Real-time monitoring viscosity variation in carcinogenesis evolution models by a red-emitting rotor

Monitoring of the viscosity levels in cells and tissues is of great significance for the preliminary diagnosis related to abnormal viscosity. However, tracking of the viscosity level of tumors in different growth stages at the tissue level has not been reported. Therefore, a new viscosity-sensitive fluorescent probe (TA-I) with large Stokes shift and high viscosity dependence is in this work designed to visualize the viscosity level of tumors at different growth stages. And this probe exhibited a 20-fold fluorescence enhancement in viscous medium. With the aid of TA-I, a rapidly increasing fluorescent signal (16 times) was captured in the cells stimulated by exogenous stimuli, and the probe was also successfully applied to monitor viscosity changes in inflammatory mice. In addition, the viscosity levels in tumor tissues of mice at different growth stages (3 days, 6 days and 10 days) were also visualized in tissue level and revealed that the intratumoral viscosity level is highly dependent on tumor growth period. Importantly, the decreased viscosity of drugs-treated tumor tissue was obtained by the probe. It is worth noting that this is the first time to visualize the viscosity change rule of tumor at different growth stages at the tissue level.