Bairamukov Viktor, Bukatin Anton, Landa Sergey, Burdakov Vladimir, Shtam Tatiana, Chelnokova Irina, Fedorova Natalia, Filatov Michael, Starodubtseva Maria
Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC «Kurchatov Institute», 1, Orlova Roshcha, 188300 Gatchina, Russia.
Alferov Saint Petersburg National Research Academic University of the Russian Academy of Sciences, 8/3, Khlopina St., 194021 Saint Petersburg, Russia.
Biology (Basel). 2020 Dec 23;10(1):4. doi: 10.3390/biology10010004.
While extracellular vesicles (EVs) are extensively studied by various practical applications in biomedicine, there is still little information on their biomechanical properties due to their nanoscale size. We identified isolated blood plasma vesicles that carried on biomarkers associated with exosomes and exomeres and applied atomic force microscopy (AFM) to study them at single particle level in air and in liquid. Air measurements of exosomes revealed a mechanically indented internal cavity in which highly adhesive sites were located. In contrast, the highly adhesive sites of exomeres were located at the periphery and the observed diameter of the particles was ~35 nm. In liquid, the reversible deformation of the internal cavity of exosomes was observed and a slightly deformed lipid bi-layer was identified. In contrast, exomeres were not deformed and their observed diameter was ~16 nm. The difference in diameters might be associated with a higher sorption of water film in air. The parameters we revealed correlated with the well-known structure and function for exosomes and were observed for exomeres for the first time. Our data provide a new insight into the biomechanical properties of nanoparticles and positioned AFM as an exclusive source of in situ information about their biophysical characteristics.
虽然细胞外囊泡（EVs）在生物医学的各种实际应用中得到了广泛研究，但由于其纳米级尺寸，关于它们生物力学特性的信息仍然很少。我们鉴定出分离的血浆囊泡，其携带与外泌体和外粒体相关的生物标志物，并应用原子力显微镜（AFM）在空气和液体中对其进行单颗粒水平研究。外泌体在空气中的测量显示出一个机械凹陷的内腔，其中存在高粘附位点。相比之下，外粒体的高粘附位点位于周边，观察到的颗粒直径约为35nm。在液体中，观察到外泌体内腔的可逆变形，并鉴定出脂质双层略有变形。相比之下，外粒体没有变形，观察到的直径约为16nm。直径差异可能与空气中水膜的更高吸附有关。我们揭示的参数与外泌体的已知结构和功能相关，并且首次在外粒体中观察到。我们的数据为纳米颗粒的生物力学特性提供了新的见解，并将AFM定位为关于其生物物理特性的原位信息的唯一来源。
