Quantifying the physical properties of individual exosomes containing amyloid-β42 (Aβ42) is crucial for a better understanding of an underpinning mechanism of Alzheimer's disease expression which is associated with the Aβ42 transfer. Because of the lack of proper tools, however, there have been very few studies on how the amount of Aβ42 affects the physical properties of exosomes. To answer the question, we investigated the physical properties of exosomes secreted by neuroblastoma by probing individual exosomes using electrostatic force microscopy. Interestingly, we observed that when the higher concentration of Aβ42 oligomers was fed to cells, the higher surface charge of the exosomes appeared. This result indicates that the exosomes contain more Aβ42 with the increase in Aβ42 concentration in cell media, implying that they serve as transport vesicles for Aβ42. Our approach could help to better understand how the neuronal exosomes are related to the propagation of neurodegenerative diseases and to seek how to make an early diagnosis of those diseases.

中文翻译：

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使用静电力显微镜对摄入 Aβ42 细胞分泌的单个外泌体进行纳米电学表征

量化含有淀粉样蛋白-β42 (Aβ42) 的单个外泌体的物理特性对于更好地理解与 Aβ42 转移相关的阿尔茨海默病表达的基础机制至关重要。然而，由于缺乏合适的工具，关于 Aβ42 的数量如何影响外泌体物理特性的研究很少。为了回答这个问题，我们通过使用静电力显微镜探测单个外泌体来研究神经母细胞瘤分泌的外泌体的物理特性。有趣的是，我们观察到，当更高浓度的 Aβ42 寡聚体被喂给细胞时，外泌体的表面电荷会更高。该结果表明随着细胞培养基中 Aβ42 浓度的增加，外泌体含有更多的 Aβ42，暗示它们作为 Aβ42 的转运囊泡。我们的方法可以帮助更好地了解神经元外泌体如何与神经退行性疾病的传播相关，并寻求如何对这些疾病进行早期诊断。