Mitochondria-targeted near-infrared fluorescent probe for detecting viscosity in tumor and inflammation models

Abstract

Dynamic changes in mitochondrial viscosity are key indicators of mitochondrial functional status and metabolic activity, which are closely related to the development of a variety of diseases, including cancer and inflammation. However, significant challenges remain in real-time, non-invasive monitoring and imaging of mitochondrial viscosity in complex physiological environments, especially at the in vivo level. Herein, we developed a series of mitochondria-targeted near-infrared fluorescent probes, designated PTN1-PTN4. Among these, PTN1 demonstrated high sensitivity and selectivity in responding to changes in mitochondrial viscosity, enabling effective differentiation of mitochondrial viscosity in cells under different physiological or pathological states. Furthermore, probe PTN1 was successfully applied for tumor tissue diagnosis across cellular to organ levels by monitoring mitochondrial viscosity variations, as well as non-invasive detection in an inflammation mouse model at the in vivo level. The fluorescent probe developed in this work not only provides a powerful molecular tool for investigating the association between mitochondrial dysfunction and disease, but also shows considerable potential for application in the non-invasive early diagnosis of inflammation in vivo.