Ga Tech Researchers Make Headway in Treating Spinal Cord Injuries

[boda]

ATLANTA, GA (WABE) - Scar tissue serves an important function by limiting the size of a wound.
But in spinal cord injuries, scar tissue gets in the way of nerve fibers trying to regenerate. Now, a discovery at Georgia Tech offers promise to those recovering from spinal cord injuries. WABE's Jim Burress explains.

There's an enzyme that eats away at scar tissue. But that enzyme doesn't work well at normal body temperatures.

Now, a team headed by Georgia Tech biomedical engineering professor Ravi Bellamkonda may have solved that problem. The answer involves mixing the enzyme with a type of sugar then suspending it in a gel:

"With a single injection it lasts for about six weeks and the scar is degraded and the nerves are able to grow back potentially."

and that's a big "potentially." This discovery opens one door, but there are still many elusive questions:

"After they grow back, will they find the neurons they were originally connected to? Will the brain relearn to use those neurons then to do the functional things?"

The findings are published in the Proceedings of the National Academy of Sciences.

http://www.publicbroadcasting.net/wa....Cord.Injuries

[Roger]

Here's the link to the paper at the National Academy of Sciences.


Spinal cord regeneration enabled by stabilizing, improving delivery of scar-degrading enzyme

Researchers have developed an improved version of an enzyme that degrades the dense scar tissue that forms when the central nervous system is damaged. By digesting the tissue that blocks re-growth of damaged nerves, the improved enzyme – and new system for delivering it – could facilitate recovery from serious central nervous system injuries.
The enzyme, chrondroitinase ABC (chABC), must be supplied to the damaged area for at least two weeks following injury to fully degrade scar tissue. But the enzyme functions poorly at body temperature and must therefore be repeatedly injected or infused into the body.
In a paper published November 2 in the early edition of the journal Proceedings of the National Academy of Sciences, researchers describe how they eliminated the thermal sensitivity of chABC and developed a delivery system that allowed the enzyme to be active for weeks without implanted catheters and pumps. This work was supported by the National Institutes of Health.
"This research has made digesting scar clinically viable by obviating the need for continuous injection of chABC by thermally stabilizing the enzyme and harnessing bioengineered drug delivery systems," said the paper's lead author Ravi Bellamkonda, a professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. ....................more

http://www.eurekalert.org/pub_releas...-scr102809.php

[lofulgee]

have there been any test of this enzyme in human or rat???

[antiquity]

sounds promising.

In animal studies, the enzyme's ability to digest the scar was retained for two weeks post-injury and scar remained significantly degraded at the lesion site for at least six weeks. The researchers also observed enhanced axonal sprouting and recovery of nerve function at the injury site when the thermostabilized enzyme was delivered.

The delivery system also enabled the combination of therapies. Animals treated with thermostabilized chABC in combination with sustained delivery of neurotrophin-3 -- a protein growth factor that helps to support the survival and differentiation of neurons -- showed significant improvement in locomotor function and enhanced growth of sensory axons and sprouting of fibers for the neurotransmitter serotonin...

[Wise Young]

Originally Posted by antiquity

sounds promising.

I agree. Dozens of laboratories have shown that this enzyme allows regeneration in the spinal cord of rats in the past decade. I did not know that this enzyme is thermally unstable. It is well known that the enzyme must be prepared fresh to be effective. It cannot be put into an alzet pump, for example, and released slowly into the spinal cord.

The enzyme is quite effective, however, when injected into the spinal cord. Our laboratory, for example, found that a single injection of chondroitinase into the spinal cord will clear all the CSPG within centimeters of the injection site for up to two weeks.

Wise.

[Muriel]

We used to give older horses or ones suffering from stiffness glucosamine-chondroitin and MSM it worked really well for there joints etc. I was wondering is this type of chondroitin related to the chondroitinase enzyme. (sorry i am not very scientific)

[George78]

Originally Posted by Wise Young

I agree. Dozens of laboratories have shown that this enzyme allows regeneration in the spinal cord of rats in the past decade. I did not know that this enzyme is thermally unstable. It is well known that the enzyme must be prepared fresh to be effective. It cannot be put into an alzet pump, for example, and released slowly into the spinal cord.

The enzyme is quite effective, however, when injected into the spinal cord. Our laboratory, for example, found that a single injection of chondroitinase into the spinal cord will clear all the CSPG within centimeters of the injection site for up to two weeks.

Wise.

Dear Wise,
Thanks for the follow up.
I do believe that removing scar tissue combined to intensive exercises coud help us. How far do we know if chrondroitinase could be harmful for the body?.. Is there a well known and established procedure to deliver chondroitinase into the spine?.. Do you know if any country could apply that procedure *now*?.. :-)
Many thanks
Best regards.
George

[boda]

Originally Posted by George78

Dear Wise,

I do believe that removing scar tissue combined to intensive exercises coud help us. How far do we know if chrondroitinase could be harmful for the body?.. Is there a well known and established procedure to deliver chondroitinase into the spine?..

Even on a smaller scale, wouldn't getting scar tissue out at lease be a step in the right direction. If i am not mistaken, wasn't there a study published, showing that nerves are trying to regrow, but are inhibited by the scar tissue?

[Duran]

Originally Posted by George78

Is there a well known and established procedure to deliver chondroitinase into the spine?

A British group insert a gene for chondroitinase directly into cells so that modified human cells can produce and secrete this enzyme within the spinal cord.

They believe that transplantation of these cells combined with physical rehabilitation can promote recovery.

[Wise Young]

Originally Posted by George78

Dear Wise,
Thanks for the follow up.
I do believe that removing scar tissue combined to intensive exercises coud help us. How far do we know if chrondroitinase could be harmful for the body?.. Is there a well known and established procedure to deliver chondroitinase into the spine?.. Do you know if any country could apply that procedure *now*?.. :-)
Many thanks
Best regards.
George

George78,

Until recently, chondroitinase had to be made prepared as a fresh solution daily and injected into the spinal cord. In solution, apparently the enzyme is heat sensitive. As a freeze-dried power, it does not degrade. Elizabeth Bradley was the first to show that if the chondroitinase is injected directly into the spinal cord, it will clear most of the chondroitin-6-sulfate-proteoglycan (CSPG) out of the way. She and Fawcett led the way in this work in the early 2000's. This discovery, i.e. creating a heat-stable form of the enzyme that continues to maintain its activity for a long time, should allow delivery of the enzyme to the spinal cord through a pump.

Wise.