A novel strategy for engineering hydrogels with ferromagnetic nanoparticles as crosslinkers of the polymer chains. Potential applications as a targeted drug delivery system

An efficient strategy is employed for the preparation of magnetic hybrid hydrogels consisting of functionalized CoFe2O4 magnetic nanoparticles covalently bound to a carboxymethylcellulose (CMC) polymer. The method involves the formation of an amide bond between the carboxylic groups of CMC and the amine groups of functionalized nanoparticles, which work as the crosslinking agents of the polymer chains. The hybrid hydrogels were chemically and morphologically characterized. The rheological properties of the hydrogels were also investigated with the aim to verify their behavior under an applied mechanical stress. The hybrid hydrogel turns out to be thixotropic. Thanks to the presence of magnetic nanoparticles, the hydrogel is capable of responding to an external magnetic field. Preliminary data show the possibility of loading the hydrogel with a dye, which can be considered as a drug model, to squeeze it through a syringe and to drive the material by the application of an external magnetic field.