The main objective of this work was to develop κ-carrageenan-crosslinked magnetic chitosan with different molecular weights as pH-responsive carriers for controlled release of anticancer drug sunitinib. The characterization of magnetic carriers revealed that the size of magnetic nanoparticles is affected by the molecular weight of chitosan. Drug encapsulation efficiency and release performance influenced by the size of magnetic nanoparticles. Encapsulation efficiencies of sunitinib by low, medium and high molecular weights of magnetic chitosan carriers were found to be 62.38, 69.57 and 78.42%, respectively. The in vitro sunitinib release from magnetic chitosan/κ-carrageenan carriers was pH-dependent and followed a Fickian release mechanism. Sunitinib was efficiently released from magnetic carriers into environment under acidic pHs and the release rate was size- and molecular weight-dependent. The pH-dependent release of sunitinib with a minimal release content at pH = 7.4 makes the present magnetic carriers as promising candidate for anticancer drugs with reduced side effects.
