title: Gene silencing efficiency of siRNA-PEG conjugates: effect of PEGylation site and PEG molecular weight.
abstract: Small interfering RNA (siRNA) was conjugated with poly(ethylene glycol) (PEG) at four different terminal ends (sense 3', sense 5', antisense 3', and antisense 5') via cleavable disulfide and noncleavable thioether linkages to evaluate their gene silencing efficiencies upon complexation with Lipofectamine2000. The PEGylation site at the four siRNA termini and PEG molecular weight were not critical factors to significantly affect gene silencing activities. Cleavable siRNA-PEG conjugates showed comparable gene silencing activities to naked siRNA, and exhibited sequence-specific degradation of a target mRNA. Interestingly, noncleavable siRNA-PEG conjugates were processed by Dicer, enabling to exert RNAi effect without showing a target sequence-specific manner. However, only cleavable siRNA-PEG conjugates significantly reduced the extent of INF-alpha release as compared to noncleavable siRNA-PEG conjugates, suggesting that they can be potentially used for therapeutic siRNA applications.
authors.affiliation: Department of Biological Sciences and Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea.
authors.forename: Sooyeon
authors.initials: S
authors.lastname: Jung
authors.forename: Soo Hyeon
authors.initials: SH
authors.lastname: Lee
authors.forename: Hyejung
authors.initials: H
authors.lastname: Mok
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Chung
authors.forename: Tae Gwan
authors.initials: TG
authors.lastname: Park
mesh_terms: D045744:Cell Line, Tumor; D004337:Drug Carriers / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D020868:Gene Silencing / Q000187:drug effects*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D016898:Interferon-alpha / Q000378:metabolism; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D043244:Ribonuclease III / Q000235:genetics; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
chemical_list: D004337:Drug Carriers; D016898:Interferon-alpha; D034741:RNA, Small Interfering; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D049452:Green Fluorescent Proteins; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol; D043244:Ribonuclease III