Effective and reversible DNA condensation induced by bifunctional molecules containing macrocyclic polyamines and...

A series of bifunctional molecules containing macrocyclic polyamines [12]aneN(3) and naphthyl moieties 1-3(a, b) have been designed and synthesized through efficient N-alkylation and copper-mediated alkyne-azide click reactions. Experiments on gel electrophoresis, dynamic light scattering and atomic force microscopy confirmed that 2b and 3b with two [12]aneN(3) units efficiently induced the DNA condensation at the concentration of 120 μM in less than 5 min. The condensation mechanism was studied by EB displacement fluorescence spectra, viscosity titration, and ionic strength effects. The condensation process was found to be reversible, and the presence of both naphthyl and [12]aneN(3) units in the molecules was proved to be necessary for the effective DNA condensation inductions. Cytotoxicity assay showed that the presence of triazole moieties can result in lower toxicity.