Breathe Easy

Researchers from the Wyss Institute for Biologically Inspired Engineering at Harvard University, Harvard Medical School and Children’s Hospital Boston have created a lung-on-a-chip which may help to speed pharmaceutical development by reducing reliance on animal models. The device consists of a layer of human alveolar cells separated from a layer of human endothelial cells by a porous membrane and mimics the boundary between the lung’s air sacs and capillaries. The cells on the chip can also be made to ‘breathe’ by cyclically applying a vacuum to increase the width of the membrane and stretch the cells before allowing them to contract again.

The, lung-on-a-chip has the potential to model the effects of environmental toxins, the inflammatory response to inhaled pathogens and the effectiveness of new drugs. Because the chip is transparent, responses can be captured in real time using high-resolution fluorescence microscopy. When E.Coli bacteria were introduced into the air on the ‘lung’ side of the chip, white blood cells on the ‘blood’ side of the chip migrated through the porous membrane into the air chamber to destroy the bacteria. ‘Breathing’ was found to enhance absorption of nanoparticles, some of which induced an inflammatory response and overproduction of free radicals by the lung cells.

The team are now exploring whether the system can mimic gas exchange between alveolar cells and the bloodstream and believe that the device provides proof-of-principle for the concept that organs-on-chips could replace many animal studies in the future.

The study is published in the journal Science.