A Smart Near-Infrared Carbon Dot-Metal Organic Framework Assemblies for Tumor Microenvironment-Activated Cancer Imaging and Chemodynamic-Photothermal Combined Therapy.

Tumor microenvironment (TME)-activated cancer imaging and therapy is a key to achieving accurate diagnosis and treatment of cancer and reducing the side effects. Herein, smart near-infrared carbon dot-metal organic framework MIL-100 (Fe) assemblies are constructed to achieve TME-activated cancer imaging and chemodynamic-photothermal combined therapy. First, a near-infrared emission carbon dot (RCDs) is developed using glutathione (GSH) as the precursor. Then, the RCDs@MIL-100 self-assemblies are obtained using RCDs, FeCl 3 , and trimesic acid solutions as raw materials. After the RCDs@MIL-100 enters the TME, a high concentration of GSH reduces Fe 3+ to Fe 2+ and drains the GSH, triggering the collapse of RCDs@MIL-100 skeleton and the release of RCDs and Fe 2+ , at which time the RCDs fluorescence is restored and in an "on" state to illuminate the tumor cells, which achieved cancer imaging. The released Fe 2+ reacts with H 2 O 2 in the TME to form highly reactive hydroxyl radicals (•OH) by Fenton reaction, which achieves the chemodynamic therapy of tumors. Thus, efficient synergistic chemodynamic-photothermal dual mode therapy is achieved under fluorescence imaging guidance with TME response.