In this research, to overcome the low mechanical properties of hydrogels based on poly N-isopropylacrylamide (PNIPAAm) and improve their stimuli responsive behavior and lower critical solution temperature, LCST, a new kind of hybrid magnetic nanoparticles was designed, prepared, and then grafted to (PNIPAAm-co-AAc) hydrogel through in situ dispersion copolymerization route. 3-(propylcarbamoyl)acrylic acid functionalized silica-coated magnetic nanoparticles (PC-AAc/MNPs) was prepared and used as a template for in situ dispersion copolymerization of the poly N-isopropylacrylamide (PNIPAAm) and acrylic acid (AAc) in the presence of methylene-bis-acrylamide as a cross-linking agent via free radical cross-linking polymerization. Also, controlled drug release behavior of metronidazole was investigated with prepared nanocomposite hydrogels. The vibrating sample magnetometer (VSM) illustrated superparamagnetic behavior for (PC-AAc/MNPs) and nanoparticles grafted hydrogel. Scanning electron microscopy (SEM) image of functionalized magnetic nanoparticles showed that they are spherical in shape and have the spherical structure with a diameter of about 15-30 nm. Moreover, the lower critical solution temperature (LCST) of the (PC-AAc/MNPs-g-PNIPAAm-co-AAc) hydrogel, as well as the onset temperatures, measured by the cloud point (CP) method at ~42 C. Combined magnetic properties and thermosensitive behavior of (PNIPAAm-co-AAc) grafted magnetic nanoparticles could be utilized in controlled drug-targeting delivery. Hence, metronidazole as a model drug loaded on the magnetic hydrogel nanocomposite and the amount of drug release were measured by UV-Vis spectroscopy.
