Development of synthesis method of magnetic nanoparticles modified by oleic acid and chitosan as a candidate for drug delivery agent

In this study, magnetic nanoparticles (MNPs) coated with a combination of oleic acid and chitosan were synthesized by ex situ and in situ coprecipitation methods. Morphology and particle size, crystal structure and crystallite size, chemical structure, and magnetic saturation were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourrier transform infrared, and vibrating sample magnetometer (VSM), respectively. SEM images showed that better spherical morphology is obtained by ex situ co-precipitation method. The XRD pattern identified that nanoparticles containing Fe₃O₄ and γ-Fe₂O₃. The particles and crystallite size of the nanoparticles tended to decrease with increasing oleic acid to the optimum composition. Further functionalization through the chitosan addition (crosslinked by Tripolyphosphate/sulfate) is contributed to the hydrophilicity properties of nanoparticles. Through VSM analysis, MNPs-oleic acid-chitosan showed superparamagnetic behavior with magnetic saturation reaching 32.63 emu/g. There was a linear correlation between magnetic saturation and Fe₃O₄ content of nanoparticles. Drug loading and drug release were carried out by using Doxorubicin. These nanoparticles showed a high drug loading efficiency with lower chitosan composition. Loading efficiency of Doxorubicin is related to the conjugation with carboxylic groups and hydrophobic sites from oleic acid and MNPs.