Injectable Magnetic-Nanozyme Based Thermosensitive Hydrogel for Multimodal DLBCL Therapy

Diffuse large B-cell lymphoma (DLBCL), accounting for 31% of non-Hodgkin lymphomas, remains recalcitrant to conventional therapies due to chemoresistance, metastatic progression, and immunosuppressive microenvironments. We report a novel injectable Fe₃O₄@DMSA@Pt@PLGA-PEG-PLGA hydrogel system integrating magnetothermal therapy (MHT), chemodynamic therapy (CDT), and immunomodulation. Under alternating magnetic fields (AMF), the system achieves rapid therapeutic hyperthermia (50 °C within 7 min) while activating pH/temperature-dual responsive peroxidase (POD) -like activity in Fe₃O₄@DMSA@Pt nanoparticles. Catalytic efficiency under tumor-mimetic conditions was significantly higher than Fe₃O₄@DMSA controls, generating elevated reactive oxygen species (ROS). Flow cytometry revealed 75.9% apoptotic cell death in A20 lymphoma cells at 50 °C, significantly surpassing CDT alone (24.5%). Importantly, this dual mechanism induced immunogenic cell death (ICD) characterized by 4.1-fold CRT externalization, 68% HMGB1 nuclear depletion, and 40.74 nM ATP secretion. This triggered robust dendritic cell maturation (92% CD86⁺/CD80⁺ DCs comparable to LPS controls) and T cell activation (16.9% CD25⁺/CD69⁺ ratio, 130-fold baseline). Our findings validate the therapeutic potential of magnetothermal-chemodynamic synergy for DLBCL treatment, paving the way for innovative multi-mechanism therapeutic strategies against DLBCL with potential clinical translation prospects.