title: Effect of polyethyleneglycol spacer on the binding properties of nuclear localization signal-modified liposomes to isolated nucleus.
abstract: The nuclear delivery process is a crucial barrier to successful gene delivery, especially in non-dividing cells. We previously proposed a novel strategy for the nuclear delivery of plasmid DNA (pDNA), in which the pDNA is encapsulated in lipid bilayers that had been modified with nucleus-targeting signals, including nuclear localizing signals derived from SV40 (NLS) or sugar units. In the present study, we report on an investigation of the effect of the topology of the liposome-modified NLS on its ability to bind to the isolated nucleus. NLS was directly attached to a liposome (NLS-Lip) by incorporating stearylated NLS (STR-NSL), or by modification with a polyethyleneglycol (PEG) spacer (NLS-PEG-Lip). NLS-unmodified liposomes (PEG-Lip) were used as a control. The liposomes, after labeling with 7-nitrobenz-2-oxa-1,3-diazole (NBD), were incubated with a cell homogenate derived from JAWS II cells, followed by isolation of the nuclear fraction by centrifugation. The PEG-Lip preparation showed negligible binding to the nucleus. In contrast, the binding of NLS-Lips to the nucleus gradually increased in a STR-NLS density-dependent manner. Interestingly, the binding of NLS-PEG-Lips to the nucleus is highly effective even at low density, suggesting that the presence of the PEG spacer is an important factor in improving the binding activity of NLS-modified liposomes to the nucleus. This information will be useful for the design of nucleus-targeting carriers.
authors: Faculty of Pharmaceutical Sciences, Hokkaido University.
authors: Dai
authors: D
authors: Kurihara
authors: Hidetaka
authors: H
authors: Akita
authors: Asako
authors: A
authors: Kudo
authors: Tomoya
authors: T
authors: Masuda
authors: Shiroh
authors: S
authors: Futaki
authors: Hideyoshi
authors: H
authors: Harashima
mesh_terms: D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004247:DNA / Q000008:administration & dosage / Q000235:genetics*; D004337:Drug Carriers / Q000494:pharmacology*; D018014:Gene Transfer Techniques; D008081:Liposomes; D051379:Mice; D019913:Nuclear Localization Signals / Q000235:genetics*; D022022:Nuclear Pore / Q000378:metabolism; D010957:Plasmids; D011092:Polyethylene Glycols / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004337:Drug Carriers; D008081:Liposomes; D019913:Nuclear Localization Signals; D011092:Polyethylene Glycols; D004247:DNA