title: Molecular weight-dependent gene transfection activity of unmodified and galactosylated polyethyleneimine on hepatoma cells and mouse liver.
abstract: To optimize a receptor-mediated and cell-selective gene transfer with polyethyleneimine (PEI)-based vector, we synthesized three galactosylated PEIs (Gal-PEI) with different molecular weights (PEI(1800), PEI(10,000), and PEI(70,000)) and investigated their potential as a targetable vector to asialoglycoprotein receptor-positive cells. All PEI derivatives formed complexes with plasmid DNA (pDNA), whereas the particle size of the complex became smaller on increasing the molecular weight of PEI. Transfection efficiency in HepG2 cells with PEI was highest with PEI(1800); efficiency was next highest with PEI(10,000), although the cellular association was similar. After galactosylation, Gal(19)-PEI(10,000)/pDNA and Gal(120)-PEI(70,000)/pDNA showed considerable agglutination with a galactose-recognizing lectin, but Gal(9)-PEI(1800) did not, suggesting that galactose units on the Gal(9)-PEI(1800)-pDNA complex are not sufficiently available for recognition. Gal(19)-PEI(10,000)-pDNA and Gal(120)-PEI(70,000)-pDNA complexes showed galactose-inhibitable transgene expression in HepG2 cells. Transfection efficiency was greatest with Gal(19)-PEI(10,000)/pDNA, a result that highlights the importance of obtaining a balance between the cytotoxicity and the transfection activity, both of which are found to be a function of the molecular weight of PEI. After intraportal injection, however, Gal(153)-PEI(70,000)/pDNA having a low N/P ratio was most effective, suggesting that additional variables, such as the size of the complex, are important for in vivo gene transfer to hepatocytes.
authors.affiliation: Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Morimoto
authors.forename: Makiya
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kawakami
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakano
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hattori
authors.forename: Shintaro
authors.initials: S
authors.lastname: Fumoto
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Yamashita
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Hashida
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000628:therapy*; D002460:Cell Line; D004705:Endocytosis; D005690:Galactose / Q000737:chemistry*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D037102:Lectins / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008113:Liver Neoplasms / Q000628:therapy*; D051379:Mice; D008813:Mice, Inbred ICR; D011094:Polyethyleneimine / Q000378:metabolism*; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection; D019076:Transgenes
chemical_list: D037102:Lectins; D013778:Tetrazolium Salts; D013844:Thiazoles; D011094:Polyethyleneimine; C022616:thiazolyl blue; D005690:Galactose