Amphiphilic polysaccharide-hydrophobicized graft polymeric micelles for drug delivery nanosystems

Self-assembled amphiphilic graft copolymers in aqueous solution to form polymeric micelles, have received growing scientific attention over the years. Among the polymeric micelles, hydrophobicized polysaccharides have currently become one of the hottest researches in the field of drug delivery nanosystems. It is attributable to such appealing properties as small particle size and narrow size distribution, distinctive core-shell structure, high solubilization capacity and structural stability, tumor passive localization by enhanced permeability and retention (EPR) effect, active targeting ability via tailored targeting promoiety, long-circulation property and facile preparation. The polymeric micelles self-assembled by hydrophobicized polysaccharides can be employed as targeted drug delivery nanosystem by including thermo- or pH-sensitive components or by attaching specific targeted moieties to the outer hydrophilic surface. Beside encapsulation of water-insoluble drugs, hydrophobicized polysaccharide polymeric micelles can complex with charged proteins or peptide drugs through electrostatic force or hydrogen bond, and serve as an effective non-viral vector for gene delivery. In the latter case, polymeric micelles can not only markedly protect these macromolecules from degradation by protease or ribozymes, but also increase the gene transfection efficiency. This review will highlight the state of the art self-assembled mechanism, characterization, preparation methods and surface modification of hydrophobicized polysaccharide polymeric micelles and their recent rapid applications as drug delivery nanosystems.