Embedding magnetic nanoparticles into polysaccharide-based hydrogels for magnetically assisted bioseparation.

Based on the preparation of biocompatible polysaccharide-based hydrogels with stimuli-responsive properties by the copolymerization of maleilated carboxymethyl chitosan with N-isopropylacrylamide, novel magnetic hybrid hydrogels were fabricated by the in situ embedding of magnetic iron oxide nanoparticles into the porous hydrogel networks. Scanning electron microscopy (SEM) and thermogravimetric (TG) analyses showed that the size, morphology, and content of the iron oxide nanoparticles formed could be modulated by controlling the amount of maleilated carboxymethyl chitosan. As confirmed by X-ray diffractometry (XRD), equilibrium swelling ratio, and differential scanning calorimetry (DSC) measurements, the embedding process did not induce a phase change of the magnetic iron oxide nanoparticles, and the resultant hybrid hydrogels could retain the pH- and temperature-responsive characteristics of their hydrogel precursors. By investigating the partition coefficients of bovine serum albumin as a model protein, this magnetic hydrogel material was found to hold a potential application in magnetically assisted bioseparation.