Biological stability and activity of siRNA in ionic liquidsElectronic supplementary information (ESI) available. See DOI: 10.1039/c4cc05086j

We report substantially enhanced biological stability of siRNA in a hydrated ionic liquid (IL) based on buffered choline dihydrogen phosphate (CDP). The results show that hydrated CDP IL substantially prolongs the shelf-life of siRNA for up to three months in the presence of RNase A. Remarkably, siRNA stored in the IL remained active and eGFP siRNA exhibited clear gene knockdown effects in eGFP-expressing HeLa cells. We found that CDP IL can significantly enhance the biological stability of siRNA. More importantly siRNA in IL can still maintain high levels of gene knockdown activity.