title: Transfection efficiency of lipoplexes for site-directed delivery.
abstract: Targeted gene delivery is a promising strategy to cure disease on its basic level at the site of interest. The ultrastructure, internalization, and transfection efficiency of lipoplexes was investigated. We found that at a charge ratio (rho) of 4.0 lipoplexes had optimum characteristics for gene delivery in vitro. To decrease the size of lipoplexes, we used a method of continuous-flow microfluidics. PEGylation of lipoplexes did not hinder internalization, but was found to hamper transfection. To discriminate between uptake and transfection efficiency of lipoplexes, we used fluorescence-based approaches: microscopy and FACS. To this end, GFP plasmid was labeled with Alexa 594, and, in parallel experiments, GFP plasmid was combined with rhodamine-labeled lipid. Our studies confirm that cellular uptake does not imply transfection efficiency, and that hurdles in cellular processing have to be taken before targeted gene delivery becomes an established therapeutic option.
authors: Department of Pathology, Electron Microscopy Unit, Maastricht University, Maastricht, The Netherlands.
authors: Reint K
authors: RK
authors: Jellema
authors: Paul
authors: P
authors: Bomans
authors: Niko
authors: N
authors: Deckers
authors: Liset
authors: L
authors: Ungethum
authors: Chris P M
authors: CP
authors: Reutelingsperger
authors: Leo
authors: L
authors: Hofstra
authors: Peter M
authors: PM
authors: Frederik
mesh_terms: D020285:Cryoelectron Microscopy; D004247:DNA / Q000008:administration & dosage; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D005434:Flow Cytometry; D018390:Gene Targeting / Q000379:methods*; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000008:administration & dosage* / Q000737:chemistry; D044085:Microfluidics; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009997:Osmotic Pressure; D011092:Polyethylene Glycols / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014162:Transfection / Q000379:methods*
chemical_list: D005229:Fatty Acids, Monounsaturated; D008055:Lipids; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D049452:Green Fluorescent Proteins; D011092:Polyethylene Glycols; D004247:DNA; C070046:1,2-dioleoyloxy-3-(trimethylammonium)propane