The Physicochemical and Nanotechnological Approaches to Creation of 'Rigid' DNA Nanoconstructions

Two different approaches to the creation of "rigid" (gel-like) DNA particles (or DNA nanoconstructions) are considered. The physicochemical approach is based on the formation of nanobridges between double-stranded DNA molecules ordered in quasinematic layers of cholesteric liquid-crystalline dispersion (CLCD) particles or their salting-out. This approach represents by itself a "chemical gelation" of DNA molecules realized inside the nanometric DNA particles. The formed "rigid" DNA particles have unique physicochemical properties. The nanotechnological approach is based on induction of "physical gelation" as a result of the formation of Au-clusters in the "free" space between double-stranded DNA molecules ordered in CLCD particles. This approach results in the formation of a new "rigid" DNA material. Its dis- tinctive peculiarity, in contrast to the chemically bonded "rigid" DNA particles, consists in a very weak binding affinity to the nuclear membrane filter used for atomic force microscopy. This opens up a possibility for easy manipulations with CLCD particles doped with gold nanoparticles.