Effect of metal–metal distance in Ni(II)-based metallo-supramolecular polymers: DNA binding and cytotoxicity

Two Ni(II)-based metallo-supramolecular polymers (polyNiL1 and polyNiL2) with different metal–metal distances were synthesized via (1 : 1) complexation between the Ni salts with bis(1,10-phenanthroline)s and their DNA binding properties and cytotoxicity were revealed. Short metal–metal distances (1.35 nm) in polyNiL2 showed ∼7 times stronger DNA binding properties and remarkably higher cytotoxicity to Hela-Fucci cells than long metal–metal distances (1.95 nm) in polyNiL1. Enhancement of Ni polymer-induced cell killing has been observed in a cell cycle study.