A new study published in Science describes tiny nano-robots made of DNA that search for cancer cells and destroy them while sparing healthy cells, reports New Scientist's Jessica Hamzelou. The Harvard Medical School team used a "DNA origami" method to build the bots — "a DNA modeling software that understands how DNA base pairs bind together, as well as the helical structure that results," Hamzelou says. "When they enter a shape of their choosing into the program, it returns a list of DNA strands that can be mixed together to create the desired shape." In this case, the researchers designed a "clam-like" bot that could hold a dose of cancer drugs inside, she adds. The bots were also fitted with two aptamers designed to target cancer cells only.
The team programmed the bots with aptamers that would respond to molecules expressed by leukemia cells. They then release millions of the bots into a mixture of healthy and leukemic blood cells, and three days later found that while half the cancer cells had been destroyed, none of the healthy cells had been touched, Hamzelou says. The researchers say that adding more capacity for drug delivery to the bots could lead to even more destruction of cancer cells, and that different aptamers could be designed and attached to the bots to go after different cancers.