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Just last week a California company announced it developed blood-borne metallic nanodust that could slip inside the tiniest capillaries and revolutionize magnetic resonance imaging(see In Dust They Trust). Now a group of biochemists from Carnegie Mellon University may have something even better.
The scientists say they have found a way to genetically program cells to make their own MRI markers. They say that the method will allow doctors visualize gene therapy and track where genetic drugs travel in patients.
Patients who need an MRI scan of the brain, the vascular system, or other body parts get injected with dyes, or contrast agents, to improve image quality. But dye molecules are too clunky and can't penetrate everywhere.
The Mellon approach uses an emasculated virus as a vehicle to carry a gene that makes ferritin, a "metalloprotein" which the body uses to store iron. The virus tricks targeted cells into producing their own ferritin. Since ferritin carries iron, its molecules act like nano-magnets and strong MRI markers.
"Our technology is adaptable to monitor gene expression in many tissue types," said Eric Ahrens, assistant professor of biological sciences in the Mellon College of Science. "You could link this MRI reporter gene to any other gene of interest, including therapeutic genes for diseases like cancer and arthritis, to detect where and when they are being expressed."
The Mellon report appears in the April issue of the Nature Medicine journal.