Cationic and anionic lipoplexes inhibit gene transfection by electroporation in vivo.
BACKGROUND
Nonviral gene therapy still suffers from low efficiency. Methods that would lead to higher gene expression level of longer duration would be a major advance in this field. Lipidic vectors and physical methods have been investigated separately, and both induced gene expression improvement.


METHODS
We sought to combine both chemical and physical methods. Cationic or anionic lipids can potentially destabilize the cell membrane and could consequently enhance gene delivery by a physical method such as electrotransfer. A plasmid model encoding luciferase was used, either free or associated with differently-charged lipoplexes before electrotransfer.


RESULTS
Electrotransfer alone strongly enhanced gene expression after intramuscular and intradermal injection of naked DNA. On the other hand, cationic and anionic lipoplex formulations decreased gene expression after electrotransfer, whereas poorly-charged thiourea-based complexes, brought no benefit. Pre-injection of the lipids, followed by administration of naked DNA, did not modified gene expression induced by electroporation in the skin.


CONCLUSIONS
The results obtained in the present study suggest that packing of DNA plasmid in lipoplexes strongly decreases the efficiency of gene electrotransfer, independently of the lipoplex charge. Non-aggregating complexes, such as poorly-charged thiourea-based complexes, should be preferred to increase DNA release.
Mignet
Nathalie
N
Inserm U1022- CNRS UMR8151, Paristech, Unité de Pharmacologie Chimique et Génétique et d'Imagerie, Université Paris Descartes, Paris, France. nathalie.mignet@parisdescartes.fr
Vandermeulen
Gaëlle
G
Pembouong
Gaëlle
G
Largeau
Céline
C
Thompson
Betty
B
Spanedda
Maria-Vittoria
MV
Wasungu
Luc
L
Rols
Marie-Pierre
MP
Bessodes
Michel
M
Bureau
Michel F
MF
Préat
Véronique
V
Scherman
Daniel
D
D000818:Animals; D016466:CHO Cells; D002412:Cations / Q000737:chemistry* / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000737:chemistry; D018274:Electroporation / Q000379:methods*; D005260:Female; D018014:Gene Transfer Techniques; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology; D010957:Plasmids / Q000737:chemistry / Q000235:genetics; D012867:Skin / Q000166:cytology / Q000378:metabolism; D014162:Transfection
D002412:Cations; D008081:Liposomes; D004247:DNA