Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Treatment for Stroke?

14.09.2012
Ceria nanoparticles could lessen the damage from ischemic strokes

The most common form of strokes are caused by a sudden reduction in blood flow to the brain (ischemia) that leads to an inadequate supply of oxygen and nutrients. These so-called ischemic strokes are one of the leading causes of death and disability in industrialized nations.



If they are not immediately remedied by medical intervention, areas of the brain may die off. In the journal Angewandte Chemie, Korean researchers have now proposed a new approach for supplemental treatment: Ceria nanoparticles could trap the reactive oxygen compounds that result from ischemia and cause cells to die.

When blood flow to areas of the brain is restricted, reactive oxygen compounds like superoxide radical anions (O2• –), hydrogen peroxide (H2O2), and hydroxyl radicals (HO• –) form and accumulate. These species cause oxidative damage and are responsible for tissue damage and cell death during a stroke. Nerve connections and neurovascular units are destroyed and the function of the brain in these areas stops. Despite various treatments that primarily combat the causes of reduced blood flow, such as thrombosis, there has been no way to protect nerves from oxidative damage after an acute ischemic stroke. Seung-Hoon Lee, Taeghwan Hyeon, and their team at Seoul National University hope that nanoparticles made of ceria may represent a new approach for treatment.

Cells contain enzymes that can break down reactive oxygen species: superoxide dismutases, which convert superoxide anions to hydrogen peroxide; and catalase, which splits hydrogen peroxide. Ceria nanoparticles can do both. How does this work? The cerium in ceria crystals is present in the form of Ce4+. However, if the particle size is reduced to a few nanometers in diameter, some spots on the surface are missing oxygen atoms. These places have Ce3+ instead, which can easily be reduced back to Ce4+ and can reversibly bind oxygen.

The researchers treated cell cultures with a substance that increases the concentrations of reactive oxygen species, which leads to increased cell death. Treatment with cerium oxide nanoparticles drastically improved the cell survival rate. In animal trials, the researchers induced ischemic strokes in rats. Intravenously administered ceria nanoparticles considerably reduced the stroke volume and nerve damage. An optimized, carefully balanced dose is necessary, however.

Interestingly, the concentrations of ceria nanoparticles in the healthy areas of the brain were very low, while those in the ischemic areas were drastically elevated. The researchers speculate that the ceria nanoparticles can barely pass through the intact blood-brain barrier. However, the barrier is damaged in the ischemic areas, allowing the diseased areas of the brain to be reached and oxidative damage to be stopped.

About the Author
Taeghwan Hyeon is a SNU Distinguished Fellow (Distinguished University Professor) of the School of Chemical and Biological Engineering of Seoul National University (SNU). Since 1997, his research has been focused on the synthesis and applications of uniform-sized nanoparticles. In June 2012, he was appointed as a Director of the Center for Nanoparticle Research, Institute for Basic Science (IBS).

Author: Taeghwan Hyeon, Seoul National University (Korea), http://nanomat.snu.ac.kr/index.php?mid=Director

Title: Ceria Nanoparticles that Protect against Ischemic Stroke
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201203780

Taeghwan Hyeon | Angewandte Chemie
Further information:
http://pressroom.angewandte.org.

More articles from Life Sciences:

nachricht New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>