Preparation of Fe₃O₄ magnetic nanoparticles coated with gallic acid for drug delivery

Magnetic iron oxide nanoparticles were prepared using a sonochemical method under atmospheric conditions at a Fe²⁺ to Fe³⁺ molar ratio of 1:2. The iron oxide nanoparticles were subsequently coated with chitosan and gallic acid to produce a core-shell structure. X-ray diffraction demonstrated that the magnetic nanoparticles were pure Fe₃O₄ with a cubic inverse spinel structure. Transmission electron microscopy showed that the Fe₃O₄ nanoparticles were of spherical shape with a mean diameter of 11 nm, compared with 13 nm for the iron oxide-chitosan-gallic acid (FCG) nanocarriers. The magnetic nanocarrier enhanced the thermal stability of the drug, gallic acid. Release of the active drug from the FCG nanocarrier was found to occur in a controlled manner. The gallic acid and FCG nanoparticles were not toxic in a normal human fibroblast (3T3) line, and anticancer activity was higher in HT29 than MCF7 cell lines.