Harvard medical researchers are exploring novel ways of mobilizing molecules to transport other molecular structures across certain physiologic barriers.  In this wonderfully exciting case, the transport molecule is the virus which is responsible for rabies infections.

Rabies viruses travel from the site of infection (a local wound bite) to the nerves, through which it gains access to the brain. It is one of the few viruses known to be nearly 100% deadly to mankind, when vaccination has not been administrated. Kumar and colleagues took advantage of the virus’ neurotropic ability by isolating a protein from the viral outer layer used to bind to the brain cells. They then attached an experimental drug to the purified fragment of protein, a small-interfering RNA. This RNA-peptide complex showed highly specific ability to access neurons in the brain that expressed receptors to the neurotransmitter acetylcholine. This high specificity of drug action was demonstrated to only occur in the brain, and not in other tissues of the body.

In this study, the drug was injected into the tail of the mice, targeting the blood vessels. Using small interfering RNA (siRNA) as a drug treatment for many diseases has been powerfully successful in other animal models, but the problem has always been the process of making it a practical drug for clinical application. Therefore, this new technology developed by Kumar et al sheds light into a new, non-invasive and feasible way to deliver siRNA specifically to the brain.

LINK via Brainblogger