Micro-Grooves Promise Nerve Regeneration for Handicapped

Using microscale channels cut in an ultra-thin biodegradable polymer, Surya
Mallapragada, an associate of the Department of Energy's Ames Laboratory and
a chemical engineering professor at Iowa State University, is working to
regrow nerve cells. To put the microscale grooves in the polymers, both laser
etching and reactive ion etching were used. 

The technique, which may one day allow the paralyzed to walk and the blind to
regain some vision, has been proven to work for peripheral nerve regeneration
in laboratory rats. 

Nerve cells are unlike most other biological tissue. When a nerve is severed,
the part of the neuron "downstream" of the injury typically dies off. And
neurons in the human body can be several feet long. Grafting, which works
well for other tissue such as skin, isn't the best option because of loss of
nerve function where the donor tissue is removed and the difficulty in
getting the nerve cells to line up and reconnect. 

Nerve cells aren't able to easily bridge gaps of more than one centimeter.
But, starting with biodegradable polymer films a few hundred microns thick,
Mallapragada and her colleagues etch "nerve-ready" channels three to four
microns deep to guide them on their paths. 

Mallapragada's next phase of research will be on developing arrays of
microelectrodes that would allow an interface of the optic nerve to a
so-called retinal chip. 

For further information on the project, go to
http://link.abpi.net/l.php?20030220A2