Fig. 1: Design and assembly of particle-forming DNA nanostructures.

a DNA nanostars used in the assembly of stable, size-controlled particles. Core motifs (C-stars) assemble from four different strands forming the central junction (blue) and four identical cholesterol-functionalized oligonucleotides (orange). Inner corona motifs (green) and outer corona motifs (red) each self-assemble from six different oligonucleotides. Inner corona motifs bind to the core motifs through α−α* overhangs, while outer corona motifs bind to inner corona motifs through domains β−β*. In the tested design, domain γ is a non-interacting poly-T domain, which could however be replaced with a functional moiety or aptamer useful for anchoring molecular cargoes without impacting C-star self-assembly, as demonstrated in ref. ³⁵. b Particle assembly pathway. All DNA strands are mixed in stoichiometric ratios. At high temperatures (T = 90 ^∘C) cholesterol-functionalized strands form micelles while the remaining oligonucleotides freely diffuse in solution. Upon fast quenching to T = 65 ^∘C, C-stars nucleate and grow as previously reported^35,36,37, leading to the formation of amphiphilic DNA particles whose size depends on the incubation (or growth) time t_g at T = 65 ^∘C. At this stage, individual corona motifs assemble but remain detached from the particles. When rapidly cooled down to T = 35 ^∘C, corona motifs coat the particle with a two-layer hydrophilic shell, which offers steric stabilization and prevents further coalescence.