Improving siRNA efficiency!

The use of RNA interference to silence specific disease-related genes is still inchoate and far from being used as a therapy, but scientists are working hard to speed up the process. Even though several in vitro and small animals tests have been performed, the precision and efficiency of siRNA as treatment is still not sufficient to use in humans. For example, there are still many issues when it comes to safely delivering the siRNA--- it cannot be simply injected into the body. Even though current researchers have been using virus-based vectors to deliver siRNA, one must keep in mind that there are risks attached to this method. There is the possibility that the virus becomes active; then the solution to one problem will be overshadowed by the creation of another. Moreover, the researchers must accurately determine the amount of siRNA that will be administered because a slightly deviation from the needed amount could trigger an immune response.
As it seems, there are still many details to figure out before using siRNA in the human body. However, Abe, N., Abe, H. & Ito, Y in their paper “Dumbbell-shaped nanocircular RNAs for RNA interference” demonstrated a way to solve one of the many roadblocks to efficient and precise siRNA delivery.
The enzymes in the body that attack the foreign natural RNA starts degrading the RNA at the loose ends. Therefore, in order to prevent this or delay the degradation, they decided to create dumbbell shaped RNAs. One issue with this alteration of the RNA shape was that they still needed Dicer, the enzyme that cleaves the RNA into siRNA, to recognize the RNA. Fortunately, studies showed that Dicer had no problem recognizing the dumbbell shaped RNAs. Finally, the dumbbell shaped RNAs proved to be more efficient than linear RNA in creating siRNA in both effectiveness and resistance. Therefore, this study demonstrates that slowly the barriers to using siRNA efficiently are being brought down and that, in the future, siRNA could be used safely in humans.
For more information, look at the following:
http://www.innovations-report.com/html/reports/life_sciences/report-104114.html

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http://pubs.acs.org/doi/full/10.1021/ja0754453?cookieSet=1