Findings show nanomedicine promising for treating spinal cord injuries

November 8, 2009
Findings show nanomedicine promising for treating spinal cord injuries

Enlarge

This image represents "copolymer micelles," tiny drug-delivery spheres that could be used in a new approach for repairing damaged nerve fibers in spinal cord injuries. The bottom graphs show data indicating damaged spinal cord tissue recovered its "action potential," or ability to transmit signals, after treatment with the micelles. (Purdue University's Weldon School of Biomedical Engineering)

(PhysOrg.com) -- Researchers at Purdue University have discovered a new approach for repairing damaged nerve fibers in spinal cord injuries using nano-spheres that could be injected into the blood shortly after an accident.

The synthetic "copolymer micelles" are drug-delivery spheres about 60 in diameter, or roughly 100 times smaller than the diameter of a red blood cell.

Researchers have been studying how to deliver drugs for treatment and other therapies using these spheres. Medications might be harbored in the cores and ferried to diseased or damaged tissue.

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," said Ji-Xin Cheng, an associate professor in the Weldon School of Biomedical Engineering and Department of Chemistry. "Micelles have been used for 30 years as drug-delivery vehicles in research, but no one has ever used them directly as a medicine."

Findings are detailed in a research paper appearing Sunday (Nov. 8) in the journal Nature Nanotechnology.

A critical feature of micelles is that they combine two types of polymers, one being hydrophobic and the other hydrophilic, meaning they are either unable or able to mix with water. The hydrophobic core can be loaded with drugs to treat disease.

The 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.

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," Cheng said.

Ongoing research at Purdue has shown the benefits of polyethylene glycol, or PEG, to treat animals with . The work is led by Richard Borgens, director of the Center for Paralysis Research and the Mari Hulman George Professor of Neurology in the School of Veterinary Medicine.

Findings have shown that PEG specifically targets damaged cells and seals the injured area, reducing further damage. It also helps restore cell function.

The new findings were made possible by the interdisciplinary nature of the work, which involves Borgens and other Purdue researchers, Cheng said. The collaboration included Borgens; Riyi Shi, an associate professor of biomedical engineering and basic medical sciences; and Kinam Park, Showalter Distinguished Professor of Biomedical Engineering and a professor of pharmaceutics.

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 research also showed that without the micelles treatment about 18 percent of axons recover in a segment of damaged spinal cord tested in a "double sucrose gap recording chamber." The micelles treatment boosted the axon recovery to about 60 percent. The researchers used the chamber to study how well micelles repaired damaged nerve cells by measuring the "compound action potential," or the ability of a spinal cord to transmit signals.

The experiment mimics what happens during a traumatic injury. Findings showed that micelles might be used to repair axon membranes damaged by compression injuries, a common type of spine injury.

The researchers also tracked dyed micelles in rats, demonstrating that the nanoparticles were successfully delivered to injury sites. Findings also showed micelles-treated animals recovered the coordinated control of all four limbs, whereas animals treated with conventional did not.

Source: Purdue University (news : web)

4.5 /5 (4 votes)  

Rank 4.5 /5 (4 votes)
Relevant PhysicsForums posts
  • a single mRNA strand is attached to sevaral ribosomes?
    created4 hours ago
  • Oestrogen and FSH
    created18 hours ago
  • Linear Blood Vessel Network Examples in Animals or Plants
    created20 hours ago
  • Neuroscientists: What is a Principal Cell Layer?
    createdFeb 06, 2012
  • How does slime mould grow?
    createdFeb 04, 2012
  • Why are mosquitoes and bedbugs successful?
    createdFeb 04, 2012
  • More from Physics Forums - Biology

More news stories

Nanoshell whispering galleries improve thin solar panels

Visitors to Statuary Hall in the U.S. Capitol Building may have experienced a curious acoustic feature that allows a person to whisper softly at one side of the cavernous, half-domed room and for another on ...

Nanotechnology / Nanomaterials

created 17 hours ago | popularity 4.2 / 5 (5) | comments 5 | with audio podcast

A bronze matryoshka doll: The metal in the metal in the metal

A doll in a doll, and then one more, enveloping them from the outside – this is how Thomas Faessler explains his molecule. He packs one atom in a cage within an atom framework. With their large surfaces ...

Nanotechnology / Nanomaterials

created 18 hours ago | popularity 5 / 5 (7) | comments 1 | with audio podcast

Researchers move graphene electronics into 3D

In a paper published this week in Science, a Manchester team lead by Nobel laureates Professor Andre Geim and Professor Konstantin Novoselov has literally opened a third dimension in graphene research. Their ...

Nanotechnology / Nanomaterials

created Feb 02, 2012 | popularity 5 / 5 (18) | comments 5 | with audio podcast

Harnessing plasmonics, engineers weld nanowires with light

At the nano level, researchers at Stanford have discovered a new way to weld together meshes of tiny wires. Their work could lead to exciting new electronics and solar applications. To succeed, they called ...

Nanotechnology / Nanophysics

created Feb 06, 2012 | popularity 4.8 / 5 (10) | comments 1 | with audio podcast

Engineers build first sub-10-nm carbon nanotube transistor

(PhysOrg.com) -- Engineers have built the first carbon nanotube (CNT) transistor with a channel length below 10 nm, a size that is considered a requirement for computing technology in the next decade. Not ...

Nanotechnology / Nanophysics

created Feb 01, 2012 | popularity 4.9 / 5 (29) | comments 30 | with audio podcast feature


Solar start-ups set new efficiency records

(PhysOrg.com) -- Although Alta Devices and Semprius make different types of solar panels, both start-ups have been breaking records in the past few days. Santa Clara, Calif.-based Alta Devices announced that ...

Lefties more likely to look before they leap

(Medical Xpress) -- New research from the University of Abertay Dundee has found evidence that left-handed people may be better decision makers than their right-handed counterparts.

Study examines role of bilingualism in children's development

A new study on children who are raised bilingual examined the effects on children's development of growing up speaking two languages. The study found that different factors were responsible for the language- and non-language-related ...

Getting caffeine fix as easy as taking deep breath

(AP) -- Move over, coffee and Red Bull. A Harvard professor thinks the next big thing will be people inhaling their caffeine from a lipstick-sized tube. Critics say the novel product is not without its risks.

Japan electronic giants eye chip merger: reports

Three of Japan's biggest electronics companies are to join forces in a chip-making venture, according to reports, days after a swathe of dire results from a sector struggling to compete globally.

Hundreds of gamers flock to Brazil tech fest

Hundreds of geeks and gamers braved Sao Paulo's torrid heat Tuesday to play online video games at the fifth edition of Brazil's Campus Party, an annual, week-long technology fest.