Zeitschrift für Karzinogenese und Mutagenese

Abstrakt

Photodynamic Therapy Effects of Hybrid Liposomes Including Indocyanine Green against a Xenograft Mouse Model Mice of Colorectal Cancer in vivo

Hideaki Ichihara, Masaki Okumura, Yoko Matsumoto

Aim: To examine the photodynamic therapy (PDT) effects of hybrid liposomes (HLs) composed of L-α- dimyristoylphosphatidylcholine (DMPC), polyoxyethylene (25) dodecyl ether (C12 (EO) 25), and indocyanine green (ICG) in human colorectal cancer cells (HCT116) in vitro and in vivo.

Materials and Methods: HL/ICG composed of 89 mol% DMPC, 10 mol% C12 (EO) 25, and 1 mol% ICG were prepared by sonication. The inhibitory effects of PDT-HL/ICG in a subcutaneous xenograft mouse model of colorectal cancer were examined in vivo.

Results: The inhibitory effects of HL/ICG irradiated with far-red light laser on the growth of HCT116 cells were observed. A remarkable reduction in tumor weight in xenograft mouse models intravenously treated with PDT-HL/ ICG after subcutaneous inoculation of HCT116 cells was verified in vivo. The occurrence of Reactive Oxygen Species (ROS) from PDT-HL/ICG treatment was observed in HCT116 cells based on ROS detection using fluorescence microscopy in vitro. An increase in peroxidation products in tumor cells of colorectal cancer xenograft model mice intravenously administered with PDT-HL/ICG was observed in micrographs via immunostainingusing anti-8- hydroxy-2'-deoxyguanosine (8-OHdG).

Conclusion: ROS-inducing therapeutic effects of PDT-HL/ICG in a xenograft model after subcutaneous inoculation with human colorectal cancer cells were revealed for the first time in vivo.