title: Negatively charged self-assembling DNA/poloxamine nanospheres for in vivo gene transfer.
abstract: Over the past decade, numerous nonviral cationic vectors have been synthesized. They share a high density of positive charges and efficiency for gene transfer in vitro. However, their positively charged surface causes instability in body fluids and cytotoxicity, thereby limiting their efficacy in vivo. Therefore, there is a need for developing alternative molecular structures. We have examined tetrabranched amphiphilic block copolymers consisting of four polyethyleneoxide/polypropyleneoxide blocks centered on an ethylenediamine moiety. Cryo-electron microscopy, ethidium bromide fluorescence and light and X-ray scattering experiments performed on vector-DNA complexes showed that the dense core of the nanosphere consisted of condensed DNA interacting with poloxamine molecules through electrostatic, hydrogen bonding and hydrophobic interactions, with DNA molecules also being exposed at the surface. The supramolecular organization of block copolymer/DNA nanospheres induced the formation of negatively charged particles. These particles were stable in a solution that had a physiological ionic composition and were resistant to decomplexation by heparin. The new nanostructured material, the structure of which clearly contrasted with that of lipoplexes and polyplexes, efficiently transferred reporter and therapeutic genes in skeletal and heart muscle in vivo. Negatively charged supramolecular assemblies hold promise as therapeutic gene carriers for skeletal and heart muscle-related diseases and expression of therapeutic proteins for local or systemic uses.
authors.affiliation: L'institut du Thorax, Inserm U533, Faculté de Médecine, 44035 Nantes, France. bruno.pitard@nantes.inserm.fr
authors.forename: Bruno
authors.initials: B
authors.lastname: Pitard
authors.forename: Mahajoub
authors.initials: M
authors.lastname: Bello-Roufaï
authors.forename: Olivier
authors.initials: O
authors.lastname: Lambert
authors.forename: Peggy
authors.initials: P
authors.lastname: Richard
authors.forename: Léa
authors.initials: L
authors.lastname: Desigaux
authors.forename: Sarah
authors.initials: S
authors.lastname: Fernandes
authors.forename: Caroline
authors.initials: C
authors.lastname: Lanctin
authors.forename: Hélène
authors.initials: H
authors.lastname: Pollard
authors.forename: Mehdi
authors.initials: M
authors.lastname: Zeghal
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Rescan
authors.forename: Denis
authors.initials: D
authors.lastname: Escande
mesh_terms: D000818:Animals; D020285:Cryoelectron Microscopy; D004247:DNA / Q000008:administration & dosage* / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D005260:Female; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods*; D051379:Mice; D018101:Mice, Inbred mdx; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D043942:Nanotubes / Q000737:chemistry / Q000648:ultrastructure; D011092:Polyethylene Glycols / Q000737:chemistry*; D051381:Rats; D014961:X-Ray Diffraction
chemical_list: D005029:Ethylenediamines; D011092:Polyethylene Glycols; D004247:DNA