A swarm of nanobots made of DNA can store molecules in their folds and deliver them to specific cells by performing complex calculations.
Nano-sized entities made of DNA that are able to perform the same kind of logic operations as a silicon-based computer have been introduced into a living animal. The DNA computers – known as origami robots because they work by folding and unfolding strands of DNA – travel around the insect's body and interact with each other, as well as the insect's cells. When they uncurl, they can dispense drugs carried in their folds.
"DNA nanorobots could potentially carry out complex programs that could one day be used to diagnose or treat diseases with unprecedented sophistication," says Daniel Levner, a bioengineer at the Wyss Institute at Harvard University.
Levner and his colleagues at Bar Ilan University in Ramat-Gan, Israel, made the nanobots by exploiting the binding properties of DNA. When it meets a certain kind of protein, DNA unravels into two complementary strands. By creating particular sequences, the strands can be made to unravel on contact with specific molecules – say, those on a diseased cell. When the molecule unravels, out drops the package wrapped inside. The team has now injected various kinds of nanobots into cockroaches. Because the nanobots are labelled with fluorescent markers, the researchers can follow them and analyse how different robot combinations affect where substances are delivered. The team says the accuracy of delivery and control of the nanobots is equivalent to a computer system.
"This is the first time that biological therapy has been able to match how a computer processor works," says co-author Ido Bachelet of the Institute of Nanotechnology and Advanced Materials at Bar Ilan University. "Unlike electronic devices, which are suitable for our watches, our cars or phones, we can use these robots in life domains, like a living cockroach," says Ángel Goñi Moreno of the National Center for Biotechnology in Madrid, Spain. "This opens the door for environmental or health applications."
DNA has already been used for storing large amounts of information and circuits for amplifying chemical signals, but these applications are rudimentary compared with the potential benefits of the origami robots.