In the presence of ultraviolet light, the nanoparticle shrinks from 150 to 40 nanometers.
As anyone who has played with a powerful laser or just suffered a bad sunburn can attest, light has an impressive power to physically change objects. And now we know that light can make nanoparticles expand and contract like miniature Hoberman Spheres
. MIT and Harvard researchers engineered nanoparticles that shrink to less than a third of their original size
when exposed to ultraviolet rays; in the darkness or under visible light, they open back up to their more stable, larger size. Nanoparticles have been touted
as an effective way to deliver cancer-killing drugs straight to tumors
without harming healthy cells in the process. But the structure of a tumor can block all but the smallest particles---those less than 100 nanometers (billionths of a meter)---from penetrating to the cancer’s heart. To deliver drugs to the entire ...
