A team of Swedish and American scientists has shown for the first time that carbon nanotubes can be broken into water and carbon dioxide by an enzyme — myeloperoxidase (MPO) — found in white blood cells.

This enzyme is expressed in certain types of white blood cell (neutrophils), which use it to neutralize harmful bacteria.

Carbon nanotubes were once considered biopersistent and potentially toxic.

“This means that there might be a way to render carbon nanotubes harmless, for example in the event of an accident at a production plant,” says says Bengt Fadeel, associate professor at the Swedish medical university Karolinska Institutet. “But the findings are also relevant to the future use of carbon nanotubes for medical purposes.”