title: Junk DNA enhances pEI-based non-viral gene delivery.
abstract: Gene therapy aims at delivering exogenous DNA into the nuclei of target cells to establish expression of a therapeutic protein. Non-viral gene delivery is examined as a safer alternative to viral approaches, but is presently characterized by a low efficiency. In the past years several non-viral delivery strategies have been developed, including cationic polymer-based delivery. One of the most described and most active polymers is linear pEI. This study addresses questions regarding formulating highly efficient pEI-based polyplexes. By mixing reporter plasmid DNA with non-coding junk DNA it was shown that the amount of reporter plasmid can be significantly decreased in linear pEI-based transfection while maintaining transfer activity. Junk DNA maximally exerts its function when co-delivered with active DNA within the same pEI complexes rather than upon co-delivery of distinct junk DNA/pEI and active DNA/pEI complexes. We conclude that not the total amount of active DNA, but rather the total amount of active DNA-containing particles is the limiting factor in pEI-mediated transfection.
authors.affiliation: Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80.082, 3508 TB Utrecht, The Netherlands. E.V.B.vanGaal@uu.nl
authors.forename: Ethlinn V B
authors.initials: EV
authors.lastname: van Gaal
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Oosting
authors.forename: Wim E
authors.initials: WE
authors.lastname: Hennink
authors.forename: Daan J A
authors.initials: DJ
authors.lastname: Crommelin
authors.forename: Enrico
authors.initials: E
authors.lastname: Mastrobattista
mesh_terms: D000818:Animals; D019556:COS Cells; D002470:Cell Survival; D002522:Chlorocebus aethiops; D021901:DNA, Intergenic / Q000737:chemistry*; D015870:Gene Expression / Q000235:genetics; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007097:Imines / Q000737:chemistry*; D010316:Particle Size; D010957:Plasmids / Q000737:chemistry* / Q000235:genetics; D011095:Polyethylenes / Q000737:chemistry*; D055672:Static Electricity; D014162:Transfection; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D021901:DNA, Intergenic; D007097:Imines; D011095:Polyethylenes; C485184:enhanced green fluorescent protein; C505405:poly(ethylene imine); D049452:Green Fluorescent Proteins; D001616:beta-Galactosidase