title: Optimization of liganded polyethylenimine polyethylene glycol vector for nucleic acid delivery.
abstract: The delivery of nucleic acids into cells is an attractive approach for cancer therapy. Polyethylenimine (PEI) is among the most efficient nonviral carriers. Recent studies have demonstrated that PEI can be conjugated to targeting ligands, such as epidermal growth factor (EGF) and transferrin (Schaffert et al., 2011; Abourbeh et al., 2012; Ogris et al., 1999). Herein we present a simplified protocol for producing homogeneous preparations of PEGylated linear PEI: LPEI-PEG2k. We generated two well-characterized copolymers, with ratios of LPEI to PEG of 1:1 and 1:3. These copolymers were further conjugated through disulfide bonds to a Her-2 targeting moiety, Her-2 affibody. This reaction yielded two triconjugates that target Her-2 overexpressing tumors. Polyplexes were formed by complexing plasmid DNA with the triconjugates. We characterized the biophysical properties of the conjugates, and found that the triconjugate 1:3 polyplex had lower ζ potential, larger particle size, and more heterogeneous shape than the triconjugate 1:1 polyplex. Triconjugate 1:1 and triconjugate 1:3 polyplexes were highly selective toward cells that overexpress Her-2 receptors, but triconjugate 1:1 polyplex was more efficient at gene delivery. Our studies show that the biophysical and biological properties of the conjugates can be profoundly affected by the ratio of LPEI:PEG2k:ligand. The procedure described here can be adapted to generate a variety of triconjugates, simply by changing the targeting moiety.
authors.affiliation: Unit of Cellular Signaling, Department of Biological Chemistry and ‡Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem , Givat Ram, Jerusalem 91904, Israel.
authors.forename: Salim
authors.initials: S
authors.lastname: Joubran
authors.forename: Maya
authors.initials: M
authors.lastname: Zigler
authors.forename: Neta
authors.initials: N
authors.lastname: Pessah
authors.forename: Shoshana
authors.initials: S
authors.lastname: Klein
authors.forename: Alexei
authors.initials: A
authors.lastname: Shir
authors.forename: Nufar
authors.initials: N
authors.lastname: Edinger
authors.forename: Anna
authors.initials: A
authors.lastname: Sagalov
authors.forename: Yair
authors.initials: Y
authors.lastname: Razvag
authors.forename: Meital
authors.initials: M
authors.lastname: Reches
authors.forename: Alexander
authors.initials: A
authors.lastname: Levitzki
mesh_terms: D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003851:Deoxyribonucleases / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry*; D006801:Humans; D008024:Ligands; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000737:chemistry / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014162:Transfection
chemical_list: D004247:DNA; D003851:Deoxyribonucleases; D004337:Drug Carriers; D008024:Ligands; D011092:Polyethylene Glycols; D011094:Polyethyleneimine; D018719:Erb-b2 Receptor Tyrosine Kinases; D011993:Recombinant Fusion Proteins; D013438:Sulfhydryl Compounds