AIE fluorescent probes for monitoring cell membrane fluidity/lipid droplet change during alcoholic liver disease

Alcoholic liver disease (ALD) has attracted widespread attention because of the ever-increasing alcohol consumption and high morbidity. However, there is still no effective detection method to prevent the deterioration of the disease. Cholesterol, as the main component of the cell membrane (CM), often transported to lipid droplets (LDs) for storage in hepatocytes. Meanwhile, abnormal changes of cholesterol could cause liver diseases, such as Tangier disease. Based on cholesterol could serve as a hub that affects the cell membrane fluidity (CMF) and the number of LDs, we planned to study the microscopic changes of CMF and LDs in ALD. As viscous media could limit the intramolecular motion of fluorescent probes, aggregation induced emission luminogens (AIEgens), which typically have rotators and vibrators in their structures and emit strongly in the aggregate state, may be promising candidates for CMF and LD study. So two AIE probes (TPCN and NDPB) were designed and synthesized based on the typical AIE skeleton, tetraphenylethylene (TPE), which could selectively target CMs and LDs, respectively. These probes exhibited high chemical stability, controllable emission, and excellent subcellular specificity. They successfully sensed the correlated changes of CMs and LDs in ALD model, which would contribute to understanding the microscopic process of ALD pathogenesis and further development of ALD therapeutic drugs.