Biocompatible 2D Titanium Carbide (MXenes) Composite Nanosheets for pH-Responsive MRI-Guided Tumor Hyperthermia

The emerging of two-dimensional (2D) MXenes significantly broadens the family members and versatile applications of 2D materials, but the rational design of MXene-based composites and their specific applications in theranostic biomedicine are still challenging. In this work, we report, for the first time, on the elaborate design of the Ti 3 C 2 -based composite MXene (MnO x /Ti 3 C 2 ) for highly efficient theranostic applications against cancer. These MnO x /Ti 3 C 2 composite MXenes have been constructed by triggering a simple redox reaction to in situ grow small MnO x nanosheets on the surface of Ti 3 C 2 . These MnO x /Ti 3 C 2 composite MXenes have been developed as multifunctional theranostic agents for efficient magnetic resonance (MR) and photoacoustic (PA) dual-modality imaging-guided photothermal therapy (PTT) against cancer. Especially, the decoration of the MnO x component onto MnO x /Ti 3 C 2 realizes the unique tumor microenvironment-responsive T 1 -weighted MR imaging of tumors, and the high photothermal-conversion performance not only endows the MnO x /Ti 3 C 2 with desirable contrast-enhanced PA-imaging property but also realizes the highly efficient tumor ablation and tumor-growth suppression. The in vivo biocompatibility of these MnO x /Ti 3 C 2 –SP composite nanosheets has also been systematically evaluated and revealed. This work not only paves a new way for the multifunctionalization of 2D MXenes simply by integrating other functional components but also broadens their versatile applications in theranostic nanomedicine.