title: Long circulating, cationic liposomes containing amino-PEG-phosphatidylethanolamine.
abstract: Ligand attachment to polyethylene glycol (PEG) grafted, long circulating liposomes at the polymer terminus is of interest for targeting but the effect of positively charged groups is unknown. Amino-polyethylene glycol-phosphatidylethanolamine (AminoPEG-PE), prepared in four steps from alpha-amino-omega-hydroxy-PEG, was tested for influence on liposome interactions in vivo: blood circulation and biodistribution. Despite surface amines on each liposome conferring cationic behavior, in vivo properties are comparable to those obtained with methoxy-PEG-PE. The consequences are profound for targeting and possibly systemic delivery of cationic lipidic-polynucleotide complexes.
authors.affiliation: Liposome Technology Inc., Menlo Park, CA 94025.
authors.forename: S
authors.initials: S
authors.lastname: Zalipsky
authors.forename: E
authors.initials: E
authors.lastname: Brandeis
authors.forename: M S
authors.initials: MS
authors.lastname: Newman
authors.forename: M C
authors.initials: MC
authors.lastname: Woodle
mesh_terms: D000588:Amines / Q000378:metabolism; D000818:Animals; D005260:Female; D008081:Liposomes; D010714:Phosphatidylethanolamines / Q000008:administration & dosage / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D000588:Amines; D008081:Liposomes; D010714:Phosphatidylethanolamines; D011092:Polyethylene Glycols