Intratumoral hypoxia significantly constrains the susceptibility of solid tumors to oxygen-dependent photodynamic therapy (PDT), and effort to reverse such hypoxia has achieved limited success to date. Herein, we developed a novel engineered bacterial system capable of targeting hypoxic tumor tissues and efficiently mediating the photodynamic treatment of these tumors. For this system, we genetically engineered Escherichia coli to express catalase, after which we explored an electrostatic adsorption approach to link black phosphorus quantum dots (BPQDs) to the surface of these bacteria, thereby generating an engineered E. coli/BPQDs (EB) system. Following intravenous injection, EB was able to target hypoxic tumor tissues. Subsequent 660 nm laser irradiation drove EB to generate reactive oxygen species (ROS) and destroy the membranes of these bacteria, leading to the release of catalase that subsequently degrades hydrogen peroxide to yield oxygen. Increased oxygen levels alleviate intratumoral hypoxia, thereby enhancing BPQD-mediated photodynamic therapy. This system was able to efficiently kill tumor cells in vivo, exhibiting good therapeutic efficacy. In summary, this study is the first to report the utilization of engineered bacteria to facilitate PDT, and our results highlight new avenues for BPQD-mediated cancer treatment.

Nanoenzymes perceive the properties of enzyme‐like catalytic activity, thereby offering significant cancer therapy potential. In this study, Fe3O4@MnO2, a magnetic field (MF) targeting nanoenzyme with a core‐shell structure, is synthesized and applied to radiation enhancement with using glucose oxidase (GOX) for combination therapy. The glucose is oxidized by the GOX to produce excess H2O2 in an acidic extracellular microenvironment, following which the MnO2 shell reacts with H2O2 to generate O2 and overcome hypoxia. Concurrently, intracellular glutathione (GSH)—which limits the effects of radiotherapy (RT)—can be oxidized by the MnO2 shell while the latter is reduced to Mn2+ for T1‐weighed MRI. The core Fe3O4, with its good magnetic targeting ability, can be utilized for T2‐weighed MRI. In summary, the work demonstrates that Fe3O4@MnO2, as a dual T1‐ and T2‐weighed MRI contrast agent with strong biocompatibility, exhibits striking potential for radiation enhancement under magnetic targeting.

In combating cancer, ultrasound (US)-triggered sonodynamic therapy (SDT) manifests a wide range of promising applications as a noninvasive treatment modality, thus showing potential to overcome the shortcomings and disadvantages of...