Medical boffins looking for the best way to deliver therapeutic stem cell treatments to the brain have come up with something that sounds like a Spider Jerusalem habit: snorting stem cells into the nose like cheap speed.
Other options all have their drawbacks. Drilling through the skull and injecting the stem cells is painful and carries some risks. You can also inject them into the bloodstream but only a fraction reach their target due to the blood-brain barrier.
The nose, however, might be a viable alternative. In the upper reaches of the nasal cavity lies the cribriform plate, a bony roof that separates the nose from the brain. It is perforated with pin-size holes, which are plugged with nerve fibres and other connective tissue. Since proteins, bacteria and viruses can enter the brain this way, Lusine Danielyan at the University Hospital of Tübingen in Germany, and her colleagues, wondered if stem cells would also migrate into the brain through the cribriform plate.
When the researchers pre-treated the nasal membrane of the mice with an enzyme called hyaluronidase to loosen the junctions between epithelial cells, even more stem cells entered the brain through the nose.
Other researchers have shown that you can also deliver therapeutic proteins such as neural growth factor into the brain in this way. If the results of this study can be repeated in humans, snorting stem cells might be a way of getting large numbers of cells into the brain without surgery. Repeated doses could also be given in the form of nasal drops.
I seem to remember a band of musicians in William Gibson’s Bridge trilogy who injected fetal tissue for kicks; snorting it would have been just that little bit more rock’n’roll, don’t you think?