Dept. of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea 305-701.
Biotechnol Prog. 2010 Jan-Feb;26(1):57-63. doi: 10.1002/btpr.310.
For therapeutic applications of small interfering RNA (siRNA), serum stability, enhanced cellular uptake, and facile endosome escape are key issues for designing carriers. In this study, green fluorescent protein (GFP) siRNA was conjugated to a six-arm polyethylene glycol (PEG) derivative via a reducible disulfide linkage (6PEG-siRNA). The 6PEG-siRNA conjugate was also functionalized with a cell penetrating peptide, Hph1 to enhance its cellular uptake property (6PEG-siRNA-Hph1). The 6PEG-siRNA-Hph1 conjugate was electrostatically complexed with cationic self-crosslinked fusogenic KALA peptide (cl-KALA) to form multifunctional polyelectrolyte complex micelles for gene silencing. The resultant siRNA complex formulation with multiple PEG chains showed superior physical stability and resistance to enzymatic degradation. The 6PEG-siRNA-Hph1/cl-KALA complexes exhibited enhanced GFP gene silencing efficiency for MDA-MB-435 cells in the serum containing condition. The current reducible and multifunctional polyelectrolyte complex micelles are expected to have high potential for efficient delivery of therapeutic siRNA.
为了将小干扰 RNA（siRNA）应用于治疗，设计载体时需要考虑血清稳定性、增强细胞摄取和易于从内涵体逃逸等关键问题。在本研究中，通过还原型二硫键将绿色荧光蛋白（GFP）siRNA 连接到六臂聚乙二醇（PEG）衍生物上（6PEG-siRNA）。6PEG-siRNA 还通过细胞穿透肽 Hph1 进行功能化，以增强其细胞摄取特性（6PEG-siRNA-Hph1）。6PEG-siRNA-Hph1 与阳离子自交联融合肽 KALA（cl-KALA）静电复合形成用于基因沉默的多功能聚电解质复合胶束。具有多个 PEG 链的所得 siRNA 复合制剂表现出优异的物理稳定性和对酶降解的抗性。在含血清的条件下，6PEG-siRNA-Hph1/cl-KALA 复合物对 MDA-MB-435 细胞中的 GFP 基因沉默效率更高。目前，这种可还原的多功能聚电解质复合胶束有望成为高效递送治疗性 siRNA 的载体。
