Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanoparticles reboot blood flow in brain Rice University, Baylor College of Medicine discovery might aid emergency care of traumatic brain-injury victims

New research funded primarily by the Department of Defense would help emergency care workers and battlefield medics stabilize blood flow in the brains of traumatic injury victims. Rice University and Baylor College of Medicine in Houston developed a nanoparticle-based antioxidant that quickly quenches free radicals that interfere with regulation of the brain’s vascular system.
New research funded primarily by the Department of Defense would help emergency care workers and battlefield medics stabilize blood flow in the brains of traumatic injury victims. Rice University and Baylor College of Medicine in Houston developed a nanoparticle-based antioxidant that quickly quenches free radicals that interfere with regulation of the brain’s vascular system.

Abstract:
A nanoparticle developed at Rice University and tested in collaboration with Baylor College of Medicine (BCM) may bring great benefits to the emergency treatment of brain-injury victims, even those with mild injuries.

Nanoparticles reboot blood flow in brain Rice University, Baylor College of Medicine discovery might aid emergency care of traumatic brain-injury victims

Houston, TX | Posted on August 23rd, 2012

Combined polyethylene glycol-hydrophilic carbon clusters (PEG-HCC), already being tested to enhance cancer treatment, are also adept antioxidants. In animal studies, injections of PEG-HCC during initial treatment after an injury helped restore balance to the brain's vascular system.

The results were reported this month in the American Chemical Society journal ACS Nano.

A PEG-HCC infusion that quickly stabilizes blood flow in the brain would be a significant advance for emergency care workers and battlefield medics, said Rice chemist and co-author James Tour.

"This might be a first line of defense against reactive oxygen species (ROS) that are always overstimulated during a medical trauma, whether that be to an accident victim or an injured soldier," said Tour, Rice's T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science. "They're certainly exacerbated when there's trauma with massive blood loss."

In a traumatic brain injury, cells release an excessive amount of an ROS known as superoxide (SO) into the blood. Superoxides are toxic free radicals, molecules with one unpaired electron, that the immune system normally uses to kill invading microorganisms. Healthy organisms balance SO with superoxide dismutase (SOD), an enzyme that neutralizes it. But even mild brain trauma can release superoxides at levels that overwhelm the brain's natural defenses.

"Superoxide is the most deleterious of the reactive oxygen species, as it's the progenitor of many of the others," Tour said. "If you don't deal with SO, it forms peroxynitrite and hydrogen peroxide. SO is the upstream precursor to many of the downstream problems."

SO affects the autoregulatory mechanism that manages the sensitive circulation system in the brain. Normally, vessels dilate when blood pressure is low and constrict when high to maintain an equilibrium, but a lack of regulation can lead to brain damage beyond what may have been caused by the initial trauma.

"There are many facets of brain injury that ultimately determine how much damage there will be," said Thomas Kent, the paper's co-author, a BCM professor of neurology and chief of neurology at the Michael E. DeBakey Veterans Affairs Medical Center in Houston. "One is the initial injury, and that's pretty much done in minutes. But a number of things that happen later often make things worse, and that's when we can intervene."

Kent cited as an example the second burst of free radicals that can occur after post-injury resuscitation. "That's what we can treat: the further injury that happens because of the necessity of restoring somebody's blood pressure, which provides oxygen that leads to more damaging free radicals."

In tests, the researchers found PEG-HCC nanoparticles immediately and completely quenched superoxide activity and allowed the autoregulatory system to quickly regain its balance. Tour said ROS molecules readily combine with PEG-HCCs, generating "an innocuous carbon double bond, so it's really radical annihilation. There's no such mechanism in biology." While an SOD enzyme can alter only one superoxide molecule at a time, a single PEG-HCC about the size of a large protein at 2-3 nanometers wide and 30-40 nanometers long can quench hundreds or thousands. "This is an occasion where a nano-sized package is doing something that no small drug or protein could do, underscoring the efficacy of active nano-based drugs."

"This is the most remarkably effective thing I've ever seen," Kent said. "Literally within minutes of injecting it, the cerebral blood flow is back to normal, and we can keep it there with just a simple second injection. In the end, we've normalized the free radicals while preserving nitric oxide (which is essential to autoregulation). These particles showed the antioxidant mechanism we had previously identified as predictive of effectiveness."

The first clues to PEG-HCC's antioxidant powers came during nanoparticle toxicity studies with the MD Anderson Cancer Center. "We noticed they lowered alkaline phosphatase in the liver," Tour said. "One of our Baylor colleagues saw this and said, ‘Hey, this looks like it's actually causing the liver cells to live longer than normal.'

"Oxidative destruction of liver cells is normal, so that got us to thinking these might be really good radical scavengers," Tour said.

Kent said the nanoparticles as tested showed no signs of toxicity, but any remaining concerns should be answered by further tests. The researchers found the half-life of PEG-HCCs in the blood - the amount of time it takes for half the particles to leave the body - to be between two and three hours. Tests with different cell types in vitro showed no toxicity, he said.

The research has implications for stroke victims and organ transplant patients as well, Tour said.

Next, the team hopes to have another lab replicate its positive results. "We've repeated it now three times, and we got the same results, so we're sure this works in our hands," Kent said.

First authors of the paper are BCM graduate student Brittany Bitner, Rice graduate student Daniela Marcano and former Rice postdoctoral researcher Jacob Berlin, now an assistant professor of molecular medicine at the Beckman Research Institute of the City of Hope, Duarte, Calif. Co-authors are all at BCM: Roderic Fabian, associate professor of neurology; Claudia Robertson, professor of neurosurgery; Leela Cherian, research instructor of neurosurgery; Mary Dickinson, associate professor of molecular physiology; Robia Pautler, associate professor of molecular physiology; and James Culver, a graduate student in molecular physiology.

The research was funded by the Department of Defense's Mission Connect Mild Traumatic Brain Injury Consortium, the National Science Foundation, the National Institutes of Health and the National Heart, Lung and Blood Institute.

####

For more information, please click here

Contacts:
Rice University contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728


Baylor College of Medicine contact:
Graciela Gutierrez
713-798-7841

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Tour Group:

Related News Press

News and information

Metal oxide sandwiches: New option to manipulate properties of interfaces February 8th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Canadian physicists discover new properties of superconductivity February 8th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

The iron stepping stones to better wearable tech without semiconductors February 8th, 2016

Nanomedicine

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

UTHealth research looks at nanotechnology to help prevent preterm birth February 7th, 2016

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Discoveries

Metal oxide sandwiches: New option to manipulate properties of interfaces February 8th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

The iron stepping stones to better wearable tech without semiconductors February 8th, 2016

Announcements

Metal oxide sandwiches: New option to manipulate properties of interfaces February 8th, 2016

Canadian physicists discover new properties of superconductivity February 8th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

From allergens to anodes: Pollen derived battery electrodes February 8th, 2016

Military

Scientists guide gold nanoparticles to form 'diamond' superlattices: DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond February 4th, 2016

Researchers develop completely new kind of polymer: Hybrid polymers could lead to new concepts in self-repairing materials, drug delivery and artificial muscles January 30th, 2016

Nano-coating makes coaxial cables lighter: Rice University scientists replace metal with carbon nanotubes for aerospace use January 28th, 2016

Scientists build a neural network using plastic memristors: A group of Russian and Italian scientists have created a neural network based on polymeric memristors -- devices that can potentially be used to build fundamentally new computers January 28th, 2016

Research partnerships

Scientists take key step toward custom-made nanoscale chemical factories: Berkeley Lab researchers part of team that creates new function in tiny protein shell structures February 6th, 2016

Polar vortices observed in ferroelectric: New state of matter holds promise for ultracompact data storage and processing February 4th, 2016

Spin dynamics in an atomically thin semi-conductor February 1st, 2016

Graphene shown to safely interact with neurons in the brain January 31st, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic