No, it’s not alphabet spaghetti – it’s DNA shapes (Image: Bryan Wei, Mingjie Dai and Peng Yin, Wyss Institute for Biologically Inspired Engineering at Harvard University)

LEGO, eat your heart out. Blocks of DNA have been programmed to automatically build themselves into nanoscopic structures. Eventually the DNA programmes will be sophisticated enough to churn out minuscule therapeutic devices that work inside the body.

Single-stranded DNA has already proved itself to be a useful addition to the nanotechnologist’s toolbox. A very long strand can be intricately folded into complex 3D structures through a process known, appropriately, as DNA origami. These structures could be used to ferry drugs to specific sites in the human body.

But those long strands typically come from a virus, which raises the possibility that the body will attack the structures. Now, Peng Yin and colleagues at Harvard University have designed a similar technology that relies entirely on synthetic DNA. “Our structures could be made to be highly biocompatible,” he says.


Instead of folding one long strand of viral DNA, Yin’s team designed short synthetic DNA strands that can fold into a small tile, just 7 by 3 nanometres in size. “Each tile acts like a Lego block,” he says. Tiles automatically interlock with neighbouring tiles that carry a complementary DNA sequence. This means that with a bit of forward planning, the team could design a complete set of tiles that lock together to create more than 100 shapes – including any letter of the alphabet.

The synthetic DNA shapes could dodge the immune system, buying them more time to shuttle drugs to the right tissue (Nature, DOI: 10.1038/nature11075).