Nanomedicine may help spinal cord injuries

WEST LAFAYETTE, Ind., Nov. 10 (UPI) -- Purdue University scientists say they've developed a technique that uses nanomedicine to help repair damaged spinal cord nerve fibers.

The researchers say their new approach involves injecting nanospheres into the bloodstream shortly after an accident. The synthetic "copolymer micelles" are drug-delivery spheres about 60 nanometers in diameter, or roughly 100 times smaller than the diameter of a red blood cell.

Although micelles have been used routinely to deliver drugs in various therapies, the Purdue researchers say they've demonstrated the micelles themselves repair damaged axons -- fibers that transmit electrical impulses in the spinal cord.

"That was a very surprising discovery," Associate Professor Ji-Xin Cheng, who led the study, said. "Micelles have been used for 30 years as drug-delivery vehicles in research, but no one has ever used them directly as a medicine."

The scientists said micelles might be used instead of more conventional "membrane sealing agents," including polyethylene glycol, which makes up the outer shell of the micelles. Because of the nanoscale size and the polyethylene glycol shell of the micelles, they are not quickly filtered by the kidney or captured by the liver, enabling them to remain in the bloodstream long enough to circulate to damaged tissues.

The study is detailed in the journal Nature Nanotechnology.