ARC Centre of Excellence for Functional Nanomaterials, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia.
J Colloid Interface Sci. 2012 Mar 1;369(1):453-9. doi: 10.1016/j.jcis.2011.12.046. Epub 2011 Dec 23.
In this paper, we report the novel finding that the cellular delivery efficiency of siRNAs or their mimic double-stranded (ds)DNA using layered double hydroxide (LDH) nanoparticles is dependent upon the nucleotide sequence. Efficacy of LDH-mediated delivery of four different siRNAs into cortical neurons and NIH 3T3 cells was found to vary widely (from 6 to 80%, and 2-11%, respectively). Our investigation into the formation of dsDNA-LDH complexes through monitoring the dsDNA:LDH mass ratio at the point of zero charge (PZC) indicated that the degree of intercalation of the individual dsDNA sequences into the LDH nanoparticles varied significantly. The dsDNA:LDH mass ratio at the PZC was found to be dependent on the nucleotide sequence. We further observed that PZC for each sequence was positively related to the extent of LDH-mediated internalization of the equivalent siRNA into neurons and fibroblasts. This novel finding therefore suggests that the mass ratio at the PZC is a useful predictive tool with which to assess the intercalation efficiency of selected siRNA sequences into the LDH interlayer and subsequent internalization into the cell cytoplasm. This finding will allow a more controlled approach to the design of suitable siRNA sequences for LDH-mediated siRNA delivery.
在本文中，我们报告了一个新的发现，即使用层状双氢氧化物（LDH）纳米颗粒将 siRNA 或其模拟双链（ds）DNA 递送到细胞中，其效率取决于核苷酸序列。我们发现，四种不同的 siRNA 通过 LDH 介导递送到皮质神经元和 NIH 3T3 细胞中的效率差异很大（分别为 6-80%和 2-11%）。通过监测等电点（PZC）处的 dsDNA：LDH 质量比，我们研究了 dsDNA-LDH 复合物的形成，结果表明，各个 dsDNA 序列插入 LDH 纳米颗粒的程度差异很大。在 PZC 处的 dsDNA：LDH 质量比取决于核苷酸序列。我们进一步观察到，每个序列的 PZC 与等量 siRNA 进入神经元和成纤维细胞的 LDH 介导内化程度呈正相关。因此，这一新发现表明，PZC 处的质量比是一种有用的预测工具，可用于评估选定的 siRNA 序列与 LDH 层间的插入效率以及随后进入细胞质的内化效率。这一发现将允许更可控的方法来设计适合 LDH 介导的 siRNA 递送的 siRNA 序列。
