title: Targeting of lipid-protamine-DNA (LPD) lipopolyplexes using RGD motifs.
abstract: The incorporation of pegylated lipid into Lipid-Protamine-DNA (LPD-PEG) lipopolyplexes causes a decrease of their in vitro transfection activity. This can be partially attributed to a reduction in particle binding to cells. To restore particle binding and specifically target LPD formulations to tumor cells, the lipid-peptide conjugate DSPE-PEG5K-succinyl-ACDCRGDCFCG-COOH (DSPE-PEG5K-RGD-4C) was generated and incorporated into LPD formulations (LPD-PEG-RGD). LPD-PEG-RGD was characterized with respect to its biophysical and biological properties. The Incorporation of DSPE-PEG5K-RGD-4C ligands into LPD formulations results in a 5 and a 15 fold increase in the LPD-PEG-RGD binding and uptake, respectively, over an LPD-PEG formulation. Enhancement of binding and uptake resulted in a 100 fold enhancement of transfection activity. Moreover, this transfection enhancement was specific to cells expressing appropriate integrin receptors (MDA-MB-231). Huh7 cells, known for their low level of alphavbeta3 and alphavbeta5 integrin expression, failed to show RGD mediated transfection enhancement. This transfection enhancement can be abolished in a competitive manner using free RGD peptide, but not an RGE control peptide. Results demonstrated RGD mediated enhanced LPD-PEG cell binding and transfection in cells expressing the integrin receptor. These formulations provide the basis for effective, targeted, systemic gene delivery.
authors.affiliation: Targeted Genetics Corporation, Seattle, Washington 98101, USA.
authors.forename: Pierrot
authors.initials: P
authors.lastname: Harvie
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dutzar
authors.forename: Todd
authors.initials: T
authors.lastname: Galbraith
authors.forename: Sally
authors.initials: S
authors.lastname: Cudmore
authors.forename: Daniel
authors.initials: D
authors.lastname: O'Mahony
authors.forename: Pervin
authors.initials: P
authors.lastname: Anklesaria
authors.forename: Ralph
authors.initials: R
authors.lastname: Paul
mesh_terms: D001667:Binding, Competitive; D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D006801:Humans; D008024:Ligands; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry* / Q000493:pharmacokinetics; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D010316:Particle Size; D010957:Plasmids / Q000737:chemistry / Q000235:genetics; D011092:Polyethylene Glycols / Q000737:chemistry; D011479:Protamines / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D044967:Serum / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
chemical_list: D008024:Ligands; D008055:Lipids; D008081:Liposomes; D009842:Oligopeptides; D011479:Protamines; D011092:Polyethylene Glycols; C047981:arginyl-glycyl-aspartic acid; D004247:DNA