DNA nanostructure serum stability: greater than the sum of its partsThis article is part of the 'Nucleic acids: new life, new materials' web themed issue.Electronic supplementary information (ESI) available: Detailed sequence information, 3D DNA assembly protocols, additional figures and ligation protocols. See DOI: 10.1039/c2cc37556g

Simple chemical modifications to oligonucleotide ends with hexaethylene glycol and hexanediol are shown to significantly increase nuclease resistance under serum conditions. The modified oligonucleotides were used to construct DNA prismatic cages in a single step and in quantitative yield. These cages further stabilize their strands towards nucleases, with lifetimes of 62 hours in serum. The cages contain a large number of single-stranded regions for functionalization, illustrating their versatility for biological applications. A combination of end-modifications and 3D topology is shown to stabilize DNA triangular prisms in fetal bovine serum up to 62 hours.