Chhour Peter, Kim Johoon, Benardo Barbara, Tovar Alfredo, Mian Shaameen, Litt Harold I, Ferrari Victor A, Cormode David P
Department of Radiology, ‡Department of Bioengineering, and §Department of Medicine, Division of Cardiovascular Medicine, Perelman School of Medicine of the University of Pennsylvania , 3400 Spruce Street, 1 Silverstein, Philadelphia, Pennsylvania 19104, United States.
Bioconjug Chem. 2017 Jan 18;28(1):260-269. doi: 10.1021/acs.bioconjchem.6b00566. Epub 2016 Nov 18.
With advances in cell therapies, interest in cell tracking techniques to monitor the migration, localization, and viability of these cells continues to grow. X-ray computed tomography (CT) is a cornerstone of medical imaging but has been limited in cell tracking applications due to its low sensitivity toward contrast media. In this study, we investigate the role of size and surface functionality of gold nanoparticles for monocyte uptake to optimize the labeling of these cells for tracking in CT. We synthesized gold nanoparticles (AuNP) that range from 15 to 150 nm in diameter and examined several capping ligands, generating 44 distinct AuNP formulations. In vitro cytotoxicity and uptake experiments were performed with the RAW 264.7 monocyte cell line. The majority of formulations at each size were found to be biocompatible, with only certain 150 nm PEG functionalized particles reducing viability at high concentrations. High uptake of AuNP was found using small capping ligands with distal carboxylic acids (11-MUA and 16-MHA). Similar uptake values were found with intermediate sizes (50 and 75 nm) of AuNP when coated with 2000 MW poly(ethylene-glycol) carboxylic acid ligands (PCOOH). Low uptake values were observed with 15, 25, 100, and 150 nm PCOOH AuNP, revealing interplay between size and surface functionality. Transmission electron microscopy (TEM) and CT performed on cells revealed similar patterns of high gold uptake for 50 nm PCOOH and 75 nm PCOOH AuNP. These results demonstrate that highly negatively charged carboxylic acid coatings for AuNP provide the greatest internalization of AuNP in monocytes, with a complex dependency on size.
随着细胞疗法的进展，用于监测这些细胞迁移、定位和活力的细胞追踪技术的关注度持续增长。X射线计算机断层扫描（CT）是医学成像的基石，但由于其对造影剂的低敏感性，在细胞追踪应用中受到限制。在本研究中，我们研究了金纳米颗粒的尺寸和表面功能对单核细胞摄取的作用，以优化这些细胞的标记以便在CT中进行追踪。我们合成了直径范围为15至150nm的金纳米颗粒（AuNP），并研究了几种封端配体，生成了44种不同的AuNP制剂。用RAW 264.7单核细胞系进行了体外细胞毒性和摄取实验。发现每种尺寸的大多数制剂具有生物相容性，只有某些150nm聚乙二醇功能化颗粒在高浓度下会降低活力。发现使用带有远端羧酸的小封端配体（11-MUA和16-MHA）时AuNP的摄取量很高。当用2000MW聚（乙二醇）羧酸配体（PCOOH）包被时，中等尺寸（50和75nm）的AuNP具有相似的摄取值。观察到15、25、100和150nm PCOOH AuNP的摄取值较低，揭示了尺寸和表面功能之间的相互作用。对细胞进行的透射电子显微镜（TEM）和CT显示，50nm PCOOH和75nm PCOOH AuNP的高金摄取模式相似。这些结果表明，AuNP的高度带负电荷的羧酸涂层在单核细胞中提供了最大的AuNP内化，并且对尺寸有复杂的依赖性。
