title: Gene delivery using dimethyldidodecylammonium bromide-coated PLGA nanoparticles.
abstract: In this present work we describe a poly(lactic-co-glycolic acid) (PLGA) nanoparticle formulation for intracellular delivery of plasmid DNA. This formulation was developed to encapsulate DNA within PLGA nanoparticles that combined salting out and emulsion-evaporation processes. This process reduced the requirement for sonication which can induce degradation of the DNA. A monodispersed nanoparticle population with a mean diameter of approximately 240 nm was produced, entrapping a model plasmid DNA in both supercoiled and open circular structures. To induce endosomal escape of the nanoparticles, a superficial cationic charge was introduced using positively charged surfactants cetyl trimethylammonium bromide (CTAB) and dimethyldidodecylammonium bromide (DMAB), which resulted in elevated zeta potentials. As expected, both cationic coatings reduced cell viability, but at equivalent positive zeta potentials, the DMAB coated nanoparticles induced significantly less cytotoxicity than those coated with CTAB. Fluorescence and transmission electron microscopy demonstrated that the DMAB coated cationic nanoparticles were able to evade the endosomal lumen and localise in the cytosol of treated cells. Consequently, DMAB coated PLGA nanoparticles loaded with a GFP reporter plasmid exhibited significant improvements in transfection efficiencies with comparison to non-modified particles, highlighting their functional usefulness. These nanoparticles may be useful in delivery of gene therapies to targeted cells.
authors.affiliation: School of Pharmacy, Queens University of Belfast, Belfast, UK.
authors.forename: François
authors.initials: F
authors.lastname: Fay
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Quinn
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Gilmore
authors.forename: Paul A
authors.initials: PA
authors.lastname: McCarron
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Scott
mesh_terms: D000818:Animals; D001965:Bromides / Q000378:metabolism* / Q000494:pharmacology; D002412:Cations; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology; D004247:DNA / Q000302:isolation & purification; D004587:Electrophoresis, Agar Gel; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism*; D051379:Mice; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D010316:Particle Size; D011100:Polyglycolic Acid / Q000378:metabolism*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D000644:Quaternary Ammonium Compounds / Q000378:metabolism* / Q000494:pharmacology; D013010:Sonication; D013499:Surface Properties / Q000187:drug effects; D013501:Surface-Active Agents / Q000494:pharmacology; D014162:Transfection / Q000379:methods*
chemical_list: D001965:Bromides; D002412:Cations; D002593:Cetrimonium Compounds; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C046112:didodecyldimethylammonium; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D004247:DNA; D000077286:Cetrimonium