Fabrication of a graphene/C60 nanohybrid via γ-cyclodextrin host–guest chemistry for photodynamic and photothermal therapy

Abstract

The wonderful chemical structures and characteristics of low-dimensional carbon materials have exciting applications in life sciences. In the present study, we developed a facile strategy to conjugate C₆₀ with graphene via host–guest chemistry for targeted phototherapy. A versatile carrier based on folic acid-functionalized graphene (GO-FA) and comprising γ-cyclodextrin (γ-CD) at its surface was assembled via π–π interaction, creating hybrid structures with drug storage and tumor targeting properties. This γ-CD-modified graphene (GO-FA/Py-γ-CD) is capable of hosting pristine C₆₀ molecules for the fabrication of a GO-FA/Py-γ-CD/C₆₀ nanohybrid. The hybridization of GO-FA, γ-CD, and C₆₀ hinders the aggregation of C₆₀, promotes cellular uptake, enhances light absorption, and finally demonstrates enhanced phototherapy effects of GO-FA/Py-γ-CD/C₆₀. Under Xe lamp irradiation (2 W cm⁻²) for 4 min, GO-FA/Py-γ-CD/C₆₀ simultaneously causes heating and intracellular ROS production, which further significantly reduces the cell viability to 16.2% at low content of loading (30 μg mL⁻¹). Moreover, it represents an excellent tumor killing efficiency, better than that of the other reported graphene/C₆₀ nanohybrids; thus, this material is suitable for applications in phototherapy of cancer.