title: Conjugation of siRNA with comb-type PEG enhances serum stability and gene silencing efficiency.
abstract: A thiol-modified siRNA targeting the enhanced green fluorescence protein (eGFP) gene was conjugated with RAFT-synthesized, pyridyl disulfide-functional poly(PEG methyl ether acrylate)s (p(PEGA)s). siRNA-p(PEGA) conjugates demonstrated significantly enhanced in vitro serum stability and nuclease resistance compared to the unmodified and thiol-modified siRNA. The complexes of siRNA-p(PEGA) conjugates with a fusogenic peptide, KALA ((+)/(-) = 2) inhibited the protein expression approximately 28-fold more than the KALA complex of the unmodified siRNA. The protein inhibition caused by siRNA-p(PEGA)-KALA complexes (56 ± 5%-58 ± 3% of the fluorescence expressed in non-treated cells) was comparable to the effect of the unmodified siRNA-lipofectamine complex (77 ± 7%).
authors.affiliation: School of Biotechnology and Biomolecular Sciences (BABS), The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Gunasekaran
authors.forename: Thi H
authors.initials: TH
authors.lastname: Nguyen
authors.forename: Heather D
authors.initials: HD
authors.lastname: Maynard
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Davis
authors.forename: Volga
authors.initials: V
authors.lastname: Bulmus
mesh_terms: D002460:Cell Line; D045744:Cell Line, Tumor; D020868:Gene Silencing; D015316:Genetic Therapy / Q000295:instrumentation*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D011092:Polyethylene Glycols / Q000737:chemistry*; D020871:RNA Stability; D034741:RNA, Small Interfering / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism*; D044967:Serum / Q000201:enzymology*
chemical_list: D034741:RNA, Small Interfering; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D011092:Polyethylene Glycols; D012260:Ribonucleases