'Lab on a chip' could one day be tool in doctors' offices, clinics

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Published: Wednesday, October 7, 2009 | 3:54 PM ET
Canadian Press Sheryl Ubelacker, Health Reporter, THE CANADIAN PRESS

TORONTO - Canadian researchers have developed a "lab-on-a-chip" device that measures estrogen from minuscule samples of blood and tissue - a technology they believe could one day be used to more quickly assess a woman's risk of developing breast cancer.

While only a prototype now, scientists at the University of Toronto predict a more refined version of the gadget could become a routine screening tool in doctors' offices and clinics within five years.

The chip can analyze blood or tissue samples a thousand times smaller than those required for conventional laboratory testing, said co-principal investigator Aaron Wheeler. That would mean a small prick of a needle could capture enough for analysis, as opposed to drawing vials of blood or performing a scar-leaving tissue biopsy, possibly under general anesthetic.

The amount of blood or tissue needed for assessing levels of estrogen or other hormones would be comparable to "a droplet of rain on your windshield," said Wheeler, a professor of biomedical engineering.

It could also, in some cases, do away with complex, expensive and time-consuming laboratory testing.

"So what we've done is replace the technician and a several-hour procedure with what we call a lab-on-a-chip device," said Wheeler, noting that the technology can produce results in minutes.

The credit card-sized gadget uses a method called digital microfluidics. Minute droplets of fluid containing tissue are manipulated electrically on the surface to pull out the hormone so it can be measured.

"Droplets can be essentially made to dance across the surface, and by dance I mean the droplets can be made to move, merge and mix, allowing us to carry out complicated laboratory processes using extremely small sample volumes," he said.

"This new method that we've developed might become a routine screen. We might put this in a clinic and this might be part of the yearly checkup," he said. "What I'm envisioning is that the doctor would have this particular pocket-sized device and would be able to collect the sample and then within a matter of minutes we could have an answer."

The report on the research is the cover story in Thursday's debut issue of the journal Science Translational Medicine.

Prof. Jon Cooper, an expert on lab-on-a-chip technology at the University of Glasgow, called the research a "good piece of work, and it does nicely illustrate how you can integrate many technologies in a lab-on-a-chip device."

But one challenge the researchers will face is developing a chip that won't be too costly for the market because of the complexity of the materials it contains, said Cooper, who was not involved in the research. Its ultimate price tag would depend on how much demand the product would generate: higher volumes would mean a lower cost per unit, he said.

Dr. Noha Mousa, a collaborator on the project, said the chip has been successfully used to measure estrogen levels from breast tissue. While not a diagnostic tool for breast cancer itself, it can determine whether estrogen levels are elevated - a sign that a woman may be at high risk for the disease.

But the chip can also be used to perform regular - and non-invasive - testing of women taking hormone-blocking drugs like aromatase inhibitors, designed to prevent breast cancer, to see if the medications are working.

"I believe this method will be useful for many applications in women's health and I also believe we are able to apply the same technique to many other steroid hormones," Mousa told a media teleconference. For example, testosterone levels could be tested to help assess prostate cancer risk.

The device could also be used to ascertain the degree of estrogen in women undergoing fertility treatments, who typically have blood drawn two to three times a month to see if they are responding to the drugs and are ovulating, she said.

"So we hope that we can save them the huge amount of blood we take from them by using this chip," Mousa said.

Dr. Christine Williams, director of research for the Canadian Cancer Society's research institute, said another potential use would be to monitor hormone levels in women being treated for estrogen-positive breast cancer who are taking anti-estrogen drugs.

"At the moment it's not practical to monitor local levels of estrogen in the breast because that would involve a biopsy," said Williams, noting that the society is funding the research.

"We know that high levels of (estrogen) can be indicative of breast cancer, so this would be another way of monitoring those women to see if there's an upswing or surge in estrogen. They could then go on a preventive or early treatment regimen."

Dorothy Funk of Portage La Prairie, Man., is part of a clinical trial with two of her sisters (a third had to drop out) to test a new anti-estrogen drug. The four women, whose mother and two maternal aunts died of breast cancer, are considered at high risk for the disease.

Every six months, they have to have blood drawn to test their estrogen levels, and Funk, 54, called the lab-on-a-chip idea "fantastic."

"Any strides that they are making I think it's wonderful. And the least invasive they can be, the better for us as women. I'm thinking of my daughter, my granddaughter. I was very excited to hear about this."