title: Characterization of a novel diolein-based LPDII vector for gene delivery.
abstract: LPDII vectors are non-viral vehicles for gene delivery comprised of polycation-condensed plasmid DNA (polyplexes) complexed with anionic pH-sensitive liposomes. Here, we describe a novel LPDII formulation containing polyethylenimine (PEI) polyplexes complexed with anionic pH-sensitive liposomes composed of diolein/cholesteryl hemisuccinate (CHEMS) (6:4 mol/mol). The pH-sensitivity of diolein/CHEMS liposomes was evaluated through quantitative fluorescence measurements of calcein release and particle size analysis. The results indicated that diolein/CHEMS liposomes are stable at physiological pH, but undergo rapid aggregation and fluorescence dequenching at pH values < or =5.0. Using a luciferase reporter gene, in vitro transfection of KB oral cancer cells showed that the transfection efficiency of LPDII vectors was superior to other well-characterized polyplexes and lipoplexes. Results further showed that gene delivery using diolein-containing LPDII vectors was dependent on the PEI nitrogen/DNA phosphate (N/P) ratio, the lipid/DNA weight ratio and the cell line being transfected. Replacing PEI with poly-L-lysine as the DNA condensing agent resulted in only a moderate reduction in transfection activity. Moreover, in contrast to LPDII formulations incorporating dioleoylphosphatidylethanolamine (DOPE), the transfection efficiency of diolein-based LPDII vectors was sustained in media containing up to 50% fetal bovine serum. Since diolein-based LPDII vectors mediate efficient gene transfer and retain their transfection activity in the presence of serum, diolein may be a promising alternative to DOPE for the construction of non-viral vectors for in vivo gene delivery.
authors.affiliation: Division of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, Ohio State University, Rm 542 LM Parks Hall, 500 W 12th Ave, Columbus, OH 43210, USA.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Guo
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gosselin
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D004075:Diglycerides / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods*; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D008081:Liposomes; D051379:Mice; D010957:Plasmids / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D011094:Polyethyleneimine / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
chemical_list: D004075:Diglycerides; D008081:Liposomes; D011094:Polyethyleneimine; C013965:diolein