Thursday, December 13, 2007
Biopolymers - Beating the crap out of biomonomers
Actually, I don't know if biomonomers are are better or not. I'm running out of headlines ideas.
GATech, an underappreciated powerhouse of neural engineering, reports that a couple researchers have been using "ACh-like" chemical to stimulate CNS nerve growth (in the spine). I've only got the news bites (linked below), but here's how it goes, I think.
Previous work has shown that laminin induces nerve regeneration by providing a scaffolding signal for the sprouting processes to travel down. Laminin dissolves quickly, though, making it a poor choice when not dealing with a petri dish. Part of regeneration is not only providing the necessary trophic environment, but also activating the growing fibers. Using a polymer with ACh binding domains, these GATechies were able to get both the scaffolding and activation needed to induce regeneration. There are also issues of how much activation is needed, which can be tested by just varying the number of embedded ACh binding sites - in this case they settled on 70% max.
One problem that remains is that the polymer does not dissolve at all, meaning that long term implantation could eventually lead to biocompatibility problems down the road, but I assume that some savvy chemist will make a dissolvable polymer replacement as soon as the timecourse for reinnervation is determined (don't want it dissolving too quick or too slow).
If complete reinnervation isn't possible, this could also be used to direct nerve growth from severed cells, to a biochip interface for using a BCI (depending on how much axon retraction there is).
Reports here and here.