In experiments, nanoshells are injected into an animal’s bloodstream, where “targeting” agents applied to them seek out and attach to the surface receptors of cancerous cells. Illumination with infrared light “raises the cells’ temperature to 55 degrees Celsius” and burns away the tumor, she (scientist) says.
Nanotechnology is also supplying new instruments for examining cancer, potentially yielding new insights. Adam T. Woolley, an assistant professor of chemistry and biochemistry at Brigham Young University, has created a method for examining mutations in DNA to determine a person’s genetic predisposition for developing cancer. He uses a technique called atomic force microscopy (AFM), a nanoscale variation on old record players—but with a needle tip only about 10 nanometers across. Woolley first deposits DNA molecules on silicon or mica, the surfaces of which are so flat that the DNA protrudes above them. Then, he explains, he uses AFM “to examine the topography of the DNA to locate the positions of mutations in it.”
“The difference in size between the native and mutated sequences of DNA is extremely small—about a tenth of a nanometer—which is at the limit of what the AFM can see,” says Woolley. So he uses gold nanoparticles of about 10 nanometers to mark the mutations’ positions—this way, AFM can readily see them. Examining the DNA at this level lets Woolley identify whether a double mutation occurs, which can pose a greater genetic cancer risk than a single one. Conventional techniques for looking at chromosomes can’t determine such information. Woolley’s work has great diagnostic potential, says Ferrari; Identifying the genetic markers for cancer might permit prevention before the first tumor cell ever forms.