Protein-Resistant Biodegradable Amphiphilic Graft Copolymer Vesicles as Protein Carriers.

The protein adsorption and self-assembly behavior of biocompatible graft copolymer, poly(lactide-co-diazidomethyl trimethylene carbonate)-g-poly(ethylene glycol) [P(LA-co-DAC)-g-PEG], were systematically studied. The graft copolymers showed enhanced resistance to non-specific protein adsorption compared with their block copolymer counterparts, indicative of the increased effect of PEG density beyond PEG length. Diverse nanostructures including vesicles can be assembled from the amphiphilic graft copolymers with well-defined nano-sizes. Hemoglobin (Hb), as a model protein, can be entrapped in the formed vesicles and keep the gas-binding capacity. The reduced release rate of Hb from graft copolymer vesicles indicated the relatively stable membrane packing compared with block copolymer counterpart.