June 26, 2009

'Chemical Nose' May Sniff Out Cancer Earlier

FRIDAY, June 26 (HealthDay News) -- Doctors may some day be able to sniff out cancer with a "chemical nose," a new report suggests.

Researchers at Georgia Institute of Technology and the University of Massachusetts at Amherst say they have developed highly sensitive sensors that pick up subtle differences on the surface of a cell that indicate if it is healthy or cancerous, even whether the cancer is metastatic or not.

The team's report, published online in this week's issue of the Proceedings of the National Academy of Sciences, said the sensors have successfully distinguished between healthy and cancerous human and animal cells, even from the same individual.

"This result is key. It shows that we can differentiate between the three cell types in a single individual using the chemical nose approach," researchers and chemist Vincent Rotello, of the University of Massachusetts, said in a news release.

The sensors use the polymer PPE, or para-phenyleneethynylene, and three gold nanoparticles that tend to bond with the surface of chemically abnormal cells. When an abnormal cell surface grabs on to the gold nanoparticles, the PPE breaks off and glows. The glowing PPE pattern helps scientists identify the cell type, as a cancer cell has slightly different proportions of biomarkers on its surface than a healthy cell.

"You often don't get a big signal for the presence of cancer," Rotello said. "It's a subtle thing."

"Our new method uses an array of sensors to recognize not only known cancer types, but it signals that abnormal cells are present. That is, the chemical nose can simply tell us something isn't right, like a 'check engine' light, though it may never have encountered that type before," he said.

The researchers next hope to test the chemical nose on real animal tissue as opposed to cultured tissue and refine their ability to decipher the information the detection system gives them.

"We're getting complete identification now, and this can be improved by adding more and different nanoparticles. So far we've experimented with only three, and there are hundreds more we can make," Rotello said.

More information

The National Cancer Institute has more about cancer.

-- Kevin McKeever
SOURCE: University of Massachusetts at Amherst, news release, June 22, 2009
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