Effect of sugar alcohol on colloidal stabilization of magnetic nanoparticles for hyperthermia and drug delivery applications

Abstract

We have successfully introduced sugar alcohol (mannitol) onto the surface of iron oxide magnetic nanoparticles and investigated its role on their colloidal stabilization. The mannitol functionalized magnetic nanoparticles (MMNPs) were prepared through co-precipitation of Fe+2 and Fe3+ ions in basic medium under N2 atmosphere followed by in-situ coating of D-mannitol. The formation of iron oxide nanoparticles is evident from XRD and TEM analysis. The coating of nanoparticles with mannitol is analyzed by FTIR, TGA, DLS and zeta-potential measurements. It has been observed that the presence of mannitol on the surface of nanoparticles strongly affect their surface potential and colloidal stability. They show room temperature superparamagnetism with optimal magnetization of 60.5 emu/g at 20 kOe and protein resistant behaviour in physiological medium. These MMNPs were employed as drug delivery carrier using anticancer drug, doxorubicin hydrochloride (DOX). The drug molecules were loaded onto the surface of nanoparticles through electrostatic interactions between positively charged DOX and negatively charged MMNPs. A loading efficiency of 60% has been observed at DOX to MMNPs ratio (w/w) of 1:10 and the loaded drug showed pH dependent sustained release characteristics. Further, MMNPs exhibited good self-heating ability under applied AC magnetic field, thus they can be used as efficient heating source for hyperthermia therapy.