Scientists hope to break new ground in cancer treatment using "DNA origami" - making it possible to deliver drugs from minuscule medicine cabinets made of DNA.
Jorgen Kjems of the Centre for DNA Nanotechnology at Aarhus University, Denmark, and colleagues claim that a self-assembling DNA "box" created by them, which can be opened with DNA "keys", may one day be filled with drugs, injected into the blood, and then unlocked when and where the drugs are required.
It was three years ago when Paul Rothemund, of the California Institute of Technology in Pasadena, had created a map of the Americas using nothing but DNA.
The researcher, whose technique exploited the fact that complementary DNA bases attach to each other, used small sections of DNA to "sew" two parts of a longer single DNA strand together, creating folds to carve out the map's shape.
Kjems' research team have now come up with the first piece of 3D DNA origami, by sewing six 2D surfaces together to form a cuboid that measures 42 nanometres by 36nm by 36nm.
Describing their work, the researchers have revealed that the box has a detachable lid that is kept in place by a security strand of DNA.
They say that the keys are built from a strand of DNA that displaces this security strand because it binds more strongly to the sequence of bases on the lid. This unlocks the box, they add.
The researchers reckon that such keys may one day be utilised to unlock a cancer drug-filled DNA box at a tumour site, reports New Scientist magazine.
Given that they can be designed to open only if more than one key is used, or with one of a number of keys, such DNA boxes may also be used as logic gates in future computers.