7/1/2013
An Illinois graduate student is refining innovative imaging technology to detect small tumors and atherosclerosis at very early stages.
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An Illinois graduate student is refining innovative imaging technology to detect small tumors and atherosclerosis at very early stages.
Joanne Li, a graduate student in the Department of Nuclear, Plasma and Radiological Engineering (NPRE), recently earned a highly prestigious graduate assistantship from the Midwest Cancer Nanotechnology Training Center (M-CNTC), sponsored by the National Institutes of Health (NIH), to support her work.
Li, who works with NPRE affiliate professor Stephen Boppart, said the research holds particular promise for detecting heart disease before it can cause major damage.
“Some MIs (myocardial infarctions) are caused by blockages of fat lipids and cholesterol inside the coronary arteries around the heart. With the current technology, that’s hard to see because these vessels are deep within the chest. You wouldn’t know it’s happened until after a heart attack occurs,” she said. “The object is to detect before the heart attack happens.”
Li’s research employs Positron Emission Tomography (PET) and Cerenkov luminescence imaging. Li injects into the blood vessels of lab rats microspheres containing radioactive isotope Copper 64, a commonly used PET isotope. The isotope creates Cerenkov luminescence, producing a blue light much weaker but similar to that of a pulse created in a nuclear reactor.
However, living tissue tends to absorb the blue light.
“It’s hard to see the light from the outside if the microsphere agents are really deep,” Li said.
To counteract this, Li adds quantum dots to the inside of the microspheres. The dots are made of cadmium selenide, a semiconductor. The blue light emitted from the isotope excites the quantum dots, converting the blue light to red.
“If the light is red or near-infrared, it has a chance of being seen,” she said.
Li said the protein peptides on the outside of the microspheres work like puzzle pieces that fit into specific areas in the blood vessels around the tumors or atherosclerotic lesions so that the microspheres settle in a damaged area of the body, indicating where the potential damage is.
Working on this project the past year, Li now is collecting more data to verify her results. Boppart said of Li's work, “Joanne’s targeted multimodal microsphere contrast agents are very unique, especially in the way they can convert light to longer wavelengths. The oil-based composition of the microspheres also makes the Cerenkov luminescence process more efficient in tissue. These agents very likely have the potential for detecting early changes in heart disease or new blood vessel growth around tumors.”
Li will earn her master’s degree in December, and then plans to continue for a Ph.D. She earned her bachelor’s degree in chemical engineering from the University of Washington in Seattle, and interned at the Pacific Northwest National Laboratory.
In addition to the NIH support, Li is an Illinois Grainger Engineering Surge Fellow.
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Writer/Contact: Susan Mumm, coordinator, Alumni Relations & Development Office, Department of Nuclear, Plasma and Radiological Engineering, 217/244-5382.
If you have any questions about the College of Engineering, or other story ideas, contact Rick Kubetz, editor, Engineering Communications Office, University of Illinois at Urbana-Champaign, 217/244-7716.