Researchers at Purdue University have been able to limit the damage from spinal injury to rats by treating the injury quickly. The treatment involves injection of a polymer that fuses with damaged nerve cell membranes, sealing any holes and preventing the damage from spreading.
Animals treated with the polymer shortly after injury regained use of all four limbs, while untreated animals did not.
The inflammation caused by a spinal injury often has a cascading effect, leading to death of many more nerve cells than were originally damaged. This all starts when the outer membrane of some of the nerve cells gets damaged.
Soap and detergents are the best known micelle-formers. They dissolve in water and can also combine with oily dirt, which normally avoids water, bringing the dirt along into the water.
Everyone knows that oil and water don't mix, and this fact is part of the problem facing researchers trying to find a way to seal off nerve damage. Membranes are largely lipid (fat), while their surroundings are watery. Any injected agent that can fuse with and repair a membrane must be similar in structure to the membrane and also has to make its way through a watery environment (the blood) to the injury site. So the agent has to be both water−loving and oil−loving at the same time.
This is a job for micelles.
Micelles are structures that can interact with both oil and water. A micelle can form when a substance has both oil soluble and water soluble parts. Soap and detergents are the best known micelle−formers. They dissolve in water and can also combine with oily dirt, which normally avoids water, bringing the dirt along into the water.
Synthetic micelles have been used in the past as drug delivery systems, a way of getting a drug past the cell membrane's lipid barrier and into the cells. Here, the researchers created a synthetic polymer which has an outer water−loving head and an inner fat−loving core. When injected, this combination allows the polymer to migrate through the blood to the damaged nerve cells and then to seal up any holes in their membranes.
The study was published online by Nature Nanotechnology on November 8, 2009.