggs, a new lab-on-a-chip device now shows you exactly what your brain looks like on drugs.
Called a Network Formation Assay (NFA), the chip lets researchers test compounds faster and more reliably. A normal drug test takes up to 10 hours because each compound is tested 30 times at 10 different doses. With this new chip, it will take just a few hours at most.
The breakthrough chip is covered with a hydrophobic polymer etched with a hexagonal array. The polymer is repulsive to extracellular matrix proteins which cells use to bind — so the cells automatically fall within the hexagonal array. From there, testers can assess if the cells have formed the necessary connections indicating a lack of toxicity.
"There are estimated to be around 30,000 chemicals that are not fully tested for their toxicological risk," says Jonathan West a micro-engineer at the University of Dortmund in Germany, who developed the new chip with colleagues.
In-vitro neurotoxicity tests involve growing nerve cells and counting the number of axons and dendrites that grow between them. An axon is the long slender projection of a nerve cell which conducts electrical impulses. The dendrites are the branches that receive electrochemical stimulation. This connectivity is a basic function of a healthy brain, and therefore its disruption is a good predictor for neurotoxicity.
With these improved in-vitro tests, fewer toxic compounds would make their way to the animal-testing stage.
"Companies are looking for something like this so they can quickly find molecules that are least toxic before moving on to animal tests," says Kelly Bérubé, a cell biologist at the University of Cardiff in Wales. "You would save lots and lots of animals. This has to be the way to go."
The ethical treatment of animals is not the only rationale for promoting these types of tests. Animal testing is expensive. It costs about $1,000 to run tests on small animals. In addition, many European countries are banning such tests for cosmetics as of 2013 … and drug testing might not be far behind.
Researchers are now looking to develop similar chips for other cell types like stem cells.
(Source: Technology Review)