title: Formulation and delivery of siRNA by oleic acid and stearic acid modified polyethylenimine.
abstract: This study was conducted to formulate a nonviral delivery system for the delivery of small interfering RNA (siRNA) to B16 melanoma cells in vitro. For this purpose, oleic and stearic acid modified derivatives of branched polyethylenimine (PEI) were prepared and evaluated. The hydrophobically modified polymers increased siRNA condensation up to 3 folds as compared to the parent PEI. The modified PEIs exhibited up to 3-fold higher siRNA protection from degradation in fetal bovine serum as compared to the parent PEI. The formulated complexes were shown to enter B16 cells in a time-dependent fashion, reaching over 90% of the cells after 24 h, as compared to only 5% of the cells displaying siRNA uptake in the absence of any carrier. A proportional reduction in siRNA cell uptake was observed with reduced polymeric content in the formulations. When used to deliver various doses of siRNA to B16 cells, the modified PEIs were superior or comparable to some of the commercially available transfection agents; the hydrophobically modified polymers gave 3-fold increased siRNA delivery than the parent PEI, approximately 5-fold higher delivery than jetPEI and Metafectene, a comparable delivery to Lipofectamine 2000, but a 1.6-fold decreased delivery compared to INTERFERin, which was the most efficient reagent in our hands. Using an siRNA specific for integrin alpha(v), a dose-dependent decrease in integrin alpha(v) levels was demonstrated in B16 cells by flow cytometry, revealing a more pronounced reduction of integrin alpha(v) levels for oleic- and stearic-acid modified PEIs. The overall results suggested that the hydrophobically modified PEIs provide a promising delivery strategy for siRNA therapeutic applications.
authors.affiliation: University of Alberta, Edmonton T6G 2N8, Canada.
authors.forename: Aws
authors.initials: A
authors.lastname: Alshamsan
authors.forename: Azita
authors.initials: A
authors.lastname: Haddadi
authors.forename: Vanessa
authors.initials: V
authors.lastname: Incani
authors.forename: John
authors.initials: J
authors.lastname: Samuel
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Lavasanifar
authors.forename: Hasan
authors.initials: H
authors.lastname: Uludağ
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D039482:Integrin alpha5 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D015394:Molecular Structure; D019301:Oleic Acid / Q000737:chemistry* / Q000633:toxicity; D011094:Polyethyleneimine / Q000737:chemistry* / Q000633:toxicity; D034741:RNA, Small Interfering / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D044967:Serum / Q000378:metabolism; D013229:Stearic Acids / Q000737:chemistry* / Q000633:toxicity
chemical_list: D039482:Integrin alpha5; D034741:RNA, Small Interfering; D013229:Stearic Acids; D019301:Oleic Acid; C031183:stearic acid; D011094:Polyethyleneimine