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Staphylococcus aureus has become one of the most common pathogens in clinical tissue infection, and it is easy to form biofilm. Incomplete removal of biofilms often leads to recurrent infections, and more serious is the possibility of bacteria developing drug resistance. Therefore, the effective eradication of refractory biofilms is essential. Herein, a temperature-sensitive hydrogel was prepared by doping the photothermal carbon dots (PTCDs) chelated by Ag+, and the AIPH which could produce alkyl radicals in response to heat into the thermodissolved gelatin. Under the irradiation of 660 nm laser, the PTCDs generated heat to dissolve the hydrogel, and promoted chelation of silver ions in PTCDs for chemical sterilization. Meanwhile, the heat generated by the PTCDs induced the 2,2′-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH) to produce alkyl free radical sterilization, achieving the purpose of photothermal/thermodynamic/chemical synergistic to kill Staphylococci aureus and destroy its biofilm. Therefore, the biocompatible PTCDs@Ag-AIPH hydrogel proposed in this study was a promising composite that could eliminate biofilms and promoted wound healing, showing good potential in future biomedical applications.

Abstract Sonodynamic therapy (SDT), a tumor treatment modality with high tissue penetration and low side effects, is able to selectively kill tumor cells by producing cytotoxic reactive oxygen species (ROS) with ultrasound‐triggered sonosensitizers. N‐type inorganic semiconductor TiO2 has low ROS quantum yields under ultrasound irradiation and inadequate anti‐tumor activity. Herein, by using atomic layer deposition (ALD) to create a heterojunction between porous TiO2 and CoOx, the sonodynamic therapy efficiency of TiO2 can be improved. Compared to conventional techniques, the high controllability of ALD allows for the delicate loading of CoOx nanoparticles into TiO2 pores, resulting in the precise tuning of the interfaces and energy band structures and ultimately optimal SDT properties. In addition, CoOx exhibits a cascade of H2O2→O2→·O2− in response to the tumor microenvironment, which not only mitigates hypoxia during the SDT process, but also contributes to the effect of chemodynamic therapy (CDT). Correspondingly, the synergistic CDT/SDT treatment is successful in inhibiting tumor growth. Thus, ALD provides new avenues for catalytic tumor therapy and other pharmaceutical applications.