Sonodynamic therapy (SDT) has attracted widespread interest in biomedicine, owing to its novel and noninvasive therapeutic method triggered by ultrasound (US). Herein, the Ti₃C₂ MXene nanosheets (Ti₃C₂ NSs) are developed as good sonosensitizers via a two-step method of chemical exfoliation and high-temperature treatment. With the high-temperature treatment, the oxygen defect of Ti₃C₂ MXene nanosheets (H–Ti₃C₂ NSs) is greatly increased. Therefore, the electron (e⁻) and hole (h⁺) generated by US can be separated faster due to the improved degree of oxidation, and then the recombination of e⁻-h⁺ can be prevented with the abundant oxygen defect under US irradiation, which induced the sonodynamic efficiency greatly to improve around 3.7-fold compared with Ti₃C₂ NSs without high-temperature treatment. After PEGylation, the H–Ti₃C₂-PEG NSs show good stability and biocompatibility. In vitro studies exhibit that the inherent property of mild photothermal effect can promote the endocytosis of H–Ti₃C₂-PEG NSs, which can improve the SDT efficacy. In vivo studies further display that the increased blood supply by the mild photothermal effect can significantly relieve hypoxia in the tumor microenvironment, showing photothermal therapy (PTT) enhanced SDT. Most importantly, the H–Ti₃C₂-PEG NSs can be biodegraded and excreted out of the body, showing no significant long-term toxicity. Our work develops the defective H–Ti₃C₂ NSs as high-efficiency and safe sonosensitizers for photothermal-enhanced SDT of cancer, extending the biomedical application of MXene-based nanoplatforms.

声动力学疗法 (SDT) 由于其由超声波 (US) 触发的新型无创治疗方法而引起了生物医学的广泛兴趣。在此，Ti ₃ C ₂ MXene 纳米片（Ti ₃ C ₂ NSs）通过化学剥离和高温处理两步法开发为良好的声敏剂。随着高温处理，Ti ₃ C ₂ MXene纳米片（H-Ti ₃ C ₂ NSs）的氧缺陷大大增加。因此，电子 (e ⁻ ) 和空穴 (h ⁺由美国产生的）可以被分离更快由于氧化的改进的程度，然后e的重组^- -h ⁺可以与US辐射下丰富的氧缺陷，其引起的声动力效率大大改善周围能够防止3.7倍与未经高温处理的Ti ₃ C ₂ NSs相比。聚乙二醇化后，H–Ti ₃ C ₂ -PEG NSs 显示出良好的稳定性和生物相容性。体外研究表明，温和的光热效应的固有特性可以促进 H-Ti ₃ C ₂ -PEG NSs的内吞作用，从而提高 SDT 的功效。体内研究进一步表明，温和的光热效应增加的血液供应可以显着缓解肿瘤微环境中的缺氧，表明光热疗法（PTT）增强了 SDT。最重要的是，H-Ti ₃ C ₂ -PEG NSs 可以生物降解并排出体外，没有显着的长期毒性。我们的工作开发了有缺陷的 H-Ti ₃ C ₂ NSs 作为高效、安全的声敏剂，用于癌症的光热增强 SDT，扩展了基于 MXene 的纳米平台的生物医学应用。