BODIPYS Based Fluorescent Markers To Monitor Autophagic Lysosomes and Lipid Droplets in TNBC

Lysosomal enzymes and high accumulation of lipid droplets are associated with breast cancer. The lysosomes and lipid droplets were monitored by BODIPYs, acting as autophagy activators in cancer cells. BD-1 and BD-2 were synthesized and characterized by Mass, UV-visible, fluorescence, and NMR spectroscopies. In BODIPYs, the effect of carbazole groups was reflected by the large Stokes shifts (2143-1651 cm^-1) and red fluorescence. BODIPYs generated ROS and induced autophagy in triple negative breast cancer cells (MDA-MB-231) under white light. Confocal experiments revealed that BD-1 and BD-2 preferentially colocalized in lysosomes and lipid droplets. Autophagic lysosomes and lipid droplets released Ca²⁺ ions in the cytoplasm, which was evident with blue fluorescence of Fura-2M dye. In combination with an autophagy inhibitor, BD-1 displayed excellent photocytotoxicity (5.57 μM) on triple negative breast cancer cells under white light. This work demonstrates the potential of BODIPYs as theranostic agents for the photodynamic therapy against TNBC.