Negatively charged self-assembling DNA/poloxamine nanospheres for in vivo gene transfer.
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.
Pitard
Bruno
B
L'institut du Thorax, Inserm U533, Faculté de Médecine, 44035 Nantes, France. bruno.pitard@nantes.inserm.fr
Bello-Roufaï
Mahajoub
M
Lambert
Olivier
O
Richard
Peggy
P
Desigaux
Léa
L
Fernandes
Sarah
S
Lanctin
Caroline
C
Pollard
Hélène
H
Zeghal
Mehdi
M
Rescan
Pierre-Yves
PY
Escande
Denis
D
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
D005029:Ethylenediamines; D011092:Polyethylene Glycols; D004247:DNA