Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
Nanoscale. 2019 Oct 3;11(38):17878-17893. doi: 10.1039/c9nr04981a.
Engineered nanomaterials (ENMs) are increasingly used in consumer products due to their unique physicochemical properties, but the specific hazards they pose to the structural and functional integrity of endothelial barriers remain elusive. When assessing the effects of ENMs on vascular barrier function, endothelial cell monolayers are commonly used as in vitro models. Monolayer models, however, do not offer a granular understanding of how the structure-function relationships between endothelial cells and tissues are disrupted due to ENM exposure. To address this issue, we developed a micropatterned endothelial cell pair model to quantitatively evaluate the effects of 10 ENMs (8 metal/metal oxides and 2 organic ENMs) on multiple cellular parameters and determine how these parameters correlate to changes in vascular barrier function. This minimalistic approach showed concerted changes in endothelial cell morphology, intercellular junction formation, and cytoskeletal organization due to ENM exposure, which were then quantified and compared to unexposed pairs using a "similarity scoring" method. Using the cell pair model, this study revealed dose-dependent changes in actin organization and adherens junction formation following exposure to representative ENMs (Ag, TiO2 and cellulose nanocrystals), which exhibited trends that correlate with changes in tissue permeability measured using an endothelial monolayer assay. Together, these results demonstrate that we can quantitatively evaluate changes in endothelial architecture emergent from nucleo-cytoskeletal network remodeling using micropatterned cell pairs. The endothelial pair model therefore presents potential applicability as a standardized assay for systematically screening ENMs and other test agents for their cellular-level structural effects on vascular barriers.
由于具有独特的物理化学性质，工程纳米材料（ENMs）越来越多地用于消费产品，但它们对内皮屏障的结构和功能完整性造成的具体危害仍难以捉摸。在评估 ENMs 对血管屏障功能的影响时，通常将内皮细胞单层用作体外模型。然而，单层模型不能深入了解由于 ENM 暴露导致内皮细胞和组织之间的结构-功能关系如何被破坏。为了解决这个问题，我们开发了一种微图案化的内皮细胞对模型，以定量评估 10 种 ENMs（8 种金属/金属氧化物和 2 种有机 ENMs）对多种细胞参数的影响，并确定这些参数如何与血管屏障功能的变化相关。这种简化方法显示，由于 ENM 暴露，内皮细胞形态、细胞间连接形成和细胞骨架组织发生协同变化，然后使用“相似性评分”方法对暴露和未暴露的细胞对进行定量比较。使用细胞对模型，本研究揭示了代表性 ENMs（Ag、TiO2 和纤维素纳米晶体）暴露后肌动蛋白组织和黏附连接形成的剂量依赖性变化，这些变化趋势与使用内皮单层测定法测量的组织通透性变化相关。总之，这些结果表明，我们可以使用微图案化细胞对定量评估核-细胞骨架网络重塑引起的内皮结构变化。因此，内皮细胞对模型具有作为一种标准化测定法的潜在适用性，可用于系统筛选 ENMs 和其他测试剂对血管屏障的细胞水平结构影响。
