Fluorinated Chitosan-Mediated Intracellular Catalase Delivery For Enhanced Photodynamic Therapy Of Oral Cancer

A pH-responsive fluorinated chitosan-chlorin e6 (FC-Ce6) was employed here for the intracellular delivery of catalase to relieve the hypoxic micro-environment. Upon simple mixing, FC-Ce6 and catalase co-assemble to form stable nanoparticles, which show a greatly improved cross-membrane penetration capacity compared with catalase alone or nonfluorinated CS-Ce6/catalase nanoparticles. Under catalase catalysis, a high concentration of intracellular H2O2 can be transformed into O-2. Upon irradiation, due to the continuous formation of cytotoxic singlet oxygen (O-1(2)), our nanoparticles showed superior anti-cancer activity in contrast to free Ce6 and nonfluorinated CS-Ce6/catalase nanoparticles. Our study proposes an effective intracellular catalase delivery system to overcome hypoxia for enhanced PDT against oral cancer.