Force spectroscopy reveals membrane fluctuations and surface adhesion of extracellular nanovesicles impact their elastic behavior
Journal article, 2025
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.
elasticity
lipid bilayer
force spectroscopy
extracellular vesicles
atomic force microscopy
Author
Fredrik Stridfeldt
Royal Institute of Technology (KTH)
Vikash Pandey
Stockholm University
Hanna Kylhammar
Royal Institute of Technology (KTH)
Moein Talebian Gevari
Uppsala University
Prattakorn Metem
Royal Institute of Technology (KTH)
Vipin Agrawal
Stockholm University
Robert R. McCormick School of Engineering and Applied Science
André Görgens
Karolinska Institutet
Karolinska University Hospital
Universitats Klinikum Essen und Medizinische Fakultat
Doste R. Mamand
Karolinska Institutet
Karolinska University Hospital
Jennifer Gilbert
Chalmers, Life Sciences, Chemical Biology
Lukas Palmgren
Student at Chalmers
Margaret Holme
Chalmers, Life Sciences, Chemical Biology
Oskar Gustafsson
Karolinska University Hospital
Karolinska Institutet
Samir El Andaloussi
Karolinska University Hospital
Karolinska Institutet
Dhrubaditya Mitra
Stockholm University
Apurba Dev
Uppsala University
Royal Institute of Technology (KTH)
Proceedings of the National Academy of Sciences of the United States of America
0027-8424 (ISSN) 1091-6490 (eISSN)
Vol. 122 16 e2414174122Subject Categories (SSIF 2025)
Condensed Matter Physics
Biophysics
DOI
10.1073/pnas.2414174122
Related datasets
Atomic Force Microscopy (AFM) Data of Exosomes and Liposomes [dataset]
DOI: https://doi.org/10.5281/zenodo.15113782