title: Octaarginine-modified multifunctional envelope-type nano device for siRNA.
abstract: The multifunctional envelope-type nano device (MEND) is a novel non-viral gene delivery system for plasmid DNA (pDNA) and oligodeoxynucleotides (ODN). We showed previously that octaarginine-modified MEND (R8-MEND) produces a high transfection activity without cytotoxicity via macropinocytosis and efficient release of a condensed DNA core to the cytosol. In the present study, we succeeded in developing an efficient method for packaging siRNA into the R8-MEND, and its silencing effect was compared with that of transfection reagent TransIT-TKO. A polycation able to condense siRNA was screened for by measuring the size and zeta-potential of complexes formed between siRNA and the polycations poly-l-lysine (PLL), stearyl octaarginine (STR-R8) and protamine. Only STR-R8 was able to condense siRNA to form nano particles (<100 nm), whereas all three polycations were able to condense pDNA or ODN. The siRNA packaged in R8-MEND inhibited luciferase activity by more than 80% in HeLa cells stably expressing luciferase. Much amount of siRNA was internalized into the cells as R8-MEND, and siRNA was effectively released from lipid envelope of MEND to cytoplasm near the nucleus. Consequently, R8-MEND can deliver condensed siRNA into cells to produce an efficient and persistent silencing effect with minimum cytotoxicity.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kogure
authors.forename: Shiroh
authors.initials: S
authors.lastname: Futaki
authors.forename: Hideyoshi
authors.initials: H
authors.lastname: Harashima
mesh_terms: D004339:Drug Compounding; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry; D011479:Protamines / Q000737:chemistry; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D014162:Transfection
chemical_list: D009842:Oligopeptides; D011479:Protamines; D034741:RNA, Small Interfering; C448619:octaarginine; D011107:Polylysine; D008156:Luciferases