Premium
Micellization and Reversible pH‐Sensitive Phase Transfer of the Hyperbranched Multiarm PEI–PBLG Copolymer
Author(s) -
Tian Huayu,
Chen Xuesi,
Lin Hao,
Deng Chao,
Zhang Peibiao,
Wei Yen,
Jing Xiabin
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200501322
Subject(s) - micelle , copolymer , cationic polymerization , amphiphile , polymerization , polymer chemistry , polyethylenimine , aqueous solution , chain transfer , polyelectrolyte , chemical engineering , materials science , aqueous two phase system , chemistry , polymer , organic chemistry , radical polymerization , transfection , biochemistry , engineering , gene
A novel, hyperbranched, amphiphilic multiarm biodegradable polyethylenimine‐poly(γ‐benzyl‐ L ‐glutamate) (PEI–PBLG) copolymer was prepared by the ring‐opening polymerization of γ‐benzyl‐ L ‐glutamate– N ‐carboxyanhydride (BLG–NCA) with hyperbranched PEI as a macroinitiator. The copolymer could self‐assemble into core‐shell micelles in aqueous solution with highly hydrophobic micelle cores. As the PBLG content was increased, the size of the micelles increased and the critical micelle concentration (CMC) decreased. The surface of the micelles had a positive ζ potential. The cationic micelles were capable of complexing with plasmid DNA (pDNA), which could be released subsequently by treatment with polyanions. The PEI–PBLG copolymer formed unimolecular micelles in chloroform solution. The pH‐sensitive phase‐transfer behavior exhibited two critical pH points for triggering the encapsulation and release of guest molecules. Both the encapsulation and release processes were rapid and reversible. Under strong acidic or alkaline conditions, the release process became partially or completely irreversible. Thus, this copolymer system should be an attractive candidate for a gene‐ or drug‐delivery system in aqueous media and could provide the phase‐transfer carriers between water and organic media.