Nanosized Multifunctional Polyplexes for Receptor-Mediated SiRNA Delivery
Nanosized Multifunctional Polyplexes for Receptor-Mediated SiRNA Delivery
复制标题
DOI：
10.1021/nn300960m
复制
发表时间：
2012-06-01
期刊：
影响因子：
17.1
通讯作者：
Wagner, Ernst
中科院分区：
文献类型：
--
作者：
Dohmen, Christian;Edinger, Daniel;Wagner, Ernst
尽管在过去的十年里，我们对RNAi的了解以及我们对设计和合成活性和安全的siRNA的知识有了很大的提高，但靶向递送仍然是siRNA疗法发展的主要限制。一方面，实际的考虑决定了可靠的化学可重复地提供精确的载体分子。另一方面，多步骤交付过程需要相当复杂的动态多功能载体。我们提出了一种单分散、多功能的载体系统，用固相支撑化学方法合成，用于体内和体外的siRNA传递。该序列定义的组件包括精确的阳离子(寡乙氨基)酰胺核，末端由两个半胱氨酸终止，用于生物可逆多链稳定，在限定的中心位置连接到作为细胞靶向配体的单分散聚乙二醇链上，该单分散聚乙二醇链连接到末端叶酸。与内溶性流感多肽-iRNA偶联物的络合形成了流体力学直径为6 nm的纳米功能多聚体。证实了载体系统的每个功能亚结构对于特定和有效的基因沉默的必要性。纳米多聚体在体内表现出稳定性，受体特异性细胞靶向性，以及受体阳性肿瘤中EG5基因的沉默。这些颗粒的纳米级外观可以通过低聚物设计(直径从5.8到8.8 nm)进行精确控制。完整的表面电荷屏蔽和高稳定性导致良好的体内耐受性，并且不会在肝、肺、脾等非靶向组织中蓄积。由于其体积小，siRNA多聚体可以有效地被肾脏清除。
Although our understanding of RNAi and our knowledge on designing and synthesizing active and safe siRNAs significantly increased during the past decade, targeted delivery remains the major limitation in the development of siRNA therapeutics. On one hand, practical considerations dictate robust chemistry reproducibly providing precise carrier molecules. On the other hand, the multistep delivery process requires dynamic multifunctional carriers of substantial complexity. We present a monodisperse and multifunctional carrier system, synthesized by solid phase supported chemistry, for siRNA delivery in vitro and in vivo. The sequence-defined assembly includes a precise cationic (oligoethanamino)amide core, terminated at the ends by two cysteines for bioreversible polyplex stabilization, at a defined central position attached to a monodisperse polyethylene glycol chain coupled to a terminal folic acid as cell targeting ligand. Complexation with an endosomolytic influenza peptides-iRNA conjugate results in nanosized functional polyplexes of 6 nm hydrodynamic diameter. The necessity of each functional substructure of the carrier system for a specific and efficient gene silencing was confirmed. The nanosized polyplexes showed stability in vivo, receptor-specific cell targeting, and silencing of the EG5 gene in receptor-positive tumors. The nanosized appearance of these particles can be precisely controlled by the oligomer design (from 5.8 to 8.8 nm diameter). A complete surface charge shielding together with the high stability result in good tolerability in vivo and the absence of accumulation in nontargeted tissues such as liver, lung, or spleen. Due to their small size, siRNA polyplexes are efficiently cleared by the kidney.