Targeted Polymersome Delivery of siRNA Induces Cell Death of Breast Cancer Cells Dependent upon Orai3 Protein Expression
Targeted Polymersome Delivery of siRNA Induces Cell Death of Breast Cancer Cells Dependent upon Orai3 Protein Expression
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DOI：
10.1021/la300874z
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发表时间：
2012-09-04
期刊：
影响因子：
3.9
通讯作者：
Kokkoli, Efrosini
中科院分区：
文献类型：
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作者：
Pangburn, Todd O.;Georgiou, Katerina;Kokkoli, Efrosini
聚合体是一种由嵌段共聚物在水溶液中自组装的聚合囊泡，近年来作为潜在的药物递送剂被广泛研究。过去的工作强调肽功能化聚合体是一种非常有前途的靶向递送系统。然而，很少有报道调查聚合体作为基因递送剂的能力。在这项研究中，我们报道了siRNA在由聚（1,2-丁二烯）-b-聚（环氧乙烷）组成的肽功能化聚合体内的包封和递送。特别是，PR_b肽功能化的聚合物囊泡被证明是一种很有前途的siRNA递送系统。PR_b是一种特异性靶向α (5) β(1)整合素的纤维连接蛋白模拟肽。我们以Orai3基因为靶点敲低siRNA，发现包裹siRNA的pr_b功能化聚合物囊泡在一定程度上特异性降低了T47D乳腺癌细胞的细胞活力，同时保留了非癌性MCF10A乳腺癌细胞的活力。通过pr_b功能化的聚合物囊泡传递siRNA与目前商业化的siRNA转染剂相比，产生的癌细胞活力降低幅度较小，但在传递系统的相对毒性方面比较有利。最后，通过共聚焦显微镜观察pr_b功能化聚合物囊泡对荧光囊泡的递送和囊泡释放，并通过细胞器染色评估其与细胞内体和溶酶体的共定位。观察到聚合体主要在早期内体细胞内区室释放其包被，数据可能表明一些逃逸到细胞质中。这些结果代表了有希望的第一代siRNA靶向递送模型系统。
Polymersomes, polymeric vesicles that self-assemble in aqueous solutions from block copolymers, have been avidly investigated in recent years as potential drug delivery agents. Past work has highlighted peptide-functionalized polymersomes as a highly promising targeted delivery system. However, few reports have investigated the ability of polymersomes to operate as gene delivery agents. In this study, we report on the encapsulation and delivery of siRNA inside of peptide-functionalized polymersomes composed of poly(1,2-butadiene)-b-poly(ethylene oxide). In particular, PR_b peptide-functionalized polymer vesicles are shown to be a promising system for siRNA delivery. PR_b is a fibronectin mimetic peptide targeting specifically the alpha(5)beta(1) integrin. The Orai3 gene was targeted for siRNA knockdown, and PR_b-functionalized polymer vesicles encapsulating siRNA were found to specifically decrease cell viability of T47D breast cancer cells to a certain extent, while preserving viability of noncancerous MCF10A breast cells. siRNA delivery by PR_b-functionalized polymer vesicles was compared to that of a current commercial siRNA transfection agent, and produced less dramatic decreases in cancer cell viability, but compared favorably in regards to the relative toxicity of the delivery systems. Finally, delivery and vesicle release of a fluorescent encapsulate by PR_b-functionalized polymer vesicles was visualized by confocal microscopy, and colocalization with cellular endosomes and lysosomes was assessed by organelle staining. Polymersomes were observed to primarily release their encapsulate in the early endosomal intracellular compartments, and data may suggest some escape to the cytosol. These results represent a promising first generation model system for targeted delivery of siRNA.