Visualizing hepatic M1 macrophages with a dual-target-recognizing photoacoustic nanoprobe for identifying non-alcoholic steatohepatitis

• • The nanoprobe achieved selective M1φ imaging via dual targeting of GLUTs and NO activation, with enhanced PA signal intensity correlating with M1φ abundance during NAFLD progression in diabetic mice (12-week vs. 19-week). • • In vivo PA imaging at 6 h post-injection distinguished NASH from NAFL based on distinct signal enhancement patterns, validated by histology (Oil Red O, H&E, Masson) and flow cytometry (F4/80+/CD86+ cell rates). • • The probe demonstrated high selectivity for NO, enabling specific imaging of M1φ over other macrophage phenotypes, reducing non-specific uptake and improving sensitivity. • • The study provides a non-invasive diagnostic strategy for NASH, potentially reducing reliance on liver biopsy and enabling longitudinal monitoring of disease progression.