Med-Chemist: Chitosan could repair spinal damage

Tuesday, April 20, 2010

Chitosan could repair spinal damage - first evidence....

Polyethylene glycol (PEG) was reported to seal and repair damaged spinal cord nerve cells, by repairing the damaged membranes of nerve cells. Researchers lead by Richard Borgens and his team claimed that, PEG can restore the spinal cord's ability to transmit signals to the brain. However, there is one possible clinical drawback: PEG's breakdown products are potentially toxic.

So, is there a biodegradable non-toxic compound that is equally effective at targeting and repairing damaged nerve membranes? Borgens teamed up with physiologist Riyi Shi and chemist Youngnam Cho, who pointed out that some sugars are capable of targeting damaged membranes. Borgens and his team has now come up with an interesting finding i.e., chitosan (see structure; source : Wikipedia) can repair damaged nerve cell membranes.

Having initially tested mannose and found that it did not repair spinal cord nerve membranes, Cho decided to test a modified form of chitin, one of the most common sugars that is found in crustacean shells. Converting chitin into chitosan, Cho isolated a segment of guinea pig spinal cord, compressed a section, applied the modified chitin and then added a fluorescent dye that could only enter the cells through damaged membranes. Viewing a section of the spinal cord under the microscope, Cho was amazed to see that the spinal cord was completely dark and none of the dye had entered the nerve cells and Cho concluded that Chitosan had repaired the damaged cell membranes.

Borgens is extremely excited by this discovery that chitosan is able to locate and repair damaged spinal cord tissue and is even more enthusiastic by the prospect that nanoparticles of chitosan could also target delivery of neuroprotective drugs directly to the site of injury.