A The structure of T-TTD. B Schematic illustration of T-TTD dots-mediated PDT in a human cholangiocarcinoma xenograft mouse model. C Fluorescent images of different cells after incubation with T-TTD dots for 4 h. Red fluorescence: T-TTD dots. Blue fluorescence: nuclei. Green fluorescence: cytoskeleton. Scale bars: 50 μm. D Photograph of a xenograft tumor 3 days after different treatments (white circles). H&E staining for pathological changes and TUNEL staining for apoptosis (green) in tumor sections. Scale:100 μm. Reproduced with permission .