The near-infrared (NIR) fluorescence imaging modality has great potential for application in biomedical imaging research owing to its unique characteristics, such as low tissue autofluorescence and noninvasive visualization with high spatial resolution. Although a variety of NIR fluorophores are continuously reported, the commercially available NIR fluorophores are still limited, owing to complex synthetic processes and poor physicochemical properties. To address this issue, a small molecular NIR fluorophore (SMF800) was designed and developed in the present work to improve in vivo target-specific fluorescence imaging. After conjugation with pamidronate (PAM) and bovine serum albumin (BSA), the SMF800 conjugates exhibited successful in vivo targeting in bone and tumor tissues with low background uptake, respectively. The improved in vivo performance of the SMF800 conjugate demonstrated that the small molecular NIR fluorophore SMF800 can be widely used in a much broader range of imaging applications. The structure of SMF800, which was developed by considering two important physicochemical properties, water solubility and conjugatability, is first introduced. Therefore, this work suggests a simple and rational approach to design small, hydrophilic, and conjugatable NIR fluorophores for targeted bioimaging.

中文翻译：

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合理设计小分子近红外荧光团以改进体内荧光成像

近红外（NIR）荧光成像模式由于其独特的特性，例如低组织自发荧光和高空间分辨率的无创可视化，在生物医学成像研究中具有巨大的应用潜力。尽管各种近红外荧光团不断被报道，但由于合成过程复杂且理化性质差，商业上可用的近红外荧光团仍然有限。为了解决这个问题，本研究设计并开发了一种小分子近红外荧光团（SMF800），以改善体内目标特异性荧光成像。与帕米膦酸 (PAM) 和牛血清白蛋白 (BSA) 缀合后，SMF800 缀合物分别在低背景摄取的情况下成功体内靶向骨和肿瘤组织。SMF800 缀合物改进的体内性能表明小分子 NIR 荧光团 SMF800 可广泛用于更广泛的成像应用。首先介绍了SMF800的结构，该结构是考虑两个重要的理化性质：水溶性和缀合性而开发的。因此，这项工作提出了一种简单合理的方法来设计用于靶向生物成像的小型、亲水性和可共轭的近红外荧光团。