This work proposed a method for fabricating poly(lactic-co-glycolic acid) (PLGA) nanoparticles (ca. 70 nm) loaded with indocyanine green (ICG) molecules by an antisolvent crystallization method using dimethyl sulfoxide (DMSO) as a good solvent and water as a poor solvent. ICG molecules were loaded to PLGA nanoparticles by mixing PLGA, polyethylenimine, and polyethylene glycol (PEG) in DMSO with polyvinyl alcohol, albumin, and ICG in water. The ICG-loaded PLGA nanoparticle colloid solutions emitted fluorescence even at high ICG concentrations. Not only the tissues of a tumor-bearing mouse but also the tumor could be imaged with an IVIS system by injecting ICG-loaded PLGA nanoparticle colloid solution into the tail vein of the mouse and measuring the emitted fluorescence intensity, though some ICG-loaded PLGA nanoparticles were trapped in tissues such as the liver and spleen due to insufficient PEGylation. Thus, this work showed that ICG-loaded PLGA nanoparticles have potential for cancer imaging.

Graphical abstract

中文翻译：

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负载吲哚菁绿的聚乳酸-乙醇酸共聚物纳米粒子的制备及荧光成像性能

这项工作提出了一种方法，该方法使用二甲亚砜（DMSO）作为良好溶剂，通过反溶剂结晶方法制备了负载有吲哚花青绿（ICG）分子的聚乳酸-乙醇酸共聚物（PLGA）纳米粒子（约70 nm），并且水作为不良溶剂。通过将DMSO中的PLGA，聚乙烯亚胺和聚乙二醇（PEG）与水中的聚乙烯醇，白蛋白和ICG混合，将ICG分子加载到PLGA纳米颗粒上。加载了ICG的PLGA纳米胶体溶液即使在高ICG浓度下也能发出荧光。通过将装有ICG的PLGA纳米胶体溶液注入小鼠的尾静脉并测量其发射的荧光强度，不仅可以用IVIS系统对携带肿瘤的小鼠的组织进行成像，而且还可以使用IVIS系统对肿瘤进行成像。尽管由于不充分的PEG化，一些ICG负载的PLGA纳米颗粒被困在肝和脾等组织中。因此，这项工作表明载有ICG的PLGA纳米颗粒具有用于癌症成像的潜力。

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