Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Getting better visualization of joint cartilage through cationic CT contrast agents

03.09.2009
In its quest to find new strategies to treat osteoarthritis and other diseases, a Boston University-led research team has reported finding a new computer tomography contrast agent for visualizing the special distributions of glycosaminoglycans (GAGs) – the anionic sugars that account for the strength of joint cartilage.

Assessing the local variations in GAGs are of significant interest for the study of cartilage biology and for the diagnosis of cartilage disease like osteoarthritis, which afflicts more than 27 million in people in the United States

In their research paper, "Effect of Contrast Agent Change on Visualization of Articular Cartilage Using Computer Tomography: Exploiting Electrostatic Interactions for Improved Sensitivity," just published on line in the Journal of the American Chemical Society, they describe new contrast agents that selectively bind to the GAGs in articular cartilage.

Articular or joint cartilage is the smooth hydrated tissue in the ends of bones in load-bearing joints, such as knees, hips and shoulders. The loss of GAGs from these joints is the hallmark of osteoarthritis, a degenerative joint disease in which wear or trauma results in damage to the cartilage surface.

To better see the differentiation between healthy and unhealthy cartilage, contrast agents provide the visual tool to assess GAG content. However, the current contrast agents used with computer tomography or magnetic resonance imaging (MRI) rely on limited diffusion of the anionic or negative ion-charged contrast agents into the target tissue, the study noted.

So researchers hypothesized that cationic contrast agents would be electrostatically attracted to anionic GAGs to provide a more sensitive technique for imaging cartilage. And they focused on using the more widely accessible CT equipment because it can image cartilage and bone simultaneously, enable rapid three-dimensional reconstruction of the tissue and achieve higher spatial resolution over shorter acquisition times compared to MRI systems.

The team synthesized three cationic or positive ion-charged iodine-based X-ray contrast agents. Using the femur of a rabbit, they reported gaining better and more specific images for the cartilage tissue than with current negative ion-charged contrast agents.

"Compared to commercially available contrast agents under the same experimental conditions, these new cationic agents are three times more sensitive for imaging cartilage," said Mark W. Grinstaff, Boston University Professor of Chemistry and Biomedical Engineering who led the team with Brian D. Snyder, MD, Ph.D. an orthopedic surgeon at Children's Hospital and Harvard Medical School.

Snyder noted that the ability to acquire information about localized GAG content, morphology and cartilage thickness on tissue samples will, in the future, aid in the diagnosis and treatment of osteoarthritis.

And while the data presented a compelling case for continued development of cationic CT contrast agents, the research team cautioned that the suitability for in vivo applications remains to be determined, adding that toxicity levels and radiation dosage will be the focus of future studies.

"However, the ability to characterize ex vivo cartilage samples is clearly evident," the study concludes. "Currently obtaining data about the spatial distribution of biochemical components in tissue samples is largely accomplished using histology, which is destructive and time consuming, and thus the use of contrast agents in conjunction with CT imaging will result in readily available, nondestructive alternative to histology."

In addition to Grinstaff and Snyder, the study's other Boston University authors are Neel S. Joshi, a postdoctoral student in the Department of Chemistry and Prashant N. Bansal, and Rachel C. Stewart, both graduate students in the Department of Biomedical Engineering.

The study was funded by the Coulter Foundation.

Ronald Rosenberg | EurekAlert!
Further information:
http://www.bu.edu

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Big data approach to predict protein structure

27.03.2017 | Life Sciences

Parallel computation provides deeper insight into brain function

27.03.2017 | Life Sciences

Weather extremes: Humans likely influence giant airstreams

27.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>