BOULDER, Colo., April 3 (UPI) -- U.S. scientists have found DNA-wrapped, single-walled carbon nanotubes smaller than about 200 nanometers can enter human lungs, posing a health risk.
National Institute of Standards and Technology researchers found human lung cells selectively absorb short nanotubes, which are being considered for use in electronic displays, fuel cells and water filtration systems.
Single-walled carbon nanotubes, or SWCNTs, are tiny cylinders -- essentially single-sheet rolls of carbon atoms. They are many times stronger than steel and possess superlative thermal, optical and electronic properties but safety and biocompatibility are undetermined.
"Published data citing in vitro toxicity are particularly inconsistent and widely disputed," said biomaterials scientist Matthew Becker and his NIST colleagues. He said concerns about health and safety impacts of SWCNTs could derail efforts to fast track the development of nanotubes for advanced technology applications.
"Our results demonstrate that cellular uptake in ... lung cells depends significantly on the length of the nanotubes," Becker said. "This is the first of many steps in the critical goal of reducing health risk by de novo engineering of the nanotubes themselves."
The research is to be detailed in the journal Advanced Materials.
