From Scientific American:
A team of researchers, led by Sangeeta Bhatia, an associate professor at HST and in M.I.T.’s department of electrical engineering and computer science, report in Advanced Materials that they have developed and tested injectable multifunctional nanoparticles—particles billionths of a meter in size—that they expect to become a new, potent weapon against cancer. (To provide some perspective, the width of a human hair is about 80,000 nanometers, or 0.003 inches.)
Nanoparticles could help treat cancer in a number of ways. They could be introduced into the bloodstream to locate and map tumors so that physicians would know what they were up against. Nanoparticles could also be designed to carry a payload of drugs that could be released near or even inside tumors to shrink or eliminate them. HST researchers have experimented with polymer-coated iron oxide nanoparticles held together by DNA tethers to help them create a visual image of a tumor through magnetic resonance imaging. To test the particles, the researchers implanted mice with a tumorlike gel saturated with nanoparticles and placed those mice into the wells of cup-shaped electrical coils, which activated the nanoparticles via magnetic pulses. Exposing the nanoparticles to a low-frequency electromagnetic field causes them to radiate heat that, in turn, erases the tethers and releases the drugs.