Multimode evaluating the fluctuation of lipid droplets polarity in acute kidney injury and tumor models

Lipid droplets (LDs) polarity changes are closely associated with the occurrence and development of various diseases. Simultaneously observing the LDs polarity fluctuations through fluorescence intensity, fluorescence wavelength, and fluorescence lifetime could greatly improve the accuracy of different pathological processes. We herein present a novel multimode two-photon aggregation-induced emission fluorescent probe (TP-LDs) for sensitively detecting the polarity changes in LDs. TP-LDs showed good photostability and high selectivity for LDs even at low concentrations. Furthermore, TP-LDs could detect the LDs polarity changes in the acute kidney injury (AKI) cell model and distinguish lung cancer cells and normal cells through fluorescence intensity, fluorescence lifetime, and fluorescence wavelength. Moreover, for the first time, we revealed LDs polarity changes in the AKI mouse model and its treatment. Most importantly, TP-LDs can differentiate tumor tissues from normal tissues in the A549 tumor-bearing mouse model and distinguish normal lung tissues from cancerous tissues in humans. Thus, the multimode polarity-sensitive fluorescent probe holds a robust tool for AKI and tumor evaluation in cells and animals as well as provides new insights into lung cancer diagnosis in clinical.