Local and systemic delivery of siRNAs for oligonucleotide therapy.

RNA interference (RNAi) is a relatively new found phenomenon of posttranscriptional gene silencing to regulate the expression of multiple genes involved in a wide range of biological processes. The gene-silencing technology via RNAi has also been developed into a commonly anti-gene method. Furthermore, in vivo data indicate that small interfering RNAs (siRNAs) may be used to treat human diseases. However, the most challenging issue to a successful in vivo application is the development of a delivery system that can transport siRNA molecules into the tissues and/or the cells of interest. Also, the evaluation of siRNA potency in vivo is central for the selection of therapeutic siRNAs. In this chapter, the effects of atelocollagen-delivered siRNAs in live animals were monitored using bioluminescence imaging.