Sonodynamic therapy has received increasing attention for cancer treatments as an alternative to photodynamic therapy. However, its clinical applications have been limited by the lack of a sonosensitizer that is capable of producing sufficient amounts of reactive oxygen species (ROS) in response to ultrasound (US) exposure. Herein, PEGylated mesoporous silica–titania nanoparticles (P‐MSTNs) are prepared and used as US‐responsive nanocarriers for cancer sonotheranostics. Perfluorohexane (PFH), which is chosen as the gas precursor, is physically encapsulated into P‐MSTNs using the oil‐in‐water emulsion method. Owing to the vaporization of the gas precursor, PFH@P‐MSTNs (137 nm in diameter) exhibit a strong photoacoustic signal in vivo for at least 6 h. Compared to P‐MSTNs, PFH@P‐MSTNs generate significantly higher amounts of ROS due to the nanobubble‐induced cavitation in the presence of US. When systemically administered to tumor‐bearing mice, PFH@P‐MSTNs effectively accumulate in the tumor site due to the passive targeting mechanism. Consequently, PFH@P‐MSTNs show much higher antitumor efficacy than P‐MSTNs due to the enhanced cavitation‐mediated ROS generation in response to US exposure. It is considered that PFH@P‐MSTNs may hold significant potential for cancer sonotheranostics.

中文翻译：

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空化诱导介孔二氧化硅-二氧化钛纳米粒子用于癌症超声治疗。

声动力学疗法作为光动力疗法的替代方案已越来越受到癌症治疗的关注。但是，其临床应用受到缺少声敏剂的限制，该声敏剂能够响应于超声（US）暴露而产生足够量的活性氧（ROS）。在此，制备了聚乙二醇化的介孔二氧化硅-二氧化钛纳米粒子（P-MSTN），并用作对癌症超声治疗的US响应纳米载体。使用水包油乳液法将被选作气体前体的全氟己烷（PFH）物理封装到P-MSTN中。由于气体前体的汽化，PFH @ P‐MSTN（直径137 nm）在体内至少6 h内显示出强的光声信号。与P‐MSTN相比，PFH @ P‐MSTN由于存在US的纳米气泡引起的空化作用而产生大量的ROS。当全身给药于荷瘤小鼠时，由于被动靶向机制，PFH @ P-MSTN有效地积聚在肿瘤部位。因此，PFH @ P-MSTNs显示出比P-MSTNs高得多的抗肿瘤功效，这是由于响应美国暴露而增加了空化介导的ROS生成。据认为，PFH @ P‐MSTNs可能在癌症超声治疗中具有巨大潜力。PFH @ P‐MSTNs比P‐MSTNs具有更高的抗肿瘤功效，这是因为响应美国暴露，空化介导的ROS生成增强。据认为，PFH @ P‐MSTNs可能在癌症超声治疗中具有巨大潜力。PFH @ P‐MSTNs比P‐MSTNs具有更高的抗肿瘤功效，这是因为响应美国暴露，空化介导的ROS生成增强。据认为，PFH @ P‐MSTNs可能在癌症超声治疗中具有巨大潜力。