Novel dual-responsive near-infrared fluorescent bio-probe for visualizing lipid droplet accumulation in living cell and non-alcoholic fatty liver mouse models

Abstract

The prevalence of non-alcoholic fatty liver disease (NAFLD) continues to increase among the population and has become a global health issue. Abnormal accumulation of lipid droplets (LDs) is a key characteristic of NAFLD, therefore, accurate diagnosis of different degrees of NAFLD can be achieved by monitoring changes in lipid droplets in the organism. This study designed and synthesized three novel near-infrared dual-responsive fluorescent bio-probe ED-1, ED-2 and ED-3, which used triphenylamine as the main body. Compared with the biosensors ED-2 and ED-3, ED-1 showed higher sensitivity to changes in polarity and viscosity through intramolecular charge transfer (lCT) and twisted intramolecular charge transfer (TlCT) effects, and had better anti-interference performance, excellent light stability and higher biological safety. Therefore, further research was conducted on the bio-probe ED-1, meanwhile, cell imaging results showed that ED-1 could accurately track the accumulation of LDs in HepG2 cells induced by different concentrations of oleic acid. It was worth noting that ED-1 had demonstrated the ability to distinguish between normal liver regions and fatty liver at the tissue and organ levels in NAFLDN mouse models. The above results indicated that the bio-probe ED-1 was a promising tool for studying the pathological and physiological processes of NAFLD, and could be used to accurately determine different degrees of fatty liver.

Keywords: Dual-response; Fluorescent bio-probe; Lipid droplet; Live imaging; NAFLD.