论文部分内容阅读
There is great need for methods or agents that effectively deliver bio-molecules, including proteins and nucleic acids into cells, tissues, and organs for therapeutic and molecular biological applications.An effective amount of oligonucleotide must be delivered into the target cells to elicit therapeutic effects.However, the size and polyanionic nature of oligonucleotides are a major concern for their cellular delivery.Currently viral-and lipid-based delivery systems are commonly used for oligonucleotide delivery.However, these methods have been shown to cause cell infectivity and toxicity.In the past prodrug approach of synthesis of mononucleoside phosphotriesters incorporating S-acyl-2-thioethyl (SATE) groups as enzyme labile transient phosphate protections have been shown to allow the intracellular delivery of 5-mononucleotides2.However they have draw back of cellular toxicity.Therefore, improved delivery systems, which do not cause immunotoxicity or cytotoxicity in the host, are needed for therapeutic and molecular biological applications of oligonucleotides.Our presentation will discuss synthesis, purification and biological activity of oligonucleotides bearing one or multiple BMEG groups as triester function into defined sequence oligonucleotides.We show many advantages of Incorporating BMEG Groups in Oligonucleotides, such as BMEG is lipophilic in nature and facilitates increased cellular uptake.Further it masks negative charge on phosphate,decreases overall negative charge of oligonucleotides.BMEG further provides stability against ubiquitous nucleases in serum and cytoplasm.BMEG acts as prodrug-thioester group is hydrolysed by cellular estarases releasing oligonucleotide for its intended mechanism of action in the target cell.