title: Liposome encapsulated polyethylenimine/ODN polyplexes for brain targeting.
abstract: Despite high in vitro transfection efficiency, the use of the cationic polymer polyethylenimine (PEI) for systemic application is limited due to its rapid blood clearance and accumulation by RES sites upon intravenous administration of PEI/DNA polyplexes. Therefore, it is important to improve the properties of the PEI/DNA complex with respect to extending the systemic circulation time and suppression of RES uptake. In this study, we applied PEGylated liposome technology for systemic delivery of PEI polyplex of oligodeoxynucleotides (ODN), based on encapsulation of the PEI/ODN polyplexes into PEGylated liposomes. The PEI/ODN polyplex was prepared with a low-branched PEI with MW 2.7 kDa and 20-mer double stranded ODN and was then entrapped into PEGylated liposomes with 95% loading efficiency, leading to a virus-like structure with approximately 130 nm diameter. The PEG-stabilized liposome (PSL) entrapping PEI/ODN polyplexes remained stable in the presence of serum. Upon intravenous administration, the DNA in the PSL was cleared from systemic circulation at a significantly slower rate as compared to the naked PEI/ODN complex. Furthermore, targeting of the PSL with antibody specific to transferrin receptor redirected biodistribution of the entrapped ODN, leading to significant accumulation in the targeted organ, i.e. brain. Encapsulation of the PEI/ODN polyplexes within a long-circulating liposome provided a promising ODN delivery system for in vivo application.
authors.affiliation: Department of Pharmaceutical Sciences, Texas Tech University Health Science Center, Amarillo, 79106, USA.
authors.forename: Young Tag
authors.initials: YT
authors.lastname: Ko
authors.forename: Raktima
authors.initials: R
authors.lastname: Bhattacharya
authors.forename: Ulrich
authors.initials: U
authors.lastname: Bickel
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D045744:Cell Line, Tumor; D002850:Chromatography, Gel; D020285:Cryoelectron Microscopy; D016503:Drug Delivery Systems / Q000379:methods*; D004705:Endocytosis / Q000187:drug effects; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D007097:Imines / Q000737:chemistry*; D008081:Liposomes / Q000138:chemical synthesis / Q000737:chemistry*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics; D009838:Oligodeoxyribonucleotides / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D010316:Particle Size; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry*; D014018:Tissue Distribution; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics
chemical_list: C519184:1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy-poly(ethylene glycol 2000); D007097:Imines; D008081:Liposomes; D016328:NF-kappa B; D009838:Oligodeoxyribonucleotides; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D011095:Polyethylenes; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; C505405:poly(ethylene imine); D011092:Polyethylene Glycols