Putting the next generation of medicines on pharmacy shelves hinges on an intensive search for ways of safely and effectively delivering a silencing message to genes that are at the basis of innumerable diseases. That's the gist of an article about the status of drug development based on RNA interference - nature's gene-silencing mechanism - in the Sept. 7 issue of Chemical + Engineering News (C+EN), ACS's weekly newsmagazine.
In the cover story, C&EN Senior Editor Lisa M. Jarvis explains that cells use it to control the activity of genes. Cells naturally use strands of material called silent interfering RNA, or siRNA, to reroute the instructions for making proteins so they never get made. For years, scientists have been excited by the idea of using siRNA as drugs, introducing it to patients to turn off production of disease-causing proteins. They initially thought that they could simply inject bits of siRNA into patients and knock down diseases.
Jarvis describes a growing realization that to get inside cells siRNA would need to hitch a ride. To date, the delivery vehicles of choice wrap siRNA inside a tiny bubble of lipids, polymers, or other materials. But those vehicles can reach only so many places, and they aren't so good at unloading their genetic passengers. The article details a range of efforts underway in the pharmaceutical industry and academic labs to develop new and better siRNA delivery technologies.