Regenerating Damaged Nerves with “Pac-Man” Cells
Biomedical engineers have found an unlikely ally in the struggle to regrow damaged nerves—the foot soldiers of the body’s immune system.
Macrophages are known as the Pac-Man of the immune system and form the body’s first line of defense against invasion—they indiscriminately engulf and eat most anything deemed a dangerous trespasser, whether it’s a bacterium or cellular debris from deceased tissue. Recent research, however, has shown that some macrophages also promote healing.
In a study appearing online the week of June 12 in the Proceedings of the National Academy of Sciences, researchers from Duke University have shown that summoning these pro-healing macrophages can greatly help regrow severed nerves in rats. The approach comes close to equaling the current best treatment—a surgical transplant using a nerve stripped from another part of the patient’s body.
“There’s been a long-held view that the best way to regrow severed nerves is to provide all sorts of matrix and growth proteins to coax repair,” said Ravi Bellamkonda, professor of biomedical engineering and Vinik Dean of the Pratt School of Engineering at Duke. “We’ve completely shifted that view by finding new players who have remained behind the scenes. We believe this approach will also have a major impact on regenerative medicine, even beyond this specific application.”
The peripheral nervous system includes nerves that run from the spinal cord to the rest of the body. It connects and controls movements, the digestive system, heart, lungs and other organs. When these relatively long cells—which can stretch for a meter or more—are damaged or severed, the injury is not easily healed.
The current standard of care, called an autograft, involves surgically removing a less important nerve, like the one running down the back of the calf, and grafting it into the damaged area. But the treatment has several drawbacks. A sensory neuron replacing a motor neuron is not a perfect replacement, painful neuromas can occur at the healing site, the patient loses the function of another nerve and, in the case of extensive injuries, there are only so many semi-disposable nerves in the body to harvest.
Researchers have long been working on an alternative approach using “nerve bridges” to span these gaps. The idea is to introduce a tube filled with growth factors and other goodies across the gap to coax the regrowth of the existing nerve, like luring a dog out of a hiding place with treats. But despite efforts to find the optimal combination of tube material, growth factors, proteins and other helpers, nothing has come close to matching the autograft’s success.
Bellamkonda and his group were travelling down this same road until some salamanders lost their tails.
“We saw a study showing that the early presence of macrophages were vital to a salamander’s ability to regenerate its tail,” said Nassir Mokarram, assistant research professor of biomedical engineering at Duke. “We also knew that rare instances of nerve regeneration were accompanied by a surge of these cells right after the injury occurred. Those two observations gave us the inspiration to see if the same idea could be applied with nerve bridges.”
In 2012, Bellamkonda and Mokarram showed that nerve regeneration could be increased in rats by forcing macrophages to become the pro-healing variety that secrete healing compounds. In the new paper, the researchers take their work a step further. Instead of issuing orders to make mature macrophages switch roles, they filled the nerve bridge with a biological signal shown to attract younger, undifferentiated cells destined to become pro-healing macrophages.
“Instead of retraining the demolition and cleanup crew, we hired a new workforce with a future in construction,” said Mokarram. “The results were significantly better. This is the closest anyone has ever been to equaling the efficacy of an autograft, and we did it with nothing more than a tube and the recruitment of the body’s own immune system.”
The researchers next plan to test the approach using a specialized nanofiber material they developed that has already proven better at bridging nerve endings than the tubes used in this proof-of-concept study.
“We’re the first group to prove this immunological approach to healing works with nerves in rodents,” said Mokarram. “We think this work will open a path to using similar methods in the much more complex and difficult arenas of the spinal cord and brain.”
Learn more: Regenerating Damaged Nerves with “Pac-Man” Cells
The Latest on: Nerve regeneration
AxoGen, Inc. to Report First Quarter 2018 Financial Results and Host Conference Call on April 30,
on April 18, 2018 at 4:11 am
About AxoGen AxoGen ( AXGN) is the leading company focused specifically on the science, development and commercialization of technologies for peripheral nerve regeneration and repair. We are passionate about helping to restore peripheral nerve function and ... […]
Global Nerve Repair & Regeneration Market Competitive landscape: Medtronic plc, Stryker Corporation
on April 16, 2018 at 11:10 pm
The global Nerve Repair & Regeneration market research report distils the most essential aspects of the Nerve Repair & Regeneration market and presents them in the form of a comprehensive and cohesive document. The findings of Nerve Repair & Regeneration ... […]
Global Nerve Repair & Regeneration Market Overview 2017-2026: Boston Scientific Incorporation
on April 15, 2018 at 11:18 pm
Apr 16, 2018 (marketresearch.biz via COMTEX) -- The report on the global Nerve Repair & Regeneration market is an insightful reference data for established players as well as new entrants in the Global Nerve Repair & Regeneration market. The data shown in ... […]
SANUWAVE Health, Inc. Announces the Eighth “SHOCK THIS” Blog
on April 12, 2018 at 7:00 am
She is regarded as a world leader in nerve regeneration enhancement and in developing minimal immunosuppression regimens following transplantation. Dr. Siemionow specializes in microsurgery, hand surgery, peripheral nerve surgery, transplantation ... […]
AxoGen Offers An Exciting Story At Nosebleed Prices
on April 12, 2018 at 5:31 am
Neuromas can form when nerves are cut during a surgery but not repaired – the nerves try (unsuccessfully) to regenerate and create tangled masses of nerve fibers and other tissue. This is more common in some surgeries than others (very common in ... […]
Contralateral Cervical Nerve Transfer for Arm Paralysis
on April 11, 2018 at 2:04 pm
According to an expected nerve regeneration speed of 1 in. per month, it would take 3 to 4 months to regenerate to the pectoralis major muscle. The subsequent branches are the thoracodorsal nerve, long thoracic nerve, and triceps branch of the radial nerve. […]
Gene jumpstarts regeneration of damaged nerve cells
on April 10, 2018 at 12:33 pm
Searching the entire genome, a Yale research team has identified a gene that when eliminated can spur regeneration of axons in nerve cells severed by spinal cord injury. The Yale team found more than 580 different genes that may play a role in regeneration ... […]
Nerve Regeneration and Repair Market Making CAGR of 11.7% by Analysis Showing Products Offered & Services Strategies, Key Insights by 2024
on April 10, 2018 at 10:35 am
Nerve Regeneration and Repair Market, By Type (Biomaterials (Nerve Conduits, Nerve Protectors, Nerve Wraps, Nerve Connectors), Neurostimalation (Internal (SCS, DBS, VNS, SNS, GES), External (TENS, TMS, RES))), By Indication (Failed Back Surgery Syndrome ... […]
Gene jumpstarts regeneration of damaged nerve cells
on April 10, 2018 at 9:29 am
Searching the entire genome, a Yale research team has identified a gene that when eliminated can spur regeneration of axons in nerve cells severed by spinal cord injury. "For the first time, the limits on nerve fiber regeneration were studied in an ... […]
Nerve Regeneration Market 2018 by Top Leaders, Business Figures CAGR of 11.3% during and Prediction by 2023
on April 9, 2018 at 5:03 am
Get a Sample Report @ https://www.marketresearchfuture.com/sample_request/1202. The global nerve regeneration market is segmented on the basis of product, by application, and by method. On the basis of product, it is segmented into biomaterials ... […]
via Google News and Bing News