From Harvard Magazine:
In the not-so-distant future, a new kind of robot, one of the tiniest ever made, may have the ability to track down and destroy cancer cells. Films like Fantastic Voyage (1966) and Innerspace (1987) have long conjured fictional images of microscopic submarines or machinery that can travel inside the human body to cure ailments. Now Shawn Douglas, a research fellow at Harvard’s Wyss Institute for Biologically Inspired Engineering, is working on making that a reality. In a recent issue of the journal Science, Douglas described a method for creating tiny machines—roughly the size of a virus—out of strands of protein and DNA.
These devices, dubbed “DNA nanorobots,” are short hexagonal tubes made of interwoven DNA that can open along their length like a clamshell. At one end is a DNA “hinge,” and at the other, a pair of twisted DNA fragments that act as “latches” to hold the device shut. Inside the nanorobot, Douglas can enclose molecules of almost any substance, essentially turning it into a molecular “delivery truck” that can transport medication to specific cells in the body. “Our goal is to make tools that can zero in on malfunctioning cells,” he says. “We want to be able to fix things when they break—when cells go haywire due to cancer or other diseases where things just aren’t working correctly. To do that, I think it makes sense to master this kind of nanoscale construction.”