A lipophilic AIEgen for lipid droplet imaging and evaluation of the efficacy of HIF-1 targeting drugs.

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that mediates the cellular response to hypoxia. The upregulation of HIF-1 expression in hypoxic cells can induce the accumulation of lipid droplets (LDs), and the LD levels can in turn reflect the expression level of HIF-1. Herein, we report a LD-specific luminogen with aggregation-induced emission characteristics (AIEgen), and have explored its potential applications in the evaluation of the inhibitory efficacy of HIF-1 targeting drugs. Compared to Nile red, this AIEgen shows a larger Stokes shift, better photostability, a more sensitive response to changes in dye concentration and a broader quantitative range. We found that the AIEgen can be used for semi-quantifying LD levels in cancer cells under hypoxic conditions, and for evaluating the inhibitory efficacy of HIF-1 targeting drugs. This work provides a simple and cost-effective strategy for screening HIF-1-targeted drugs, which may also be an alternative for evaluating the drug efficacy of other LD-related diseases.