A 2-(benzothiazol-2-yl)-phenolato platinum(II) complex as potential photosensitizer for combating bacterial infections in lung cancer chemotherapy†.

Cancer and antibiotic resistance are two global health threats that usually hamper clinical chemotherapeutic efficacy. Particularly for lung cancer, bacterial infections frequently arise thereby complicating the course of cancer treatment. In this sense, three new neutral luminescent cycloplatinated(II) photosensitizers of the type [Pt(dmba)(L)] (dmba = N , N -dimethylbenzylamine-κ N ,κ C ; L = 2-(benzo[ d ]oxazol-2-yl)-phenolato-κ N ,κ O 1 , 2-(benzo[ d ]thiazol-2-yl)-phenolato-κ N ,κ O 2 , and 2-(1-methyl-1H-benzo[ d ]imidazole-2-yl)phenolato-κ N ,κ O 3) have been characterized and developed to potentially eliminate both resistant bacteria and lung cancer cells. The phototherapeutic effects of complex 2 have been evaluated using low doses of blue light irradiation. Complex 2 exerted promising photoactivity against pathogenic Gram-positive bacteria strains of clinical interest, displaying a phototoxic index (PI) of 15 for methicillin-resistant Staphylococcus aureus , one of the major microorganisms predominating lung infections. Likewise, the anticancer activity of 2 was also increased upon light irradiation in human lung A549 cancer cells (PI = 36). Further in vitro experiments with this platinum(II) complex suggest that ROS-generating photodynamic reactions were involved upon light irradiation, thus providing a reasonable mechanism for its dual anticancer and antibacterial activities. [Display omitted] • Synthesis and characterization of new cyclometalated platinum(II) complexes containing N^O ligands. • 2 showed antibacterial activity against multi-drug resistant bacterial strains under visible light irradiation. • Ability of 2 to photo-generate singlet oxygen and photocatalytic oxidation of NADH. • Compound 2 also induced lung cancer cell death after blue light irradiation through ROS generation. [ABSTRACT FROM AUTHOR]