Two-Dimensional Tantalum Carbide (MXenes) Composite Nanosheets for Multiple Imaging-Guided Photothermal Tumor Ablation

MXenes, an emerging family of graphene-analogues two-dimensional (2D) materials, have attracted continuous and tremendous attention in many application fields because of their intrinsic physiochemical properties and high performance in versatile applications. In this work, we report on the construction of tantalum carbide (Ta₄C₃) MXene-based composite nanosheets for multiple imaging-guided photothermal tumor ablation, which has been achieved by rational choice of the composition of MXenes and their surface functionalization. A redox reaction was activated on the surface of tantalum carbide (Ta₄C₃) MXene for in situ growth of manganese oxide nanoparticles (MnO_x/Ta₄C₃) based on the reducing surface of the nanosheets. The tantalum components of MnO_x/Ta₄C₃ acted as the high-performance contrast agents for contrast-enhanced computed tomography, and the integrated MnO_x component functionalized as the tumor microenvironment-responsive contrast agents for T₁-weighted magnetic resonance imaging. The photothermal-conversion performance of MnO_x/Ta₄C₃ composite nanosheets not only has achieved contrast-enhanced photoacoustic imaging, but also realized the significant tumor-growth suppression by photothermal hyperthermia. This work broadens the biomedical applications of MXenes, not only by the fabrication of family members of biocompatible MXenes, but also by the development of functionalization strategies of MXenes for cancer-theranostic applications.