Paper Title
Arginine Functionalizing Single-Walled Carbon Nanotubes as Non-Viral Vectors For Efficient Intracellular Sirna Delivery

Abstract
Carbon nanotubes (CNTs) have been applied for drug, antigen and nucleic acid delivery into cancer cells both in vitro and in vivo. Due to their nano-needle structure, they are supposed to enter directly into the cytoplasm likely upon an endocytosis-independent mechanism while they can also enter the cell by receptor-mediated strategy. In this study, an efficient nanocarrier for nucleic acid delivery was synthesized by covalently conjugating siRNA to arginine functionalized CNTs. The prepared nanocarrier efficiently transports siRNA into the cytoplasm and showed 10�30% silencing activity. However, the nanocarrier showed significant reduction in toxicity and increased silencing activity. Probably, the type of functionalization of carbon nanotubes might be a key parameter to obtainan efficient and non-cytotoxic CNT-based delivery system. Nevertheless, in view of the present results, preference should currently be given to designing biocompatible targeted CNTs as an efficient nonviral vector for nucleic acid delivery. Keywords- Carbon nanotube; nonviral vector; gene delivery; functionalization