MRI scans use a combination of radio waves and magnetic fields to create an image of tissues within the body. In recent experiments, MRI is being used to image the vasculature of the brain and parts of the hypothalamus. Using contrast agents in MRI, it is possible to gain enhanced detail in acquired images. A contrast agent can improve the signal of tissues during a scan. The typical agent used is Magnevist (Gadolinium-DTPA). One issue with Magnevist is that the gadolinium portion can become toxic by becoming unattached from the rest of the molecule. The Kent State Chemistry Department has recently synthesized two new nanoparticles, a gadolinium-based nanoparticle (GdNP) and a gold-based nanoparticle. GdNP is approximately ten times stronger than Gd-DTPA allowing the GdNP to provide the same contrast enhancement with ten percent of the concentration needed with Magnevist. Targeting agents further decrease the number of molecules needed for the desired image, by binding to specific areas of the tissues being researched. This reduces the toxicity of the Gd by having less enter the body. The targeting agents used are fluorogold (FG) and evans blue (EB). FG targets neuroendocrine cells in the hypothalamus while EB targets serum albumin (SA) in the blood vessels. The nanoparticles being worked with bind to EB or FG, allowing the SA or the neuroendocrine cells to contrast more with the surrounding tissue. Beyond MRI, these nanoparticle techniques can also be used in microscopy.
Dr. Robert Clements
Mr. John Shelestak
Using MRI, we have been able to take images of the tissues in the body, specifically regions of the brain. With the addition of contrast agents, further detailed images can be taken. The standard contrast agents use gadolinium with an outer shell to hold the ion in place. The gadolinium portion is toxic when detached from the rest of the molecule. To solve help solve this issue, two new nanoparticles have recently been developed to use as contrast agents, one gadolinium-based (GdNP) and the other gold-based. GdNP is approximately ten times stronger than the typical contrast agents, resulting in ten times less toxicity. With targeting agents that bind to specific areas of prominence, even less gadolinium is used while retaining high image quality.