Posted: February 14, 2008

Tiny material, big risk

(Nanowerk News) Liming Dai, a University of Dayton chemical and materials engineering professor, and Yiling Hong, a UD assistant biology professor have made a breakthrough in determining the safety of microscopic carbon materials sometimes used for gene, drug or cancer therapies.
When they introduced carbon nanotubes into mouse embryonic stem cells, they found that carbon nanotubes could damage DNA.
"DNA is genetic material. If the DNA is mutated, the mutation could be passed on to future generations (offspring),” Hong said.
Dai said it's important to understand why certain nanomaterials are toxic and how to control their toxicity, because more people are being exposed to nanomaterials. Slight modifications to their structures or surfaces can be the difference between a medical marvel and medical hazard.
Nanomaterials, the family which includes carbon nanotubes, can be as much as 8,000 times smaller than a strand of hair. They already are used in cosmetics, stain-resistant fabric and ointments.
The next step is to identify ways to create safer carbon nanotubes through surface modification and examine how other nanomaterials work in the entire bodies of animals, according to Hong.
Lin Zhu and Dong Wook Chang, in UD's biology and chemical and materials engineering departments, respectively, also helped with the study. The American Chemical Society's Nano Letters published the group's findings in November.
Nanowerk (First nanotechnology genotoxicity tests find that carbon nanotubes could damage DNA) said the study is the first of its kind evaluating the potential toxicity of a nanomaterial on the molecular level. DNA is at the molecular level, which is smaller than the cellular level.
In previous work with biocompatibility of other nanomaterials on the cellular level last year, Dai published findings that carbon nanodiamonds were safe. Dai performed that research with UD graduate student Amanda Schrand, Saber Hussain of the Air Force Research Lab and Eiji Osawa of Japan's NanoCarbon Institute Ltd. They received support from Japan's New Energy and Industrial Technology Development Organization, the Oak Ridge Institute for Science and Education, the Dayton Area Graduate Studies Institute and the National Science Foundation.
UD ranks second in the nation for industry-and government-funded materials research and is the largest private university in Ohio.
Source: University of Dayton