These teensy particles can also be used to deliver targeted contrast agents to tumors that can be picked up by MRI scans better than conventional agents, which would allow physicians to more easily check if a tumor is shrinking after treatment.

Biotech companies are beginning to take notice of Bhatia's work and the field of designer nano-particles. She is working with famed M.I.T. biologist and Nobel Laureate Phillip Sharp to apply this technology to something called RNA interference (RNAi).

That mechanism uses strands of RNA—the molecules in a cell that activate and interact with DNA—to shut down the action of genes and other RNA.

Sharp co-founded Alnylam, a Cambridge, Massachusetts, company that is developing therapeutics that wants to use bioengineered RNAi to shut down genes that are causing disease.

But Alnylam and others have been stymied by how to deliver the RNAi to the intended target. Bhatia thinks her particles attached to the RNAi might do the trick.

Bhatia's breakthroughs come in the wake of another recent announcement that scientists at the University of California in Berkeley were able to create what amounts to a radio using nano carbon tubes designed to act as both antennae and receivers.

One day, these mini-radios might be used to transmit information into a cell. The Berkeley team tested their device by transmitting the first-ever human music heard in nanospace: Good Vibrations by the Beach Boys.

Radio-controlled particles and nano-radios are still years away from being used in humans—Bhatia's work was done in mice—but these technologies are beginning to assuage the doubt that accompanied the early days of so-called nano-technology, which seemed more hype than reality about a cute word for a unit of measurement that is extremely small.

One question: If nano-particles work, and one day we have zillions of them tethered hither and yon in our livers, brains and hearts waiting to be activated by a radio signal, will there be a "garage-door opener effect"?

That is, when I click my nano-particle to deliver my meds as I walk down the street, will I accidentally activate nano-particles circulating in other people nearby?