Chemodynamic Therapeutic Nanoplatform with Activatable NIR-II Ratiometric Fluorescence for Self-Evaluating Fenton...

Real-time evaluation of the Fenton reactivity of chemodynamic therapy (CDT) agents is critical for developing effective CDT agents. However, the development of CDT agents capable of self-evaluating Fenton reactivity remains challenging. Herein, using ^·OH as an indicator of Fenton reaction, we report a CDT nanoplatform, DCNP@FM-Fe²⁺-PEG (DFFP), which integrates a ^·OH-activatable NIR-II ratiometric fluorescent nanoprobe and a Fenton agent (Fe²⁺), for self-evaluating Fenton reactivity. DFFP can induce cell apoptosis by converting intracellular H₂O₂ into ^·OH and depleting GSH. In the presence of ^·OH, NIR-II fluorescence signal of DFFP at 1050 nm under 808 nm excitation (F_1050Em,808Ex) would be enhanced, while its fluorescence signal at 1550 nm under 980 nm excitation (F_1550Em,980Ex) remained stable. DFFP was able to self-evaluate its Fenton reactivity by ^·OH-activatable F_1050Em,808Ex/F_1550Em,980Ex signal, and it exhibited excellent anticancer effect. This strategy provides a new approach to construct CDT agents capable of self-evaluating the Fenton reactivity in real time.