title: PEGylation potentiates hepatoma cell targeted liposome-mediated in vitro gene delivery via the asialoglycoprotein receptor.
abstract: Hepatocellular carcinoma is a burgeoning health issue in sub-Saharan Africa and East Asia where it is most prevalent. The search for gene medicine treatment modalities for this condition represents a novel departure from current treatment options and is gaining momentum. Here we report on nonPEGylated and on sterically stabilized PEGylated cationic liposomes decorated with D-galacto moieties linked to 24.1 Å spacers for asialoglycoprotein receptor (ASGP-R)-targeted vehiculation of pCMV-luc plasmid DNA. Cargo DNA is fully liposome associated at N/P ratio=3:1 and is partially protected from the effects of serum nucleases. Moreover, at this ratio, lipoplex dimensions (89-97 nm) are compatible with the requirements for extravasation in vivo. Ethidium displacement assays show that the reporter DNA is in a less condensed state when bound to PEGylated liposomes than with nonPEGylated liposomes. PEGylated lipoplexes were well tolerated by both HEK293 (ASGP-R-negative) and HepG2 (ASGP-R-positive) cell lines and delivered DNA to the human hepatoma cell line HepG2 by ASGP-R mediation at levels three-fold greater than nonPEGylated lipoplexes. PEGylated ASGP-R-targeted liposomes reported in this study possess the required characteristics for hepatotropic gene delivery and may be considered for further application in vivo.
authors.affiliation: Non-viral Gene Delivery Laboratory, Discipline of Biochemistry, Westville Campus, University of KwaZulu-Natal, P. Bag X54001, Durban, 4000, South Africa.
authors.forename: Nkosiyethu K
authors.initials: NK
authors.lastname: Mkhwanazi
authors.affiliation: Molecular Sciences Institute, Department of Chemistry, University of the Witwatersrand, P. Bag 3, Wits 2050, South Africa.
authors.forename: Charles B
authors.initials: CB
authors.lastname: de Koning
authors.affiliation: Department of Chemistry and Polymer Sciences, Stellenbosch University, P. Bag X1, Matieland 7602, South Africa.
authors.forename: Willem A L
authors.initials: WAL
authors.lastname: van Otterlo
authors.affiliation: Non-viral Gene Delivery Laboratory, Discipline of Biochemistry, Westville Campus, University of KwaZulu-Natal, P. Bag X54001, Durban, 4000, South Africa, Phone: +27 31 2607981, Fax: +27 31 2607942.
authors.forename: Mario
authors.initials: M
authors.lastname: Ariatti
authors.affiliation: Non-viral Gene Delivery Laboratory, Discipline of Biochemistry, Westville Campus, University of KwaZulu-Natal, P. Bag X54001, Durban, 4000, South Africa.
authors.forename: Moganavelli
authors.initials: M
authors.lastname: Singh
mesh_terms: D037263:Asialoglycoprotein Receptor / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020285:Cryoelectron Microscopy; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018014:Gene Transfer Techniques; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism*; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D037263:Asialoglycoprotein Receptor; D008081:Liposomes; D011092:Polyethylene Glycols; D004247:DNA
keywords: HepG2 cells; asialoglycoprotein receptor; gene delivery; lipoplexes