Force spectroscopy reveals membrane fluctuations and surface adhesion of extracellular nanovesicles impact their elastic behavior

• 成果类型: Article
• 署名作者: Stridfeldt, Fredrik; Pandey, Vikash; Kylhammar, Hanna; Gevari, Moein Talebian; Metem, Prattakorn; Agrawal, Vipin; Goergens, Andre; Mamand, Doste R.; Gilbert, Jennifer; Palmgren, Lukas; Holme, Margaret N.; Gustafsson, Oskar; El Andaloussi, Samir; Mitra, Dhrubaditya; Dev, Apurba
• 署名单位: Royal Institute of Technology; Royal Institute of Technology; Nordic Institute for Theoretical Physics; Stockholm University; Uppsala University; Royal Institute of Technology; Stockholm University; Karolinska Institutet; Karolinska Institutet; Karolinska University Hospital; University of Duisburg Essen; Karolinska Institutet; Karolinska University Hospital; Chalmers University of Technology
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8989
• DOI: 10.1073/pnas.2414174122
• 发表日期: 2025-04-22
• 关键词: red-blood-cells; transient pores; vesicles; bilayers; indentation; DYNAMICS; shells; MODULI; fluid

摘要

The elastic properties of nanoscale extracellular vesicles (EVs) are believed to influence their cellular interactions, thus having a profound implication in intercellular communication. However, accurate quantification of their elastic modulus is challenging due to their nanoscale dimensions and their fluid-like lipid bilayer. We show that the previous attempts to develop atomic force microscopy-based protocol are flawed as they lack theoretical underpinning as well as ignore important contributions arising from the surface adhesion forces and membrane fluctuations. We develop a protocol comprising a theoretical framework, experimental technique, and statistical approach to accurately quantify the bending and elastic modulus of EVs. The method reveals that membrane fluctuations play a dominant role even for a single EV. The method is then applied to EVs derived from human embryonic kidney cells and their genetically engineered classes altering the tetraspanin expression. The data show a large spread; the area modulus is in the range of 4 to 19 mN/m and the bending modulus is in the range of 15 to 33 kBT, respectively. Surprisingly, data for a single EV, revealed by repeated measurements, also show a spread that is attributed to their compositionally heterogeneous fluid membrane and thermal effects. Our protocol uncovers the influence of membrane protein alterations on the elastic modulus of EVs.