title: Effective small interfering RNA delivery in vitro via a new stearylated cationic peptide.
abstract: A crucial bottleneck in RNA interference-based gene therapy is the lack of safe and efficient delivery systems. Here, a novel small interfering RNA (siRNA) delivery peptide, STR-HK, was constructed by conjugating a stearyl end to the N-terminus of the peptide sequence HHHPKPKRKV, where PKPKRKV is an altered sequence of the nucleus localization signal (PKKKRKV) and contributes to the cytosol localization of STR-HK-siRNA complexes. Histidine is a linker and plays an important role in disrupting the endosomal membrane via the proton sponge effect. As expected, STR-HK formed complexes with siRNA with a particle size of 80-160 nm in diameter and efficiently delivered Cy3-labeled glyceraldehyde 3-phosphate dehydrogenase siRNA into PC-3 human prostate cancer cells. The transfection efficiency of STR-HK at molar ratio of 60/1 was comparable to that of Lipofectamine 2000, one of the most efficient commercially available transfection reagents. Furthermore, the STR-HK-siRNA complexes exhibited minimal cytotoxicity, which was significantly lower than that of Lipofectamine. Taken together, the strategy of conjugating the stearyl moiety with HHHPKPKRKV as a non-viral siRNA delivery system is advantageous.
authors.affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada ; Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada.
authors.forename: Baoling
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada ; Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada.
authors.forename: Ran
authors.initials: R
authors.lastname: Pan
authors.affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada.
authors.forename: Diana
authors.initials: D
authors.lastname: Askhatova
authors.affiliation: Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada ; Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Chen
mesh_terms: D002412:Cations; D045744:Cell Line, Tumor; D015316:Genetic Therapy; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry / Q000493:pharmacokinetics; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics; D014162:Transfection / Q000379:methods*
chemical_list: D002412:Cations; D010455:Peptides; D034741:RNA, Small Interfering
keywords: RNA interference; cellular uptake; cytotoxicity; gene silencing; physicochemical characterization