Semiconductor quantum dots (QDs) have served as superior optically active nanomaterials for molecular imaging and photodynamic therapy (PDT), but the low singlet oxygen (¹O₂) quantum yield and lack of tumor selectivity have limited their applications for tumor PDT in vivo. Here, we report the rational engineering of QDs into tumor-targeting hybrid nanoparticles through micelle-encapsulating a pre-assembled unique QD-Zn-porphyrin complex, a highly fluorescent organic photosensitizer rhodamine 6G (R6G), and a near-infrared fluorophore NIR775 with folic acid labeled phospholipid polymers. These nanoparticles have large porphyrin payloads and strong light absorption capability, thus contributing to an extremely high ¹O₂ quantum yield (∼0.91) via an efficient dual energy transfer process. In vivo studies show that they can preferably accumulate in tumors through folate receptor-mediated active delivery, permitting non-invasive fluorescence imaging and effective PDT of tumors in living mice. This study highlights the utility of hybrid semiconductor QDs for both tumor imaging and PDT in vivo.

中文翻译：

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合理设计半导体量子点，可实现显着的¹ O ₂产生，用于肿瘤靶向的光动力疗法

半导体量子点（QDs）已成为分子成像和光动力疗法（PDT）的优良光学活性纳米材料，但是单线态氧（¹ O ₂）的量子产率低和缺乏肿瘤选择性限制了它们在体内肿瘤PDT中的应用。在这里，我们报告通过胶束封装预先组装的独特QD-Zn-卟啉复合物，高荧光有机光敏剂若丹明6G（R6G）和具有叶酸标记的磷脂聚合物。这些纳米粒子具有大的卟啉有效负载和强大的光吸收能力，因此有助于产生极高的¹ O _2。通过高效的双重能量转移过程获得的量子产率（约0.91）。体内研究表明，它们优选可通过叶酸受体介导的主动递送积聚在肿瘤中，从而允许在活体小鼠中进行无创荧光成像和有效的肿瘤PDT。这项研究强调了混合半导体QDs在体内肿瘤成像和PDT中的实用性。