Department of Biological Sciences and Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
Bioconjug Chem. 2011 Oct 19;22(10):1962-9. doi: 10.1021/bc200172p. Epub 2011 Sep 23.
In this study, siRNAs terminated with thiol groups were multimerized and cross-linked using ∼5 nm gold nanoparticles (AuNPs) via Au-S chemisorption that can be intracellularly reduced. AuNPs immobilized with single-stranded antisense siRNA were assembled with those with single-stranded sense siRNA via complementary hybridization or assembled with those with single-stranded dimeric sense siRNA. The multimerized siRNA cross-linked by AuNPs showed increased charge density and enhanced enzymatic stability, and exhibited good complexation behaviors with a polycationic carrier, linear polyethylenimine (L-PEI). The resultant multi-siRNA/AuNPs/L-PEI polyelectrolyte complexes exhibited far greater gene silencing efficiencies of green fluorescent protein (GFP) and vascular endothelial growth factor (VEGF) compared to naked siRNA complexes. They could also be visualized by micro-CT imaging. The results suggest that AuNP-mediated multimerization of siRNAs could be a rational approach to achieve both gene silencing and imaging at a target tissue simultaneously.
在这项研究中，通过金 - 硫（Au-S）化学吸附将带有巯基的 siRNA 进行多聚化和交联，这种 Au-S 化学吸附可以在细胞内被还原。通过互补杂交将带有单链反义 siRNA 的 AuNP 与带有单链正义 siRNA 的 AuNP 组装在一起，或者将带有单链二聚体正义 siRNA 的 AuNP 与带有单链正义 siRNA 的 AuNP 组装在一起。通过 AuNP 交联的多聚化 siRNA 表现出增加的电荷密度和增强的酶稳定性，并与聚阳离子载体线性聚乙烯亚胺（L-PEI）表现出良好的复合物行为。与裸 siRNA 复合物相比，所得的多 siRNA/AuNP/L-PEI 聚电解质复合物对绿色荧光蛋白（GFP）和血管内皮生长因子（VEGF）的基因沉默效率要高得多。它们也可以通过 micro-CT 成像进行可视化。结果表明，AuNP 介导的 siRNA 多聚化可能是一种合理的方法，可以同时在靶组织中实现基因沉默和成像。
