Scaffolded DNA origami of a DNA tetrahedron molecular container

We describe a strategy of scaffolded DNA origami to design and construct 3D molecular cages of tetrahedron geometry with inside volume closed by triangular faces. Each edge of the triangular face is ∼54 nm in dimension. The estimated total external volume and the internal cavity of the triangular pyramid are about 1.8 × 10-23 and 1.5 × 10-23 m3, respectively. Correct formation of the tetrahedron DNA cage was verified by gel electrophoresis, atomic force microscopy, transmission electron microscopy, and dynamic light scattering techniques. DNA has been considered an ideal material for building nanostructures at nanometer to micrometer scale because of its well-characterized double helical model and highly specific Watson-Crick base pairing. In recent years, a variety of one-dimensional (1D) and two-dimensional (2D) DNA nanostructures have been developed and utilized as templates for directed assembly of other materials.1 To date, a few examples of polyhedral three-dimensional (3D) DNA con-structs2 have been demonstrated through either one-step or hierarchical assembly approach, further proving that DN