Design of deformable chitosan microspheres loaded with superparamagnetic iron oxide nanoparticles for embolotherapy detectable by magnetic resonance imaging

► Ionotropic gelation and genipin crosslinking yielded chitosan microbeads with SPIO. ► Release of SPIO from chitosan micromatrices increased in PBS with lysozyme. ► In vitro phantom study determined suitable SPIO concentrations for in vivo study. ► Retention of embolized chitosan microspheres could be monitored for 18 weeks.