BY CORY MIMMS
Surgeons sometimes leave things inside patients — needles, scissors, even scalpels. Those items easily show up on X-rays, allowing doctors to find and remove them. But not surgical sponges. They require extra precaution; most sponges are marked with barium, which is difficult to see on X-rays. Portland State University chemistry professor Andrea Goforth and her graduate assistant, Anna Brown, have developed a better way to tag sponges using bismuth. Denser than lead and nontoxic, bismuth nanoparticles are perfect X-ray deflectors, and by infusing them in silicone they can be stitched into surgical sponges. “The heavier the atoms the better they scatter X-rays,” Goforth says. These bismuth markers — bismarkers — show up bright white on X-rays, making them practically impossible to miss. The preliminary patent application was filed last June and Goforth now is seeking an industry partner for the next stage of development: manufacturing, marketing and selling. She isn't finished with her bismuth research, though. “My original concept was that these would be injectable contrast agents,” Goforth says. By modifying them to bind with certain types of cells and then injecting them into the bloodstream, the particles could be used to find tumors.