Surface Stabilization of Diblock PEG-PLGA Micelles by Polymerization ofN-Vinyl-2-pyrrolidone

This paper presents a new approach to improving the physical stability of biodegradable poly-(ethylene glycol)-block-poly[(DL-lactic acid)-co-(glycolic acid)] (PEG-PLGA) micelles. A hydroxyl-terminated PEG monomethacrylate (PEGmer) macroinitiator was used to prepare a methacrylate-end-capped PEG-PLGA diblock copolymer by the ring-opening polymerization of D,L-lactide and glycolide. The surface-exposed methacrylate groups in the shell layer of the micelles can be polymerized with N-vinyl-2-pyrrolidone. The resulting micelles show substantially enhanced stability.