Snipstad Sofie, Hak Sjoerd, Baghirov Habib, Sulheim Einar, Mørch Ýrr, Lélu Sylvie, von Haartman Eva, Bäck Marcus, Nilsson K Peter R, Klymchenko Andrey S, de Lange Davies Catharina, Åslund Andreas K O
Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
Cytometry A. 2017 Aug;91(8):760-766. doi: 10.1002/cyto.a.22853. Epub 2016 Apr 14.
In vitro and in vivo behavior of nanoparticles (NPs) is often studied by tracing the NPs with fluorescent dyes. This requires stable incorporation of dyes within the NPs, as dye leakage may give a wrong interpretation of NP biodistribution, cellular uptake, and intracellular distribution. Furthermore, NP labeling with trace amounts of dye should not alter NP properties such as interactions with cells or tissues. To allow for versatile NP studies with a variety of fluorescence-based assays, labeling of NPs with different dyes is desirable. Hence, when new dyes are introduced, simple and fast screening methods to assess labeling stability and NP-cell interactions are needed. For this purpose, we have used a previously described generic flow cytometry assay; incubation of cells with NPs at 4 and 37°C. Cell-NP interaction is confirmed by cellular fluorescence after 37°C incubation, and NP-dye retention is confirmed when no cellular fluorescence is detected at 4°C. Three different NP-platforms labeled with six different dyes were screened, and a great variability in dye retention was observed. Surprisingly, incorporation of trace amounts of certain dyes was found to reduce or even inhibit NP uptake. This work highlights the importance of thoroughly evaluating every dye-NP combination before pursuing NP-based applications. © 2016 International Society for Advancement of Cytometry.
纳米颗粒（NPs）的体外和体内行为通常通过用荧光染料追踪纳米颗粒来研究。这要求染料在纳米颗粒内稳定掺入，因为染料泄漏可能会对纳米颗粒的生物分布、细胞摄取和细胞内分布产生错误解读。此外，用痕量染料标记纳米颗粒不应改变纳米颗粒的性质，如与细胞或组织的相互作用。为了能够使用各种基于荧光的检测方法进行通用的纳米颗粒研究，用不同染料标记纳米颗粒是很有必要的。因此，当引入新的染料时，需要简单快速的筛选方法来评估标记稳定性和纳米颗粒与细胞的相互作用。为此，我们使用了先前描述的通用流式细胞术检测方法；将细胞与纳米颗粒在4°C和37°C下孵育。在37°C孵育后通过细胞荧光确认细胞与纳米颗粒的相互作用，在4°C未检测到细胞荧光时确认纳米颗粒与染料的保留情况。对用六种不同染料标记的三种不同纳米颗粒平台进行了筛选，观察到染料保留存在很大差异。令人惊讶的是，发现掺入痕量的某些染料会减少甚至抑制纳米颗粒的摄取。这项工作强调了在进行基于纳米颗粒的应用之前彻底评估每种染料与纳米颗粒组合的重要性。© 2016国际细胞计量学促进会。
