Glutathione conjugated superparamagnetic Fe3O4-Au core shell nanoparticles for pH controlled release of DOX

Glutathione (GSH) coated gold-iron oxide core shell nanoparticles (GS-Au-Fe3O4) were prepared by coating glutathione shell on nanoparticles to reduce the dose dependent behaviour of anticancer drug, doxorubicin (DOX). The resultant nanoparticles were characterized using XPS, FTIR, HR-TEM with STEM profile to analyze the GSH shell over the surface. The GS-Au-Fe3O4 nanoparticles were loaded with DOX and maximum drug entrapment capacity of 54% was observed in 48 h. In-vitro drug release were evaluated using UV-vis and Fluorescence spectroscopy. The results show that drug release is facilitated under acidic conditions as well as by extracellular glutathione spiking. Cytotoxicity and cellular uptake was studied on HeLa cells where GS-Au-Fe3O4 nanoparticles lead to significantly higher uptake of DOX as compared to free drug. The use of glutathione conjugation thus act as an efficient drug delivery vehicle which requires significantly low concentration of GS-Au-Fe3O4 nanoparticles for DOX release besides triggering drug release by using redox active GSH.