Engineers
at the University of Sheffield have developed a method of assisting
nerves damaged by traumatic accidents to repair naturally, which could
improve the chances of restoring sensation and movement in injured
limbs.

   

In a collaborative study with Laser Zentrum Hannover in Germany and published April 23, 2012 in the journal Biofabrication, the team describes a new method for making medical devices called nerve guidance conduits or NGCs.

   

The
method is based on laser direct writing, which enables the fabrication
of complex structures from computer files via the use of CAD/CAM
(computer aided design/manufacturing), and has allowed the research team
to manufacture NGCs with designs that are far more advanced than
previously possible.

   

Currently
patients with severe traumatic nerve damage suffer a devastating loss
of sensation and/or movement in the affected limb. The traditional
course of action, where possible, is to surgically suture or graft the
nerve endings together. However, reconstructive surgery often does not
result in complete recovery.

   

“When
nerves in the arms or legs are injured they have the ability to
re-grow, unlike in the spinal cord; however, they need assistance to do
this,” says University of Sheffield Professor of Bioengineering, John
Haycock. “We are designing scaffold implants that can bridge an injury
site and provide a range of physical and chemical cues for stimulating
this regrowth.”

   

The
new conduit is made from a biodegradable synthetic polymer material
based on polylactic acid and has been designed to guide damaged nerves
to re-grow through a number of small channels.

   

“Nerves
aren’t just like one long cable, they’re made up of lots of small
cables, similar to how an electrical wire is constructed,” says lead
author Dr Frederik Claeyssens, of the University’s Department of
Materials Science and Engineering. “Using our new technique we can make a
conduit with individual strands so the nerve fibres can form a similar
structure to an undamaged nerve.”

   

Once the nerve is fully regrown, the conduit biodegrades naturally.

   

The team hopes that this approach will significantly increase recovery for a wide range of peripheral nerve injuries.

   

In
laboratory experiments, nerve cells added to the polymer conduit grew
naturally within its channelled structure and the research team is now
working towards clinical trials.

   

“If
successful we anticipate these scaffolds will not just be applicable to
peripheral nerve injury, but could also be developed for other types of
nerve damage too. The technique of laser direct writing may ultimately
allow production of scaffolds that could help in the treatment of spinal
cord injury,” says Dr Claeyssens.

   

“What’s
exciting about this work is that not only have we designed a new method
for making nerve guide scaffolds which support nerve growth, we’ve also
developed a method of easily reproducing them through micromolding,” he
adds. “This technology could make a huge difference to patients
suffering severe nerve damage.”

   

This research was funded by the Engineering and Physical Sciences Research Council.

Source:  University of Sheffield