Reduced Graphene Nanosheets for Anticancer Photothermal Therapy

Abstract

This thesis introduces the delivery of fluorescent chemical loaded onto reduced graphene nanosheet for antitumor effect with near infrared light radiation. In this study, IR-808, a chemical responsive to near infrared light 808nm, was used. As a targeting purpose, AMD 3100 which targets overexpressed surface receptor CXCR4 in tumor cells is conjugated with the fluorescent chemical, IR-808 and results in AMDpIR as a final form. After loading of AMDpIR to rGO, delivery to the tumor tissue was achieved and induced photothermal effect of rGO and IR-808 with near infrared light radiation. IR-808 produces singlet oxygen (1O2)when near infrared light is applied and the singlet oxygen produced results in the destruction of the structure in IR-808. However, when IR-808 was loaded onto rGO, the singlet oxygen produced will be attached to rGO and cannot be involved in the change of structure of IR-808. As a result, IR-808 loaded onto rGO shows a greater stability when near infrared light is applied compared to the form without rGO and the long-lasting structure of IR-808 induces a greater photothermal effect. The in-vivo antitumor efficacy of AMDpIR-rGO was evaluated in a SCC-7 tumor xenograft model. The group treated with AMDpIR-rGO showed a 2 fold increase in the accumulation at tumor site compared to the other groups. Additionally, the highest temperatures was detected at the specific tumor site where near infrared light radiation was applied with a potent antitumor effect. Taken together, the study proves the possibility on the photo-stability, synergistic photothermal effect and the targeting effect induced by near infrared light on rGO.