First evidence that chitosan could repair spinal damage

Apr 16, 2010

Spinal injuries are some of the most debilitating that anyone can suffer. However, Richard Borgens and his team from the Center for Paralysis Research at the Purdue School of Veterinary Medicine can now offer spinal cord damage sufferers some hope. They publish their discovery in the Journal of Experimental Biology that chitosan, a sugar, can target and repair damaged spinal cord nerve membranes and restore nerve function.

Richard Borgens and his colleagues from the Center for Paralysis Research at the Purdue School of Veterinary Medicine have a strong record of inventing therapies for treating . From Ampyra, which improves walking in multiple sclerosis patients to a spinal cord simulator for spinal injury victims, Borgens has had a hand in developing therapies that directly impact patients and their quality of life.

Another therapy that is currently undergoing testing is the use of polyethylene glycol (PEG) to seal and repair damaged spinal cord nerve cells. By repairing the damaged membranes of nerve cells, Borgens and his team 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. 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. Could they find a sugar that restored spinal cord activity as effectively as PEG? Borgens and his team publish their discovery that chitosan can repair damaged nerve cell membranes in The on 16 April 2010.

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. If the chitosan repaired the crushed membranes then the spinal cord tissue would be unstained, but if the chitosan had failed, the spinal cord neurons would be flooded with the fluorescent dye. Viewing a section of the spinal cord under the microscope, Cho was amazed to see that the spinal cord was completely dark. None of the dye had entered the . Chitosan had repaired the damaged cell membranes.

Next Cho tested whether a dose of chitosan could prevent large molecules from leaking from damaged spinal cord cells. Testing for the presence of the colossal enzyme lactate dehydrogenase (LDH), Borgens admits he was amazed to see that levels of LDH leakage from chitosan treated spinal cord were lower than from undamaged spinal cords. Not only had the sugar repaired membranes at the compression site but also at other sites where the cell membranes were broken due to handling. And when the duo tested for the presence of harmful reactive oxygen species (ROS), released when ATP generating mitochondria are damaged, they found that ROS levels also fell after applying chitosan to the damaged tissue: chitosan probably repairs mitochondrial membranes as well as the nerve cell membranes.

But could chitosan restore the spinal cord's ability to transmit electrical signals to the brain through a damaged region? Measuring the brain's response to nerve signals generated in a guinea pig's hind leg, the duo saw that the signals were unable to reach the brain through a damaged spinal cord. However, 30·min after injecting chitosan into the rodents, the signals miraculously returned to the animals' brains. Chitosan was able to repair the damaged spinal cord so that it could carry signals from the animal's body to its brain.

Borgens is extremely excited by this discovery that chitosan is able to locate and repair damaged 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 'giving us a dual bang for our buck,' says Borgens.

Explore further: Ultrasound enhancement provides clarity to damaged tendons, ligaments

More information: Cho, Y., Shi, R. and Borgens, R. B. (2010). Chitosan produces potent neuroprotection and physiological recovery following traumatic spinal cord injury. J. Exp. Biol. 213, 1513-1520. http://jeb.biologists.org

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plasticpower
not rated yet Apr 16, 2010
This is awesome! Did I really just read it took 30 minutes to repair a spinal cord injury in a laboratory mouse? This is insane! Awesome news! One of the worst things that could possibly happen to someone is paralysis after an unfortunate accident or for whatever other reason. The fact that this can be cheaply reversed with some sugar is simply mind blowing.
pulasthi_kanchana
not rated yet Apr 16, 2010
this is soo cool. In ayuveda they use crustacean shell's in treating spinal cord injuries. Though i am not so sure about effectiveness of it. It seems they knew this effect 1000s of year ago. But if this could be applied, it will be a great hope many many people.
CarolinaScotsman
not rated yet Apr 16, 2010
How long after the damage is the treatment effective? Does it only repair new damage or does it help old damage as well? In other words, will folks who have had nerve damage for years be able to benefit?
Ballgame
not rated yet Apr 16, 2010
As a very well educated paraplegic, I can safely state that all Spinal Cord Injury (SCI) treatments are for new injuries. After a certain length of time for a complete SCI (and it's very quick - within a year or so) the muscles atrophy to a point that one cannot recover from... without nervous tissue the muscles atrophy entirely and cannot be brought back. The function loss is complete and permanent.

However, there is hope that for older incomplete SCI (those who still have some function below the injury site) that certain treatments (I imagine this one too) can improve the function a person already has.
newsreader
5 / 5 (1) Apr 16, 2010
Amazing. It will be interesting to see what treatments arise from this discovery.
trekgeek1
5 / 5 (1) Apr 16, 2010
Absolutely amazing. Will I see paralysis cured within my lifetime? I certainly hope so. Maybe Ray Kurtzweil was correct, we may actually cure death within 30 years. The rate of technological advancement in all areas is amazing. I truly am experiencing the exponential growth of technology. Has anyone else noticed how new advancements seem to be approaching much faster than 10 years ago?