Synthesis and properties of biomimetic poIy(L-glutamate)-b-poly(2-acryloyloxyethyllactoside)-b-poly(L-glutamate) triblock copolymers

A novel class of biomimetic glycopolymer-polypeptide triblock copolymers [poly(L-glutamate)-poly(2-acryloyloxyethyllactoside)-poly(L-glutamate)] was synthesized by the sequential atom transfer radical polymerization of a protected lactose-based glycomonomer and the ring-opening polymerization of beta-benzyl-L-glutamate N-carboxyanhydride. Gel permeation chromatography and nuclear magnetic resonance analyses demonstrated that triblock copolymers with defined architectures, controlled molecular weights, and low polydispersities were successfully obtained. Fourier transform infrared spectroscopy of the triblock copolymers revealed that the alpha-helix/beta-sheet ratio increased with the poly(benzyl-L-glutamate) block length. Furthermore, the water-soluble triblock copolymers self-assembled into lactose-installed polymeric aggregates; this was investigated with the hydrophobic dye solubilization method and ultraviolet-visible analysis. Notably, this kind of aggregate may be useful as an artificial polyvalent ligand in the investigation of carbohydrate-protein recognition and for the design of site-specific drug-delivery systems. (C) 2004 Wiley Periodicals, Inc.