Using tiny gold particles embedded with dyes, researchers have shown that they can identify tumors under the skin of a living animal. These tools may allow doctors to detect and diagnose cancer earlier and less invasively
Studded with antibody fragments called ScFv peptides that bind cancer cells, the gold particles grab onto tumors after their injection into a mouse. When illuminated with a laser beam, the tumor-bound particles send back a signal that is specific to the dye, scientists at Emory University and the Georgia Institute of Technology report.
The results appear online Dec. 23 in the journal Nature Biotechnology and are scheduled for publication in the Jan. 1, 2008 print edition.
"This is a new class of nanotechnology agents for tumor targeting and imaging," says senior author Shuming Nie, PhD, a professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
Dr. Nie and his collaborators at the Emory/Georgia Tech Cancer Nanotechnology Center of Excellence have been developing light-emitting semiconductor crystals called "quantum dots" into tools for cancer detection and treatment for several years. However, colloidal gold, or gold particles in suspension, offers advantages compared with quantum dots in that the gold appears to be non-toxic and the particles produce a brighter, sharper signal, Dr. Nie says.
"The detail is like a fingerprint, and because of the enhancement provided by the gold surface, the signal from the dye tags is very bright," he says, adding that the distinct peaks in the dye signal mean several different probes could be used at the same time.
"The tags' rich spectroscopic signatures provide the capability of using several probes at once, but that will require more sophisticated computational tools," says May Dongmei Wang, PhD, assistant professor of biomedical engineering and director of biocomputing and bioinformatics in the ca
|Contact: Vince Dollard|