In the search for effective in vivo carriers for therapeutic applications of siRNAs, Nishina, Unno and coworkers utilized alpha-tocopherol (vitamin E) as a carrier molecule.⁽¹⁾ They hypothesized that a molecule that had its own transport pathway, was essential for target tissue cells, yet was not synthesized within the cells would be an ideal in vivo carrier conjugate. Their results indicate that alpha-tocopherol is a safe and effective carrier for delivery of siRNA into the liver. Following their lead, we have modified alpha-tocopherol with the mixed polarity TEG linker, and produced the corresponding phosphoramidite (BA0357) which is useful for modification of oligonucleotides either internally or at the 5'-terminus.

For alternative phosphoramidites, see LK2163 and LK2194. For post-synthetic tocopherol labeling please see our Tocopherol-TEG azide (FC 8160).

Ref:

1. Nishina, K.; Unno, T.; Uno, Y.; Kuboodera, T.; Kanouchi, T.; Mizusawa, H.; Yokota, T. Molecular Therapy 2008, 16, 724–740.