Photodynamic therapy (PDT) kills cancer cells by converting tumour oxygen into reactive singlet oxygen ((1)O2) using a photosensitizer. However, pre-existing hypoxia in tumours and oxygen consumption during PDT can result in an inadequate oxygen supply, which in turn hampers photodynamic efficacy. Here to overcome this problem, we create oxygen self-enriching photodynamic therapy (Oxy-PDT) by loading a photosensitizer into perfluorocarbon nanodroplets. Because of the higher oxygen capacity and longer (1)O2 lifetime of perfluorocarbon, the photodynamic effect of the loaded photosensitizer is significantly enhanced, as demonstrated by the accelerated generation of (1)O2 and elevated cytotoxicity. Following direct injection into tumours, in vivo studies reveal tumour growth inhibition in the Oxy-PDT-treated mice. In addition, a single-dose intravenous injection of Oxy-PDT into tumour-bearing mice significantly inhibits tumour growth, whereas traditional PDT has no effect. Oxy-PDT may enable the enhancement of existing clinical PDT and future PDT design.

中文翻译：

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全氟化碳纳米颗粒在光动力疗法中增强了活性氧水平并抑制了肿瘤生长。

光动力疗法（PDT）通过使用光敏剂将肿瘤氧转化为反应性单线态氧（（1）O2）杀死癌细胞。但是，肿瘤中预先存在的缺氧和PDT期间的氧气消耗会导致氧气供应不足，从而阻碍光动力功效。在这里，为了克服这个问题，我们通过将光敏剂加载到全氟化碳纳米液滴中来创建氧自富光动力疗法（Oxy-PDT）。由于全氟化碳具有更高的氧容量和更长的（1）O2寿命，因此负载的光敏剂的光动力效应得到了显着增强，这可以通过（1）O2的加速生成和更高的细胞毒性来证明。在直接注射入肿瘤后，体内研究显示在Oxy-PDT治疗的小鼠中，肿瘤的生长受到抑制。此外，向荷瘤小鼠单次静脉注射Oxy-PDT可以显着抑制肿瘤的生长，而传统的PDT则没有效果。Oxy-PDT可以增强现有的临床PDT和将来的PDT设计。