Fabrication and characterization of a triple functionalization of graphene oxide with Fe3O4, folic acid and doxorubicin as dual-targeted drug nanocarrier

A novel triple functionalized drug delivery system was synthesized by encapsulation of superparamagnetic graphene oxide (GO) and doxorubicin (DOX) with folic acid (FA) conjugated chitosan (CHI). The carrier exhibited a high loading efficiency (0.98 mg/mg), a high saturation magnetization (10.5 emu/g) and a prolonged release rate. A real-time monitoring method on the drug release from graphene oxide (GO) was reported using DOX as the model drug. The release mechanism of DOX at different pH was investigated via monitoring the time dependency of the accumulative drug release. Results show that the drug release of DOX was pH sensitive as observed at pH 5.3 and pH 7.4 PBS solutions, the lower pH values lead to weaker hydrogen bonds and degradation of CHI, and thus result in a higher release rate of DOX. Especially, this system could be applied as a dual-targeted drug nanocarrier by combined biological (active) and magnetical (passive) targeting capabilities. Our research suggests that a novel triple functionalized, pH-responsive nanocarrier for anticancer drug has been synthesized. (C) 2013 Elsevier B.V. All rights reserved.