A pH-sensitive nanoplatform encapsulating lipid droplets specific near-infrared fluorescent probe for in vivo imaging of mice carotid artery plaques

Abstract

Effective real-time monitoring and tracking of lipid droplets (LDs) are crucial for precise diagnosis of atherosclerotic plaques and surveillance of pathological progression, while there is no effective in vivo LDs targeted imaging strategy in clinical. To this end, this study prepared a one-step synthesis of a novel near-infrared (NIR) fluorescent probe with aggregation-induced emission (AIE) properties, enabling visualization of intracellular LDs in living cells. To overcome the probe's hydrophobicity and suboptimal signal-to-noise ratio, we further engineered a pH-responsive nanoplatform to enhance probe's performance for achieving precise plaque imaging. This nanoplatform (named as ZY-P1-PMEA NPs) exhibited compact size (88 nm), large Stokes shift (96.6 nm), high stability, excellent dispersibility in aqueous media, and favorable biocompatibility, offers distinct advantages in LDs imaging. Notably, ZY-P1-PMEA NPs maintains stability under physiological conditions, while the nanoparticles (NPs) rapidly respond to the acidic microenvironment of lysosome, releasing ZY-P1 to specifically recognize intracellular LDs and enabling fluorescence imaging of plaques. Leveraging its superior photophysical properties, this NIR probe further facilitated in vivo imaging of carotid artery plaques in ApoE -/ -mice. Therefore, the ZY-P1-PMEA NPs represent a promising fluorescent nanoprobe and a potential candidate for detecting atherosclerotic plaques.