Triangulated Wireframe Structures Assembled Using Single-Stranded DNA Tiles

The
field of structural DNA nanotechnology offers a wide range
of design strategies with which to build structures with a desired
aspect ratio, size, and shape. Compared with traditional close-packed
DNA structures, triangulated wireframe structures require less material
per surface or volume unit and improve the stability in biologically
relevant conditions due to the reduced electrostatic repulsion. Herein,
we expand the design space of the DNA single-stranded tile method
to cover a range of anisotropic, finite, triangulated wireframe structures
as well as a number of one-dimensional crystalline assemblies. These
structures are composed of six-arm junctions with a single double
helix as connecting edges that assemble in physiologically relevant
salinities. For a reliable folding of the structures, single-stranded
spacers 2–4 nucleotides long have to be introduced in the junction
connecting neighboring arms. Coarse-grained molecular dynamics simulations
using the oxDNA model suggests that the spacers prevent the stacking
of DNA helices, thereby facilitating the assembly of planar geometries.