The effect of montmorillonite in graphene oxide/chitosan nanocomposite on controlled release of gemcitabine

In this study, a system was investigated for controlled delivery of gemcitabine (GEM), an anti-cancer drug with short biological half-life time (8-17 min), using graphene oxide (GO)/montmorillonite (MMT)/chitosan (CS) nanocomposite. The structure, morphology, zeta potential, and thermal stability of the nanocomposite were evaluated by FT-IR, XRD, zeta potential analyzer, FESEM, and TGA. The results revealed that the GO interacted with positively charged GEM and CS surface. Also, the drug was intercalated between the silicate layers of MMT, and this phenomenon is responsible for more protection of the drug from burst release. The positive zeta potential of GO/GEM/CS/MMT nanocomposite (+ 16.5 mV) promotes physical stability and interaction with the negative domains of the cell membrane. A significant synergistic effect of GO and MMT on the controlled release of GEM from the drug delivery system-based chitosan matrix has been obtained. The nanocomposite with 17 wt% MMT in the release media with pH of 7.4 provided the optimal combination of drug release rate and drug release content, whereas the time for GEM 50% release (T-50%) was obtained about 2 h. The non-Fickian diffusion mechanism and Korsmeyer-Peppas kinetic model were confirmed for release of GEM from drug-loaded nanocomposites. Finally, to investigate the efficiency of nanocomposite as an anti-cancer drug delivery system, an in vitro cytotoxicity assay was also carried out using breast cancer cell line MDA-MB-231. Results confirmed that the prepared nanocomposite could be used as a potential breast cancer therapy system for the controlled delivery of GEM.