Neuron Array Advances Toxicity Testing

from Highlights in Chemical Technology:

Scientists in Germany have developed an alternative to animal testing for rapid screening and identification of chemicals that pose a health risk to the human nervous system.

Neurotoxicity laboratories worldwide face the daunting challenge of screening a growing catalogue of chemicals to identify those that could pose risk to human health, following the introduction of the EU's Reach legislation. Toxicity testing is traditionally done using animals but with spiraling costs in terms of cash and number of animals, reliable in vitro assays are needed. Lack of comparable read-outs between in vivo and in vitro systems can present problems, explains Jonathan West at the University of Dortmund, Germany, but West says he may have overcome this problem using a neural network.

Their new testing platform, called a network formation assay (NFA), monitors connections (or outgrowths) between specifically placed neurons and their neighbours. The formation of these connections is one of the basic principles of memory and learning, and its disturbance is frequently a clinical sign of neurotoxicity, says West. "Because NFA examines neuron connections it represents an in vitro model that is comparable to the in vivo state," he adds.

West placed human neurons within a hexagonal array using cell patterning and could then easily monitor the formation of the network. Exposing the array to acrylamide, a neurotoxic reference compound inhibited network formation and distinguished between neurotoxic and cytotoxic effects. Without the need to locate the neurons or measure the lengths of the connections, means that a typical assay takes only three hours compared with up to 200 hours for manual testing.

"This simple and smart application of micro-engineered systems can significantly improve standard biological protocols," says Marco Cecchini, an expert in high-resolution patterning of biomaterials, at the National Enterprise for nanoScience and nanoTechnology, Pisa, Italy.