Remote-control nanoparticles deliver drugs directly into tumor

MIT scientists have devised remotely controlled nanoparticles that, when pulsed with an electromagnetic field, release drugs to attack tumors. The innovation could lead to the improved diagnosis and targeted treatment of cancer. In earlier work the team developed injectable multi-functional nanoparticles designed to flow through the bloodstream, home to tumors and clump together. Clumped particles help clinicians visualize tumors through magnetic resonance imaging (MRI). With the ability to see the clumped particles, MIT scientists asked the next question: "Can we talk back to them?" The answer is yes, the team found.

The system that makes it possible consists of particles that are superparamagnetic, a property that causes t! hem to give off heat when they are exposed to a magnetic field. Tethered to these particles are active molecules, such as therapeutic drugs. Exposing the particles to a low-frequency electromagnetic field causes the particles to radiate heat that, in turn, melts the tethers and releases the drugs. The waves in this magnetic field have frequencies between 350 and 400 kilohertz -the same range as radio waves. These waves pass harmlessly through the body and heat only the nanoparticles. The tethers in the system consist of strands of DNA. Two strands of DNA link together through hydrogen bonds that break when heated. In the presence of the magnetic field, heat generated by the nanoparticles breaks these, leaving one strand attached to the particle and allowing the other to float away with its cargo.

Source "MIT":[http://web.mit.edu/newsoffice/2007/nanodrugs-1120.html]

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