Encapsulation of circular DNA and non-organic particles inside virus-Like DNA origami icosahedrons.*

The principle of quasi-equivalence, annunciated by Caspar and Klug in 1962, articulates how icosahedral viruses can be constructed using a minimal number of distinct sub-units. Following this scheme, we used DNA origami to construct 5MDa monomers of 3-fold symmetry, which interact through base stacking and shape complementarity and self-assemble into icosahedrons. We encapsulated cargo by functionalizing the interior facing portion of the monomers with single stranded DNA that was complementary to strands on cargo. Two categories of cargo were utilized. The first type of cargo were gold colloids, which were functionalized with complementary ssDNA to the monomers. These colloids were smaller than a monomer and did not bridge between monomers. The second type of cargo was 2.5 MDa circular ssDNA, which could bridge between monomers. The assembly yield was studied as a function of the monomer concentration, interaction strength, and amount of encapsulated cargo.