Intracellular Trafficking and Unpacking of siRNA/Quantum Dot-PEI Complexes Modified with and without Cell Penetrating Peptide: Confocal and Flow Cytometric FRET Analysis

Autor: Tg Park Tae Gwan Park, Ik Kim In-Kyoung Kim, Hyukjin Lee
Rok vydání: 2010
Předmět:
Zdroj: Bioconjugate Chemistry. 21:289-295
ISSN: 1520-4812
1043-1802
Popis: Cationic quantum dots (QDs) were utilized to complex small interfering RNA (siRNA) for studying intracellular trafficking, unpacking, and gene silencing. Positively charged polyethylenimine (PEI) was covalently conjugated on the surface of QDs to complex with cyanine dye labeled vascular endothelial growth factor siRNA (cy5-VEGF siRNA) for the formation of nanosized polyelectrolyte complexes (PEC). Fluorescence resonance energy transfer (FRET) was achieved between cy5-VEGF siRNA and PEI conjugated QDs (QD625) in the complex. From confocal microscopic analysis, intracellular uptake and release of siRNA from the PEC were visualized as a function of incubation time. The extent of cy5-siRNA release from the PEC was quantitatively evaluated by flow cytometric analysis. In addition, PEI conjugated QDs were further modified with a protein transduction domain (PTD) from human transcriptional factor, Hph-1. The two siRNA/QD-PEI complexes with and without Hph-1 have shown markedly different intracellular uptake behaviors and unpacking kinetics of cy5-siRNA. However, they exhibited similar extent of VEGF gene knockout regardless of Hph-1, but showed much higher gene silencing efficiency than siRNA/PEI complexes. The present study demonstrates that PEI conjugated QDs can be utilized as a useful siRNA carrier to analyze intracellular trafficking and unpacking pathway as well as to effectively silence a target gene.
Databáze: OpenAIRE