title: Self-aggregating 1.8kDa polyethylenimines with dissolution switch at endosomal acidic pH are delivery carriers for plasmid DNA, mRNA, siRNA and exon-skipping oligonucleotides.
abstract: Efficiency of polyethylenimine (PEI) for nucleic acid delivery is affected by the size of the carrier and length of the nucleic acids. For instance, PEIs with molecular weights between 10-30kDa provide optimal DNA delivery activity whereas PEIs with molecular weights below 1.8kDa are ineffective. The activity of PEI is also severely diminished by substitution of DNA for shorter nucleic acids such as mRNA or siRNA. Here, through chemical modification of the primary amines to aromatic domains we achieved nucleic acid delivery by the 1.8kDa polyethylenimine (PEI) particles. This modification did not affect the PEI buffering abilities but enhanced its pH-sensitive aggregation, enabling stabilization of the polyplex outside the cell while still allowing nucleic acid release following cellular entry. The aromatic PEIs were then evaluated for their gene, mRNA, siRNA and 2'O-methyl phosphorothioate oligonucleotide in vitro transfection abilities. The salicylamide-grafted PEI showed to be a reliable carrier for delivering nucleic acids with cytoplasmic activity such as the mRNA and siRNA or nuclear diffusible oligonucleotide. It was then further equipped with polyethyleneglycol (PEG) and the delivery efficiency of the copolymer was tested in vivo for regeneration of dystrophin in the muscle of mdx mouse through a 2'O-methyl phosphorothioate-mediated splicing modulation. Intramuscular administration of polyplexes resulted in dystrophin-positive fibers in a mouse model of Duchenne muscular dystrophy without apparent toxicity. These findings indicate that precise modifications of low molecular weight PEI improve its bio-responsiveness and yield delivery vehicles for nucleic acids of various types in vitro and in vivo.
authors.affiliation: Molecular and Pharmaceutical Engineering of Biologics, CNRS - Université de Strasbourg UMR 7242, Boulevard Sebastien Brant, 67412 Illkirch, France; Faculté de Pharmacie - Université de Strasbourg, 74 Route du Rhin, F-67400 Illkirch, France.
authors.forename: Manuela
authors.initials: M
authors.lastname: Chiper
authors.affiliation: Faculté de Pharmacie - Université de Strasbourg, 74 Route du Rhin, F-67400 Illkirch, France; Laboratory of Therapeutic Innovation UMR 7200, CNRS - Université de Strasbourg, France.
authors.forename: Nassera
authors.initials: N
authors.lastname: Tounsi
authors.affiliation: Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, United States.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Kole
authors.affiliation: Faculté de Pharmacie - Université de Strasbourg, 74 Route du Rhin, F-67400 Illkirch, France; Laboratoire de Conception et d'Application de Molécules Bioactives, CNRS - Université de Strasbourg UMR 7199, France; Genethon, 91000 Evry, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Kichler
authors.affiliation: Molecular and Pharmaceutical Engineering of Biologics, CNRS - Université de Strasbourg UMR 7242, Boulevard Sebastien Brant, 67412 Illkirch, France. Electronic address: zuber@unistra.fr.
authors.forename: Guy
authors.initials: G
authors.lastname: Zuber
mesh_terms: D000818:Animals; D004247:DNA / Q000008:administration & dosage* / Q000235:genetics; D005091:Exons; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018101:Mice, Inbred mdx; D054735:Phosphorothioate Oligonucleotides / Q000008:administration & dosage* / Q000235:genetics; D010957:Plasmids / Q000008:administration & dosage* / Q000235:genetics; D011094:Polyethyleneimine / Q000737:chemistry*; D012333:RNA, Messenger / Q000008:administration & dosage* / Q000235:genetics; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics
chemical_list: D054735:Phosphorothioate Oligonucleotides; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011094:Polyethyleneimine; D004247:DNA
keywords: Delivery system; Exon-skipping; Gene delivery; Muscular dystrophy; Phosphorothioate RNA; Polyethylenimine (PEI); Transfection; mRNA delivery; mdx mice; siRNA delivery