US scientists have found that a polymer laced with chemicals that mimic a key neurotransmitter has the ability to trigger the regeneration of damaged nerve cells.
Yadong Wang, a researcher at the Georgia Institute of Technology in Atlanta, believes that scaffolds made from the material may eventually facilitate the development of new neurons in people with damaged optic nerves, and thereby restore sight to them.
When damage occurs, neuronal activity dramatically decreases. Since some damaged nerves do not respond to growth factors unless also stimulated by neuronal activity, the decrease in it hinders the restoration of damaged nerves.
"It's a catch-22 situation," New Scientist journal quoted Wang as saying.
Working with graduate student Christiane Gumera, Wang has now developed a polymer laced with chemicals that mimic a neurotransmitter called acetylcholine that relays, amplifies, and modulates signals sent between neurons.
The researchers were of the opinion that the polymer could cause damaged nerve cells to regenerate.
"The polymer's 'backbone' is like a string. But every once in a while there's a branch coming off which has a chemical that mimics a neurotransmitter," said Wang.
During experiments with cultured cells, the researcher found that the polymer could simulate the growth of neuritis, the fibre-like projections that connect neurons, at a rate of 0.7 millimetres a day.
The researchers are now planning to involve in their research honeycomb-like scaffolds made from the polymer to encourage nerve regeneration in rats. They believe that such structures may not only be helpful in stimulating nerve regeneration, but also direct its growth.
"We could use these to bridge severed nerve ends," Wang said.
The biodegradable character of the polymer raises the likelihood that the scaffolds will safely break down once the job completes. Wang believes that similar scaffolds can be used to repair spinal injury also.
However, there are some experts who are sceptical about the efficiency of Wang's method.
"This scar tissue acts like a wall," says Martin Schwab of the Brain Research Institute at the University of Zurich in Switzerland, adding that this wall blocks regenerating nerves from passing through.
Wang also admits that scar tissue may be a major problem, but he is hopeful that the polymer might be used to treat neurodegenerative disorders another way, that is, by stimulating stem cells to differentiate into neurons.
"We have preliminary data to suggest that this may be possible. But we need to do more experiments to prove it," he said.
The study has been reported in the journal Advance Materials.