Synthesis and characterization of superparamagnetic chitosan–dextran sulfate hydrogels as nano carriers for colon-specific drug delivery

The purpose of this study was to examine chitosan (CS)–dextran sulfate (DS) nanoparticles coated iron oxide as drug carriers detectable using magnetic resonance imaging (MRI) technique. The 5-aminosalicylic acid (5-ASA) was chosen as model drug molecule. CS–DS hydrogels were formulated by a complex coacervation process under mild conditions. The influence of process variables, including the two ionic polymers, on particle size, and hydrogel entrapment of 5-ASA was studied. The in vitro release of 5-ASA were also evaluated, and the integrity of 5-ASA in the release fraction was assessed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The release of 5-ASA from hydrogel was based on the ion-exchange mechanism. The CS–DS hydrogel developed based on the modulation of ratio show promise as a system for controlled delivery of drug detectable using magnetic resonance imaging (MRI) technique.