Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Game-changing nanodiamond discovery for MRI

15.01.2010
Dramatically enhanced image contrast could revolutionize diagnostics and therapeutics

A Northwestern University study shows that coupling a magnetic resonance imaging (MRI) contrast agent to a nanodiamond results in dramatically enhanced signal intensity and thus vivid image contrast.

"The results are a leap and not a small one -- it is a game-changing event for sensitivity," said Thomas J. Meade, the Eileen Foell Professor in Cancer Research in the Weinberg College of Arts and Sciences and the Feinberg School of Medicine. "This is an imaging agent on steroids. The complex is far more sensitive than anything else I've seen."

Meade led the study along with Dean Ho, assistant professor of biomedical engineering and mechanical engineering in the McCormick School of Engineering and Applied Science.

Ho already has demonstrated that the nanodiamonds have excellent biocompatibility and can be used for efficient drug delivery. This new work paves the way for the clinical use of nanodiamonds to both deliver therapeutics and remotely track the activity and location of the drugs.

The study, published online by the journal Nano Letters, also is the first published report of nanodiamonds being imaged by MRI technology, to the best of the researchers' knowledge. The ability to image nanodiamonds in vivo would be useful in biological studies where long-term cellular fate mapping is critical, such as tracking beta islet cells or tracking stem cells.

MRI is a noninvasive medical imaging technique that uses an intravenous contrast agent to produce detailed images of internal structures in the body. MRI is capable of deep tissue penetration, achieves an efficient level of soft tissue contrast with high spatial and time-related resolution, and does not require ionizing radiation.

Contrast agents are used in MRI because they alter the relaxivity (contrast efficacy indicator) and improve image resolution. Gadolinium (Gd) is the material most commonly used as an MRI contrast agent, but its contrast efficacy can be improved.

Meade, Ho and their colleagues developed a gadolinium(III)-nanodiamond complex that, in a series of tests, demonstrated a significant increase in relaxivity and, in turn, a significant increase in contrast enhancement. The Gd(III)-nanodiamond complex demonstrated a greater than 10-fold increase in relaxivity -- among the highest per Gd(III) values reported to date. This represents an important advance in the efficiency of MRI contrast agents.

Ho and Meade imaged a variety of nanodiamond samples, including nanodiamonds decorated with various concentrations of Gd(III), undecorated nanodiamonds and water. The intense signal of the Gd(III)-nanodiamond complex was brightest when the Gd(III) level was highest.

"Nanodiamonds have been shown to be effective in attracting water molecules to their surface, which can enhance the relaxivity properties of the Gd(III)-nanodiamond complex," said Ho. "This might explain why these complexes are so bright and such good contrast agents."

"The nanodiamonds are utterly unique among nanoparticles," Meade said. "A nanodiamond is like a cargo ship -- it gives us a nontoxic platform upon which to put different types of drugs and imaging agents."

The biocompatibility of the Gd(III)-nanodiamond complex underscores its clinical relevance. In addition to confirming the improved signal produced by the hybrid, the researchers conducted toxicity studies using fibroblasts and HeLa cells as biological testbeds.

They found little impact of the hybrid complex on cellular viability, affirming the complex's inherent safety and positioning it as a clinically significant nanomaterial. (Other nanodiamond imaging methods, such as fluorescent nanodiamond agents, have limited tissue penetration and are more appropriate for histological applications.)

Nanodiamonds are carbon-based materials approximately four to six nanometers in diameter. Each nanodiamond's surface possesses carboxyl groups that allow a wide spectrum of compounds to be attached to it, not just gadolinium(III).

The researchers are exploring the pre-clinical application of the MRI contrast agent-nanodiamond hybrid in various animal models. With an eye towards optimizing this novel hybrid material, they also are continuing studies of the structure of the Gd(III)-nanodiamond complex to learn how it governs increased relaxivity.

Meade has pioneered the design and synthesis of chemical compounds for applications in cancer detection, cellular signaling and gene regulation. Ho has pioneered the development of nanodiamonds and has demonstrated their efficiency as drug delivery vehicles. Both are members of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

The Nano Letters paper is titled "Gd(III)-Nanodiamond Conjugates for MRI Contrast Enhancement." In addition to Ho and Meade, other authors of the paper are Lisa M. Manus (first author), Daniel J. Mastarone, Emily A. Waters, Xue-Qing Zhang, Elise A. Schultz-Sikma, and Keith W. MacRenaris, all from Northwestern University.

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Physics and Astronomy:

nachricht When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>