Integration of nanozymes and metastructures on implants for confined sono-enhanced catalytic therapy

Nanocatalytic medicine offers an innovative paradigm for disease treatment, yet systemic administration of nanomaterials raises critical biosafety concerns that restrict its application potential. While implant catalytic medicine represents a promising alternative, insufficient surface-active sites weaken its catalytic therapeutic performance. Here, we propose a universal confined sono-enhanced catalytic strategy realized by integrating nanozymes and metastructures into implants. The porous acoustic metastructure afforded abundant nanozyme immobilization sites and captured ultrasound to generate turbulent flow for fast mass transfer and thermal energy to activate the reaction system, synergistically improving the nanozyme's catalytic activity. As a proof of concept, the biocompatible FeO_x nanozyme was modified onto the acoustic metastructured TiO₂ coating on a titanium implant to achieve enhanced catalytic therapy against infection/tumor. In the infection/tumor microenvironments, the FeO_x nanozyme could catalyze H₂O₂ to ˙OH for bacteria/tumor killing, which was significantly amplified by the synergistic acoustic-thermal and acoustic streaming effects of TiO₂ metastructures activated by ultrasound. Meanwhile, this hierarchical micro-nanostructured coating exhibited good biocompatibility and promoted osteogenesis. Importantly, this strategy can be extended to other material systems to achieve sono-enhanced catalytic therapies and repairs for different diseases. The concept of confined sono-enhanced catalytic therapy based on nanozyme-decorated metastructures may make a difference in implant catalytic medicine and smart-responsive biomaterials.