A chitosan-modified graphene nanogel for noninvasive controlled drug release

A near infrared (NIR) triggered drug delivery platform based on the chitosan-modified chemically reduced graphene oxide (CRGO) incorporated into a thermosensitive nanogel (CGN) was developed. CGN exhibited an NIR-induced thermal effect similar to that of CRGO, reversible thermo-responsive characteristics at 37-42 degrees C and high doxorubicin hydrochloride (DOX) loading capacity (48 wt%). The DOX loaded CGN (DOX-CGN) released DOX faster at 42 degrees C than at 37 degrees C. The fluorescence images revealed DOX expression in the cytoplasm of cancer cells when incubated with DOX-CGN at 37 degrees C but in the nucleus at 42 degrees C. Upon irradiation with NIR light (808 nm), a rapid, repetitive DOX release from the DOX-CGN was observed. Furthermore, the cancer cells incubated with DOX-CGN and irradiated with NIR light displayed significantly greater cytotoxicity than without irradiation owing to NIR-triggered increase in temperature leading to nuclear DOX release. These results demonstrate CGN's promising application for on-demand drug release by NIR light. (C) 2013 Elsevier Inc. All rights reserved.