Until very recently, nanotechnologists—scientists
who build devices and materials one atom or molecule at a time—concentrated
almost entirely on electronics, computers, telecommunications and
materials manufacture. Now biomedical nanotechnology, in which bioengineers
construct tiny particles combining inorganic and biological materials,
is pushing to the forefront of this rapidly advancing field of science.
Shuming Nie, associate professor of biomedical engineering and director
of cancer nanotechnology at the Winship Cancer Institute, highlighted
recent research in this area last month at the 225th national meeting
of the American Chemical Society in New Orleans.
“We believe biomedical nanotechnology soon will produce major
advances in molecular diagnostics, therapeutics, molecular biology
and bioengineering,” said Nie, who came to Emory and Georgia
Tech’s shared Coulter Department of Biomedical Engineering
from Indiana University.
“Already, scientists have begun to develop functional nanoparticles
that are linked to biological molecules such as peptides, proteins
and DNA,” Nie said.
Nanoparticles assume special properties by virtue of their miniature
size that distinguish them from larger particles, including changes
in color, as they shrink 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
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 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 to deliver controlled amounts of drugs into genetically classified