Research Horizons Magazine
November 27, 2002

The Color of Cancer: Pioneering Nanotechnology Research Offers New Ways to Detect and Treat Cancer

A researcher's tiny, colored "dots" may hold the key to early detection, clinical diagnosis and treatment of cancer.

Professor Shuming Nie's research is funded by the Georgia Cancer Coalition, a public-private partnership established by the Georgia General Assembly in 2001. Photo: Shuming Nie 300 dpi JPG version

Zinc sulfide-capped cadmium selenide nanocrystals or "quantum dots" are the foundation of a novel technology developed by Shuming Nie, an associate professor in the Coulter Department of Biomedical Engineering at the Georgia Institute of Technology and Emory University. His ongoing research is funded by the Georgia Cancer Coalition (GCC), a public-private partnership established by the Georgia General Assembly in 2001.

Nie's work provides a way, in effect, to color-code biological molecules such as genes and proteins, thereby allowing doctors to view a spectrographic profile of an individual's unique body chemistry and identify the actual location and distribution of selected molecules in cells and tissues.

Applying the profiling technique to the molecules or markers associated with cancer may enable doctors to isolate the disease at its earliest stages, Nie says. The process may be useful for advancing the understanding of cancer pathology, he adds.

The image above represents the ten fluorescent-emission colors of zinc sulfide-capped cadmium selenide nanocrystals, or "quantum dots," excited with a near-ultraviolet lamp. The dots are the foundation for a novel technology developed by Shuming Nie. Photo: Shuming Nie

The technology involves embedding the fluorescent, semiconducting quantum dots inside micron-sized, polystyrene beads. Nie synthesizes the dots in different colors by varying their size. Embedding dots of different sizes and quantities gives the beads a unique optical signature.

Nie attaches biological macromolecules, such as antibodies, to the beads and applies them to cells and tissue samples in the laboratory. There, antibodies attached to the beads adhere to specific molecules, permitting identification of their location and determining the number of molecules present.

So far, Nie has produced dots with 10 levels of intensity in 10 visible colors and four colors in the near-infrared portion of the spectrum. Combining these characteristics aids identification of a nearly unlimited number of molecules simultaneously.

Image above shows immuno-fluorescent images of human cancer cells labeled with green quantum dots. Photo: Shuming Nie 300 dpi JPG version

"There are 30,000 to 60,000 genes and maybe a million proteins, so I tell people that there's not enough biological information for this technology," he jokes.

Cancer cells have certain characteristics or markers. After targeting and labeling these markers with color-coded quantum dots, Nie's computer-based algorithm converts the optical information into biological data. He then knows which markers are present, as well as their distribution over the surface of a cell. The patterns formed by the optical information may indicate the presence of cancer.

The technique allows simultaneous analysis of the markers in clinical tissue specimens, and also detects the tiniest molecular abnormalities - a tremendous step forward for early cancer detection.

Nie likens the process to that of identifying a criminal.

"If you say only that he is 1.8 meters tall, there are too many people who fit that description," Nie explains. "Then you say he weighs 180 pounds, and that reduces the number. Say he has black hair, and you've narrowed the list of suspects further, and so on until you get an accurate description of the criminal."

The quantum-dot technology could also prove useful for developing targeted, more effective cancer treatment, Nie says. Doctors have long been puzzled by the individual patient variation in the performance of medicines. The interaction between a drug and an individual's body chemistry may hold the answer, Nie says.

"We believe the reason why drugs work on some people and not others is because of their different molecular profiles - genes and proteins," he explains. "If you can make such a profile, you can probably determine if a drug is going to be effective for that person."

In the case of cancers, he adds, "The presence of a particular panel of markers could mean that a certain drug will work."

The applications of quantum dots in science, engineering and medicine have resulted in tremendous advances, Nie says. "People often associate nanotechnology with microelectronics or optoelectronics or memory systems," he adds, "but it has turned out that one of the first practical applications of nanotechnology is in biology and medicine."

Bioplex Corporation was founded by the technology-transfer company LaunchCyte Inc. to commercialize Nie's quantum-dot technology for human health applications, including drug discovery and clinical diagnostics. Bioplex is based in Pittsburgh, while its research and development operations are housed at Emtech Bio, an Atlanta-based, business incubator operated by Georgia Tech and Emory University.

Formerly a professor of chemistry at Indiana University at Bloomington, Nie is among the first group of researchers brought to Georgia Tech and Emory by the Georgia Cancer Coalition. Its Distinguished Cancer Clinicians and Scientists Program recruits and supports expert medical scientists who are making significant contributions leading to increased understanding of the causes and mechanisms of cancer, and to developing more effective cancer therapies. At Indiana, Nie conducted much of the research that led to his quantum-dot technology. Now headquartered at Emory, Nie is director of cancer nanotechnology at the Winship Cancer Institute and associate professor of biomedical engineering, chemistry, hematology and oncology.

In the next 10 years, the $1 billion Cancer Coalition initiative is expected to bring 150 researchers and clinicians to Georgia universities and medical centers to strengthen cancer-related programs and create new initiatives for early detection, leading-edge treatment, research, prevention and education.

RESEARCH NEWS & PUBLICATIONS OFFICE
Georgia Institute of Technology
75 Fifth Street, N.W., Suite 100
Atlanta, Georgia 30308 USA

MEDIA RELATIONS CONTACTS:
Jane Sanders (404-894-2214); E-mail: jane.sanders@edi.gatech.edu; Fax: (404-894-4545) or John Toon (404-894-6986); E-mail: john.toon@edi.gatech.edu.

TECHNICAL CONTACT: Shuming Nie (404-712-8595); E-mail: (snie@emory.edu).

WRITER: Gary Goettling