Figure 2.

Schematic illustrations of the four main approaches to molecular self-assembly using PNA. (A) A PNA amphiphile is composed of a PNA strand (red) conjugated to a hydrophobic domain (yellow). When assembled in solution nanostructures such as spheres or fibers with a hydrophobic core are formed and the PNA are displayed on their surface in high density. (B) PNA can bind complementary sequences of DNA to form hybrid duplexes. These hybrids can then be used to generate typical nucleic acid assemblies such as G-quadruplex, or more elaborated designs using structural DNA nanotechnology methods. (C) PNA molecules as short as di-PNAs, have been shown to assemble through a combination of Watson–Crick interactions and aromatic stacking into different nanostructures with unique physical properties. (D) The co-assembly of PNA with cyanuric acid, a small molecule exhibiting three thymine-like faces, allows the organization of poly-adenine PNA into fibers