title: Galactose-functionalized cationic polycarbonate diblock copolymer for targeted gene delivery to hepatocytes.
abstract: To mediate selective gene delivery to hepatocytes via the asialoglycoprotein receptors (ASGP-Rs), we designed and synthesized well-defined and narrowly dispersed galactose- and glucose-functionalized cationic polycarbonate diblock copolymers (designated as Gal-APC and Glu-APC, respectively) using organocatalytic ring-opening polymerization of functionalized carbonate monomers, with a subsequent quaternization step using bis-tertiary amines to confer quaternary and tertiary amines for DNA binding and endosomal buffering, respectively. The sugar-functionalized diblock copolymers effectively bound and condensed DNA to form positively charged nanoparticles (<100 nm in diameter and ≈30 mV zeta-potential) that were stable under high physiological salt conditions. In comparison to the control Glu-APC/DNA complexes, Gal-APC/DNA complexes mediated significantly higher gene expression in ASGP-R positive HepG2 cells with no significant difference observed in ASGP-R negative HeLa cells. The co-incubation of Gal-APC/DNA complexes with a natural ASGP-R ligand effectively led to a decrease in gene expression, hence providing evidence for the ASGP-R mediated endocytosis of the polyplexes. Importantly, the Gal-APC/DNA complexes induced minimal cytotoxicities in HepG2 cells at the N/P ratios tested. Taken together, the galactose-functionalized cationic polycarbonate diblock copolymer has potential for use as a non-viral gene vector for the targeted delivery of therapeutic genes to hepatocytes in the treatment of liver diseases.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, Singapore, 138669, Singapore.
authors.forename: Zhan Yuin
authors.initials: ZY
authors.lastname: Ong
authors.forename: Chuan
authors.initials: C
authors.lastname: Yang
authors.forename: Shu Jun
authors.initials: SJ
authors.lastname: Gao
authors.forename: Xi-Yu
authors.initials: XY
authors.lastname: Ke
authors.forename: James L
authors.initials: JL
authors.lastname: Hedrick
authors.forename: Yi
authors.initials: Y
authors.lastname: Yan Yang
mesh_terms: D002412:Cations / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D005690:Galactose / Q000737:chemistry* / Q000378:metabolism*; D018014:Gene Transfer Techniques; D005947:Glucose / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D015394:Molecular Structure; D010316:Particle Size; D011076:Polycarboxylate Cement / Q000737:chemistry / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D002412:Cations; D011076:Polycarboxylate Cement; C005506:polycarbonate; D004247:DNA; D005947:Glucose; D005690:Galactose
keywords: cationic polycarbonate; galactose; gene delivery; liver-targeting; organocatalytic ring-opening polymerization