A gel, made from a horse chestnut extract, may improve the imaging of tumors, including prostate cancer, using radioactive tracer molecules. A research team now hopes that, using the gel, it will be possible to develop a skin cream that might improve cancer detection in the clinic. The team — led by Dr. George John, a professor in the Division of Science at City College of New York, and Dr. Jan Grimm, a physician-scientist at Sloan Kettering Institute and the Memorial Sloan Kettering Cancer Center — published their findings in the journal ACS Applied Materials & Interfaces. The study was titled “Radiation-Responsive Esculin-Derived Molecular Gels as Signal Enhancers for Optical Imaging.” The so-called Cerenkov light is often used in cancer imaging. The light — which is the blue glow seen in nuclear reactors — can also illuminate biological molecules, but is not really optimal for use in the body. It has a low intensity, and blue light is scattered and absorbed in tissues, the researchers said. So while it is a valuable tool in cancer diagnostics, scientists are trying to find ways to improve its use. Researchers turned to a compound found in horse chestnut, called esculin. Their esculin-containing gel turned out to have the right properties to improve imaging using Cerenkov light — by having both scintillating and fluorescent properties, the gel alters the way light is reflected in tumors. An image, included in the