A lipid droplets specific probe for imaging of atherosclerosis and fibrocalcific bicuspid aortic valves

Lipid droplets (LDs) have been regarded as potential targets for the diagnosis of cardiovascular diseases. However, conventional LDs imaging strategies suffer from invasive sample collection and tedious histological preparations. Although fluorescence imaging has showed good performance in LDs imaging, ideal probes are still in urgent demand. In this work, fluorescent probe, namely, MeTTI was prepared for LDs visualization in cells and tissues. MeTTI exhibited low fluorescence quantum yield in dimethyl sulfoxide (Φf = 0.2 %), while the value in the solid state was obvious increased (Φf = 3.5 %), suggesting the aggregation-induced emission (AIE) property of MeTTI. Meanwhile, MeTTI would form excimers (emission ranged 750–850 nm) in water, and it showed good biocompatibility. Moreover, MeTTI exhibited impressive fluorescence emission enhancement in oleic acid (Φf = 34.7 %) compared to that in water (Φf = 1.11 %), which can specifically stain LDs in cells, atherosclerosis (AS) plaques and human fibrocalcific bicuspid aortic valves (FBAV) with high ratio of signal to noise. In addition, MeTTI could also monitor the dynamic changes of LDs in cells. These results were expected to provide a simple tool for studying the pathogenesis of cardiovascular diseases with lipid deposition and triggering enthusiasm to develop new imaging techniques for the diagnosis of these diseases.