The researchers from the Karolinska Institute in Stockholm, Sweden; the University of Pittsburgh and the U.S. National Institute for Occupational Safety and Health said their finding that the enzyme myeloperoxidase can break down nanotubes contradicts previous theory that carbon nanotubes are not broken down in the body or in nature.
"Previous studies have shown that carbon nanotubes could be used for introducing drugs or other substances into human cells," said Karolinska Associate Professor Bengt Fadeel. "The problem has been not knowing how to control the breakdown of the nanotubes, which can cause unwanted toxicity and tissue damage. Our study now shows how they can be broken down biologically into harmless components."
Fadeel said the finding represents a breakthrough in nanotechnology and nanotoxicology, since it shows an endogenous enzyme can break down carbon nanotubes.
"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," he said. "But the findings are also relevant to the future use of carbon nanotubes for medical purposes."
The research is reported in the journal Nature Nanotechnology.