Tuesday, December 16, 2008

Intrathecal Delivery of siRNA

We wanted to present yet another publication referencing successful delivery of siRNA using i-FectTM:

Suneeta Tumati, Tally Largent Milnes, Henry I. Yamamura, Todd W. Vanderah, William R. Roeske and Eva V. Varga. Intrathecal Raf-1-selective siRNA attenuates sustained morphine-mediated thermal hyperalgesia. doi:10.1016/j.ejphar.2008.10.033

...siRNAs stock solutions (100 μM) were prepared in double distilled RNAse free water and stored in aliquots at −80 °C. For intrathecal treatment, aliquots of the stock solution (2 μg of the appropriate siRNA) were mixed (1:5 v/v)with i-Fect transfection reagent (Neuromics, Edina, MN). After recovery from the surgery (5–7 days), the animals received intrathecal injections (2 ug siRNA/10 ul/rat) of either a lipid encapsulated Raf-1-selective siRNA mixture (Smart pool siRNA, Dharmacon Inc; Chicago, IL, Cat # L-087699-00) (Raf-1 siRNA groups) or i-Fect encapsulated non-targeting dsRNA (Dharmacon, #D-001810-01-20) (control mismatch siRNA groups) or the transfection lipid alone, once daily, for 3 days, as described earlier (Gardell et al., 2002). Intrathecal injections of the siRNAs or the transfection agent alone did not cause any sign of behavioral toxicity. Western blots, using a Raf-1-selective antibody, indicated that intrathecal treatment with the Raf-1-selective siRNA mixture for 3 days significantly reduced Raf-1 protein levels in the dorsal root ganglion and in the dorsal horn of the spinal cord...