Functionalized graphene/C60 nanohybrid for targeting photothermally enhanced photodynamic therapy

The unique structures and properties of nanocarbons will provide fascinating applications in biomedicine. Here we report a new strategy to combine C-60 with graphene for targeting phototherapy. Folic acid (FA) and polyethylene glycol (PEG) were conjugated onto graphene oxide (GO) via an imide linkage. Using nucleophilic addition, the FA-GO-PEG/C-60 nanohybrid was then prepared. The versatile platform of FA-GO-PEG for C-60 dramatically improved tumor targeting, which has been demonstrated by a cellular uptake assay. Owing to the doping effect and the inhibition of aggregation, the hybridization process also significantly enhanced the phototoxicity of FA-GO-PEG/C-60. More importantly, the photothermal therapy (PTT) of FA-GO-PEG/C-60 can cause obvious cell damage, which may further enhance the photodynamic therapy (PDT) efficacy against cancer cells. As expected, the combined PDT and PTT treatment with FA-GO-PEG/C-60 showed remarkably improved and synergistic effects compared to PTT or PDT alone. This study presents the potential of nanocarbons for synergistic phototherapy of cancer.