Nanotechnology Offers Exciting Possibilities for Imaging and Treatment of Breast Cancer

Dec 08, 2005, 00:00 ET from San Antonio Breast Cancer Symposium

    SAN ANTONIO, Dec. 8 /PRNewswire/ -- Nanotechnology, using particles as
 small as 100 nanometers in size, is offering exciting new possibilities for
 finding and treating breast tumors, according to speakers at the 28th Annual
 San Antonio Breast Cancer Symposium being held this week. Two researchers from
 Rice University in Houston, Texas, offered enticing insights into how these
 minute particles can be manipulated to have different properties, and tagged
 with antibodies to target them specifically at cancer cells.
     Jennifer West, PhD, has studied the unique optical properties of
 nanoshells. These particles consist of a nonconducting core (for example,
 silicon) surrounded by a metal shell of varying thickness. They are "tunable,"
 in that their ability to respond to light varies with the thickness of the
 shell and core size. Nanoshells can be designed so that they either scatter or
 absorb light that hits them. Nanoshells designed to absorb incident light heat
 up and can potentially be used to kill cells. Nanoshells that scatter incident
 light may improve our ability to image breast cancer.
     Dr. West is particularly interested in gold nanoshells, because they
 respond to near-infrared light, a wavelength that is easily transmitted
 through biological tissue. In a series of preliminary experiments in tissue
 culture cells and animals, she has demonstrated that nanoshells will
 accumulate in tumors, especially when they are coated with tumor-specific
 antibodies. Once accumulated, the nanoshells can be used to treat the tumor
 with heat or, when designed to scatter light, act as highly effective contrast
 agents to improve imaging.
     Near infrared light can penetrate biological tissue to a depth of 15 cm,
 and can also be delivered via catheter-based fiber-optic cable, so that
 although this technology has not yet been applied in humans, clinical
 application seems feasible and promising.
     Lon Wilson, PhD, also from Rice University, has looked at the therapeutic
 and imaging possibilities of carbon-based molecular scaffolds, specifically
 fullerenes (bucky balls) and carbon-based nanotubes. Although these structures
 are easily absorbed into cells, when properly constructed they are nontoxic
 and nonimmunogenic in mammals, and are excreted from the system quickly. Both
 fullerenes and nanotubes can have metals inserted into them, and Dr. Wilson
 has looked specifically at structures into which gadolinium has been inserted
 as potential contrast agents for high resolution magnetic resonance imaging.
 Other gadolinium-complexed contrast agents are routinely used for MRI, but are
 quite toxic. Gadofullerenes are five times as efficient as these agents,
 making them more effective as contrast agents. Gadolinium carbon nanotubes are
 even more powerful as contrast agents, some of the highest efficacies every
 recorded. In addition, by cycling magnetic fields in cells containing
 gadolinium carbon structures, sufficient thermal energy can be generated to
 kill targeted cells.

SOURCE San Antonio Breast Cancer Symposium