Researchers at the University of Toronto (UT) have used nanomaterials on a microchip to create a diagnostic test that's sensitive enough to identify the type and severity of a person's cancer in under an hour. The technology also is being developed for use to diagnose infectious diseases with the same speed.
"Today, it takes a room filled with computers to evaluate a clinically relevant sample of cancer biomarkers and the results aren't quickly available," Shana Kelley, lead investigator on the project and a co-author of a study appearing in Nature Nanotechnology, told Medical Device Daily. "Our team was able to measure biomolecules on an electronic chip the size of your fingertip and analyze the sample within half an hour. The instrumentation required for this analysis can be contained within a unit the size of a BlackBerry."
And the group already has plans to spin out a company to develop the new test with an eye on getting to market within five years.
"We designed this platform to be highly sensitive and practical because we wanted it to be something cheap enough to manufacture and make it into clinical use," Kelley said. "It's very straightforward microfabrication of the chip. The chips are outsourced, but what's special about it is that we grow nanostructures on the chips. By introducing nanostructured elements on the chip, we improve sensitivity of biomolecular detection by many orders of magnitude. That's pretty difficult to do without PCR. The platform is also quite versatile."
Kelley's team originally found that conventional, flat metal electrical sensors were inadequate to sense cancer's particular biomarkers, which is why they designed and fabricated a chip and then decorated it with nanometer-sized wires and molecular bait.
In addition to applications in cancer, the chip would have strong use in diagnosing infectious diseases.
"A very important application is in using this platform for infectious disease diagnosis," she said. "One of the advantages is that it's very fast. We can do our detection runs in minutes and see the appearance of robust signals. For infectious disease, it's time sensitive. For cancer diagnosis, the next day is usually good enough. But with infectious disease you want to know that patients' status immediately, especially in a hospital setting. That's what we're working very hard on now - to show we can interface our chips with a way to break up bacteria and get the same kind of sensitivity to discriminate different pathogens."
Regarding its original use for cancer, the microchip senses the signature biomarkers that indicate the presence of cancer at the cellular level, even though these biomolecules, which are genes that indicate aggressive or benign forms of the disease and differentiate subtypes of the cancer, are typically present only at very low levels in biological samples.
Results are available in about 30 minutes, compared with existing tests which yield results in a matter of days.
"We demonstrated that we can use this microchip to look at RNA samples isolated from cell lines or patient biopsy samples for prostate cancer," she said. "We have very high sensitivity and good specificity when challenging the platform with heterogeneous samples."
The actual surface structure of the sensor element is nanoscale while the features on the chip are microns in scale.
"The more fine the nanostructure the more sensitive the device becomes," Kelley said. "The nanostructures on the chip boost sensitivity."
So far her team has worked on small numbers of samples and is now scaling up to work with much larger batches.
"We're in the process of figuring out how to get it out of university lab and into an entity that can refine it," she said. "Were' probably going to spin out a company, but the economic situation isn't great now. If it was a few years ago it would be a lot easier to drum up the money. We think it can be in the clinic within five years. But it'll likely be pretty easy for us to beat that estimate."
Kelley's team includes UT engineering professor Ted Sargent, who is also UT's Canada Research Chair in Nanotechnology, along with an interdisciplinary team from Princess Margaret Hospital (Toronto) and Queen's University (Kingston, Ontario).
"Uniting DNA – the molecule of life – with speedy, miniaturized electronic chips is an example of cross-disciplinary convergence," said Sargent. "By working with outstanding researchers in nanomaterials, pharmaceutical sciences and electrical engineering, we were able to demonstrate that controlled integration of nanomaterials provides a major advantage in disease detection and analysis."
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