A 100-fold leap to GigaDalton DNA nanotech

DNA, present in almost every cell, is increasingly being used as a building material to construct tiny, but sophisticated structures such as autonomous 'DNA walkers' that can move along a microparticle surface, fluorescent labels for diagnostic applications, 'DNA boxes' that serve as smart drug-delivery vehicles programmed to open up at disease sites to release their therapeutic content, or programmable factories for nanoparticles of defined sizes and shapes for new optical and electronic applications.

To accommodate these functions, researchers at Harvard's Wyss Institute for Biologically Inspired Engineering and around the world have developed ways that allow DNA strands to self-assemble into increasingly complex 3D structures such as scaffolded DNAorigamis. DNA origamis, however, are limited in their sizes because they rely on the availability of scaffold strands that can be difficult to manufacture and manipulate. In 2012, Peng Yin and his team at the Wyss Institute presented an alternative method in Nature (2D) and Science (3D) that is based on DNA 'bricks', which do not use a scaffold but rather are able to connect like interlocking Lego bricks and thereby self-assemble into origami-sized structures with prescribed shapes.

As reported in Nature, the team leapfrogged their technology by two orders of magnitude, enabling next-generation DNA bricks to self-assemble into three-dimensional nanostructures that are 100 times more complex than those created with existing methods. DNA origami andfirst generation DNA bricks self-assemble from hundreds of unique components to produce nanostructures on the MegaDalton scale, whereas the new DNA bricks approach allows 10,000 components to self-assemble into GigaDalton-sized structures (1 GigaDalton equals 1000 MegaDaltons or 1 billion Daltons). The study provides user-friendly computational tools to design DNA nanostructures with complex cavities (and possibly surfaces) that have the potential to serve as building components in numerous nanotechnological applications in medicine and engineering.