Self-assembly, drug-delivery behavior, and cytotoxicity evaluation of amphiphilic chitosan-graft-poly (1,4-dioxan-2-one) copolymers

A series of biocompatible and amphiphilic chitosangraft- poly(1,4-dioxan-2-one) (CS-g-PPDO) copolymers were synthesized using a low molecular weight chitosan (M-n - 5x10(3) Da). The resulting copolymers could self-assemble into micelles in aqueous medium. The critical micelle concentration, size, and morphology of the micelles were characterized by fluorescence spectra, dynamic light scattering (DLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). These polymer micelles were used as drug carriers for nimodipine (a model drug). It was found that nimodipine was released from the micelles for periods as long as 100 h without a burst release occurring. In addition, the MTT assay showed that the CS-g-PPDO copolymers exhibited low cytotoxicity and good biocompatibility with L929 cells, highlighting the potential of these copolymers as drug-delivery carriers.