Encapsulation of magnetic nanoparticles in poly(methyl methacrylate) by miniemulsion and evaluation of hyperthermia in U87MG cells

Abstract

Magnetic nanoparticles (MNPs) are promising materials for hyperthermia treatment and magnetic targeting systems. The objective of this work was to synthesize and characterize magnetic nanoparticles coated with oleic acid (MNPsOA) loaded with poly(methyl methacrylate) prepared by miniemulsion polymerization (MNPs-PMMA) and evaluate their cytotoxicity in murine fibroblast (L929) cells, blood biocompatibility (hemolysis assay) and hyperthermia (HPT) in human glioblastoma (U87MG) cells. The MNPs-PMMA nanoparticles presented average mean diameter of 99±1.9nm with a polydispersity index (PdI) of 0.13±0.15 and saturation magnetization (Ms) value of 34emu/g of iron oxide, as well as superparamagnetic proprieties. The MNPs-PMMA nanoparticles did not present cytotoxicity in murine fibroblast (L929) and U87MG cells. HPT assays were applied, demonstrating that AC magnetic field application (1MHz and 40Oe) for 3min or 6min reduced the viability cells by 75% and 52% respectively. Morphological analyses showed that U87MG cells treated with 0.1μgmL−1 of MNPs-PMMA nanoparticles shrank after AC magnetic field application for 6min, resulting in a region of hypoxia. Hemolysis assay showed that MNPs-PMMA nanoparticles presented high blood biocompatibility. Our results indicate that MNPs-PMMA nanoparticles obtained by miniemulsion polymerization have the potential to be used as carrier systems for HPT.