Renal Clearable New NIR Probe: Precise Quantification of Albumin in Biofluids and Fatty Liver Disease State Identification through Tissue Specific High Contrast Imaging in Vivo

Development of a highly photostable, renal clearable, and nontoxic new NIR probe (CyG) for precise quantification of albumin in different biofluids and liver targeted in vivo albumin visualization is demonstrated. CyG's inherent property to interact selectively with albumin among different biomolecules in intracellular environment with high degree of sensitivity helps CyG in targeted liver imaging. In addition to its long excitation/emission wavelengths (λ_ex = 740 nm, λ_em = 804 nm), which are much above the biological tissue opaque window (400-700 nm) ensuring better photon penetration, diminished tissue autofluorescence and high contrasts, its molecular mass and size are far below the renal cutoff and hence, CyG qualifies as imaging material for clinical studies. We anticipate that CyG will provide new strategies to overcome the pitfall of present day albumin detection methods as well as accelerate the detection process at relatively lower costs without compromising the accuracy of detection. Moreover, the renal excretion kinetic and intrahepatic albumin binding affinity of CyG can further be used to differentiate between fatty liver from healthy liver in an experimentally arrived mouse model using noninvasive technique.