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Lin D.,Tianjin University | Huang Y.,Beijing Institute of Technology | Jiang Q.,Beijing Institute of Technology | Zhang W.,Tianjin University | And 8 more authors.
Biomaterials | Year: 2011

The multiformity in polymer structure and conformation design provides a great potential in improving the gene silencing efficiency of siRNA by polymer vectors. In order to provide information on the polymer design for siRNA delivery, the structural contributions of blocked or grafted poly(2-dimethylaminoethyl methacrylate) on PEGylated polycaprolactone nanoparticles (NPs) in siRNA delivery were studied. Herein, two kinds of self-assembly nanoparticles (NPs) formed by amphiphilic cationic polymers, methoxy poly(ethylene glycol)-block-polycaprolactone-block-poly(2-dimethylaminoethyl methacrylate) (mPEG-PCL-b-PDMAEMA, PEC. bD) and methoxy poly(ethylene glycol)-block-(polycaprolactone-graft-poly(2-dimethylaminoethyl methacrylate)) (mPEG-PCL-g-PDMAEMA, PEC. gD), were used to deliver siRNA for in vitro and in vivo studies. The physiochemical properties including size and zeta potential of PEC. bD NPs/siRNA and PEC. gD NPs/siRNA complexes were characterized. In vitro cytotoxicity, cellular uptake and siRNA knockdown efficiency were evaluated in HeLa-Luc cells. The endosome escape and intracellular distribution of PEC. bD NPs/siRNA and PEC. gD NPs/siRNA in HeLa-Luc cells were also observed. In vivo polymer mediated siRNA delivery and the complexes distribution in isolated organs were studied using mice and tumor-bearing mice. At the same total degree of polymerization (DP) of DMAEMA, PEC. gD NPs/siRNA complexes possessed higher zeta potentials than PEC. bD NPs/siRNA complexes (at the same N/P ratio), which may be the reason that PEC. gD NPs/siRNA complexes can deliver more siRNA into the cytoplasm and lead to higher in vitro luciferase and lamin A/C silencing efficiency than PEC. bD NPs/siRNA complexes. The in vivo imaging measurement and histochemical analysis also confirmed that siRNA could be delivered to lungs, livers, pancreas and HeLa-Luc tumors more efficiently by PEC. gD NPs than PEC. bD NPs. Meanwhile, the PDMAEMA chains of PEC. gD could be shortened which provides benefits for clearing. Therefore, PEC. gD NPs have great potential to be used as efficient non-viral carriers for in vivo siRNA delivery. © 2011 Elsevier Ltd. Source

Cheng Q.,Peking University | Huang Y.,Peking University | Zheng H.,Jiangnan University | Wei T.,National Center for Nanosciences and Technology of China | And 10 more authors.
Biomaterials | Year: 2013

Small interfering RNA (siRNA) has a huge potential for the treatment or prevention of various diseases. However, to realize the therapeutic potential of siRNA drugs, efficient, tissue-specific and safe delivery technologies must be developed. Here we synthesized two kinds of polymers (PEGylated poly(2-aminoethyl methacrylate) labeled as PEG-b-PAEM or PEA, and guanidinylated PEGylated poly(2-aminoethyl methacrylate) marked as PEG-b-PAEM-co-PGEM or PEAG) using atom transfer radical polymerization and evaluated their capability of mediating siRNA delivery in vitro and in vivo. Both polymers presented excellent siRNA encapsulation ability, formed regular nanostructures with siRNA, robustly mediated cellular internalization and cytoplasmic localization of siRNA, and resulted in targeted gene knockdown efficiently. However, PEAG showed much more outstanding abilities referring to above evaluating indicators compared with PEA. Both PEA/siRNA and PEAG/siRNA polyplexes displayed strong liver, lung and spleen accumulation in mice for a long time after intravenous administration. PEAG/siApoB polyplexes (single dose at 1 mg/kg) further repressed ApoB expression in liver and resulted in block of lipid transportation. In addition, both polymers delivered high amounts of siRNA into tumor tissue in the Hela-Luc xenograft murine model. More siRNA accumulated in tumor with the increase of N/. P ratio and PEAG/siRNA polyplexes showed higher siRNA accumulation than PEA/siRNA polyplexes at the same N/. P ratio. These findings set the stage for further studies of structural-functional mechanisms and developments of siRNA therapeutics. © 2013 . Source

Hong J.,Peking University | Huang Y.,Peking University | Li J.,Peking University | Yi F.,Peking University | And 11 more authors.
FASEB Journal | Year: 2010

Double-stranded small interfering RNAs (siRNAs) are important modulators of biological processes and hold great promise for therapeutic applications. However, serum processing of synthetic siRNAs is still largely unknown. To address this issue, serum degradation assays of 125 siRNAs were first performed in this study. Four siRNA categories of distinct serum stability were identified, including a group of siRNAs that were stable in their native form for both in vitro and in vivo assays. Fine mapping of the cleavage events occurring in serum treatment demonstrated that most occurred at two vulnerable sites, leading to a speculation that rational modification of these sites might protect most siRNAs from serum degradation. For proof of concept, an exhaustive siRNA modification study was performed. In addition to the consistent stabilization pattern revealed at these sites, our study further showed that a single modification made at the cleavage site stabilized the siRNAs to a large extent, highlighting the importance of these sites in siRNA degradation. In summary, the present study provided a comprehensive picture of serum processing of siRNA as well as a starting point for a rational siRNA modification strategy, both of which are of great importance to in vivo and therapeutic applications of siRNA. © FASEB. Source

Inhibitors that can inhibit expression of FAM3B gene to reduce the levels of expression products, or can combine the expression products to reduce the activity of promoting lipid synthesis of FAM3B gene product are provided, wherein the inhibitors are one or more inhibitors selected from the group consisting of small interfering RNAs, antisense oligonucleotides, antibodies against FAM3B proteins and active organic compounds. Cells, vectors or inhibitor compositions, comprising such inhibitors, methods for inhibiting expression of FAM3B gene or inhibiting the activity of promoting lipid synthesis of FAM3B gene product using the inhibitors are provided. Methods for treating diseases mediated by expression of FAM3B gene using such inhibitors and uses of the inhibitors in preparing pharmaceuticals for preventing and/or treating the disease mediated by FAM3B gene expression are also provided.

Suzhou Ribo Life Science Co. | Date: 2012-09-10

Provided are a double-stranded nucleic acid and use thereof in ribonuclease detection, and a ribonuclease detection method and use thereof in tumor detection and/or diagnosis. Specifically, a double-stranded nucleic acid substrate comprises at least one ribonuclease sensitive site. The activity and content of the ribonuclease in a sample are detected by analyzing the degradation of the double-stranded nucleic acid substrate by the ribonuclease. Also provided are a ribonuclease detection kit and a tumor detection kit.

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