Photoacoustic imaging-guided triple-responsive nanoparticles with tumor hypoxia relief for improving chemotherapy/ photothermal/photodynamic synergistic therapy against breast cancer.

Chemo-photothermal/photodynamic synergistic therapy is a new effective cancer treatment method to overcome the limitations of single chemotherapy. However, the limited low photothermal conversion efficiency, the hypoxic tumor microenvironment, and premature leakage of the drug constrain their clinical applications. To address these challenges, an all-in-one biodegradable polydopamine-coated UiO-66 framework nanomedicine (DUPM) was developed to co-deliver the drug doxorubicin hydrochloride (DOX) and the excellent photothermal material MoO nanoparticles (NPs). The results showed that DUPM exhibited good physicochemical stability and efficiently accumulated tumor tissues under pH-, glutathione-, and NIR-triggered drug release behaviour. Of note, the synthesized MoO NPs endowed DUPM with self-supporting oxygen production and generated more reactive oxygen species (O and·OH), besides, it induces Mo-mediated redox reaction to deplete excessive glutathione thus relieving tumor hypoxia to enhance PDT, further improving synergistic therapy. Meanwhile, DUPM showed strong absorption in the near-infrared range and high photothermal conversion efficiency at 808 nm (51.50%) to realize photoacoustic imaging-guided diagnosis and treatment of cancer. Compared with monotherapy, the in vivo anti-tumor efficacy results showed that DUMP exerted satisfactory tumor growth inhibition effects (94.43%) with good biocompatibility. This study provides a facile strategy to develop intelligent multifunctional nanoparticles with tumor hypoxia relief for improving synergistic therapy and diagnosis against breast cancer.