title: How to make siRNA lipoplexes efficient? Add a DNA cargo.
abstract: BACKGROUND
  We recently reported an efficient formulation of siRNA targeting TNF-alpha, that was able to restore immunological balance in a mouse arthritis model following intravenous injection.
  
  
  METHODS
  Since this efficient formulation included the pre association of siRNA with a DNA cargo, we decided to extensively characterise siRNA lipoplexes with or without DNA cargo, in order to better understand the DNA cargo enhancing effect.
  
  
  RESULTS
  We showed that addition of DNA cargo to siRNA lipoplexes led to specific gene extinction in vitro, using reduced siRNA concentration. This procedure is also applicable to other lipid vectors, like Lipofectamine or DMRIE-C. No structural modification could be observed in siRNA lipoplexes upon addition of DNA cargo using dynamic light scattering or transmission electronic microscopy. Nevertheless, we observed some slight differences, in the amount of lipid required to obtain neutrality of the complex and in stability of the complex towards incubation with heparan sulfate.
  
  
  CONCLUSIONS
  These results suggest that the addition of DNA cargo to siRNA complexes is an easy procedure that leads to more efficient complexes to transfer siRNA at low concentration and in the presence of serum.
authors.affiliation: Inserm, U640, Paris, F-75006 France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Rhinn
authors.forename: Céline
authors.initials: C
authors.lastname: Largeau
authors.forename: Pascal
authors.initials: P
authors.lastname: Bigey
authors.forename: René Lai
authors.initials: RL
authors.lastname: Kuen
authors.forename: Magali
authors.initials: M
authors.lastname: Richard
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherman
authors.forename: Virginie
authors.initials: V
authors.lastname: Escriou
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004337:Drug Carriers / Q000737:chemistry*; D004355:Drug Stability; D005822:Genetic Vectors; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D051379:Mice; D034741:RNA, Small Interfering / Q000737:chemistry* / Q000235:genetics; D014162:Transfection / Q000379:methods*; D014407:Tumor Cells, Cultured
chemical_list: D004337:Drug Carriers; D008055:Lipids; D008081:Liposomes; D034741:RNA, Small Interfering; D004247:DNA