Facile transformation of rofecoxib into a novel near-infrared AIEgen for real-time dynamic monitoring of lipid droplets metabolism

Abstract

Lipid-related diseases that surpass other diseases cause a significant number ofglobal deaths each year. Visual monitoring the formation, dynamic movement and degradation of lipid droplets (LDs) can enhance our understanding of these diseases. Recent studies have shown that certain aggregation-induced emission (AIE) probes for LD imaging offer advantages such as high brightness, large Stokes shift and excellent photostability. In this work, we have designed and synthesized a near-infrared (NIR) LD-specific probe (RFHX-1), prepared via a one-step modification based on rofecoxib. RFHX-1 exhibited AIE properties with a large Stokes shift of up to 202 nm. Notably, RFHX-1 demonstrated a two-photon absorption property, with a cross section (б2PA) calculated to be 20.659 GM at 800 nm. Moreover, compared to the commercial probe BODIPY 493/503, RFHX-1 showed lower cytotoxicity, and improved resistance to photobleaching, making it more suitable for LD imaging. Owing to these advantages, the formation, dynamic movement and degradation of LDs in living cells were visualized and recorded in real-time. These results demonstrate that RFHX-1 is a promising tool for LD imaging, and could facilitate biomedical research on lipid-related diseases.