Fluorescence imaging method using SWIR light detects cancer early

Rutgers University (Piscataway Township, NJ) researchers have developed a fluorescence imaging method that has potential to detect cancer and other diseases earlier than before, potentially reducing the need for biopsies. It uses nanotechnology to reveal small cancerous tumors and cardiovascular lesions deep inside the body, and is showing promise in early tests in the university's schools of engineering and pharmacy.

Related: Unraveling the basis of disease with NIR molecular probes

"This technique could eventually be used to accurately determine whether a newly detected cancer has spread to nearby lymph nodes, which should help a surgeon deal with the full extent of disease during a single surgery," says Shridar Ganesan, associate director for Translational Science at the Rutgers Cancer Institute of New Jersey and clinical advisor for the project. Currently, a surgeon who can't tell how far a cancer has spread may do lymph node biopsies and wait a day for results and then perform a second surgery if needed, with its attendant trauma, risks, and costs.

The method, co-developed by Richard Riman, distinguished professor of materials science and engineering, uses shortwave infrared (SWIR) light, which penetrates skin and other tissue more deeply than visible light or the near-infrared (NIR) light used in current imaging methods. This light stimulates dyes made with nanocrystals of rare earth elements—a family of 17 similar metals that are not scarce, but are difficult to mine. Rare earths are in growing demand for electronic products such as smartphones, video screens, and electric car motors and batteries.

While scientists and physicians have long recognized the potential value of SWIR light, fluorescent dyes that react to this light have either been too toxic to use safely or could not deliver sharp images. The dyes that Prabhas Moghe, the lead researcher on the project and distinguished professor of biomedical engineering and chemical and biochemical engineering, and his team are developing encapsulate rare-earth nanocrystals in a shell of human serum albumin. They are well tolerated, distribute quickly through the body, and accumulate at the disease sites.

The researchers can employ different types rare-earth elements, which glow under slightly different colors of SWIR light, to create a family of probes that are sensitive to a variety of cancers. "In this way, we can get a precise picture of the makeup and stage of the disease," Mogue says.

The researchers have demonstrated positive results in laboratory mice, and have shown that the spread of cancer even on a very small scale can be detected earlier than with traditional techniques such as magnetic resonance imaging or NIR imaging. This may open up new avenues for early intervention.

Initial results of the research team's work appear in the journal Nature Communications; for more information, please visit http://dx.doi.org/10.1038/ncomms3199. Also, the researchers were recently awarded a $2.2 million grant from the National Institute of Biomedical Imaging and Bioengineering, part of the National Institutes of Health, to advance their research.

-----

Follow us on Twitter, 'like' us on Facebook, connect with us on Google+, and join our group on LinkedIn

Subscribe now to BioOptics World magazine; it's free!