Lipid Droplet Specific Targeted Polarity-Sensitive NIR Fluorescence Carbon Dots for Imaging Metabolic Dysfunction-Associated Steatotic Liver Disease.

Lipid droplets (LDs) are multifunctional organelles essential for lipid storage, metabolic regulation, and cellular homeostasis, and their dysregulation is closely associated with the onset and progression of metabolic dysfunction-associated steatotic liver disease (MASLD). Sensitive and specific fluorescent imaging of LDs dynamics is crucial for elucidating MASLD pathogenesis and accelerating the development of effective therapeutics. Herein, we report near-infrared fluorescent carbon dots (NIR-FCDs) with precise LDs-targeting capability and enabling high-contrast imaging of LDs distribution in AML-12 cells and MASLD mice model, exhibiting high brightness (QY: 8.6%), deep-tissue penetration (75 μm), excellent photostability (>3 h continuous irradiation), and superior signal-to-background (SBR = 26). Leveraging these properties, NIR-FCDs was applied for visualizing pathological lipid accumulation in MASLD mice models and demonstrated their utility in a drug-screening platform successfully. This work developed a robust NIR-FCDs for LDs-specific imaging and highlighted its potential to advance mechanistic studies and therapeutic discovery in metabolic liver diseases.