Angew. Chem. Int. Ed. (2015)

DNA nanotechnology, which relies on the programmability of complementary base pairing, has shown that it is possible to fabricate a wide range of increasingly complex DNA-based nanostructures for a growing range of potential applications. However, the inherent sensitivity of DNA to environmental conditions (such as extremes of pH, high temperature or low ion content, as well as the presence of deoxyribonucleases) imposes some practical limitations, particularly in biological applications. In an attempt to address some of the restrictions, Antonio Manetto and colleagues have engineered an extended DNA-catenane structure designed to be more stable. The researchers assembled a six-helix bundle of 24 oligonucleotide tiles, some of them modified with azide and alkyne groups at their termini. By spatially organizing the modified sequences, interlocked strands can form through a simple one-step click-reaction. An extension of the procedure to all 24 oligonucleotide tiles leads to a covalently linked interconnected network that is stable at high temperatures and low ion content, and to enzyme degradation.