Yang Qi, Lai Samuel K
Division of Molecular Pharmaceutics, University of North Carolina at Chapel Hill, Marsico 4213, 125 Mason Farm Road, Chapel Hill, NC, 27599, USA.
Methods Mol Biol. 2017;1530:125-137. doi: 10.1007/978-1-4939-6646-2_8.
Poly(ethylene glycol) (PEG) coatings can substantially reduce nanoparticle uptake and clearance by immune cells as well as nonspecific interactions with the biological environment, thus potentially improving nanoparticle circulation times and biodistribution in target tissues such as tumors. Naturally, the "stealth" properties of PEG coatings are critically dependent on the density and conformation of surface PEG chains. However, there are significant technical hurdles to both generating sufficiently dense PEG coatings on nanoparticles and precisely characterizing their PEG grafting densities. Here, we describe methods for preparing PEGylated polymeric nanoparticles with precisely tunable PEG coatings without the use of organic solvents, quantifying PEGylation efficiency and density using a standard fluorescence assay, and evaluating nanoparticle uptake by immune cells using flow cytometry.
聚乙二醇（PEG）涂层可以显著减少免疫细胞对纳米颗粒的摄取和清除，以及与生物环境的非特异性相互作用，从而有可能延长纳米颗粒在肿瘤等靶组织中的循环时间并改善其生物分布。自然地，PEG涂层的“隐形”特性关键取决于表面PEG链的密度和构象。然而，在纳米颗粒上生成足够致密的PEG涂层以及精确表征其PEG接枝密度都存在重大技术障碍。在此，我们描述了制备具有精确可调PEG涂层的聚乙二醇化聚合物纳米颗粒的方法，该方法不使用有机溶剂，使用标准荧光测定法定量PEG化效率和密度，并使用流式细胞术评估免疫细胞对纳米颗粒的摄取。
