New improved enzyme could help facilitate spinal cord injuries
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Christopher
- Posts: 845
- Joined: Wed Jun 18, 2003 10:09 pm
- Injury Description, Date, extent, surgical intervention etc: Date of Injury: 12/15/02
Level of Injury:
-dominant side C5, C6, & C7 avulsed. C8 & T1 stretched & crushed
BPI Related Surgeries:
-2 Intercostal nerves grafted to Biceps muscle,
-Free-Gracilis muscle transfer to Biceps Region innervated with 2 Intercostal nerves grafts.
-2 Sural nerves harvested from both Calves for nerve grafting.
-Partial Ulnar nerve grafted to Long Triceps.
-Uninjured C7 Hemi-Contralateral cross-over to Deltoid muscle.
-Wrist flexor tendon transfer to middle, ring, & pinky finger extensors.
Surgical medical facility:
Brachial Plexus Clinic at The Mayo Clinic, Rochester MN
(all surgeries successful)
"Do what you can, with what you have, where you are."
~Theodore Roosevelt - Location: Los Angeles, California USA
New improved enzyme could help facilitate spinal cord injuries
This is very promising because this enzyme has been studied and worked with since the 1970's and looks like its potential is finally coming to fruition.
Christopher
http://www.news-medical.net/news/200911 ... uries.aspx
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New improved enzyme could help facilitate spinal cord injuries
4. November 2009 02:16
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.
At physiological body temperature, chABC enzyme loses half of its enzymatic activity within one hour and their remaining functionality within three to five days. To thermostabilize the enzymes, Bellamkonda, Emory University cell biology associate professor Robert McKeon and Georgia Tech graduate student Hyun-Jung Lee mixed the enzyme with the sugar trehalose. The result -- the enzyme's activity was stabilized at internal body temperature for up to four weeks during in vitro tests.
The researchers then used a lipid microtube-hydrogel scaffold system to deliver the thermostabilized enzymes into animals via a single injection. The scaffold provided sustained delivery of the enzyme for two weeks, with the microtubes enabling slow release and the hydrogel localizing the tubes to the lesion site. This delivery system also allowed the enzyme to diffuse deeper into the tissue than did catheter delivery.
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.
"These results bring us a step closer to repairing spinal cord injuries, which require multiple steps including minimizing the extent of secondary injury, bridging the lesion, overcoming inhibition due to scar, and stimulating nerve growth," added Bellamkonda, who is also deputy director of research for GTEC, a regenerative medicine center based at Georgia Tech and Emory University, and a Georgia Cancer Coalition Distinguished Cancer Scholar.
Christopher
http://www.news-medical.net/news/200911 ... uries.aspx
===================================================
New improved enzyme could help facilitate spinal cord injuries
4. November 2009 02:16
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.
At physiological body temperature, chABC enzyme loses half of its enzymatic activity within one hour and their remaining functionality within three to five days. To thermostabilize the enzymes, Bellamkonda, Emory University cell biology associate professor Robert McKeon and Georgia Tech graduate student Hyun-Jung Lee mixed the enzyme with the sugar trehalose. The result -- the enzyme's activity was stabilized at internal body temperature for up to four weeks during in vitro tests.
The researchers then used a lipid microtube-hydrogel scaffold system to deliver the thermostabilized enzymes into animals via a single injection. The scaffold provided sustained delivery of the enzyme for two weeks, with the microtubes enabling slow release and the hydrogel localizing the tubes to the lesion site. This delivery system also allowed the enzyme to diffuse deeper into the tissue than did catheter delivery.
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.
"These results bring us a step closer to repairing spinal cord injuries, which require multiple steps including minimizing the extent of secondary injury, bridging the lesion, overcoming inhibition due to scar, and stimulating nerve growth," added Bellamkonda, who is also deputy director of research for GTEC, a regenerative medicine center based at Georgia Tech and Emory University, and a Georgia Cancer Coalition Distinguished Cancer Scholar.
