Real-time imaging of acute alcoholic liver injury in vivo via a robust viscosity probe with aggregation-induced emission nature

As the early stage of alcoholic liver disease, acute alcoholic liver injury (AALI) is usually ignored or misdiagnosed due to the lack of typical clinic symptoms, however, it will probably progress to severe liver lesions without proper intervention. Therefore, it is of great significance to develop a sensitive probe to timely diagnose AALI and monitor its progression. In this paper, AALI was found to be accompanied with the elevated intracellular viscosity originating from the malfunction of mitochondria, which enables the mitochondrial viscosity a promising biomarker for AALI. Through delicate structure engineering, a robust fluorescent probe HOTPy with aggregation-induced emission (AIE) nature was developed with sufficient aqueous solubility and prominent chemical stability, which imparted distinctive interference-resisting ability to the probe. HOTPy specifically responded to the mitochondrial viscosity in LO2 cell imaging. It further successfully diagnosed the mouse with AALI through differentiating the viscosity alternations by in vivo imaging. More importantly, when medication was applied to alleviate the liver injury of the AALI mouse, HOTPy could also dynamically track the liver improvement process in situ. In summary, HOTPy is a promising tool for diagnosis and management of AALI through real-time fluorescence imaging.