Current Status of siRNA Delivery

RNAi is a powerful research tool used to silence specific genes. It brings a new hope for gene therapy strategy. At present, it is used to treat a variety of diseases as tumour, hepatitis B, exudative age-related macular degeneration and so on. RNAi’s effector molecule is small interference RNA (siRNA). However, because of its negative charge, large molecule weight, strong polarity, short plasma half-life, readily degraded by serum endonucleases and efficiently removed by glomerular filtration, the clinical application of naked siRNA is greatly limited. Both the chemical modification of siRNA and carriers of siRNA including viral vectors and non-viral vectors can improve the stability of siRNA in vivo. Here, with the latest developments of the chemical modification of siRNA, carriers of siRNA delivery, clinical research of siRNA are summarized in this review.