Tuesday, January 27, 2004

Nanofiber Gel Could Heal Spinal Damage

Nanofiber Gel Could Heal Spinal Damage
By Dwayne Hunter, Betterhumans Staff

A gel of tiny fibers could help reverse paralysis from spinal cord injury.

The gel, created by scientists from Northwestern University in Evanston, Illinois, contains a three-dimensional network of nanoscale fibers that form a scaffold to promote neuron growth.

'We have created new materials that because of their chemical structure interact with cells of the central nervous system in ways that may help prevent the formation of the scar that is often linked to paralysis after spinal cord injury,' says research leader Samuel Stupp, director of Northwestern's Institute for Bioengineering and Nanoscience in Advanced Medicine.

Stopping scars.
Following spinal cord injury the body can produce cells called astrocytes.
Astrocytes lead to scarring and hinder injury repair, which can cause paralysis.
Stupp and colleagues have shown that their scaffold directs cell differentiation so that neural progenitor cells become neurons and not astrocytes.

The scaffold contains nanofibers made of molecules called peptide amphiphiles.
Normally, the molecules repel each other and remain liquid, but positively charged molecules such as the calcium in living tissue causes them to clump together.
They clump in such a way that they self-assemble into porous tubes about five nanometers wide and several hundred nanometers long.

Directing cells
To encourage neuron growth, Stupp and colleagues added a biological 'signal' to the mix.

When their peptide amphiphiles self-assemble into nanofibers, they present on their surface a sequence of five amino acids known to promote neuron growth.