Abstract
Depending on the dendrimer charge density (CD), the complexes of DNA with polyamidoamine G4 dendrimer exhibited three distinct nanostructures, characterized by different degrees of DNA bending. With increasing CD, the structure transformed from a square columnar mesophase to hexagonally-packed superhelices and eventually to a beads-on-string structure in which DNA wrapped around the dendrimer by 1.4 turns and penetrated into the dendrimer interior. © 2011 The Royal Society of Chemistry.