Fabrication of Smart Tantalum Carbide MXene Quantum Dots with Intrinsic Immunomodulatory Properties for Treatment of Allograft Vasculopathy

Abstract MXene nanomaterials have sparked significant interest among interdisciplinary researchers to tackle today's medical challenges. In particular, colloidal MXene quantum dots (MQDs) offer the high specific surface area and compositional flexibility of MXene while providing improvements to aqueous stability and material–cell interactions. The current study for the first time reports the development and application of immunoengineered tantalum‐carbide (Ta 4 C 3 T x ) MQDs for in vivo treatment of transplant vasculopathy. This report comes at a critical juncture in the field as poor long‐term safety of other MXene compositions challenge the eventual clinical translatability of these materials. Using rational design and synthesis strategies, the Ta 4 C 3 T x MQDs leverage the intrinsic anti‐inflammatory and antiapoptotic properties of tantalum to provide a novel nanoplatform for biomedical engineering. In particular, these MQDs are synthesized with high efficiency and purity using a facile hydrofluoric acid‐free protocol and are enriched with different bioactive functional groups and stable surface TaO 2 and Ta 2 O 5 . Furthermore, MQDs are spontaneously uptaken into antigen‐presenting endothelial cells and alter surface receptor expression to reduce their activation of allogeneic T‐lymphocytes. Finally, when applied in vivo, Ta 4 C 3 T x MQDs ameliorate the cellular and structural changes of early allograft vasculopathy. These findings highlight the robust potential of tailored Ta 4 C 3 T x MQDs for future applications in medicine.