title: Multifunctional triblock co-polymer mP3/4HB-b-PEG-b-lPEI for efficient intracellular siRNA delivery and gene silencing.
abstract: A non-viral siRNA carrier composed of mono-methoxy-poly (3-hydroxybutyrate-co-4-hydroxybutyrate)-block-polyethylene glycol-block-linear polyethyleneimine (mP3/4HB-b-PEG-b-lPEI) was synthesized using 1800 Da linear polyethyleneimine and evaluated for siRNA delivery. Our study demonstrated that siRNA could be efficiently combined with mP3/4HB-b-PEG-b-lPEI (mAG) co-polymer and was protected from nuclease degradation. The combined siRNA were released from the complexes easily under heparin competition. The particle size of the mAG/siRNA complexes was 158 nm, with a ζ-potential of around 28 mV. Atomic force microscopy images displayed spherical and homogeneously distributed complexes. The mAG block co-polymer displayed low cytotoxicity and efficient cellular uptake of Cy3-siRNA in A549 cells by flow cytometry and confocal microscopy. In vitro transfection efficiency of the block co-polymer was assessed using siRNA against luciferase in cultured A549-Luc, HeLa-Luc, HLF-Luc, A375-Luc and MCF-7-Luc cells. A higher transfection efficiency and lower cytotoxicity was obtained by mAG block co-polymer in five cell lines. Furthermore, a remarkable improvement in luciferase gene silencing efficiency of the mAG complex (up to 90-95%) over that of Lipofectamine™ 2000 (70-82%) was observed in HLF-Luc and A375-Luc cells. Additionally, a mAG/p65-siRNA complex also showed a better capability than Lipofectamine™ 2000/p65-siRNA complex to drastically reduce the p65 mRNA level down to 10-16% in HeLa, U251 and HUVEC cells at an N/P ratio of 70.
authors.affiliation: Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Chen
authors.forename: Feifei
authors.initials: F
authors.lastname: Wang
authors.forename: Xiuqun
authors.initials: X
authors.lastname: Yang
authors.forename: Biliang
authors.initials: B
authors.lastname: Zhang
mesh_terms: D004058:Diffusion; D020868:Gene Silencing; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000031:analogs & derivatives* / Q000737:chemistry; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics*; D014162:Transfection / Q000379:methods*
chemical_list: D053769:Nanocapsules; D011091:Polyesters; D034741:RNA, Small Interfering; C570666:poly(3-hydroxypropionate-co-4-hydroxybutyrate); C544016:poly(ethylene glycol)-co-poly(ethyleneimine); D011092:Polyethylene Glycols; D011094:Polyethyleneimine