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:3/28/2017)... ... March 28, 2017 , ... Neurotechnology , a provider ... and attendance tracking products: the new NCheck Cloud Bio Attendance cloud-based service and ... biometric face recognition to enable users to check in and out from anywhere ...
(Date:3/28/2017)... ... March 28, 2017 , ... In its ongoing ... website has recently developed and published an informational resource that addresses frequently asked ... on common inquiries the site’s team of third party administrator (TPA) contributors regularly ...
(Date:3/28/2017)... ... March 28, 2017 , ... A minimally invasive ... “perfect smile.” The National Association of Dental Laboratories (NADL) is informing dentists about ... aware of when utilizing dental laboratories and technicians that create these veneers. ...
(Date:3/28/2017)... Square, PA (PRWEB) , ... March 28, 2017 , ... ... online and across a variety of business channels. , While many results are ... of any public relations program. , When it comes to measurement, firms should ...
(Date:3/28/2017)... ... 28, 2017 , ... Silicon Valley Hair Institute, the San Francisco Bay Area ... about women’s hair loss. Although hair transplant procedures can be seen as more of ... genetics can be two reasons a woman may see her hair thinning. , “We ...
Breaking Medicine News(10 mins):
(Date:3/27/2017)... Calif. , March 27, 2017  Impax Laboratories, ... has appointed Paul M. Bisaro as Impax,s ... the Company,s Board, effective March 27, 2017. Mr. Bisaro ... served as Interim President and Chief Executive Officer since ... of generic and branded pharmaceutical experience, Mr. Bisaro, 56, ...
(Date:3/27/2017)... Genprex, Inc. , a privately held, clinical-stage biopharmaceutical company developing immunogene ... Chief Operating Officer, is scheduled to present a corporate overview at ... Cancer BioPartnering & Investment Forum: Tuesday, March 28, 2017 at 3:00 ... ... Future Leaders in Biotech Industry – Friday, April 7, 2017 at ...
(Date:3/24/2017)... 2017 Research and Markets has announced ... report to their offering. ... The Cell Therapy Manufacturing Market, 2017-2027 ... of cell therapy manufacturing and focuses both on contract manufacturers ... are anticipated to emerge as viable alternatives to conventional treatment ...
Breaking Medicine Technology: