Microchip uses nanotechnology to detect cancer
Last Updated: Tuesday, September 29, 2009 | 2:11 PM ET
CBC News
Canadian researchers have developed a prototype microchip that could one day lead to a portable device for diagnosing cancer in 30 minutes.
The chip uses nanotechnology — wires and materials on the scale of a billionth of a metre — to detect chemical markers that indicate the presence of cancer, as well as the cancer's type and severity.
The microchip, developed by scientists and engineers at the University of Toronto, Princess Margaret Hospital in Toronto and Queen's University in Kingston, Ont., has been successfully tested on biopsy samples from patients with prostate cancer and compared with the standard test.
"Our team was able to measure biomolecules on an electronic chip the size of your fingertip and analyze the sample within half an hour," said U of T's Shana Kelly, a professor of pharmacy and medicine and lead author of the study, which appears this week in the online issue of Nature Nanotechnology.
Analysis of biomarkers for cancer diagnosis now takes days. The biomarkers can distinguish different types of cancer and between benign and aggressive forms of cancer.
Analyzing patient samples, such as a urine sample, for cancer biomolecules can provide early detection and treatment and is less invasive than surgical biopsies.
Biomarkers can also let doctors know if a cancer treatment is working, said Tom Hudson, president of the Ontario Institute for Cancer Research.
"The discovery by Dr. Kelley and her team offers the possibility of a faster, more cost-effective technology that could be used anywhere," Hudson said in a statement.
Molecular bait
The chip is now entering the engineering stage, with an eye to creating a portable device that could provide an analysis within a half hour.
"The instrumentation required for this analysis can be contained within a unit the size of a BlackBerry," Kelley said.
And because biomarkers aren't unique to cancer, chips of this type could also be used to diagnose infectious diseases, such as HIV, bacterial infections or swine flu, the researchers suggest.
The engineering team, led by Ted Sargent, Canada Research Chair in Nanotechnology at the University of Toronto, found that conventional metal electrical sensors weren't able to detect the biomarkers or biomolecules, which are present only at very low concentrations in patient samples.
The team developed the chip and added a nanometre-sized wire mesh and "bait" to help the chip detect the biomarkers.
"It was actually necessary to tether biomolecules to the surface of the chip," Sargent told CBC Radio's As It Happens. "Those act as a kind of molecular bait, and when a patient sample was introduced on top of the chip, there was binding between our bait and the target that we were looking for."
The team designed the chip and read-out so they could tell whether a DNA biomarker was bound to the chip. When a marker wasn't present, the researchers knew they had found cancer, Sargent said.
It cost the researchers about $20 to make the chip, but it is thought this will go down as the technology is scaled up to a commercial level. It could potentially be on the market within five years.
