Macrophage-Targeting and Hydrogen-Peroxide-Responsive Fluorescent Probe for Imaging of Inflammation In Vivo

An uncontrolled immune response leads to many diseases; therefore, monitoring inflammation is crucial for the diagnosis of subsequent diseases, drug screening, and targeted therapy. Since the inflammatory response mainly occurs in macrophages, there is a need to develop more inflammatory probes with macrophage-targeting ability. Herein, we designed a macrophage-targeted and hydrogen-peroxide-activated fluorescent probe BOH-HCy-Man for real-time imaging of inflammation in vivo and a control probe BOH-HCy without the macrophage-targeting part. The larger rate constant toward H₂O₂ led to the higher sensitivity of BOH-HCy-Man (19.1-fold) than BOH-HCy (10.2-fold) in vitro. With the help of its macrophage-targeting ability, BOH-HCy-Man possessed an additional 1.6-fold fluorescent enhancement in inflamed RAW 264.7 cells or 1.3-fold fluorescent enhancement in vivo than BOH-HCy. We expected that BOH-HCy-Man will be a powerful tool for early diagnosis of inflammation related diseases.