Fig. 3: Subcellular targeting and cellular death mechanisms of G-IrC8.

a Confocal microscopy showing G-IrC8 co-localized with mitochondria-specific dye MitoTracker Deep Red in fixed and live cells. Green: G-IrC8; Red: MitoTracker Deep Red; Rr: Pearson’s correlation coefficient. b Time-lapse imaging of mitochondrial morphology changes after G-IrC8 pretreatment and laser activation. G-IrC8 fluorescence highlights the transition from tubular to fragmented mitochondrial structures over 210 seconds. c, d Quantification of mitochondrial membrane potential changes in different treatment groups, measured using MitoRed. Statistical analysis shows a significant reduction in membrane potential in the G-IrC8 + Laser group compared to other groups (*p < 0.05). e, f DNA Comet assay showing ROS-induced nuclear DNA tailing. Quantification of tail DNA percentage indicates significantly higher DNA damage in the G-IrC8 + Laser group compared to the Control, G-IrC8, and Laser groups (**p < 0.01; ****p < 0.0001). g Western blot analysis of Bax, Bcl2, Caspase 3, and cleaved-Caspase 3 in different groups. Heatmap on the right shows Bax/Bcl2 and cleaved-Caspase 3/Caspase 3 ratios, with significant increases in the G-IrC8 + Laser group compared to the Control group (p < 0.05). h Schematic illustrating the proposed mechanism of G-IrC8-induced apoptosis via mitochondrial targeting, fragmentation, ROS generation, and DNA damage