title: AFM visualization of sub-50nm polyplex disposition to the nuclear pore complex without compromising the integrity of the nuclear envelope.
abstract: It has been questioned as to whether polyplexes in the cytoplasm can reach the nuclear compartment and if so in what form. By applying atomic force microscopy (AFM) to the nuclear envelope and the nuclear pore complexes, we demonstrate that disposition of polyethylenimine (PEI)/DNA polyplexes that were microinjected into the oocytes of Xenopus laevis, as an example of a non-dividing cell, is exclusive to the nuclear pore complex (NPC). AFM images show NPCs clogged only with sub-50nm polyplexes. This mode of disposition neither altered the morphology/integrity of the nuclear membrane nor the NPC. AFM images further show polyplexes on the nucleoplasmic side of the envelope, presumably indicating species in transit. Transmission electron microscopy studies of ruptured nuclei from transfected human cell lines demonstrate the presence of sub-50nm particles resembling polyplexes in morphology compared with control preparations.
authors.affiliation: Nanomedicine Laboratory, Centre for Pharmaceutical Nanotechnology and Nanotoxicology, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen Universitetparken 2, 2100 Copenhagen Ø, Denmark.
authors.forename: Helene
authors.initials: H
authors.lastname: Andersen
authors.affiliation: Nanomedicine Laboratory, Centre for Pharmaceutical Nanotechnology and Nanotoxicology, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen Universitetparken 2, 2100 Copenhagen Ø, Denmark.
authors.forename: Ladan
authors.initials: L
authors.lastname: Parhamifar
authors.affiliation: Manchester Pharmacy School, University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
authors.forename: A Christy
authors.initials: AC
authors.lastname: Hunter
authors.affiliation: Institute für Physiologie II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany. Electronic address: shain@uni-muenster.de.
authors.forename: Victor
authors.initials: V
authors.lastname: Shahin
authors.affiliation: School of Medicine, Pharmacy and Health, Durham University, Queen's Campus, Stockton-on-Tees TS17 6BH, UK. Electronic address: moein.moghimi@gmail.com.
authors.forename: S Moein
authors.initials: SM
authors.lastname: Moghimi
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus; D004247:DNA / Q000737:chemistry*; D018014:Gene Transfer Techniques; D006801:Humans; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D022022:Nuclear Pore / Q000378:metabolism*; D009865:Oocytes; D010316:Particle Size; D011094:Polyethyleneimine / Q000737:chemistry; D014162:Transfection; D014982:Xenopus laevis
chemical_list: D011094:Polyethyleneimine; D004247:DNA
keywords: Atomic force microscopy; Nuclear envelope; Nuclear pore complex; Nucleic acid delivery; Oocytes; Polyethylenimine; Transmission electron microscopy