Spontaneous formation of MXene-oxidized sono/chemo-dynamic sonosensitizer/nanocatalyst for antibacteria and bone-tissue regeneration

Prolonged and incurable bacterial infections in soft tissue and bone are currently causing large challenges in the clinic. Two-dimensional (2D) materials have been designed to address these issues, but materials with satisfying therapeutic effects are still needed. Herein, CaO 2 -loaded 2D titanium carbide nanosheets (CaO 2 -TiO x @Ti 3 C 2 , C-T@Ti 3 C 2 ) were developed. Surprisingly, this nanosheet exhibited sonodynamic ability, in which CaO 2 caused the in situ oxidation of Ti 3 C 2 MXene to produce acoustic sensitiser TiO 2 on its surface. In addition, this nanosheet displayed chemodynamic features, which promoted a Fenton reaction triggered by self-supplied H 2 O 2 . We detected that C-T@Ti 3 C 2 nanosheets increased reactive oxygen species (ROS) production in response to sonodynamic therapy, which displayed an ideal antibacterial effect. Furthermore, these nanoreactors facilitated the deposition of Ca 2+ , which promoted osteogenic transformation and enhanced bone quality in osteomyelitis models. Herein, a wound healing model and prosthetic joint infection (PJI) model were established, and the C-T@Ti 3 C 2 nanosheets played a protective role in these models. Taken together, the results indicated that the C-T@Ti 3 C 2 nanosheets function as a multifunctional instrument with sonodynamic features, which might reveal information regarding the treatment of bacterial infections during wound healing. Graphical Abstract