New microchip could cut animal testing

The microfluidic system will provide data on how the body handles a drug for example, how it is eliminated and how it is metabolised. It is hoped the chip will speed up a process that currently makes for laborious and tedious work.

The 22mm microfluidic circuit, developed initially by researchers at Cornell University​, contains an arrangement of interconnected "organ" or "tissue" compartments, which will assess the effects of a potential new drug, compound in animals, or humans, in a high throughput manner. In addition, the system is also an in vivo surrogate.

Each compartment contains a culture of living cells from animals or humans to mimic the function of particular organs and tissues, such as liver, heart, lung or fat cells.

The compartments are connected by microchannels through which a blood substitute (culture medium) circulates.

The test drug is added to this culture medium and circulates round the device. Its effects on the cells within each compartment can then be measured.

"What we are trying to do is to mimic what goes on in the body on a micro scale,"​ said Dr Leslie Benet, professor of biopharmaceutical sciences at the University of California, San Francisco.

"The idea is to run the chip as if it were, for example, a rat or a dog, and to be able to tell whether this particular animal is going to be appropriate for further testing,"​ he explained.

Dr Benet added that the chip would save a lot of animal studies, but would not eliminate them. Animal testing will still be needed by the regulatory agencies for preclinical toxicology and efficacy testing.

"The microfluidic system should make the animal tests more efficient by identifying which species is most relevant in a particular case,"​ he said.

With an increasing number of multinational pharmaceutical and biotechnology companies adopting a 'fail early, fail cheaply' approach, the early introduction of microfluidic technologies now offer the promise of reducing attrition rates during clinical development.

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

By assessing a drug's effect on different tissues, and by being able to mimic the normal interplay of enzymes and transporters, the new microchip should be more efficient than standard cell culture experiments.

The ability to detect issues with pharmacokinetics before the drug moves into clinical testing will ultimately save considerable resources in time and money for pharmaceutical and biotechnology companies.

Tests for a drug's pharmacokinetics have traditionally been associated with the later stages (and thus higher risk) stages of drug development.

However, with the number of drug targets as well as the volume of assay points performed in high-throughput screens rapidly expanding, it has become vital to rapidly and efficiently triage 'potential hits,' having significant toxicity profiles.