"ATTACK OF THE QUANTUM DOTS" A NEW SCI-FI CLASSIC? NO, BUT IT
WILL BE COMING SOON, PERHAPS TO SAVE A LIFE NEAR YOU.
Released into the circulatory system, an army of these semiconductor crystals, each 100,000 times smaller than the diameter of a human hair, searches diligently, cell to cell. Armored in a coating designed to protect them from the body’s destructive enzymes, these quantum dots have received orders, in the form of conjugated antibodies, to find cancer cells bearing matching antigens.
“And then the lights go on!” exclaims nanotechnology expert Shuming Nie, a researcher in the Coulter Department of Biomedical Engineering at Emory and Georgia Tech and in Emory’s Winship Cancer Institute.
Under a simple laser light, the dots have begun to glow with fluorescent colors, clearly visible through the skin of the laboratory mouse. Dr. Nie grins excitedly, like a kid with a new video game. He believes what he is seeing will change the outcomes for men diagnosed with prostate cancer.
The dots indicate the location of prostate tumor cells hidden deep in the mouse’s body. Nie has labeled the quantum dots with tiny permutations of colors, each one a probe for a specific gene or protein. Ordinary imaging procedures can use only one dye at a time. Theoretically, says Nie, quantum dots could simultaneously tag hundreds or even thousands of different proteins.
That means the quantum dot army can send back massive amounts of intelligence about which genes and proteins are hidden in a patient’s prostate cancer, far more information than is now available from tissue analysis. Knowing the precise fingerprint of a person’s cancer makes it possible to individualize treatment. The next battalion of nanoparticles can deliver a controlled amount of the ideal drug mixture directly to the cells, before yet another glowing group arrives to monitor the effectiveness of the therapy.
There’s more down the road. Emory researchers also are developing ways quantum dots can detect cancer-related genes and proteins in blood and saliva, in hopes of turning nanotechnology into a noninvasive screening method for cancer that has not yet been diagnosed.
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