title: PEI-g-chitosan, a novel gene delivery system with transfection efficiency comparable to polyethylenimine in vitro and after liver administration in vivo.
abstract: Polyethylenimine-graft-chitosan (PEI-g-chitosan) was synthesized by performing cationic polymerization of aziridine in the presence of water-soluble oligo-chitosan (M(n) = 3400). The absolute molecular weight and chemistry of the PEI-g-chitosan obtained were characterized using GPC, 13C and 1H NMR, respectively. The results indicated that all the amines of chitosan were grafted with oligo-PEI, and the average length of the oligo-PEI side chains was determined by the feed molar ratio of aziridne/amine in chitosan. PEI-g-chitosan of M(n) = 7400 with a polydispersity index (PDI) of 1.50, and PEI side chains of M(n) = 206 was prepared for gene delivery. Gel electrophoresis showed that DNA migration was retarded completely at a N/P ratio of 2.5/1, indicating good DNA condensation capability of PEI-g-chitosan. The sizes and the zeta-potentials of the complexes of PEI-g-chitosan/DNA were characterized. The cytotoxicity of PEI-g-chiotsan was evaluated, and the results reflected that PEI-g-chitosan had a lower cytotoxicity than PEI (25 K). Gene transfection efficiency of PEI-g-chitosan in HepG2, HeLa, and primary hepatocytes cells and after administration in the common bile duct of rat liver was determined. Remarkably, PEI-g-chitosan showed a higher transfection efficiency than that of PEI (25 K) both in vitro and in vivo. The systematic distribution and the distribution in liver of the gene expression of the complexes of PEI-chitosan/DNA were determined as well.
authors.affiliation: Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602.
authors.forename: Kokhou
authors.initials: K
authors.lastname: Wong
authors.forename: Guobin
authors.initials: G
authors.lastname: Sun
authors.forename: Xueqing
authors.initials: X
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Dai
authors.forename: Ye
authors.initials: Y
authors.lastname: Liu
authors.forename: Chaobin
authors.initials: C
authors.lastname: He
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry; D004247:DNA / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000378:metabolism; D008297:Male; D010957:Plasmids / Q000235:genetics; D011094:Polyethyleneimine / Q000008:administration & dosage* / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection / Q000379:methods*
chemical_list: D011094:Polyethyleneimine; D004247:DNA; D048271:Chitosan