Sangeeta Bhatia, M.D., Ph.D.
Massachusetts Institute of Technology
NIEHS grantees developed a simple and sensitive test that produces a color change in urine when colon cancer is present in mice. According to the authors, this test has potential for use in low-resource settings for rapid detection of colon cancer.
The early stage technology uses ultra-small gold nanoclusters (AuNCs) connected to a protein carrier called neutravidin. The researchers designed the nanosensors to be disassembled by specific tumor enzymes known as matrix metalloproteinases (MMPs), which help promote the growth and spread of tumors. MMP enzymes are produced in colon tumors, so they can serve as a biological marker that cancer is present.
The researchers injected the AuNC nanosensors into mice and found that when the nanosensors were broken up by MMPs, they passed through the kidney and were released in the urine. They found that urine from tumor-bearing mice became bright blue in less than one hour, exhibiting a 13-fold increase in blue color signal compared with urine samples from healthy mice. They also found that the nanosensors were eliminated completely by mice — both with and without cancer — through excretion within four weeks of injection and with no evidence of toxicity.
According to the authors, engineered nanosensors that indicate the presence of different enzymes may be translatable to a range of diseases in which enzyme activity can serve as a biomarker, including other cancers and infectious diseases.
Citation: Loynachan CN, Soleimany AP, Dudani JS, Lin Y, Najer A, Bekdemir A, Chen Q, Bhatia SN, Stevens MM. 2019. Renal clearable catalytic gold nanoclusters for in vivo disease monitoring. Nat Nanotechnol 14(9):883–890.