Ir(III) Half-Sandwich Photosensitizers with a π-Expansive Ligand for Efficient Anticancer Photodynamic Therapy
Carlos Gonzalo‐Navarro, Elisenda Zafon, Juan Ángel Organero, Félix A. Jalón, João Carlos Lima, Gustavo Espino, Ana M. Rodrı́guez, Lucı́a Santos, Artur J. Moro, Sílvia Barrabés, Jessica Castro, Javier Camacho-Aguayo, Anna Massaguer, Blanca R. Manzano, Gema Durá
Abstract
N ligands. Complexes with the more π-expansive ligand are very effective photosensitizers with phototoxic indexes PI > 2000. Furthermore, PI values of 63 were achieved with red light. Time-dependent density functional theory (TD-DFT) calculations nicely explain the effect of the π-expansion. The complexes produce reactive oxygen species (ROS) at the cellular level, causing mitochondrial membrane depolarization, cleavage of DNA, nicotinamide adenine dinucleotide (NADH) oxidation, as well as lysosomal damage. Consequently, cell death by apoptosis and secondary necrosis is activated. Thus, we describe the first class of half-sandwich iridium cyclometalated complexes active in PDT.