RNA Structure and Design Section, RNA Biology Laboratory, National Cancer Institute, Frederick, MD, USA.
RNA Structure and Design Section, RNA Biology Laboratory, National Cancer Institute, Frederick, MD, USA; Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA.
Nanomedicine. 2020 Jun;26:102176. doi: 10.1016/j.nano.2020.102176. Epub 2020 Mar 6.
Translation potential of RNA interference nanotherapeutics remains challenging due to in vivo off-target effects and poor endosomal escape. Here, we developed novel polyplexes for controlled intracellular delivery of dicer substrate siRNA, using a light activation approach. Sulfonated polyethylenimines covalently linked to pyropheophorbide-α for photoactivation and bearing modified amines (sulfo-pyro-PEI) for regulated endosomal escape were investigated. Gene knock-down by the polymer-complexed DsiRNA duplexes (siRNA-NPs) was monitored in breast cancer cells. Surprisingly, sulfo-pyro-PEI/siRNA-NPs failed to downregulate the PLK1 or eGFP proteins. However, photoactivation of these cell associated-polyplexes with a 661-nm laser clearly restored knock-down of both proteins. In contrast, protein down-regulation by non-sulfonated pyro-PEI/siRNA-NPs occurred without any laser treatments, indicating cytoplasmic disposition of DsiRNA followed a common intracellular release mechanism. Therefore, sulfonated pyro-PEI holds potential as a unique trap and release light-controlled delivery platform for on-demand gene silencing bearing minimal off target effects.
由于体内的脱靶效应和较差的内体逃逸，RNA 干扰纳米疗法的翻译潜力仍然具有挑战性。在这里，我们使用光激活方法开发了新型的用于控制体内递送达尔底物 siRNA 的超分子复合物。用光激活共价连接到焦脱镁叶绿酸-α的磺化聚乙烯亚胺，并带有修饰的胺（磺化焦-PEI）用于调节内体逃逸。在乳腺癌细胞中监测聚合物复合 DsiRNA 双链体（siRNA-NP）的基因敲低。令人惊讶的是，sulfo-pyro-PEI/siRNA-NP 未能下调 PLK1 或 eGFP 蛋白。然而，用 661nm 激光对这些与细胞相关的超分子复合物进行光激活，明显恢复了两种蛋白质的下调。相比之下，非磺化焦-PEI/siRNA-NP 的蛋白下调无需任何激光处理，表明 DsiRNA 的细胞质分布遵循常见的细胞内释放机制。因此，磺化焦-PEI 作为一种独特的陷阱和释放光控递药平台具有潜力，可按需进行基因沉默，具有最小的脱靶效应。
