Light-triggered C60 release from a graphene/cyclodextrin nanoplatform for the protection of cytotoxicity induced by nitric oxide

Abstract

An ultraviolet (UV) light-triggered nanocarbon hybrid is developed for controlled C₆₀ release with excellent nitric oxide (NO) quenching ability. This nanocarrier, consisting of reduced graphene oxide (rGO) and β-cyclodextrin (β-CD), is capable of hosting azobenzene functionalized C₆₀ (Azo–C₆₀) synthesized by diazo chemistry. The hybridization of rGO, β-CD and Azo–C₆₀ enhances cellular uptake and limits the aggregation of C₆₀, and shows enhanced protective effects on NO-induced cytotoxicity. More interestingly, azo groups can reversibly switch between trans- and cis-isomers upon UV irradiation, so that the Azo–C₆₀ molecules exhibit photo-controlled release from rGO/β-CD in living cells. In vitro studies show that rGO/β-CD/C₆₀ treated with UV irradiation causes higher NO scavenging efficacy, which further significantly increases the cell viability from 32.6% to 88.4% at low loading levels (50 μg mL⁻¹). This represents an excellent NO quenching efficiency, better than other reports of the graphene/C₆₀ nanohybrids, and indicates that this material can be an effective nanoplatform to combat oxidative damage. As the host–guest chemistry and diazo chemistry are versatile and universally applicable, it is worth noting that the present strategy can also be applied in preparing other photo-responsive nanohybrids, which should be valuable for use in life science and materials science.