Tumor hypoxia can cause undesirable barriers for many therapeutic interventions, especially for oxygen-dependent photodynamic therapy (PDT). To ameliorate hypoxia and enhance the cancer therapeutic efficacy, herein, catalase-like platinum (Pt) nanoparticles (NPs) were designed as nanoenzyme to anchor onto the surface of black phosphorus nanosheets (BP NSs), followed by Ce6 conjugation and subsequent PEGylation to obtain BP/Pt-Ce6@PEG NSs. As-prepared BP/Pt-Ce6@PEG NSs could decompose endogenous H₂O₂ into O₂ in situ to relieve tumor hypoxia, affording enhanced reactive oxygen species (ROS) production. In vitro cytotoxicity studies demonstrated the best therapeutic effect of BP/Pt-Ce6@PEG NSs in comparison to that of BP/Pt NSs or Ce6 alone. In vivo experiments on the 4T1 tumor xenograft mouse model showed that BP/Pt-Ce6@PEG NSs could efficiently alleviate tumor hypoxia and eliminate tumor cells, presenting excellent oxygen self-supplied photodynamic and photothermal synergistic therapy therapeutic efficacy. These results highlight that platinum nanoenzyme functionalization is promising to raise the intratumoral oxygen level to surmount tumor hypoxia for efficient tumor treatment.

肿瘤缺氧可导致许多治疗干预的不良屏障，尤其是对于氧依赖性光动力疗法（PDT）。为了改善缺氧并增强癌症的治疗功效，本文将过氧化氢酶样铂（Pt）纳米颗粒（NPs）设计为纳米酶，将其锚定在黑磷纳米片（BP NSs）的表面，然后进行Ce6缀合并随后进行聚乙二醇化，从而获得BP / Pt-Ce6 @ PEG NSs。制备的BP / Pt-Ce6 @ PEG NSs可以将内源性H ₂ O ₂原位分解为O ₂ ，以减轻肿瘤的缺氧，增强活性氧（ROS）的产生。体外细胞毒性研究表明，与单独使用BP / Pt NSs或Ce6相比，BP / Pt-Ce6 @ PEG NSs的最佳治疗效果。在4T1肿瘤异种移植小鼠模型上的体内实验表明BP / Pt-Ce6 @ PEG NSs可以有效缓解肿瘤缺氧并消除肿瘤细胞，具有出色的氧自给自足的光动力和光热协同治疗功效。这些结果表明，铂纳米酶功能化有望提高肿瘤内的氧水平以克服肿瘤的缺氧，从而有效地治疗肿瘤。