Dr. Shuming Nie, PhD, professor in the Coulter Department of Biomedical Engineering at Emory University and the Georgia Institute of Technology and director of cancer nanotechnology at Emory's Winship Cancer Institute, highlights recent research in at the 225th National Meeting of the American Chemical Society on March 27.
"We believe biomedical nanotechnology will soon produce major advances in molecular diagnostics, therapeutics, molecular biology and bioengineering," Dr. Nie says. "Already, scientists have begun to develop functional nanoparticles that are linked to biological molecules such as peptides, proteins and DNA."
Nanoparticles assume special properties by virtue of their miniature size that distinguish them from larger particles, including changes in color as they grow smaller and smaller. Because of their compact structure, nanoparticles emit light and can act as a fluorescent tag. This makes them highly suitable as contrast agents for magnetic resonance imaging (MRI), in positron emission tomography (PET) for molecular imaging in patients, or as fluorescent tracers in optical microscopy. Nanoparticles also have advantages over conventional dyes: they fade less quickly, they are less toxic to cells and they can be used in combination to create almost an infinite number of colors.
Although nanoparticles are similar in size to biomolecules such as proteins and DNA, human-made nanoparticles can be engineered to have specific or multiple functions. Bioconjugated quantum dots, consisting of different sized dots embedded in tiny beads made of polymer material, can be finely tuned to a myriad of different colors that can tag a multitude of different proteins or genetic sequences in a process called "multiplexing."
By chemically binding the quantum dots to particular genes and proteins, scientists including Dr. Nie are developing molecular nanoprobes to rapidly analyze biopsy tissue from cancer patients, to monitor the effectiveness of drug therapy, as scaffolding in tissue engineering, and as "smart bombs" to deliver controlled amounts of drugs into genetically classified tumor cells.