title: Layer-by-layer deposition of oppositely charged polyelectrolytes on the surface of condensed DNA particles.
abstract: DNA can be condensed with an excess of poly-cations in aqueous solutions forming stable particles of submicron size with positive surface charge. This charge surplus can be used to deposit alternating layers of polyanions and polycations on the surface surrounding the core of condensed DNA. Using poly-L-lysine (PLL) and succinylated PLL (SPLL) as polycation and polyanion, respectively, we demonstrated layer-by-layer architecture of the particles. Polyanions with a shorter carboxyl/backbone distance tend to disassemble binary DNA/PLL complexes by displacing DNA while polyanions with a longer carboxyl/backbone distance effectively formed a tertiary complex. The zeta potential of such complexes became negative, indicating effective surface recharging. The charge stoichiometry of the DNA/PLL/SPLL complex was found to be close to 1:1:1, resembling poly-electrolyte complexes layered on macrosurfaces. Recharged particles containing condensed plasmid DNA may find applications as non-viral gene delivery vectors.
authors.affiliation: Mirus Corporation, 545 Science Drive, Madison, WI 53711, USA. vladimirt@genetransfer.com
authors.forename: V S
authors.initials: VS
authors.lastname: Trubetskoy
authors.forename: A
authors.initials: A
authors.lastname: Loomis
authors.forename: J E
authors.initials: JE
authors.lastname: Hagstrom
authors.forename: V G
authors.initials: VG
authors.lastname: Budker
authors.forename: J A
authors.initials: JA
authors.lastname: Wolff
mesh_terms: D000838:Anions / Q000378:metabolism*; D002412:Cations / Q000378:metabolism*; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004337:Drug Carriers; D004573:Electrolytes / Q000378:metabolism*; D005427:Flocculation; D018625:Microscopy, Atomic Force; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011107:Polylysine / Q000031:analogs & derivatives / Q000378:metabolism; D012995:Solubility; D014461:Ultracentrifugation; D014867:Water
chemical_list: D000838:Anions; D002412:Cations; D004337:Drug Carriers; D004573:Electrolytes; C060309:succinyl-polylysine; D014867:Water; D011107:Polylysine; D004247:DNA