Navigation Links
Lab-grown nerves promote nerve regeneration after injury

PHILADELPHIA Researchers at the University of Pennsylvania School of Medicine have engineered transplantable living nerve tissue that encourages and guides regeneration in an animal model. Results were published this month in Tissue Engineering.

About 300,000 Americans suffer peripheral nerve injuries every year, in many cases resulting in permanent loss of motor function, sensory function, or both. These injuries are a common consequence of trauma or surgery, but there are insufficient means for repair, according to neurosurgeons. In particular, surgeons need improved methods to coax nerve fibers known as axons to regrow across major nerve injuries to reconnect healthy targets, for instance muscle or skin.

"We have created a three-dimensional neural network, a living conduit in culture, which can be transplanted en masse to an injury site," explains senior author Douglas H. Smith, MD, Professor, Department of Neurosurgery and Director of the Center for Brain Injury and Repair at Penn. Smith and colleagues have successfully grown, transplanted, and integrated axon bundles that act as 'jumper cables' to the host tissue in order to bridge a damaged section of nerve."

Previously, Smith and colleagues have "stretch-grown" axons by placing neurons from rat dorsal root ganglia (clusters of nerves just outside the spinal cord) on nutrient-filled plastic plates. Axons sprouted from the neurons on each plate and connected with neurons on the other plate. The plates were then slowly pulled apart over a series of days, aided by a precise computer-controlled motor system.

These nerves were elongated to over 1 cm over seven days, after which they were embedded in a protein matrix (with growth factors), rolled into a tube, and then implanted to bridge a section of nerve that was removed in a rat.

"That creates what we call a 'nervous-tissue construct'," says Smith. "We have designed a cylinder that looks similar to the longitudinal arrangement of the nerve axon bundles before it was damaged. The long bundles of axons span two populations of neurons, and these neurons can have axons growing in two directions - toward each other and into the host tissue at each side.

The constructs were transplanted to bridge an excised segment of the sciatic nerve in rats. Up to 16 weeks post-transplantation, the constructs still had their pre-transplant shape, with surviving transplanted neurons at the extremities of the constructs spanned by tracts of axons.

Remarkably, the host axons appeared to use the transplanted axons as a living scaffold to regenerate across the injury. The authors found host and graft axons intertwined throughout the transplant region, suggesting a new form of axon-mediated axonal regeneration. "Regenerating axons grew across the transplant bridge and became totally intertwined with the transplanted axons," says Smith

Axons throughout the transplant region showed extensive myelination, the fatty layer surrounding axons. What's more, graft neurons had extended axons beyond the margins of the transplanted region, penetrating deep into the host nerve. Remarkably, the constructs survived and integrated without the use of immunosuppressive drugs, challenging the conventional wisdom regarding immune tolerance in the peripheral nervous system.

The researchers suspect that the living nerve-tissue construct encourages the survival of the supporting cells left in the nerve sheath away from the injury site. These are cells that further guide regeneration and provide the overall structure of the nerve.

"This may be a new way to promote nerve regeneration where it may not have been possible before," says co-first author D. Kacy Cullen, PhD, a post doctoral fellow in the Smith lab. "It's a race against time - if nerve regeneration happens too slowly, as may be the case for major injuries, the support cells in the extremities can degenerate, blunting complete repair. Because our living axonal constructs actually grow into the host nerve sheath, they may 'babysit' these support cells to give the host more time to regenerate."


Contact: Karen Kreeger
University of Pennsylvania School of Medicine

Related medicine news :

1. Be Free From Exam Nerves
2. New Pathways Studied to Repair Nerves
3. Baby's Blindness Resolved, Nerves in Knee Regenerated and Other Unusual Complimentary Therapies from BiomagScience
4. Brain cells help neighboring nerves regenerate
5. Overactive nerves in head and neck may account for ringing in the ears
6. Protein in human hair shows promise for regenerating nerves
7. Capitol Hill Briefing Scheduled for March 24 to Promote Colorectal Cancer Screening and Care
8. Indoor Tanning Association Promotes Responsible Tanning for Spring Breakers
9. Telehealth for diabetes promotes aging at home, not in the hospital
10. Medical Disposables Promotes Jennifer Munoz as Vice President of Marketing
11. Availity Promotes Russ Thomas to President and Chief Operating Officer
Post Your Comments:
Related Image:
Lab-grown nerves promote nerve regeneration after injury
(Date:11/24/2015)... Texas (PRWEB) , ... November 24, 2015 , ... Charitable ... all charitable donations are made in the last five weeks of the year totalling ... was created in 2012 to connect the nation’s charities with those individuals who want ...
(Date:11/24/2015)... (PRWEB) , ... November 24, 2015 , ... ... national leaders when it comes to several aspects of orthopedic care. They have ... replacements, orthopedic surgeries and general orthopedic care. , Becker's Hospital Review selected ...
(Date:11/24/2015)... (PRWEB) , ... November 24, 2015 , ... In response ... growing epidemic as deaths from prescription opioids in the United States grew 400 percent ... In 2013 alone, opioids were involved in 37 percent of all fatal drug overdoses. ...
(Date:11/24/2015)... ... , ... Serenity Point Rehabilitation, a holistic treatment center for substance abuse located ... the staff members at their recovery center. The videos highlight some of the various ... the things that make their recovery program so unique. , “Making the decision to ...
(Date:11/24/2015)... ... November 24, 2015 , ... Chiropractic student Katie Benson received ... in Overland Park, Kansas. Benson, a fifth-trimester student in the university’s College of ... on October 16. , “Katie is very excited and greatly appreciative to receive ...
Breaking Medicine News(10 mins):
(Date:11/24/2015)... NEW DELHI , November 25, 2015 ... fear invoked due to repeated failure of IVF cycles. ... Rani Bhatia was totally dejected and had lost all hopes that ... the first Indian miracle child conceived after failure of ... to abroad (UK) before they decided to take one last ...
(Date:11/24/2015)... Colo. , Nov. 24, 2015  Array ... that its Chief Executive Officer, Ron Squarer ... Healthcare Conference in New York.  The public is ... webcast on the Array BioPharma website.Event:Piper Jaffray Annual ... , Wednesday, December 2, 2015Time:1:30 p.m. Eastern Time ...
(Date:11/24/2015)... November 2015 Avery Biomedical Devices ... ist erfreut, die Berufung von Anders Jonzon, ... zu können.   ... Foto -   ... 1984-1986 war er Fellow des Cardiovascular Institute ...
Breaking Medicine Technology: