|
(Ivanhoe Newswire) Tiny drug-bearing nano-spheres roughly 100 times smaller than a red blood cell, injected into the blood shortly after an accident, offer new hope for repairing damaged nerve fibers in spinal cord injuries.
The synthetic "copolymer micelles" are drug-delivery spheres about 60 nanometers in diameter. Researchers have been searching for a way to deliver drugs for cancer treatment and other therapies using these spheres. Medications might be harbored in the cores and ferried to diseased or damaged tissue.
Text Continues Below
Purdue researchers have now shown that the micelles themselves repair damaged axons, fibers that transmit electrical impulses in the spinal cord. "That was a very surprising discovery," Ji-Xin Cheng, an associate professor in the Weldon School of Biomedical Engineering and Department of Chemistry, was quoted as saying. "Micelles have been used for 30 years as drug-delivery vehicles in research, but no one has ever used them directly as a medicine."
Micelles combine two types of polymers, one hydrophobic and the other hydrophilic, referring to their inability or ability to mix with water. The hydrophobic core, which cannot mix with water, can be loaded with drugs to treat disease.
The micelles might be used instead of conventional "membrane sealing agents," including polyethylene glycol, which makes up the outer shell of the micelles. Because of their nanoscale size and polyethylene glycol shell, micelles 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.
In research led by biomedical engineering doctoral student Yunzhou Shi, the micelles also were shown to be non-toxic at the concentrations required. "With the micelles, you need only about 1/100,000th the concentration of regular polyethylene glycol," said Cheng.
Ongoing research at Purdue has shown the benefits of polyethylene glycol, or PEG, to treat animals with spinal cord injuries. Findings have shown that PEG specifically targets damaged cells and seals the injured area, reducing further damage. It also helps restore cell function.
Findings showed that cores made of particular materials work better than others at restoring function to damaged axons, which are slender extensions of nerve cells. The micelles treatment boosted axon recovery from 18 percent to about 60 percent.
The experiment mimicked what happens during a traumatic spinal cord injury. Findings showed that micelles might be used to repair axon membranes damaged by compression injuries, a common type of spine injury. Findings also showed micelles-treated animals recovered the coordinated control of all four limbs, whereas animals treated with conventional polyethylene glycol did not.
SOURCE: Nature Nanotechnology, November 8, 2009
If this story or any other Ivanhoe story has impacted your life or prompted you or someone you know to seek or change treatments, please let us know by contacting Melissa Medalie at mmedalie@ivanhoe.com
This article was reported by Ivanhoe.com, who offers Medical Alerts by e-mail every day of the week. To subscribe, go to: http://www.ivanhoe.com/newsalert/.
|
.gif)
