Dual-sensitive GO-based self-assembly for the delivery of a hydrophobic anti-cancer drug

Abstract

Encapsulation and release of water-insoluble drugs has been a challenge. In this paper, a pH/glutathione (GSH) dual-responsive self-assembly based on graphene oxide (GO) was designed and fabricated for the effective delivery of the anti-cancer drug, quercetin (QU). The pH-sensitive poly(2-(diisopropylamino ethylmethacrylate) (PDPA) was synthesized and grafted onto GOvia a disulfide bond (GO–PDPA). Then, the hydrophobic QU was loaded onto GO–PDPA followed by coating with chitosan (CHI) to obtain a biological medium-stable GO-based self-assembly (GO–PDPA–CHI). Dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) were used to investigate their size and zeta-potential, morphology, and chemical structures. The coating of chitosan on GO–PDPA not only increased the pH sensitivity of the carrier but also reduced its drug leakage from 60% to 40% at a pH of 7.4. Drug release experiments also showed that under the stimulus of pH and GSH, the drug cumulative release amount was over 75%. The dual-sensitive GO-based self-assembly exhibits great potential as a drug carrier for hydrophobic drugs in cancer therapy.