Multifunctional Theranostic 2D Vanadium Carbidel for Enhanced Cancer Immunotherapy

Abstract The application of 2D MXene materials in the biomedical field has been widely explored. Apart from excellent photothermal properties, their role in modulating various immune cells and overcoming immune‐suppressive tumor microenvironments is waiting to be discovered. In this work, a novel multifunctional 2D vanadium carbide is constructed that degrades in situ in the tumor microenvironment. Various characterizations and first‐principles calculations indicated that V ₄ C ₃ nanosheets exhibit excellent light absorption and photothermal conversion capabilities in the NIR‐II biological window. The photothermal and X‐ray absorption properties of V ₄ C ₃ nanosheets enabled dual‐modal photoacoustic imaging/computerized tomography (PA/CT) imaging functionality. The V ₄ C ₃ nanosheets in the tumor microenvironment decomposed under the effect of H ₂ O ₂ and GSH, triggering a Fenton‐like reaction. The photothermal ablation and reactive oxygen species (ROS) generation capabilities enabled V ₄ C ₃ nanosheets to convert cold tumors into hot ones (macrophage: M2→M1) and induce reactions like immunogenic cell death (ICD). Dendritic cell (DC) cells matured under the ICD stimulation, which promoted T cell activation, reduced Treg cells and thus effectively enhanced tumor immunotherapy. The multiple properties including imaging, photothermal, enzyme‐driven, and immune functions enable V ₄ C ₃ nanosheets to ablate tumors effectively. This study provides an example for the research of the multifunctional exploration and application of MXene in biomedicine filed.