The mix of science and art that is referred to as DNA origami has produced many a microscopic wonder, from a DNA-based rendition of the Mona Lisa to doughnuts and teddy bears. Using DNA to make a nanoscale version of the most famous painting ever pales in comparison to one German research team’s recent feat: making a manipulable robotic arm from DNA that could have great impact in the medical field.
The team of researchers at the Technical University of Munich led by Friedrich Simmel has published in Science journal their report which documents how they were able to use electricity to drive a DNA arm at speeds up to 100,000 times faster than ever before. They did so by combining semi-rigid, double-stranded DNA helices which comprise the 25-nanometer ‘arm’ and tying that arm to a DNA platform through a with pliable, single-strand of DNA.
Because DNA carries a negative charge, the application of an electrical field allows for the rapid manipulation of the arm, which can act as a ‘nano-scale cargo carrier’ that responds to electrically-issued movement commands given via remote control. None of this would be possible without the growing field of DNA origami, in which DNA strands are manipulated into sequences which can be more easily folded to fit the researchers’ needs.
“Genes are made up from different sequences of these building block components, and the order in which they appear in a strand of DNA is what encodes genetic information,” said Matteo Palma of Queen Mary University of London. “But by precisely designing different A, G, T and C sequences, scientists have recently been able to develop new ways of folding DNA into different origami shapes, beyond the conventional double helix.”
The electric field which dictates the movement of the acidic, negatively charged DNA can be fine-tuned to produce precise, rapid movement. That movement is held in check by researchers’ ability to stick up strands of DNA from the underlying platform, limiting the arm’s range of movement when necessary. The hope is that eventually, this technology will allow doctors to create biosensors that allow for patient examination on a molecular level.
“We hope that this leads to genuine molecular assembly lines in which several robot arms co-operate to (programmably) control molecular processes or assemble nanostructures,” Simmel said.