(598b) Synthesis and Characterization of Polymer-Iron Oxide Composite Nanoparticles for Medical Applications

Magnetic nanoparticles, with their unique physical properties, are being studied for a wide range of biomedical applications such as imagining, targeted delivery, and hyperthermia treatment of cancer. In order to be successful in these applications, surface modifications play an essential role. In most cases, surface modification is needed to increase the stability of the particles in solution. When the particles have biological applications, the surface modifications are used to increase the biocompatibility of the particles or to facilitate delivery of a therapeutic. In this study, composite nanoparticles were developed and assessed for potential medical applications. Two types of composite nanoparticles were produced: core-shell nanocomposites and nanogel composites. Core-shell nanocomposites were prepared by using atomic transfer radical polymerization to grow a polymer shell on a magnetic core. Superparamagnetic iron oxide (Fe3O4) nanoparticles were obtained via a one-pot co-precipitation reaction and through subsequent ligand exchanges poly(ethylene glycol) 400 dimethacrylate (PEG400DMA) was crosslinked to the surface. Nanogel composites were prepared by a precipitation polymerization with the magnetic nanoparticles in solution. As the nanogels formed, the magnetic nanoparticles were entrapped in the polymer matrix. Fourier transform infrared spectroscopy and thermal gravimetric analysis were used to verify the presence and the amount of polymer. The heating properties of the composite nanoparticles under alternating magnetic field were explored and specific absorbance rate determined. Potential biocompatibility was determined by cell viability studies exposing NIH 3T3 murine fibroblasts to the nanoparticle systems.