title: Imaging in solution of (Lys)(16)-containing bifunctional synthetic peptide/DNA nanoparticles for gene delivery.
abstract: The physical properties of non-viral vector/DNA nanoparticles in physiological aqueous solution are poorly understood. A Fluid Particle Image Analyser (FPIA), normally used for analysis of industrial and environmental fluids, was used to visualise individual (Lys)(16)-containing peptide/DNA particles. Eight (Lys)(16)-containing synthetic peptides were used to generate peptide/DNA particles at a constant + to - charge ratio of 2.8:1 with 10 microg/ml of plasmid DNA in phosphate buffered saline. Dynamic Light Scattering (DLS) and gene delivery studies were also performed. We present the first images of non-viral vector/DNA nanoparticles in physiological aqueous solution, together with precise measurements of individual particle size and shape in solution and, for the first time, an accurate measure of particle number. Particle size and shape, particle number, and efficiency for gene delivery varied markedly with different peptides. Under standard conditions for in vitro gene delivery, we estimate approximately 60 peptide/DNA nanoparticles per target cell, each containing approximately 70,000 plasmids. This novel capacity to image individual vector/DNA nanoparticles in solution and to count them accurately will enable a more precise assessment of non-viral gene delivery systems, and a more quantitative interpretation of gene delivery experiments.
authors.affiliation: Department of Clinical Sciences, Rayne Institute, King's Denmark Hill Campus, 123 Coldharbour Lane, London SE5 9NU, UK.
authors.forename: Louise
authors.initials: L
authors.lastname: Collins
authors.forename: Michael
authors.initials: M
authors.lastname: Kaszuba
authors.forename: John W
authors.initials: JW
authors.lastname: Fabre
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D003435:Crotalid Venoms / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000737:chemistry* / Q000378:metabolism; D016023:Integrins / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011107:Polylysine / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D003435:Crotalid Venoms; D016023:Integrins; D010446:Peptide Fragments; C458882:polylysine-molossin peptide; D011107:Polylysine; D004247:DNA