Size and morphology controllable core cross‐linked self‐aggregates from poly(ethylene glycol‐b‐succinimide) copolymers

We developed a simple route to prepare stabilized micelles and nanovesicles in aqueous solutions. A hydrophobic poly(succinimide) (PSI) was conjugated with the hydrophilic poly(ethylene glycol) (PEG) as a new type of cross‐linkable unit. Spherical aggregates were formed when dissolving the amphiphilic PEG₆₈₂‐b‐PSI₁₃₀ copolymer in aqueous solutions directly, and polymer nanovesicles were prepared by a precipitation‐dialysis method using PEG₄₅₅‐b‐PSI₁₃₀ copolymer. Bifunctional primary amine was added to the micelle or nanovesicle solutions to prepare cross‐linked structures via aminolysis reaction of the succinimide units. The degree of cross‐linking was controlled by adjusting the molar ratio of the cross‐linker to the succinimide units. Increasing the degree of cross‐linking leads to the compaction of the micelle core thus reduced diameter. The cross‐linked polymer micelles or nanovesicles maintained their morphology in extremely diluted solutions because of their structural stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010