pH-responsive polymeric micelle carriers for siRNA drugs.
pH-responsive polymeric micelle carriers for siRNA drugs.
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DOI：
10.1021/bm100652w
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发表时间：
2010-11-08
影响因子：
6.2
通讯作者：
Stayton, P. S.
中科院分区：
文献类型：
--
作者：
Convertine, A. J.;Diab, C.;Prieve, M.;Paschal, A.;Hoffman, A. S.;Johnson, P. H.;Stayton, P. S.
小干扰RNA(SiRNA)有效沉默特定基因表达的能力为基于RNA干扰(RNAi)的新疗法提供了基础。有效地从细胞摄取通过内体转运途径将siRNA输送到细胞质仍然是一个巨大的挑战。在此之前，我们利用可控的可逆加成断裂链转移(RAFT)聚合方法合成了一类新型的两嵌段共聚物siRNA载体。载体由一个带正电的甲基丙烯酸二甲氨基乙酯(DMAEMA)和第二个pH响应型内体释放块组成，后者由DMAEMA和丙基丙烯酸(PAA)按大致等摩尔比组成，以及甲酸丁酯(BMA)。在这里，我们描述了基于这种设计的新一代siRNA递送聚合物的开发，该聚合物具有更高的转染率和低的细胞毒性。这种设计结合了更长的内溶段，增加了疏水含量，以诱导胶束形成。通过动态光散射、核磁共振氢谱、电子显微镜和将小分子芘选择性地分配到疏水胶束核中，这些聚合物自发形成40 nm的球形胶束，临界胶束浓度(Cmc)约为2μg/ml。与阳离子壳层嵌段结合的siRNA不会扰乱胶束的稳定性，也不会显着增加颗粒尺寸。研究表明，当siRNA浓度低至12.5 nM时，两嵌段共聚物自组装成颗粒可显著增强mRNA的敲除作用。在这些条件下，基于胶束的系统显示出89%的GAPDHmRNA水平降低，而非胶束系统仅降低23%(10 NM SiRNA)。随着siRNA浓度增加到25 nM或更高，mRNA水平的降低几乎是定量的。流式细胞术分析显示，90%的细胞摄取荧光标记的siRNA，与标准的脂质转染剂相比，每个细胞的siRNA增加了3倍。这些结果证明了这种载体设计在siRNA药物输送方面的潜在用途。
The ability of small interfering RNA (siRNA) to efficiently silence the expression of specific genes provides the basis for exciting new therapies based on RNA interference (RNAi). The efficient intracellular delivery of siRNA from cell uptake through the endosomal trafficking pathways into the cytoplasm remains a significant challenge. Previously we described the synthesis of a new family of diblock copolymer siRNA carriers using controlled reversible addition fragmentation chain transfer (RAFT) polymerization. The carriers were composed of a positively-charged block of dimethylaminoethyl methacrylate (DMAEMA) to mediate siRNA binding and a second pH-responsive endosome releasing block composed of DMAEMA and propylacrylic acid (PAA) in roughly equimolar ratios, and butyl methacylate (BMA). Here we describe the development of a new generation of siRNA delivery polymers based on this design that exhibit enhanced transfection efficiency and low cytotoxicity. This design incorporates a longer endosomolytic block with increased hydrophobic content to induce micelle formation. These polymers spontaneously form spherical micelles in the size range of 40 nm with CMC (critical micelle concentration) values of approximately 2 μg/ml based on dynamic light scattering (DLS), 1H-NMR, electron microscopy, and selective partitioning of the small molecule pyrene into the hydrophobic micelle core. The siRNA binding to the cationic shell block did not perturb micelle stability or significantly increase particle size. The self-assembly of the diblock copolymers into particles was shown to provide a significant enhancement in mRNA knockdown at siRNA concentrations as low as 12.5 nM. Under these conditions the micelle--based systems showed an 89 % reduction in GAPDH mRNA levels as compared to only 23 % (10 nM siRNA) for the non-micelle system. The reduction in mRNA levels becomes nearly quantitative as the siRNA concentration is increased to 25 nM and higher. Flow cytometry analysis of fluorescent-labeled siRNA showed uptake in 90% of cells and a 3-fold increase in siRNA per cell compared to a standard lipid transfection agent. These results demonstrate the potential utility of this carrier design for siRNA drug delivery.
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DOI：
10.1016/j.jconrel.2008.10.004
发表时间：
2009-02-10
期刊：
Journal of controlled release : official journal of the Controlled Release Society
影响因子：
--
作者：
Convertine AJ;Benoit DS;Duvall CL;Hoffman AS;Stayton PS
通讯作者：
Stayton PS
影响因子：
10.8
作者：
Murthy, N;Robichaud, JR;Hoffman, AS
通讯作者：
Hoffman, AS
影响因子：
2.9
作者：
Ren, JH;Sharpe, JC;London, E
通讯作者：
London, E
影响因子：
4.6
作者：
Veron, Laurent;Ganee, Arnaud;Delair, Thierry
通讯作者：
Delair, Thierry
影响因子：
6.2
作者：
York, Adam W.;Zhang, Yilin;Holley, Andrew C.;Guo, Yanlin;Huang, Faqing;McCormick, Charles L.
通讯作者：
McCormick, Charles L.