Navigation Links
Lab-grown nerves promote nerve regeneration after injury
Date:3/19/2009

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
karen.kreeger@uphs.upenn.edu
215-349-5658
University of Pennsylvania School of Medicine
Source:Eurekalert  

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:
*Name:
*Comment:
*Email:
Related Image:
Lab-grown nerves promote nerve regeneration after injury
(Date:2/6/2016)... ... ... Shark Finds and Kevin Harrington, along with the Product Managers ... Belly Bands. , Having a dog is great—except when it wets every couch, bed, ... works, get Belly Bands, the easiest way to stop dogs from wetting on ...
(Date:2/5/2016)... ... ... Steven Tonkinson, 36, of Coconut Grove, Florida, ran the Miami Marathon on January ... year, he ran all 26.2 miles with a green 25-pound ShelterBox strapped to his ... This Sunday, while many are watching the Superbowl, Steven Tonkinson will strap on the ...
(Date:2/5/2016)... ... February 05, 2016 , ... VeloReality President ... next generation LYNX VR Indoor Trainer with multi-rider capability to an enthusiastic audience ... not only reduce the weight of the unit, they also enhance the rider's ...
(Date:2/5/2016)... , ... February 05, 2016 , ... ... setting the stage for new clinical and scientific initiatives have all marked the ... she was appointed President and CEO of the nation’s oldest cancer center, Candace ...
(Date:2/5/2016)... ... February 05, 2016 , ... ... of Popeyes Louisiana Kitchen restaurants, launched the 14th annual “Appetite for a Cure” ... adults with muscular dystrophy, ALS and related diseases that severely limit strength and ...
Breaking Medicine News(10 mins):
(Date:2/4/2016)... 4, 2016 Mettler-Toledo International Inc. (NYSE: ... Provided below are the highlights: , Sales ... with the prior year.  Reported sales decreased 3% as ... , Net earnings per diluted share as reported ... year period.  Adjusted EPS was $4.65, an increase of ...
(Date:2/4/2016)... Md. , Feb. 4, 2016 In response ... , the FDA,s Deputy Commissioner for Medical Products and Tobacco, ... plan to reassess the agency,s approach to opioid medications. The ... while still providing patients in pain access to effective relief. ... FDA will: , Re-examine the risk-benefit paradigm for ...
(Date:2/4/2016)... , Feb. 4, 2016  Blueprint Medicines ... discovering and developing highly selective investigational kinase medicines ... the appointment to its board of directors of ... with nearly 30 years of industry-related experience. ... of Blueprint Medicines. "Lonnel,s strong strategic experience developing ...
Breaking Medicine Technology: