Synthesis of magnetic/pH dual responsive dextran hydrogels as stimuli-sensitive drug carriers

Hydrogels loaded with magnetic nanoparticles have been widely researched recently as biomaterials, due to their good biocompatibility and unique magnetic characteristics. In this study, water-soluble superparamagnetic iron oxide nanoparticles (Fe3O4) prepared by coprecipitation were physically doped into the dextran hydrogels which were formed via Schiff base reactions between ethylenediamine and oxidized dextran. The combination of magnetic nanoparticles and chemical cross-linked hydrogels leads to magnetic/pH dual-sensitive hydrogels which can be used as stimuli-responsive carrier. Magnetic properties, swelling, and rheology behaviors of the resulted magnetic hydrogels were strongly affected by the Fe3O4 nanoparticle content. Moreover, doxorubicin (DOX⋅HCl) was embedded into the magnetic hydrogels and pH/magnetic sensitive release profiles were identified. The release mechanism analysis indicated that the release behaviors of DOX⋅HCl were controlled by the diffusion, swelling, and erosion processes simultaneously. The prepared hydrogel/Fe3O4 composites with dual magnetic/pH stimuli-responsiveness hold the promise to be used in various applications such as drug release.