Chemical Modifications of Synthetic RNAi Agents and in vivo Delivery Techniques

The need of using chemically modified siRNA agents for gene silencing continuously increasing as appropriate chemical modification improves their specificity, nuclease stability, potency, and in vivo cellular delivery. The future success of RNAi technology also depends on identifying drug carriers that are non-toxic and tissue-specific in directing the RNAi agents to the desired locations in a cost effective fashion. This review will cover recently reported chemically modified siRNA agents for improving specificity and potency of mRNA knockdown, their nuclease stability, cellular uptake and improved biodistribution. In addition to the chemical modifications and their biological impact, this review also focuses on the in vivo RNAi delivery techniques.