Dual H2 O2 -Amplified Nanofactory for Simultaneous Self-Enhanced NIR-II Fluorescence Activation Imaging and Synergistic Tumor Therapy.

ABSTRACT

Activatable fluorescence imaging in the second near-infrared window (NIR-II FL, 1000-1700 nm) is of great significance for accurate tumor diagnosis and targeting therapy. However, the clinical translation of most stimulus-activated nanoprobes is severely restricted by insufficient tumor response and out-of-synchronization theranostic process. Herein, an intelligent nanofactory AUC-GOx/Cel that possesses the "external supply, internal promotion" dual H2 O2 -amplification strategy for homologous activated tumor theranostic is designed. This nanofactory is constructed via a two-step biomineralization method using Au-doped Ag2 S as a carrier for glucose oxidase (GOx) and celastrol, followed by the growing of CuS to "turn off" the NIR-II FL signal. In the overexpressed H2 O2 tumor-microenvironment, the CuS featuring a responsive-degradability behavior can effectively release Cu ions, resulting in the "ON" state of NIR-II FL and Fenton-like activity. The exposed GOx can realize the intratumoral H2 O2 supply (external supply) via the effective conversion of glucose, and mediating tumor-starvation therapy; the interaction of celastrol and mitochondria can offer a substantial increase in the endogenous H2 O2 level (internal promotion), thereby significantly promoting the chemodynamic therapy (CDT) efficacy. Meanwhile, the dual H2 O2 -enhancement performance will in turn accelerate the degradation of AUC-GOx/Cel, and achieve a positive feedback mechanism for self-reinforcing CDT.