Expanding DNA alphabet adds a previously unknown dimension to nanostructures.

DNA nanotechnology has created nanostructures with astonishing complexity. However, with nanostructures becoming increasingly larger and more intricate, they have become more difficult to obtain in high yields and quality. Expanding the alphabet beyond the canonical base pairs can therefore be the key to push the technology to the next level. Here, we describe examples of DNA nanostructures built from an "anthropogenic evolvable genetic information system (AEGIS)." Because AEGIS uses the same backbone as DNA, the existing rules for designing DNA nanostructures can be readily applied to AEGIS nanostructures, which also show greater stability, both thermal and enzymatic, greater control over autonomous assembly, and good phase separation. AEGIS can have as many as 12 different units and six different pairs with Watson-Crick-Franklin geometry. Thus, if further developed, then these nanostructures may represent a previously unexplored frontier in DNA nanoscience and nanotechnology, expanding the space of "soft" biomaterial design.