Preparation of well-dispersed superparamagnetic iron oxide nanoparticles in aqueous solution with biocompatible N-succinyl-O-carboxymethylchitosan

N-succinyl-O-carboxymethylchitosan (NSOCMCS), an amphiphilic polyelectrolyte with the property of biocompatibility and functional carboxyl groups, was used as a stabilizer to prepare a well-dispersed suspension of superparamagnetic Fe3O4 nanoparticles, which were composed of a magnetite Fe3O4 core and a NSOCMCS shell. The carboxyl groups of NSOCMCS can coordinate with Fe3O4, which makes NSOCMCS chemically adsorb onto the surface of Fe3O4 nanoparticles. The stabilizing mechanisms were proven to be both the steric hindrance and electrostatic repulsion arisen from the NSOCMCS. Transmission electron microscopy showed that the resulting Fe3O4 particles were in spherical morphology with the diameter ranging from 12 to 18 nm. Magnetic property measurements indicated that NSOCMCS/Fe3O4 nanoparticles preserved superparamagnetic behavior. In vitro biocompatibility studies showed that the NSOCMCS/Fe3O4 nanoparticles had good cytocompatibility.