유전자 전달물질로서의 양전하성 변형 뉴클레오시드의 합성 및 특성 연구

Abstract

Gene therapy has gained attention as a potentially powerful method for curing disease over the past two decades, but there are still some difficulties to deliver genes into the cells. Therefore, the clinical success of gene therapy is critically dependent on efficient and safe gene delivery. For this reason, it is necessary to use delivery agents. As non-viral transfection agent, nucleoside-based cationic lipids (nucleolipids) have been developed and have some advantages: (1) low cytotoxicity compared to viral transfection agents, (2) similar structure to cell membrane, (3) favorable interactions with negatively charged gene and cell membranes, and (4) interaction with gene through electrostatic, hydrophobic interactions, and hydrogen bonding, π-π stacking, and nucleo-base recognition. The novel uridine-based cationic lipids had been synthesized for the delivery of therapeutic gene, siRNA. The 5' position of uridine was conjugated by triazole ring through click chemistry with basic amino acid, lysine and arginine or guanidine group. To make diverse length and kink on tails, octyl, dodecyl, and oleyl alkyl chain were linked at 2' and 3' positions by carbamate group. The lipoplex was prepared by using uridine-based cationic lipids and VEGF siRNA. From gel retardation assay, we found the minimal mol ratio of lipoplex between cationic nucleolipid and siRNA. This result showed nucleoside-based cationic lipids were able to bind siRNA. MTT assay was done for cytotoxicity which indicated the cationic lipids had low cytotoxicity. siRNA knockdown experiment was performed with the cationic nucleolipids and we concluded that uridine-based cationic lipids had a positive effect on siRNA delivery.