Monofunctional BODIPY-Appended Imidazoplatin for Cellular Imaging and Mitochondria-Targeted Photocytotoxicity

Raza, Md Kausar and Gautam, Srishti and Garai, Aditya and Mitra, Koushambi and Kondaiah, Paturu and Chakravarty, Akhil R (2017) Monofunctional BODIPY-Appended Imidazoplatin for Cellular Imaging and Mitochondria-Targeted Photocytotoxicity. In: INORGANIC CHEMISTRY, 56 (18). pp. 11019-11029.

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Abstract

Monofunctional platinum(II) complexes of formulation cis-Pt(NH3)(2)(L)Cl](NO3),where L is an imidazole base conjugated to 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) with emissive (L-1 in 1) and nonemissive (L-2 in 2) moieties were prepared and characterized, and their singlet oxygen-mediated photoinduced cytotoxicity was studied. The 1-methylimidazole (1-MeIm) complex 3 was prepared as a control and for structural characterization by X-ray crystallography. Complexes 1 and 2 showed strong visible absorption bands at 500 nm (epsilon = 2.7 X 10(4) M-1 cm(-1)) and 540 nm (1.4 X 10(4) M-1 cm(-1)). Complex 1 is emissive with a band at 510 nm (Phi(F) = 0.09) in 1% dimethyl sulfoxide/Dulbecco's Modified Eagle's Medium (pH 7.2). Singlet oxygen generation upon photoirradiation with visible light (400-700 nm) was evidenced from 1,3diphenylisobenzofuran titration experiments showing significant photosensitizing ability of the BODIPY complexes. Both 1 and 2 were remarkably photocytotoxic in visible light (400-700 nm, 10 J cm(-2)) in skin keratinocyte HaCaT and breast cancer MCF-7 cells giving IC50 values in nanomolar concentration. The complexes were, however, essentially nontoxic to the cells in the dark (IC50 > 80 mu M). Complex 2 having a diiodo-BODIPY unit is nonemissive but. an efficient photosensitizer with high singlet oxygen generation ability in visible light (400-700 nm). Confocal microscopy using the emissive complex 1 showed significant mitochondrial localization of the complex. Cell death via apoptotic pathway was observed from the Annexin-V-FITC/PI assay. The formation of Pt-DNA adducts was evidenced from the binding experiments of the complexes 1 and 2 with 9-ethylguanine as a model nucleobase from H-1 NMR and mass spectral studies.

Item Type:	Journal Article
Publication:	INORGANIC CHEMISTRY
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	21 Oct 2017 06:18
Last Modified:	21 Oct 2017 06:18
URI:	http://eprints.iisc.ac.in/id/eprint/58058

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