Danish scientists at the Aarhus University Center for DNA Nanotechnology created a three dimensional box made out of DNA that features a lid that can be opened when a specific DNA strand is introduced as a key. The technology may allow for targeted drug delivery, with the lid opening when sensing the presence of a particular pathogen.
MIT Technology Review reports:
To design the box, the Aarhus team developed a computer program to generate a continuous single-stranded DNA sequence that, along with smaller DNA fragments that act as staples, would self-assemble into the desired shape.
The sequence was devised with many complementary regions so that it would automatically fold into six roughly square accordion-like sheets–the sides of the box–based on DNA’s natural tendency to pair into double strands. The DNA staples, also driven by the pairing of complementary sequences, stitched the sheets’ edges together to form a hollow cube with a hinged lid.
To make the lid lockable, Kjems and his colleagues fashioned two tiny DNA latches with sticky ends. Under normal circumstances, the latches adhere to the box, holding it shut. But when the two corresponding DNA keys are added, the latches bind to those instead, allowing the lid to swing open. A pair of dye molecules, one affixed to the box’s rim and another to its lid, glow red when close together and green when far apart, providing an easy way to detect whether a box is closed or open.
Abstract in Nature…
