Dual redox-triggered shell-sheddable micelles self-assembled from mPEGylated starch conjugates for rapid drug release

Abstract

At present, diselenide bonds have been considered as a novel dual redox-sensitive linkage. Nevertheless, few studies have focused on diselenide-linked polysaccharide as new biological materials. In this work, the diselenide-linked mPEGylated starch amphiphilic copolymers (mPEG-SeSe-St), which combined the biocompatibility of polysaccharide and the stimuli-responsiveness of diselenide linkages, were developed as a novel type of PEG-detachable drug vector for rapid drug release. The amphiphilic design of the mPEG-SeSe-St enabled the formation of self-assembled micelles with spherical core–shell structures in aqueous solution. The data of well-ordered appraisals demonstrated that mPEG-SeSe-St could be disrupted in the presence of a low concentration of hydrogen peroxide (H₂O₂, 0.1% (v/v)) or glutathione (GSH, 1 mM). The process of diselenide bonds' more rapid degradation than disulfide bonds led to a synergistically enhanced release of loaded anticancer drugs (DOX) in cellular environments. These results, combined with cell viability measurements and confocal laser scanning microscopy (CLSM), indicated that mPEG-SeSe-St micelles might have appeared as a refined platform for cancer therapy.