The bright side of a heavy metal

PSU innovators Andrea Goforth and Anna Brown see Bismuth nanoparticle materials as the imaging agents of the future.

X-ray image

The office of Innovation & Intellectual Property (IIP) recently began working with exciting new innovations Dr. Andrea Mitchell Goforth—Assistant Professor in the Department of Chemistry, and Graduate Research Assistant Anna Brown are developing in Goforth’s PSU laboratory. An Oregon Nanoscience and Microtechnologies Institute (ONAMI) Signature Research Fellow, and a recipient of the Burroughs Wellcome Fund’s Career Award at the Scientific Interface Program, Dr. Goforth researches and develops nanometer-sized, inorganic imaging agents. IIP filed a provisional patent application on Dr. Goforth’s bismuth nanoparticle X-ray contrast agents last year and has been working to help see this new technology move beyond the University to those capable of putting it to good use.

Dr. Goforth’s highly radiopaque bismuth-based markers may soon have a significant impact on one of healthcare’s most widely used tools: the surgical sponge. The contrast agents employed by current X-ray opaque surgical sponges are simply not X-ray opaque enough. One such agent, barium sulfate, is frequently used for X-ray imaging in surgical sponges. While barium has a relatively high atomic number that allows it to absorb X-rays, and thus provide contrast, bismuth, with its higher atomic number, provides a much greater level of contrast, and has a very low level of toxicity. When incorporated into a surgical sponge, Dr. Goforth’s bismuth nanoparticle X-ray contrast agents can enhance the visibility of the sponge in X-ray images, reducing the risk of dangerous and costly oversights in operating rooms.

To overlook the other possible applications of Dr. Goforth’s bismuth nanoparticle X-ray contrast agents, however, would be to take the short view of its potential. “We started dreaming up a number of other composites that could be X-ray opaque,” Dr. Goforth noted. Perhaps the most exciting such application is the targeting of cells in in-vivo medical imaging. By modifying the surface chemistry of bismuth nanoparticles, a ligand tag could be attached to the nanoparticles that would bind to specifically targeted cell types and would then become visible in X-ray imaging. “We could make intra-vascular circulating X-ray contrast agents that you might be able to use for targeting and tailoring strategies to find metastatic tumors you cannot normally see on an X-ray image.” Such an application of Dr. Goforth’s bismuth nanoparticle X-ray contrast agents could radically change diagnostic procedures for the better.

Anna Brown, who makes many of the composites, which she calls “Bismarkers,” at the laboratory, listed a few other potential applications of this contrast agent technology: “We could make security tags for items invisible to the naked eye that could be used to track things like stolen bicycles, for instance. We could make inks for use in checking for imperfections in things such as auto parts. We could also create X-ray opaque plastics for use in children’s toys so that the toys would be visible in an X-ray image if they were swallowed.” The potential applications of Dr. Goforth’s technology are nearly limitless.

Where we need to see what cannot be seen, where there is a need for the additional safety and protections that could be provided by a clear look into what our eyes cannot penetrate, we find useful applications for Dr. Goforth’s bismuth nanoparticle X-ray contrast agents. The case of medical sponges is a perfect example of this need: many sponges are lost every year and bismuth contrast agents could provide a clear picture of where some might have been misplaced. “I feel like I’m using my hard, physical science background to shed light on problems in biology,” Dr. Goforth said. While bismuth may not shine itself, Dr. Goforth’s new bionanotechnology gives this particular heavy metal the ability to shine in the X-ray images of anything it’s embedded in. In the office of Innovation & Intellectual Property, we’re looking forward to a continuing partnership with Dr. Goforth as she brings new innovations to the University and to the world.