New nanodiamond contrast agent may improve imaging, detection of liver cancer tumors

Liz Meszaros, MDLinx | May 03, 2017

For clearer and more accurate imaging of liver tumors with T1- and T2-weighted MRIs, researchers from the National University of Singapore (NUS) have developed a new nanodiamond-based contrast agent that improves visibility of internal body structures, and thus, improves visualization of liver cancer tumors. Their results were recently published in the journal Nanomedicine: Nanotechnology, Biology and Medicine.

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Nanotechnology

The novel contrast agent (grey solution in larger tube), developed using nanodiamonds in combination with a manganese base, provides clearer and more accurate images of liver tumors at lower dosages. Credit: National University of Singapore.

In the diagnosis of liver cancer, T2-weighted imaging is not considered to be reliable, and tumor vascularity often confounds T1- and T2-weighted imaging.

This novel dual-mode contrast agent was developed using nanodiamonds combined with a manganese base. Nanodiamonds are carbon-based particles 2 to 8 nanometers in diameter that possess unique chemical properties that attract water molecules and thus promote proton exchange between water molecules and the paramagnetic ions (or contrast agents) that accumulate in tissues.

As a result, T1 and T2 relaxation is enhanced, providing better quality images. This contrasts with existing nanotechnology-based approaches, in which nanomaterials only improve delivery of paramagnetic ions to specific tumor sites.

Principal investigator Edward Chow, assistant professor, Cancer Science Institute of Singapore at NUS and Department of Pharmacology at NUS Yong Loo Lin of Medicine, and colleagues studied IV administration of nanodiamond-manganese complexes in an orthotopic liver cancer mouse model. Not only did they outperform current clinical contrast agents, but also reduced blood serum concentration of toxic free Mn2+ ions. Even liver tumors that cannot be visualized without contrast agents are readily visible with this nano-diamond-based dual-mode contrast agent, even when low doses are used.

“Our experiments suggest that our dual-mode contrast agent holds great promise in improving imaging for liver cancer. We are hopeful that this advancement in nanomedicine will lead to safer and more accurate diagnosis of liver cancer. Moving forward, we plan to conduct further pre-clinical safety studies for our contrast agents, with the end goal being clinical implementation. We are also looking into using our contrast agents to improve imaging for glioma and ovarian cancer,” said Dr. Chow.

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