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Georgia Researchers Use Multicolor Quantum Dots To Distinguish Cancers

by Editor1 last modified July 22, 2010 - 11:46

Multicolor quantum dots, due to their nature as tunable fluorescent nanoparticles, can make ideal tools for identifying cancer cells in tissue biopsies, according to scientists from Emory University and Georgia Institute of Technology.

Georgia Researchers Use Multicolor Quantum Dots To Distinguish Cancers

Emory U. and Gerogia Tech researchers use multi-colored quantum dots to detect Reed-Sternberg cells in tissue.

Researchers found multicolor quantum dots linked to antibodies can distinguish the Reed-Sternberg cells, characteristic of Hodgkin's lymphoma.

The team is led by Shuming Nie, PhD, the Wallace H. Coulter distinguished professor in the department of biomedical engineering at Georgia Tech and Emory University, and director of Emory’s Center for Cancer Nanotechnology Excellence, Nie is also associate director for nanotechnology bioengineering at Emory’s Winship Cancer Institute.

"Our multicolor quantum dot staining method provides rapid detection and identification of rare malignant cells from heterogeneous tissue specimens," Nie said. PhD Notably, the approach could be tuned to readily identify many types of rare cells. "The clinical utility is not limited to Hodgkin's lymphoma but potentially could be extended to detect cancer stem cells, tumor-associated macrophages and other rare cell types," Nie added.

How Multi-Color Quantum Dots
Can Detect, Distinguish Cancers
The team sought to test the discriminatory power of colored quantum dots, using four varieties at once -- white, red, green and blue. Each could detect a different protein, to stain lymph node biopsies.

The goal was to distinguish six Hodgkin's lymphoma cases from two other types of lymphoma and samples from two patients with benign growths in their lymph nodes.

Reed Sternberg cells have a distinctive appearance, but in lymph node tissue, they are usually surrounded by other white blood cells. The authors describe identifying them as a task like "finding a needle in a haystack."

Not surprisingly, medical researchers are paying special attention to the research findings. "We're excited about this technology," said Andrew Young, MD, PhD, associate professor of pathology and laboratory medicine at Emory University School of Medicine. "We expect it could help guide the type of treatment a cancer patient gets and that it could be used with a wider variety of tumor types," Young added, who is also the director of clinical laboratories at Grady Health System.

One reason for the excitement is ability to cut cost and time in diagnosis because a quantum dot approach could allow "multiplexing" – or superimposing results from the four colors on top of each other. Adding to the excitement, Young said the quantum dot technique could point oncologists towards "targeted therapies" designed for one particular type of tumor.

Today, the most reliably used approach to assign cell identity is to look at more than one protein. With standard methods, staining cells with four different antibodies would require four separate slides, and images from multiple separate slides wouldn't depict exactly the same cells. Preparing four separate slides is costly, and can even be difficult as specimen sizes are smaller to minimize the burden on the patient.

The work appears in the July 15 issue of Analytical Chemistry.

The research was supported by the National Cancer Institute, which is also a supporter of Emory’s Center for Cancer Nanotechnology Excellence.