Nerve Regeneration One Step Closer in MIT Lab

Christopher Reeve, a quadripelegic since his traumatic fall from a horse resulted in the severing of nerves in his spinal cord, always held fast to the belief that one day he would walk again. Reeve didn’t survive long enough to realize his dream, but today, scores of research scientists, many funded by his foundation, now believe that nerve regeneration is not only possible, it is within reach.

This month, neuroscientists at MIT, lead by Dr Rutledge Ellis-Behnke, repaired traumatic nerve injuries in hamsters with severed optical nerves, not by surgery, but by causing the nerves to grow together and mend. Their breakthrough was founded in the fledgling science of nanotechnology, which applies engineering on a microscopic scale.

Most importantly, the healing was observable after only one day.

“We made a cut, put the material in, and then we looked at the brain over different time points,” said Ellis-Behnke. “The first thing we saw was that the brain had started to heal itself in the first 24 hours. We had never seen that before — so that was very surprising.”

The team injected the site of the injury with a solution of peptidic nanoparticles, which are tiny particles made of amino acids, the building blocks of protein. These particles actually latched onto both ends of the severed nerve and self-assembled a bridge in the gap of the nerve with a tiny scaffold that prevented any scar tissue from forming. Scar tissue usually forms quickly and blocks the hope of restoring the nerve function. The optic nerve then grew along the scaffolding to reconnect the function. The scaffolding itself dissolved as the nerve regrew, and the gap was completely healed within 72 hours.

The restored eyesight was confirmed when the hamsters were able to complete visually driven tasks to earn food rewards.

Ellis-Behnke sees this as the first step on the long road to human applications. “Eventually what we would look at is trying to reconnect disconnected parts of the brain during stroke and trauma.” Such therapy would benefit individuals whose quality of life might otherwise diminish with loss of functionality in the brain for tasks like communication. Ellis-Behnke’s team included scientists from MIT and Hong Kong University.