title: Photochemically enhanced gene delivery of EGF receptor-targeted DNA polyplexes.
abstract: Epidermal growth factor receptor (EGFR) targeted DNA polyplexes, containing polyethylenimine (PEI) conjugated with EGF protein as cell-binding ligand for endocytosis and polyethylene glycol (PEG) for masking the polyplex surface charge, mediated a 3- to 30-fold higher luciferase gene expression in HUH7, HepG2 and A431 cell transfections than analogous untargeted PEG-PEI polyplexes. Transfection levels can be further enhanced by treatment of cells with amphiphilic photosensitizers followed by illumination. In this process photosensitizers localized in membranes of endocytic vesicles are activated by light, resulting in the destruction of endocytic membrane structures and releasing co-endocytosed polyplexes into the cell cytosol. Photochemical enhanced gene expression was observed in all cell lines, with the magnitude of enhancement depending on the particular PEI polyplex formulation and cell line, ranging between 2- and 600-fold. Importantly, improved gene transfer retained EGF receptor specificity, as demonstrated by comparison with ligand-free polyplexes and by receptor antibody or ligand competition experiments. These results suggest that this combined procedure enables a dual mode of targeting polyplexes: biological targeting via EGFR interaction, combined with physical targeting with light to direct a photochemical delivery of therapeutic genes to a desired location.
authors.affiliation: Pharmaceutical Biology-Biotechnology, Department of Pharmacy, Ludwig-Maximilians-Universitaet, Butenandtstr. 5-13, D-81377 Munich, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Kloeckner
authors.forename: Lina
authors.initials: L
authors.lastname: Prasmickaite
authors.forename: Anders
authors.initials: A
authors.lastname: Høgset
authors.forename: Kristian
authors.initials: K
authors.lastname: Berg
authors.forename: Ernst
authors.initials: E
authors.lastname: Wagner
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000008:administration & dosage*; D004337:Drug Carriers; D004705:Endocytosis; D004815:Epidermal Growth Factor / Q000737:chemistry* / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D008027:Light; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D017319:Photosensitizing Agents / Q000737:chemistry*; D010957:Plasmids; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*; D014162:Transfection
chemical_list: D004337:Drug Carriers; D017319:Photosensitizing Agents; D011092:Polyethylene Glycols; D004815:Epidermal Growth Factor; D011094:Polyethyleneimine; D004247:DNA; D008156:Luciferases; D066246:ErbB Receptors