You've probably heard a lot about nanotechnology by now -- mostly about how it's the (potentially very dangerous) miracle technology of the future, which could cure cancer, help clean up the environment or, depending on how it's used or misused, wipe out civilization (check out the "Gray Goo" scenario, which we'll be addressing in an upcoming original video).

As of now, though, the nano-enhanced products on the market are very basic, like this nanotech carwash soap and nano sunblock. But very cool and real advances are being made in the arena of cancer-fighting nanotech. The possibilities are exciting: rather than blasting entire areas of the human body with radiation, killing good cells along with the bad to get rid of tumors, nanotech promises a "surgical strike" (no pun intended) that could target malignant cells alone. From Scientific American's article on the Harvard-MIT team that's spearheading the technology:

The researchers 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.) 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.

But what do they plan on tethering their nano payload to inside the body, and how will they trigger its release? That's even cooler: by tying the particles to strands of DNA.

One advantage of a DNA tether, the HST team members say, is that its melting point is tunable—scientists would be able to control when the bonds between the nanoparticles break by creating links of varying lengths with different DNA sequences. Exposing the nanoparticles to a low-frequency electromagnetic field causes them to radiate heat that, in turn, erases the tethers and releases the drugs. The waves in the magnetic field used by the HST researchers have the same frequency range as radio waves (between 350 and 400 kilohertz). These waves pass harmlessly through the body and heat only the nanoparticles. In comparison, microwaves, which would cook tissue, are about a million times more powerful with frequencies measured in the gigahertz range.

The potential here is huge, but as is the refrain with any exciting new technology, the researchers aren't sure when such treatments might be available to patients of the non-rodent variety.