Intracellular delivery of nanometric DNA particles via the folate receptor.
The size of condensed DNA particles is a key determinant for both diffusion to target cells in vivo and intracellular trafficking. The smallest complexes are obtained when each DNA molecule collapses individually. This was achieved using a designed cationic thiol-detergent, tetradecyl-cysteinyl-ornithine (C(14)COrn). The resulting particles were subsequently stabilized by air-induced dimerization of the detergent into a disulfide lipid on the DNA template. Particles are anionic (zeta potential = -45 mV), and their size (30 nm) corresponds to the volume of a single plasmid DNA molecule. The electrophoretic mobility of the condensed DNA, though quasi-neutralized, was found higher than that of the extended DNA. Moreover, the dimerized (C(14)COrn)(2) lipid was found to be an efficient transfection reagent for various cell lines. In an attempt to achieve extended circulation times and to target tumors by systemic delivery, we have coated the particles with PEG-folate residues. Plasmid DNA was condensed into monomolecular particles as described above and coated by simple mixing with DPPE-PEG-folate. Physicochemical measurements showed particles coated with 2% of DPPE-PEG(3400)-folate remain monomolecular and are stable in the cell-culture medium. Caveolae-mediated cell entry was demonstrated by ligand-dependence, by competition with excess folic acid as well as by confocal microscopy.
Laboratoire de Chimie Génétique associé CNRS/Université Louis Pasteur de Strasbourg, Faculté de Pharmacie BP 24, 67401 Illkirch, France.
Emmanuel
E
Dauty
Jean-Serge
JS
Remy
Guy
G
Zuber
Jean-Paul
JP
Behr
D016475:3T3 Cells; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D021941:Caveolae / Q000378:metabolism; D004247:DNA / Q000493:pharmacokinetics*; D003902:Detergents / Q000737:chemistry; D016503:Drug Delivery Systems; D024202:Electrophoretic Mobility Shift Assay; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000737:chemistry; D051379:Mice; D036103:Nanotechnology; D010316:Particle Size; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011956:Receptors, Cell Surface; D014162:Transfection / Q000379:methods* / Q000592:standards
D002352:Carrier Proteins; C102564:DPPE-PEG2000; D003902:Detergents; D058973:Folate Receptors, GPI-Anchored; D010714:Phosphatidylethanolamines; D011956:Receptors, Cell Surface; D011092:Polyethylene Glycols; D004247:DNA; D005492:Folic Acid