Programmability of RNA nanoparticles over (A) shape; (B) size; (C) stability; and (D) stoichiometry. (A) Schematic and AFM image of triangle, square, and pentagon RNA nanoparticles. Adapted with permission from [97]. Copyright 2014 Oxford University Press; (B) Schematic, size measurement, and AFM image of 5, 10, and 20 nm square RNA nanoparticles. Adapted with permission from [21]. Copyright 2014 American Chemical Society; (C) Secondary structure and melting profile of three 3WJs with different sequences. Adapted with permission from [105]. Copyright 2020 Royal Society of Chemistry; (D) Self-assembly of RNA dendrimers with 18 PTXs (yellow) and 3 FAs (magenta) using RNA strands with 6 PTXs, with 1 FA, and without modification. Reprinted with permission from [105]. Copyright 2020 Royal Society of Chemistry.