In the present work, we report a facile and rapid green strategy to fabricate functionalized reduced nano-graphene oxide (nrGO) as a cooperative nanotemplate for both photothermal therapy and drug loading. Graphite oxide was firstly oxidated by nitronium ions (NO2 (+)) solution at the aid of microwave heating to obtain nano-GO (nGO) with about 50 nm of diameter, and the nGO was then reduced in pure glucose at 135 °C for 30 min to obtain nrGO with about 40 nm of diameter. The nrGO exhibits excellent biocompatibility including stable dispersibility in cell culture medium and rapid cellular uptake as well as non-cytotoxicity up to 100 μg/mL. Absorption of the nrGO at 808 nm wavelength increased more than 10-folds compared with nGO. Moreover, the nrGO has the ability to load about 317 % (w/w) of doxorubicin (DOX), and the loaded DOX could be effectively released by acid condition and/or glutathione (GSH) and/or heating. Finally, a greater cancer cell death efficacy was observed in nrGO/DOX-treated cells with GSH and heating stimulation respectively or their combination. Collectively, the nrGO developed here is an outstanding cooperative nano-platform for high-efficiency photothermal therapy and controllable drug delivery.
Keywords: Biocompatibility; Drug loading; Functionalized graphene oxide; Glucose reduction; Nitronium oxidation; Photothermal effect.