Structural and Functional NIR-II Fluorescence Bioimaging in Urinary System via Clinically Approved Dye Methylene Blue

Accurate structural and functional imaging is vital for the diagnosis and prognosis of the urinary system diseases. Near-infrared region (NIR) II fluorescence imaging has shown advantages of high sensitivity, high safety, and fast feedback compared to the conventional imaging methods but limited to its clinical applicability. Herein, we first report that in vivo NIR-II fluorescence imaging of the urinary system enabled by clinically approved and renal-clearable NIR dye methylene blue, which can not only achieve clear invasive/non-invasive urography but also noninvasively detect renal function. These results demonstrate that MB assisted NIR-II fluorescence imaging holds great promise for invasive/noninvasive structural imaging of the urinary system clinically and investigation of renal function in animal models preclinically.