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Abstract Critical-sized bone defects are usually accompanied by bacterial infection leading to inflammation and bone nonunion. However, existing biodegradable materials lack long-term therapeutical effect because of their gradual degradation. Here, a degradable material with continuous ROS modulation is proposed, defined as a sonozyme due to its functions as a sonosensitizer and a nanoenzyme. Before degradation, the sonozyme can exert an effective sonodynamic antimicrobial effect through the dual active sites of MnN4 and Cu2O8. Furthermore, it can promote anti-inflammation by superoxide dismutase- and catalase-like activities. Following degradation, quercetin-metal chelation exhibits a sustaining antioxidant effect through ligand-metal charge transfer, while the released ions and quercetin also have great self-antimicrobial, osteogenic, and angiogenic effects. A rat model of infected cranial defects demonstrates the sonozyme can rapidly eliminate bacteria and promote bone regeneration. This work presents a promising approach to engineer biodegradable materials with long-time effects for infectious bone defects.

Current strategies to boost anti-tumor immune response include the use of immune checkpoint inhibitors and bispecific T cell-engaging antibodies. Here the authors describe a versatile antibody immobilization nanoplatform that can be used to deliver different combinations of immunotherapeutics, showing therapeutic superiority in pre-clinical models.

Fine controlling chemical reactions over transition metal catalysts in living systems like enzymes remains a challenge. Here, the authors develop a versatile light-controlled bioorthogonal catalyst by modifying macroporous silica-Pd0 with supramolecular complex of azobenzene and β-cyclodextrin.