A lipid droplets-targeting fluorescent probe for visualized viscosity detection in cells, zebrafish and NAFLD models.

As a global health threat, early and effective diagnosis and treatment of nonalcoholic fatty liver disease (NAFLD) is crucial. Once the optimal treatment window is missed, NAFLD will progress to various severe and irreversible liver dysfunctions, imposing a heavy burden on patients and the medical system. Here, a novel "D-π-A" type fluorescent probe (CzTP-CNPh) has been successfully constructed for exploring changes in lipid droplets (LDs) viscosity during the process of nonalcoholic fatty liver development. Research results show that probe CzTP-CNPh exhibits excellent viscosity sensitivity, high selectivity, a large Stokes shift, outstanding LDs-targeting ability and so on. Based on these advantages, this probe enables the visualization of viscosity changes in LDs within cells and zebrafish. More importantly, imaging experiments in cellular and tissue models reveal that LDs viscosity tends to increase during NAFLD progression. This work offers the insights for enhancing the understanding of LDs in pathological processes, potentially aiding in the early diagnosis of NAFLD.