NIR-II emissive nanoprobe for non-invasive monitoring of liver fibrosis and in-situ ratiometric visualization of NO gas-based therapy process

Timely detecting the progression and therapeutic effect of non-alcoholic liver disease is a great challenge due to lacking suitable non-invasive imaging methods. Herein, a novel theranostic nanoplatform based on lanthanide nanorods integrated with photo-triggered NO releasing molecule (NaYF4:Gd/Yb/Er@mSiO2-RBS) is designed for simultaneous diagnosis of liver fibrosis and second near infrared (NIR-II) ratiometric fluorescence imaging of the NO gas-based therapy of liver fibrosis. The mice with liver fibrosis present bright NIR-II emission (1000–1400 nm) via endogenous pigment secreted in liver fibrosis area under 808 nm laser excitation, enabling non-invasive diagnosis of liver fibrosis. In addition, the nanoplatform presents efficient NO gas release for therapy of liver fibrosis and 1532 nm emission activated by 980 nm laser. Importantly, after NO gas therapy, NIR-II fluorescent signal of the endogenous pigment was decreased, while the fluorescent signal around 1532 nm was increased, leading to the specific ratiometric NIR-II imaging of the therapy process with high specificity. Thus, the developed theranostic nanoprobe provided a powerful tool for timely NIR-II ratiometric detecting the progression and therapeutic effect of liver disease.