Lee Soo Hyeon, Kim Sun Hwa, Park Tae Gwan
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea.
Biochem Biophys Res Commun. 2007 Jun 1;357(2):511-6. doi: 10.1016/j.bbrc.2007.03.185. Epub 2007 Apr 9.
To develop a small interfering RNA (siRNA) delivery system with low cytotoxicity and high transfection efficiency, siRNA was conjugated to poly(ethylene glycol) via a disulfide linkage (siRNA-PEG) to prepare polyelectrolyte complex micelles (PECMs) by condensing with a cationic fusogenic peptide (KALA). The siRNA-PEG conjugate exhibited enhanced resistance to degradation from nucleases. Anionic siRNA-PEG conjugate and cationic KALA, when mixed in an aqueous phase, spontaneously formed nano-sized PECMs (<200nm) that have an inner core of charge neutralized siRNA/KALA complex surrounded by a PEG corona. Vascular endothelial growth factor (VEGF) siRNA was used to demonstrate VEGF sequence-specific gene inhibition in prostate carcinoma cells (PC-3 cells). The extent of gene silencing was gradually increased with increasing nitrogen to phosphate (N/P) ratio and the concentration of siRNA-PEG/KALA PECMs. These results suggest that the formulation of siRNA-PEG/KALA PECMs could be widely applied for intracellular delivery of various therapeutic siRNAs.
为了开发一种具有低细胞毒性和高转染效率的小干扰RNA（siRNA）递送系统，通过二硫键将siRNA与聚乙二醇（siRNA-PEG）偶联，再与阳离子融合肽（KALA）缩合制备聚电解质复合胶束（PECMs）。siRNA-PEG偶联物对核酸酶降解的抗性增强。阴离子型siRNA-PEG偶联物和阳离子型KALA在水相中混合时，会自发形成纳米尺寸的PECMs（<200nm），其内核是电荷中和的siRNA/KALA复合物，周围是PEG冠层。使用血管内皮生长因子（VEGF）siRNA来证明其在前列腺癌细胞（PC-3细胞）中对VEGF序列特异性的基因抑制作用。基因沉默程度随着氮磷（N/P）比和siRNA-PEG/KALA PECMs浓度的增加而逐渐增加。这些结果表明，siRNA-PEG/KALA PECMs制剂可广泛应用于各种治疗性siRNAs的细胞内递送。
