Smart Multilayered Assembly for Biocompatible siRNA Delivery Featuring Dissolvable Silica, Endosome-Disrupting Polycation, and Detachable PEG
Smart Multilayered Assembly for Biocompatible siRNA Delivery Featuring Dissolvable Silica, Endosome-Disrupting Polycation, and Detachable PEG
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DOI：
10.1021/nn301164a
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发表时间：
2012-08-01
期刊：
影响因子：
17.1
通讯作者：
Kataoka, Kazunori
中科院分区：
文献类型：
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作者：
Suma, Tomoya;Miyata, Kanjiro;Kataoka, Kazunori
为了克服细胞质中高效基因沉默的内在生物障碍，需要多功能的小干扰RNA(SiRNA)智能多层组装(SMA)递送系统。利用多离子材料，采用逐层法制备了一种智能多层组装材料。SMA的设计特点是具有负载siRNA的核心、瞬时稳定核心的二氧化硅夹层、内小体干扰的聚阳离子夹层和具有还原环境响应性可拆卸性的生物兼容聚乙二醇壳。差示扫描量热法和透射电子显微镜分析表明，SMA的尺寸约为160 nm，且分布窄，表面呈球形。由于聚阳离子夹层的暴露和胶体稳定性的降低，Zeta电位和尺寸的增加也证实了基于二硫键裂解的SMA的聚乙二醇可脱性。二氧化硅夹层使SMA对阴离子脂类诱导的解离具有很高的耐受性，而透析24小时后，SMA释放出大量的siRNA，这可能是由于SiO_2夹层基于平衡向硅酸盐离子的移动而逐渐溶解所致。SMA携带的siRNA在内体中的包封率显著低于非二硫化物对照(NW，不具有聚乙二醇可分离性)，这表明在聚乙二醇脱除后，SMA与暴露的、内小体破坏的夹层之间的逃逸改善了SMA在各种培养细胞中的基因沉默效率，与NIX相比，没有相关的细胞毒性。皮下荷瘤小鼠全身应用SMAS后，肿瘤组织内源性基因沉默显著，且无血液学毒性。
Multifunctional Smart Multilayered Assembly (SMA) delivery systems of small interfering RNA (siRNA) are needed to overcome the intrinsic biological barriers toward efficient gene silendng in the cell cytoplasm. In this report, a smart multilayered assembly (SMA) was fabricated by a layer-by-layer method with polyionic materials. The SMA was designed to feature a siRNA-loaded core, a transiently core-stabilizing silica interlayer, an endosome-disrupting polycation interlayer, and a biocompatible poly(ethylene glycol) (PEG) shell with reductive environment-responsive detachability. The SMA was confirmed to be approximately 160 nm in size with narrow distribution and spherical morphology by DLS and TEM analyses. The PEG detachability of the SMA based on disulfide cleavage was also confirmed by the increase in both zeta-potential and size due to the exposure of the polycation interlayer and the compromised colloidal stability. The silica interlayer rendered the SMA highly tolerant to dissociation Induced by anionic lipids, while after 24 h dialysis siRNA release from the SMA was dearly observed, presumably due to gradual dissolution of the silica interlayer based on the equilibrium shift to silicate ions. The entrapment ratio of siRNA delivered by the SMA within the endosome was significantly lower than that by nondisulfide control (NW without PEG detachability, suggesting the improved endosomal escape of SMA with the exposed, endosome-disrupting interlayer after PEG detachment SMAs induced significantly higher gene silencing efficiency in various cultured cells, compared to NIX, without associated cytotoxicity. The systemic administration of SMAs for subcutaneous tumor-bearing mice achieved significant endogenous gene silencing in tumor tissue without hematological toxicity.