Luminescent Gold Nanoparticles Track Kidney Disease

Kidney disease is known as a silent killer. That’s because the markers physicians look for to diagnose the disease, such as urea and creatinine levels in the blood, often appear normal even when up to 75% of kidney function has been lost. One inexpensive, noninvasive method for imaging kidneys is to use near-infrared fluorescence imaging to follow an organic dye as it travels through the organs. But such dyes have problems: They often don’t provide enough contrast in the kidney, and they accumulate in background tissues. Researchers led by Jie Zheng of the University of Texas, Dallas, previously reported that glutathione-coated gold nanoparticles work better than the dyes as fluorescence imaging agents for cancer detection. The nanoparticles, Zheng notes, are inexpensive and clear the body easily. Now Zheng’s lab has shown that the nanoparticles can differentiate between various stages of kidney dysfunction in a mouse model (Angew. Chem. Int. Ed. 2016, DOI: 10.1002/anie.201511148). If the results translate to people, doctors would be able to easily tell the difference among kidneys with normal function, mild dysfunction, and severe dysfunction—something they’re currently unable to do.