Fe(II)-hydrazide coordinated all-active metal organic framework for photothermally enhanced tumor penetration and ferroptosis-apoptosis synergistic therapy

The combination of ferroptosis and apoptosis that act with different mechanisms holds enormous potential in cancer treatment. However, how to simply but effectively integrate the two modalities into a single platform is an enormous challenge. Herein, based on our newly discovered Fe(II)-hydrazide coordination self-assembly strategy, we design and develop an all-active amorphous metal organic framework (aMOF) for photothermally boosted ferroptosis-apoptosis synergistic anti-tumor therapy. The aMOF is prepared via one-pot co-assembly of doxorubicin (DOX), Fe²⁺ ions and 3,3′-dithiobis(propionohydrazide) (TPH) and subsequent decoration with TPH-functionalized hyaluronic acid. The obtained DOX@FeTH is amorphous in structure, and it exhibits favorable photothermal performance and displays pH/GSH/laser triple-responsive degradation behavior. The aMOF can be specifically internalized by CD44-overexpressed 4T1 cells and efficiently inhibit GPX4 activity via disulfide bond-mediated glutathione depletion, elevate intracellular H₂O₂ level by DOX-induced NOX4 activation, and consequently amplify lipid peroxidation with the assistance of self-supplied Fe²⁺, resulting in remarkable ferroptotic cell death. Meanwhile, the released DOX causes apoptotic cell death. Moreover, the aMOF-mediated hyperthermia can promote tumor penetration and augment the synergistic efficacy. Hence, the tumors are effectively suppressed by the synergistic treatment of DOX@FeTH with laser. This work provides a new strategy for fabricating aMOFs and opens a new horizon for tumor treatment.