Layer-by-layer modification of magnetic graphene oxide by chitosan and sodium alginate with enhanced dispersibility for targeted drug delivery and photothermal therapy.

In this work, graphene oxide nanosheets loaded by magnetic iron oxide nanoparticles (mGO) was synthesized and the technique of layer-by-layer (LbL) self-assembly was utilized in the successful production of chitosan/sodium alginate functionalized mGO naocomposites for use in targeted anti-cancer drug delivery and photothermal therapy. The mGO-CS/SA nanocomposites had a diameter of ˜0.5 µm and a thickness of 40-60 nm with superparamagnetic behavior. The modified nanocomposites exhibited a decrease in agglomeration and an increase in stability in biological solution following stability tests. Meanwhile, the nonspecific protein adsorption was strongly suppressed after the modification. The mGO-CS/SA nanocomposites were loaded with doxorubicin hydrochloride (DOX) via π-π stacking and electrostatic attraction with a high drug loading amount (137%, w/w). The DOX-loaded nanocomposites (mGO-CS/SA-DOX) showed improvements in function including enhanced dispersion and noticeable pH-sensitive drug release behavior. Cellular studies denoted magnetically targeted cellular uptake characteristics and excellent photothermal effect of mGO-CS/SA, as well as concentration-dependent cytotoxicity of mGO-CS/SA-DOX. Therefore the functionalization of mGO using chitosan and sodium alginate would be beneficial in biomedical applications.