Using X-ray as the irradiation source, a photodynamic therapy process can be initiated from under deep tissues. This technology, referred to as X-ray induced PDT, or X-PDT, holds great potential to treat tumors at internal organs. To this end, one question is how to navigate the treatment to tumors with accuracy with external irradiation. Herein we address the issue with a novel, LiGa5O8: Cr (LGO:Cr)-based nanoscintillator, which emits persistent, near-infrared X-ray luminescence. This permits deep-tissue optical imaging that can be employed to guide irradiation. Specifically, we encapsulated LGO:Cr nanoparticles and a photosensitizer, 2,3-naphthalocyanine, into mesoporous silica nanoparticles. The nanoparticles were conjugated with cetuximab and systemically injected into H1299 orthotopic non-small cell lung cancer tumor models. The nanoconjugates can efficiently home to tumors in the lung, confirmed by monitoring X-ray luminescence from LGO:Cr. Guided by the imaging, external irradiation was applied, leading to efficient tumor suppression while minimally affecting normal tissues. To the best of our knowledge, the present study is the first to demonstrate, with systematically injected nanoparticles, that X-PDT can suppress growth of deep-seated tumors. The imaging guidance is also new to X-PDT, and is significant to the further transformation of the technology.

中文翻译：

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LiGa5O8：Cr基治疗性纳米粒子，用于影像引导X射线诱导的深部肿瘤光动力治疗

使用X射线作为照射源，可以从深层组织下面开始光动力治疗过程。这项被称为X射线诱导的PDT或X-PDT的技术在治疗内部器官的肿瘤方面具有巨大的潜力。为此，一个问题是如何在外部照射下准确地将治疗导引至肿瘤。在这里，我们使用一种新颖的基于LiGa5O8：Cr（LGO：Cr）的纳米闪烁体来解决这个问题，该闪烁体发出持续的近红外X射线发光。这允许可用于引导辐射的深部组织光学成像。具体而言，我们将LGO：Cr纳米颗粒和光敏剂2,3-萘酞菁包封到中孔二氧化硅纳米颗粒中。将纳米颗粒与西妥昔单抗缀合并全身注射到H1299原位非小细胞肺癌肿瘤模型中。通过监测LGO：Cr的X射线发光证实，纳米复合物可以有效地归巢于肺部肿瘤。在成像的指导下，应用外部照射，从而在有效地抑制肿瘤的同时将对正常组织的影响降至最低。据我们所知，本研究是第一个通过系统注射纳米颗粒来证明X-PDT可以抑制深部肿瘤生长的研究。成像指导对于X-PDT来说也是新的，对技术的进一步转变具有重要意义。通过系统注射纳米粒子，X-PDT可以抑制深部肿瘤的生长。成像指导对于X-PDT来说也是新的，对技术的进一步转变具有重要意义。通过系统注射纳米粒子，X-PDT可以抑制深部肿瘤的生长。成像指导对于X-PDT来说也是新的，对技术的进一步转变具有重要意义。