Microchip could reduce number of tests on animals

US researchers have developed a microchip system that promises to reduce the number of animals used in drug development. The 'animal on a chip' technology is an in vivo surrogate that comes in the form of a 22mm microfluidic circuit containing an arrangement of interconnected 'organ' or 'tissue' compartments, each containing a culture of living cells from animals or humans, thus enabling it to mimic the function of a particular organ or tissue.

The compartments are connected by microchannels through which a blood substitute (culture medium) circulates. The test drug is added to this culture medium, circulates round the device, and its effects are then analysed.

As well as cutting down the use of animals, the chip could potentially speed up drug development, reduce expenditure by increasing the efficiency of preclinical testing and provide a more efficient version of cell culture experiments.

Initially developed by researchers at Cornell University, it is designed to assess the effects of a potential new drug compound in animals, or humans, in a high throughput manner, and identify which species is most relevant in a particular case. The chip is run as if it were, for example, a rat or a dog, and thus that particular animal's suitability for further testing can be assessed.

Dr Leslie Benet, professor of biopharmaceutical sciences at the University of California San Francisco, says that while the chip will reduce the number of animal studies, it will not eliminate them, as animal testing will still be needed by the regulatory agencies for pre-clinical toxicology and efficacy testing. The chip should also provide data on how a drug is eliminated and metabolised in the body, potentially removing the need for often time-consuming tests.

'We are talking about speeding up the early stages of drug development and applying a more rational approach to getting a drug into humans,' he said.