Here, polyamidoamine grafted halloysite nanotubes (PAMAM-g-HNTs) were synthesized for loading of siRNA in order to intracellular delivery of siRNA and treat of breast cancer via gene therapy. The successful grafting of PAMAM on HNTs was confirmed by various analytical methods. The size, zeta potential, and grafting ratio of PAMAM-g-HNTs is ∼206.2 nm, +19.8 mV, and 3.04%, respectively. PAMAM-g-HNTs showed good cytocompatibility toward HUVECs (84.7%) and MCF-7 cells (82.3%) even at high concentration of 100 μg/mL. PAMAM-g-HNTs/siRNA exhibited enhanced cellular uptake efficiency of 94.3% compared with Lipofectamine 2000 (Lipo2000)/siRNA (83.6%). PAMAM-g-HNTs/small interfering RNA-vascular endothelial growth factor (siVEGF) led to 78.0% knockdown of cellular VEGF mRNA and induced 33.6% apoptosis in the MCF-7 cells, which is also much higher than that of Lipo2000/siVEGF. In vivo anti-cancer results demonstrated that PAMAM-g-HNTs/siVEGF treated 4T1-bearing mice showed enhanced anti-cancer efficacy than Lipo2000/siVEGF group. Also, the nanocarrier system showed negligible toxic effects toward the major organs of mice. In vivo fluorescence imaging studies showed that there is a slight decrease in the fluorescence signal of PAMAM-g-HNTs/cy5-siVEGF after 72 h post-injection. Therefore, PAMAM-g-HNTs show promising application as novel nanovectors for siRNA delivery and gene therapy of cancer.

中文翻译：

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通过枝状聚合物接枝的埃洛石纳米管功能化的siRNA的有效细胞内传递。

在这里，合成了聚酰胺胺接枝的埃洛石纳米管（PAMAM- g -HNTs）以装载siRNA，以进行siRNA的细胞内递送并通过基因疗法治疗乳腺癌。通过各种分析方法证实了PAMAM在HNT上的成功嫁接。PAMAM- g -HNTs的大小，ζ电势和接枝率分别约为206.2 nm，+ 19.8 mV和3.04％。即使在100μg/ mL的高浓度下，PAMAM- g -HNT对HUVEC（84.7％）和MCF-7细胞（82.3％）也显示出良好的细胞相容性。PAMAM-克用阳离子脂质体2000（Lipo2000）/ siRNA的（83.6％）相比，94.3％-HNTs / siRNA的表现出增强的细胞吸收效率。PAMAM- g ^-HNTs /小的干扰RNA-血管内皮生长因子（siVEGF）导致细胞VEGF mRNA的敲低78.0％，并诱导MCF-7细胞的33.6％凋亡，也远高于Lipo2000 / siVEGF。体内抗癌结果表明，与Lipo2000 / siVEGF组相比，经PAMAM- g -HNTs / siVEGF治疗的4T1小鼠表现出增强的抗癌功效。而且，纳米载体系统对小鼠的主要器官显示出微不足道的毒性作用。体内荧光成像研究表明，注射后72 h ，PAMAM- g -HNTs / cy5-siVEGF的荧光信号略有下降。因此，PAMAM- g- HNTs作为用于癌症的siRNA递送和基因治疗的新型纳米载体显示出有希望的应用。