title: Asialoglycoprotein Receptor-Mediated Gene Delivery to Hepatocytes Using Galactosylated Polymers.
abstract: Highly efficient, specific, and nontoxic gene delivery vector is required for gene therapy to the liver. Hepatocytes exclusively express asialoglycoprotein receptor (ASGPR), which can recognize and bind to galactose or N-acetylgalactosamine. Galactosylated polymers are therefore explored for targeted gene delivery to the liver. A library of safe and stable galactose-based glycopolymers that can specifically deliver genes to hepatocytes were synthesized having different architectures, compositions, and molecular weights via the reversible addition-fragmentation chain transfer process. The physical and chemical properties of these polymers have a great impact on gene delivery efficacy into hepatocytes, as such block copolymers are found to form more stable complexes with plasmid and have high gene delivery efficiency into ASGPR expressing hepatocytes. Transfection efficiency and uptake of polyplexes with these polymers decreased significantly by preincubation of hepatocytes with free asialofetuin or by adding free asialofetuin together with polyplexes into hepatocytes. The results confirmed that polyplexes with these polymers were taken up specifically by hepatocytes via ASGPR-mediated endocytosis. The results from transfection efficiency and uptake of these polymers in cells without ASGPR, such as SK Hep1 and HeLa cells, further support this mechanism. Since in vitro cytotoxicity assays prove these glycopolymers to be nontoxic, they may be useful for delivery of clinically important genes specifically to the liver.
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, AB T6G 2G6, Canada.
authors.forename: Bindu
authors.initials: B
authors.lastname: Thapa
authors.affiliation: Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, AB Canada.
authors.forename: Piyush
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, AB T6G 2G6, Canada.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zeng
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, AB T6G 2G6, Canada.
authors.forename: Ravin
authors.initials: R
authors.lastname: Narain
mesh_terms: D000116:Acetylgalactosamine / Q000737:chemistry*; D037263:Asialoglycoprotein Receptor / Q000378:metabolism*; D006367:HeLa Cells; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D011134:Polysaccharides / Q000737:chemistry*; D014162:Transfection / Q000379:methods*
chemical_list: D037263:Asialoglycoprotein Receptor; D011134:Polysaccharides; D000116:Acetylgalactosamine