Ultrafine agarose-coated superparamagnetic iron oxide nanoparticles (AC-SPIONs): a promising sorbent for drug delivery applications

A method for one-step synthesis of ultrafine agarose-coated superparamagnetic iron oxide nanoparticles (AC-SPIONs) was developed. The method is facile and fast and requires no organic solvent or surfactant. The average particle size of the prepared AC-SPIONs was only 20–40 nm with a narrow size distribution and with large saturation magnetization at room temperature. The obtained ultrafine nanogel particles were characterized by scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy, transmission electron microscopy and vibrating sample magnetometer techniques. The AC-SPIONs were epoxy-activated by epichlorohydrin and aminated by ammonium hydroxide. The amination of the particles was investigated by the Kaiser test. The adsorption of two model compounds (gallic acid and ellagic acid) on the functionalized nanoparticles and their releases from them were investigated spectrophotometrically in three different pH values under biological conditions. The functionalized AC-SPIONs displayed good adsorption and in vitro drug release in a phosphate-buffered saline (pH 7.4). The ultrafine AC-SPIONs can be potentially used in magnetic solid-phase extraction, drug delivery, protein purification and enzyme immobilization methods.