Exploring anticancer efficiency of mitochondria-targeted cyclometalated iridium(III) complexes

Area of Science:

• Coordination Chemistry
• Medicinal Chemistry
• Cancer Biology

Background:

• Iridium(III) complexes are explored for their photophysical and biological properties.
• Developing novel anticancer agents with improved efficacy and reduced toxicity is a critical area of research.

Purpose of the Study:

• To synthesize and characterize novel iridium(III) complexes with potential anticancer activity.
• To evaluate the in vitro and in vivo anticancer efficacy of these complexes.

Main Methods:

• Synthesis and characterization of three iridium(III) complexes: [Ir(NC)2(MPPIP)](PF6), where NC represents cyclometalating ligands (2-phenylpyridine, benzo[h]quinolone, 1-phenylisoquinolone) and MPPIP is 2-(4-(4'-methylpiperazin-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline.
• In vitro anticancer activity was assessed using the MTT assay against SGC-7901, HeLa, A549, BEL-7402, and NIH3T3 cell lines.
• Apoptotic efficiency, intracellular ROS generation, and mitochondrial membrane potential were analyzed.

Main Results:

• Complexes 1, 2, and 3 exhibited significant sensitivity towards A549 cells with low IC50 values (5.4 ± 0.3, 4.2 ± 0.03, and 3.8 ± 0.2 μM, respectively).
• The complexes induced apoptosis in a dose-dependent manner (9.92%, 11.30%, and 16.00% for complexes 1, 2, and 3).
• In vivo studies showed complex 3 possesses moderate tumor growth inhibition with no observed toxicity in major organs.

Conclusions:

• The synthesized iridium(III) complexes display promising anticancer properties, particularly against A549 lung cancer cells.
• The mechanism of action involves the induction of apoptosis, increase in intracellular ROS, and disruption of mitochondrial membrane potential.
• Complex 3 warrants further investigation as a potential therapeutic agent due to its balanced efficacy and safety profile.