Structural Exploration of Polycationic Nanoparticles for siRNA Delivery
Structural Exploration of Polycationic Nanoparticles for siRNA Delivery
复制标题
用于 siRNA 递送的聚阳离子纳米颗粒的结构探索
DOI：
10.1021/acsbiomaterials.2c00196
复制
发表时间：
2022
影响因子：
5.8
通讯作者：
Wenbo Ye
中科院分区：
文献类型：
--
作者：
Yunfeng Yan;Guangliang Zhang;Chengfan Wu;Qidi Ren;Xiaomin Liu;Fangqian Huang;Yi Cao;Wenbo Ye
RNA干扰（RNA interference，RNAi）是一种通过特异性敲低靶基因来治疗遗传性疾病的有效方法。功能性聚合物是有效递送脆弱的小干扰RNA（siRNA）的潜在载体，这是基于RNAi的治疗剂的广泛应用所需的。开发聚合物载体的化学结构的简易调节方法和阐明详细的递送机制仍然是重要的研究领域。本文采用原子转移自由基聚合方法，以甲基丙烯酸2-二甲氨基乙酯、甲基丙烯酸2-二乙氨基乙酯和甲基丙烯酸2-二丁氨基乙酯为阳离子单体，甲基丙烯酸2-丁酯、甲基丙烯酸环己酯和甲基丙烯酸2-乙基己酯为疏水单体，合成了一系列结构可控、分布窄的甲基丙烯酸酯基聚合物。这些聚合物表现出不同的疏水性，电荷密度，和pKa值，使发现有效的载体siRNA通过在体外交付试验。对于含有BMA链段的聚合物，50%的阳离子链段有利于siRNA纳米粒的形成和siRNA的体外递送。阳离子和疏水链段的不同组合的最佳比例不同。特别是，20 k PMB 0.5、PME 0.5和PEB 1.0显示出>75%的荧光素酶敲除。有效递送依赖于高siRNA结合、小尺寸的NP以及平衡的疏水性和电荷密度。细胞摄取和内体逃逸实验表明，20 k PMB 0.5的羧基甜菜碱修饰在孵育6 h后没有显著影响相应NP的内化，但显著减少了NP的内体逃逸，这导致聚合物的递送功效显著降低。这些结果为基于聚合物的siRNA递送机制提供了见解，并可能激发新型聚合物载体的开发。
RNA interference (RNAi) is a promising approach to the treatment of genetic diseases by the specific knockdown of target genes. Functional polymers are potential vehicles for the effective delivery of vulnerable small interfering RNA (siRNA), which is required for the broad application of RNAi-based therapeutics. The development of methods for the facile modulation of chemical structures of polymeric carriers and an elucidation of detailed delivery mechanisms remain important areas of research. In this paper, we synthesized a series of methacrylate-based polymers with controllable structures and narrow distributions by atom transfer radical polymerization using various combinations of cationic monomers (2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, and 2-dibutylaminoethyl methacrylate) and hydrophobic monomers (2-butyl methacrylate (BMA), cyclohexyl methacrylate, and 2-ethylhexyl methacrylate). These polymers exhibited varying hydrophobicities, charge densities, and pKavalues, enabling the discovery of effective carriers for siRNA byin vitrodelivery assays. For the polymers with BMA segments, 50% of cationic segments were beneficial to the formation of siRNA nanoparticles (NPs) and thein vitrodelivery of siRNA. The optimal ratio varied for different combinations of cationic and hydrophobic segments. In particular, 20k PMB 0.5, PME 0.5, and PEB 1.0 showed >75% luciferase knockdown. Efficacious delivery was dependent on high siRNA binding, the small size of NPs, and balanced hydrophobicity and charge density. Cellular uptake and endosomal escape experiments indicated that carboxybetaine modification of 20k PMB 0.5 did not remarkably affect the internalization of corresponding NPs after incubation for 6 h but significantly reduced the endosomal escape of NPs, which leads to the notable decrease in delivery efficacy of polymers. These results provide insights into the mechanism of polymer-based siRNA delivery and may inspire the development of novel polymeric carriers.