Balaji Panchapakesan likes to leave innocuous packages lying around, then detonate them remotely, killing any victims who are near the blast. No, he’s not an Iraqi insurgent — he’s an engineering professor at the University of Delaware, and his bombs are carbon nanotubes.
His explosions are on the nanoscale, and his victims are cancer cells. His idea that nanobombs can fight cancer in a cell-by-cell war of attrition has been effective in petri dishes.
At the heart of Panchapakesan’s nanobombs are single-walled carbon nanotubes. While these tiny structures have been heralded as the material of the future for their astounding strength, Panchapakesan is focused on one of their other strange features: When heated by a laser at an 800-nanometer wavelength, they explode.
The exact physics of the combustion aren’t well understood, but it probably works because water molecules stuck inside spaghetti-like globs of the nanotubes overheat and force the explosion to occur. Since the explosive nature of nanotubes was first discovered in 2002, some scientists have theorized that they could form a new kind of military explosive or even a rocket propellant.
Panchapakesan saw another possibility. Why not sprinkle them next to cancer cells and then blow them up like tiny improvised explosive devices? He did just that, and the method showed enormous selectivity when he focused the laser on the cells he wanted to excise.
“In other words, we can reduce the collateral damage so that we’re killing only the cells we want to kill without harming healthy cells,” he says.
By Sam Jaffe