An international team of researchers has developed motorized molecules that are capable of drilling holes in cell membranes once they are activated with ultraviolet (UV) light. The technique has the potential to deliver drugs to targeted locations or even destroy potentially dangerous cells.

As reported in Nature, the machines were tested on a variety of cells including human prostate cancer. The team showed that the molecular machines are capable of locating the target cell but they remained inactive on the membrane until exposed to UV light. Once they were given the stimulus, the cell membrane was observed to begin blebbing, then bubbles formed, leading to the eventual cellular death.

“We are moving towards realising our ambition to be able to use light-activated nanomachines to target cancer cells such as those in breast tumours and skin melanomas, including those that are resistant to existing chemotherapy,” senior author Dr Robert Pal, from Durham University, said in a statement. “Once developed, this approach could provide a potential step change in noninvasive cancer treatment and greatly improve survival rates and patient welfare globally.”

Although they talk about "motorized" and machines, you shouldn’t picture a tiny submarine (cool as that would be). These are complex molecules, but molecules nonetheless, so they obey the laws of the microworld. One of these is called Brownian motion, the erratic random movements of microparticles in a fluid.

To overcome Brownian motions, these molecules spin between 2-3 million times per second. Such power allowed them to disintegrate prostate cancer cells between 1 and 3 minutes.  

“These nanomachines are so small that we could park 50,000 of them across the diameter of a human hair, yet they have the targeting and actuating components combined in that diminutive package to make molecular machines a reality for treating disease,” co-leader Professor James Tour, from Rice University, said in a press release.  

The team is currently looking at activating the motor in different ways like two-photon absorption, infrared, or radio waves. They might be better suited to be activated inside a living organism. The team is already working on this. Experiments on microorganisms and small fish are in the works and they hope to move these tests to mice soon. If these experiments are successful and safe, a human trial could become a reality.