title: Comparison of polymeric siRNA nanocarriers in a murine LPS-activated macrophage cell line: gene silencing, toxicity and off-target gene expression.
abstract: OBJECTIVE
  Tumor necrosis factor α (TNF-α) plays a key role in the progression of rheumatoid arthritis and is an important target for anti-rheumatic therapies. TNF-α expression can be silenced with small interfering RNA (siRNA), but efficacy is dependent on efficient and safe siRNA delivery vehicles. We aimed to identify polymeric nanocarriers for anti-TNF-α siRNA with optimal efficacy and minimal off-target effects in vitro.
  
  
  METHODS
  TNF-α silencing with polymeric siRNA nanocarriers was compared in lipopolysaccharide-activated RAW 264.7 macrophages by real-time reverse transcription (RT)-PCR. Expression of non-target genes involved in inflammation, apoptosis, and cell cycle progression was determined by RT-PCR, toxicity evaluated by propidium iodide and annexin V staining.
  
  
  RESULTS
  PAMAM dendrimers (G4 and G7) and dextran nanogels mediated remarkably high concentration-dependent gene silencing and low toxicity; dioleoyltrimethylammoniumpropane-modified poly(DL-lactide-co-glycolide acid) nanoparticles, thiolated, trimethylated chitosan and poly[(2-hydroxypropyl)methacrylamide 1-methyl-2-piperidine methanol] polyplexes were less efficient transfectants. There were minor changes in the regulation of off-target genes, mainly dependent on nanocarrier and siRNA concentration.
  
  
  CONCLUSIONS
  Dextran nanogels and PAMAM dendrimers mediated high gene silencing with minor toxicity and off-target transcriptional changes and are therefore expected to be suitable siRNA delivery systems in vivo.
authors.affiliation: Department of Pharmaceutics and Analytical Chemistry Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100, Copenhagen O, Denmark.
authors.forename: Linda B
authors.initials: LB
authors.lastname: Jensen
authors.forename: Joscha
authors.initials: J
authors.lastname: Griger
authors.forename: Broes
authors.initials: B
authors.lastname: Naeye
authors.forename: Amir K
authors.initials: AK
authors.lastname: Varkouhi
authors.forename: Koen
authors.initials: K
authors.lastname: Raemdonck
authors.forename: Raymond
authors.initials: R
authors.lastname: Schiffelers
authors.forename: Twan
authors.initials: T
authors.lastname: Lammers
authors.forename: Gert
authors.initials: G
authors.lastname: Storm
authors.forename: Stefaan C
authors.initials: SC
authors.lastname: de Smedt
authors.forename: Brian S
authors.initials: BS
authors.lastname: Sproat
authors.forename: Hanne M
authors.initials: HM
authors.lastname: Nielsen
authors.forename: Camilla
authors.initials: C
authors.lastname: Foged
mesh_terms: D000818:Animals; D002460:Cell Line; D050091:Dendrimers / Q000378:metabolism; D003911:Dextrans / Q000378:metabolism; D004337:Drug Carriers / Q000378:metabolism*; D015870:Gene Expression; D020868:Gene Silencing; D008070:Lipopolysaccharides / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D000080385:Nanogels; D011092:Polyethylene Glycols / Q000378:metabolism; D011094:Polyethyleneimine / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D050091:Dendrimers; D003911:Dextrans; D004337:Drug Carriers; D008070:Lipopolysaccharides; D000080385:Nanogels; C104700:PAMAM Starburst; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; D011094:Polyethyleneimine