Krajcik Rasti, Jung Adrian, Hirsch Andreas, Neuhuber Winfried, Zolk Oliver
Institute of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nuremberg, Fahrstr. 17, 91054 Erlangen, Germany.
Biochem Biophys Res Commun. 2008 May 2;369(2):595-602. doi: 10.1016/j.bbrc.2008.02.072. Epub 2008 Feb 25.
The lipophilic nature of biological membranes restricts the direct intracellular delivery of potential drugs and molecular probes and makes intracellular transport one of the key problems in gene therapy. Because of their ability to cross cell membranes, single walled carbon nanotubes (SWNTs) are of interest as carriers of biologically active molecules, such as small interfering RNAs (siRNAs). We developed a strategy for chemical functionalization of SWNTs with hexamethylenediamine (HMDA) and poly(diallyldimethylammonium)chloride (PDDA) to obtain a material that was able to bind negatively charged siRNA by electrostatic interactions. PDDA-HMDA-SWNTs exhibited negligible cytotoxic effects on isolated rat heart cells at concentrations up to 10mg/l. PDDA-HMDA-SWNTs loaded with extracellular signal-regulated kinase (ERK) siRNA were able to cross the cell membrane and to suppress expression of the ERK target proteins in primary cardiomyocytes by about 75%. PDDA-functionalized SWNTs thus present an effective carrier system for applications in siRNA-mediated gene silencing.
生物膜的亲脂性限制了潜在药物和分子探针的直接细胞内递送，使细胞内运输成为基因治疗中的关键问题之一。由于单壁碳纳米管（SWNTs）具有穿越细胞膜的能力，因此作为生物活性分子（如小干扰RNA（siRNAs））的载体受到关注。我们开发了一种用六亚甲基二胺（HMDA）和聚二烯丙基二甲基氯化铵（PDDA）对SWNTs进行化学功能化的策略，以获得一种能够通过静电相互作用结合带负电荷的siRNA的材料。在浓度高达10mg/l时，PDDA-HMDA-SWNTs对分离的大鼠心脏细胞表现出可忽略不计的细胞毒性作用。负载细胞外信号调节激酶（ERK）siRNA的PDDA-HMDA-SWNTs能够穿过细胞膜，并将原代心肌细胞中ERK靶蛋白的表达抑制约75%。因此，PDDA功能化的SWNTs为siRNA介导的基因沉默应用提供了一种有效的载体系统。
