▎ 摘　　要

Biodegradable chitosan-graphene oxide (GO) nanocomposites possess improved mechanical properties and drug delivery performance over chitosan and could prove to be a viable, controlled and pH-sensitive transdermal drug delivery system. Chitosan nanocomposites containing varying GO contents and drug loading ratios were investigated. The nanocomposite with 2 wt % GO provided the optimal combination of mechanical properties and drug-loading capacity. It offered a faster and a more substantial release of drug than chitosan as well as a slower biodegradation rate, owing to the abundant oxygenated functional groups, hydrophilicity and large specific surface area of GO sheets. The drug delivery profiles of the nanocomposite were dependent on the drug loading ratio, with 0.84:1 being the best ratio of drug to GO for a quick and high release of the loaded drug. The nanocomposite also demonstrated pH sensitivity of drug release, releasing 48% less drug in an acidic condition than in a neutral environment. (C) 2013 Elsevier Ltd. All rights reserved.