Recently, near-infrared (NIR) fluorescent dyes such as indocyanine green (ICG) have received tremendous interest as contrast agents for use in fluorescence-guided, intraoperative cancer resection surgery. However, despite showing great promise, ICG has many shortcomings such as rapid clearance and poor tumor accumulation. To improve the selective accumulation of ICG within tumors, numerous groups have formulated ICG into nanoparticles, but these approaches can suffer from rapid leakage of ICG, use of materials that exhibit poor or incomplete excretion, or complex chemistries that are not easily amenable to scale up for clinical use. Here, we developed a simple one-step method to prepare ICG-based fluorescent micelles that are composed solely of unmodified ICG and polycaprolactone (PCL), two clinically used materials with well-characterized safety profiles. The ICG-PCL micelles are prepared via oil-in-water emulsions, and the resulting micelles exhibit a uniform size, good reproducibility, and high loading efficiency. In vivo fluorescence imaging demonstrated that the ICG-PCL micelles led to a significant improvement in the accumulation and retention of ICG, in four different tumor models, compared with free dye, making them an attractive option for image-guided surgery.

中文翻译：

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吲哚菁绿涂层的聚己内酯胶束用于肿瘤的荧光成像。

最近，近红外（NIR）荧光染料，如吲哚菁绿（ICG）作为荧光剂引导的术中癌症切除手术中使用的造影剂受到了极大的关注。然而，尽管ICG前景广阔，但仍存在许多缺点，如清除速度快和肿瘤堆积不佳。为了改善ICG在肿瘤内的选择性积累，许多组织已将ICG配制为纳米颗粒，但是这些方法可能会遭受ICG的快速泄漏，排泄不良或不完全的材料的使用，或者难​​以轻易扩大规模的复杂化学物质的困扰用于临床。在这里，我们开发了一种简单的一步法来制备基于ICG的荧光胶束，该胶束仅由未修饰的ICG和聚己内酯（PCL）组成，具有良好安全特性的两种临床使用材料。ICG-PCL胶束是通过水包油乳液制备的，所得胶束具有均一的尺寸，良好的重现性和高装载效率。体内荧光成像显示，与游离染料相比，在四种不同的肿瘤模型中，ICG-PCL胶束可显着改善ICG的积累和保留，使其成为图像引导手术的诱人选择。