Meeting the demand for efficient photosensitizers in photodynamic therapy (PDT), a series of iridium(III) complexes decorated with silicane-modified rhodamine (Si-rhodamine) was meticulously designed and synthesized. These complexes demonstrate exceptional PDT potential owing to their strong absorption in the near-infrared (NIR) spectrum, particularly responsive to 808 nm laser stimulation. This feature is pivotal, enabling deep-penetration laser excitation and overcoming depth-related challenges in clinical PDT applications. The molecular structures of these complexes allow for reliable tuning of singlet oxygen generation with NIR excitation, through modification of the cyclometalating ligand. Notably, one of the complexes (4) exhibits a remarkable ROS quantum yield of 0.69. In vivo results underscore the efficacy of 4, showcasing significant tumor regression at depths of up to 8.4 mm. This study introduces a promising paradigm for designing photosensitizers capable of harnessing NIR light effectively for deep PDT applications.

中文翻译：

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硅烷改性罗丹明修饰的铱（III）配合物：近红外光引发的光敏剂，用于有效的深层组织渗透光动力治疗

为了满足光动力治疗（PDT）中对高效光敏剂的需求，精心设计并合成了一系列硅烷修饰罗丹明（Si-罗丹明）修饰的铱（ III ）配合物。这些复合物表现出卓越的 PDT 潜力，因为它们对近红外 (NIR) 光谱有很强的吸收，特别是对 808 nm 激光刺激敏感。这一功能至关重要，可实现深穿透激光激发并克服临床 PDT 应用中与深度相关的挑战。这些配合物的分子结构允许通过环金属化配体的修饰，在近红外激发下可靠地调节单线态氧的产生。值得注意的是，其中一种配合物 ( 4 ) 表现出 0.69 的显着 ROS 量子产率。体内结果强调了4的功效，显示深度达 8.4 毫米的肿瘤显着消退。这项研究引入了一种有前途的范例，用于设计能够有效利用近红外光进行深度 PDT 应用的光敏剂。