PDT evaluation of gallium based 3G photosensitizers against triple negative breast cancer

Meso-substituted A₂B corrole (C1) and A₂B₂ porphyrin (P1) having phenylaniline derivatives were developed. Their metal complexes with Gallium(III) were prepared and studied for anti-cancer applications in photo-dynamic therapy (PDT). Ga(III)-macrocycles displayed bright emission in red region (590-700 nm) and preferentially colocalized in the endoplasmic reticulum of the breast cancer cells. Both the Ga(III) macrocycles showed ROS generation ability in breast cancer cells with bright green fluorescence as judged by confocal microscopy. The Ga(III)corrole (Ga1) exhibited decent photo-cytotoxicity against breast cancer and triple negative breast cancer cells with IC₅₀ values of 9.6 ± 2.1 and 13.8 ± 1.2 µM, respectively. Ga(III)porphyrin (Ga2) displayed good photocytotoxicity (IC₅₀ 5.5 ± 0.8 µM) in combination therapy with autophagy inhibitor (chloroquine; CQ, 50 µM) suggesting it's autophagic behaviour. Ga(III) macrocycles were found to be non-toxic to the normal RPE1 cell line under dark and light conditions, implying that they can be advantageous for cancer diagnosis applications.