title: Enhanced gene delivery using disulfide-crosslinked low molecular weight polyethylenimine with listeriolysin o-polyethylenimine disulfide conjugate.
abstract: One of the most important requirements for non-viral gene delivery systems is the ability to mediate high levels of gene expression with low toxicity. After the DNA/vector complexes are taken up by cells through endocytosis, DNA is typically contained within the endocytic compartments and rapidly degraded due to the low pH and hydrolytic enzymes within endosomes and lysosomes, limiting its accessibility to the cytosol and ultimately to the nucleus. In this study, the endosomolytic protein listeriolysin O (LLO) from the intracellular pathogen Listeria monocytogenes was conjugated with polyethylenimine (PEI) of average molecular weight 25 kDa (PEI25) via a reversible disulfide bond (LLO-s-s-PEI), and incorporated into plasmid DNA condensed with disulfide-crosslinked low molecular weight PEI 1.8 kDa (PEI1.8). We have investigated and demonstrated that high gene transfection efficiency, which is comparable to that by the most commonly used PEI25, can be achieved by reversibly crosslinking low molecular weight PEI (PEI1.8) using disulfide bonds, with greatly reduced cytotoxicity of the PEI. The reversible incorporation of LLO into the DNA condensates of PEI, through the use of the synthesized LLO-s-s-PEI conjugate, further enhances the transfection efficiency beyond that of DNA condensates with disulfide-crosslinked PEI1.8 alone.
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065, USA.
authors.forename: Suna
authors.initials: S
authors.lastname: Choi
authors.forename: Kyung-Dall
authors.initials: KD
authors.lastname: Lee
mesh_terms: D001427:Bacterial Toxins / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry; D004247:DNA / Q000008:administration & dosage / Q000138:chemical synthesis / Q000235:genetics; D004220:Disulfides / Q000138:chemical synthesis / Q000737:chemistry; D004910:Erythrocyte Membrane / Q000187:drug effects; D015870:Gene Expression; D018014:Gene Transfer Techniques; D006360:Heat-Shock Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000633:toxicity*; D006801:Humans; D008156:Luciferases / Q000235:genetics; D008970:Molecular Weight; D010957:Plasmids / Q000235:genetics; D011094:Polyethyleneimine / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D014162:Transfection
chemical_list: D001427:Bacterial Toxins; D003432:Cross-Linking Reagents; D004220:Disulfides; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D011094:Polyethyleneimine; D004247:DNA; D008156:Luciferases; C038705:hlyA protein, Listeria monocytogenes