Department of Medical Biochemistry and Global COE Program, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
J Control Release. 2012 Jun 10;160(2):177-81. doi: 10.1016/j.jconrel.2011.10.004. Epub 2011 Oct 13.
For the purpose of systemic delivery of siRNA, we previously developed polycation liposomes (PCLs) containing dicetylphosphate-tetraethylenepentamine (DCP-TEPA) as an effective siRNA carrier. In the present study, to endow these PCLs (TEPA-PCL) actively target cancer cells and angiogenic vessels, we decorated the PCLs with cyclic RGD, by using cyclic RGD-grafted distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG), and investigated the usefulness of this type of carrier (RGD-PEG-PCL) for active targeting. Firstly, the gene-silencing efficacy of siRNA for luciferase (siLuc2) formulated in RGD-PEG-PCL (RGD-PEG-PCL/siLuc2) was examined in vitro by using B16F10-luc2 murine melanoma cells stably expressing the luciferase 2 gene, where the siRNA was grafted with cholesterol at the 3'-end of the sense strand (siRNA-C) for the stable association of the siRNA with the PCL. RGD-PEG-PCL/siLuc2 showed high knockdown efficiency compared with siLuc2 formulated in PEGylated TEPA-PCL without cyclic RGD (PEG-PCL). Next, the gene-silencing efficacy of RGD-PEG-PCL/siLuc2 was examined in vivo by use of B16F10-luc2 lung metastatic model mice. The intravenous injection of RGD-PEG-PCL/siLuc2 showed high knockdown efficiency against metastatic B16F10-luc2 tumors in the lungs of the mice, as assessed with an in vivo imaging system. These data strongly suggest that systemic and active targeting siRNA delivery using RGD-PEG-PCL is useful for cancer RNAi therapy.
为了实现 siRNA 的系统递送，我们之前开发了含有二乙酰基磷酸酯-四乙五胺（DCP-TEPA）的聚阳离子脂质体（PCLs）作为有效的 siRNA 载体。在本研究中，为了使这些 PCL（TEPA-PCL）能够主动靶向癌细胞和血管生成血管，我们通过使用环状 RGD 接枝二硬脂酰基磷脂酰乙醇胺-聚乙二醇（DSPE-PEG）对 PCL 进行了修饰，并研究了这种载体（RGD-PEG-PCL）用于主动靶向的用途。首先，通过使用稳定表达荧光素酶 2 基因的 B16F10-luc2 鼠黑色素瘤细胞，体外检查了 RGD-PEG-PCL 中构建的 siRNA（RGD-PEG-PCL/siLuc2）对荧光素酶（siLuc2）的基因沉默效果，其中胆固醇接枝在正义链的 3'-末端用于 siRNA 与 PCL 的稳定结合（siRNA-C）。与没有环状 RGD 的 PEG 化 TEPA-PCL 中构建的 siLuc2 相比，RGD-PEG-PCL/siLuc2 显示出更高的敲低效率。接下来，通过使用 B16F10-luc2 肺转移模型小鼠，在体内检查了 RGD-PEG-PCL/siLuc2 的基因沉默效果。静脉注射 RGD-PEG-PCL/siLuc2 对小鼠肺部转移性 B16F10-luc2 肿瘤显示出高敲低效率，可通过体内成像系统评估。这些数据强烈表明，使用 RGD-PEG-PCL 进行系统和主动靶向 siRNA 递送对于癌症 RNAi 治疗是有用的。
