Background: RNA interference (RNAi) has emerged as one of the
most extensively explored areas of research that has promising applications in
therapeutics. As an endogenous regulatory pathway, RNAi can be used for
silencing targeted genes involved in the progression of diseases. Small interfering
RNAs (siRNA) are 21-25 nucleotides in length and work on the principle of
RNA interference. Owing to their high degree of safety, specificity, efficacy,
easy synthesis and unrestricted choice of target, siRNAs are considered appropriate for gene silencing.
Objective: This review discusses siRNA gene silencing mechanism, the challenges posed in siRNA delivery
and the strategies developed to overcome some of these hurdles using nanocarriers. A few applications of
siRNA in therapeutics are presented to highlight the utility of these strategies.
Conclusion: In spite of advantages of siRNA technology, several shortcomings such as off-target effects,
hurdles in delivering, endosomal trapping, stimulation of immune response and short half-life limit the practical
use of siRNA. However, the situation has been improved considerably using nanotechnology based tools.