Soft Core-Shell Polymeric Nanoparticles with Magnetic Property for Potential Guided Drug Delivery

Thermo, pH and magnetic field responsive core-shell particles of poly(acrylonitrile-co-N-isopropylacrylamide (p(AN-c- NIPAM)) were synthesized by microemulsion polymerization. Fe3O4 nanomagnetic particles were encapsulated inside core-shell polymeric particles during the polymerization and simultaneous crosslinking reaction of AN and NIPAM using ethylene glycol dimethacrylate (EGDMA) as a crosslinker and ammonium persulfate (APS) as initiator. To increase the hydrophilicity of the particles, the hydrophobic core, which contains nitrile groups were converted to the amidoxime group by amidoximation reaction and the conversion, was confirmed by FT-IR and swelling experiments. To demonstrate the usage of the synthesized particles as potential guided drug delivery vehicles, a calcium channel blocker, Verapamil, was used for in vitro drug release studies from p(AN-c-NIPAM), amidoximated p(AN-c- NIPAM) and composite p(AN-c-NIPAM) particle systems in phosphate buffer solution (PBS) at two different temperatures, at room (~25°C) and 40°C (> LCST: Lower Critical Solution Temperature of p(NIPAM)), respectively.