Monomolecular assembly of siRNA and poly(ethylene glycol)-peptide copolymers
Monomolecular assembly of siRNA and poly(ethylene glycol)-peptide copolymers
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DOI：
10.1021/bm7011482
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发表时间：
2008-02-01
影响因子：
6.2
通讯作者：
Radler, Joachim O.
中科院分区：
文献类型：
--
作者：
DeRouchey, Jason;Schmidt, Claudia;Radler, Joachim O.
在这项工作中，我们设计和调查复杂的形成高度均匀的单分子siRNA复合物利用嵌段共聚物组成的阳离子肽部分共价结合到聚（乙二醇）（PEG）部分。本研究的目的是设计一种含有单个siRNA分子的屏蔽siRNA构建体，以实现在大分子网络中具有增强的扩散特性的空间稳定复合物。使用14赖氨酸-PEG（K-14-PEG）线性二嵌段共聚物，实现了siRNA与PEG的化学计量1：3接枝密度的单分子siRNA复合物的形成。或者，类似的PEG化单分子siRNA颗粒通过与由结合至PEG主链的六个阳离子肽侧链组成的接枝共聚物复合来实现。通过荧光相关光谱（FCS）测量得到的复合物的流体动力学半径被发现是在良好的协议与理论预测使用聚合物刷缩放理论的PEG装饰棒状分子。进一步证明，通过在Ki和PEG嵌段之间使用OH敏感性腙或可还原的二硫键接头，可以使SiRNA-PEG复合物的PEG涂层可生物降解。为了模拟体内条件下的转运，研究了这些PEG化siRNA复合物在各种带电和不带电基质材料中的扩散。在PEG溶液中，观察到siRNA复合物的扩散系数随着聚合物浓度的增加而降低，这与半稀释溶液中探针扩散的理论一致。在带电网络中，行为要复杂得多。纤维蛋白凝胶中的FCS测量表明二嵌段共聚物从复合物中完全解离，而胶原蛋白溶液中的运输导致颗粒聚集。
In this work, we design and investigate the complex formation of highly uniform monomolecular siRNA complexes utilizing block copolymers consisting of a cationic peptide moiety covalently bound to a poly(ethylene glycol) (PEG) moiety. The aim of the study was to design a shielded siRNA construct containing a single siRNA molecule to achieve a sterically stabilized complex with enhanced diffusive properties in macromolecular networks. Using a 14 lysine-PEG (K-14-PEG) linear diblock copolymer, formation of monomolecular siRNA complexes with a stoichiometric 1:3 grafting density of siRNA to PEG is realized. Alternatively, similar PEGylated monomolecular siRNA particles are achieved through complexation with a graft copolymer consisting of six cationic peptide side chains bound to a PEG backbone. The hydrodynamic radii of the resulting complexes as measured by fluorescence correlation spectroscopy (FCS) were found to be in good agreement with theoretical predictions using polymer brush scaling theory of a PEG decorated rodlike molecule. It is furthermore demonstrated that the PEG coating of the siRNA-PEG complexes can be rendered biodegradable through the use of a OH-sensitive hydrazone or a reducible disulfide bond linker between the K, and the PEG blocks. To model transport under in vivo conditions, diffusion of these PEGylated siRNA complexes is studied in various charged and uncharged matrix materials. In PEG solutions, the diffusion coefficient of the siRNA complex is observed to decrease with increasing polymer concentration, in agreement with theory of probe diffusion in semidilute solutions. In charged networks, the behavior is considerably more,complex. FCS measurements in fibrin gels indicate complete dissociation of the diblock copolymer from the complex, while transport in collagen solutions results in particle aggregation.