Living cells as a biological analog of optical tweezers – a non-invasive microrheology approach

Hardiman, W., Clark, M., Friel, C., Huett, A., Pérez-Cota, F., Setchfield, K., Wright, A. J. and Tassieri, M. (2023) Living cells as a biological analog of optical tweezers – a non-invasive microrheology approach. Acta Biomaterialia, 166, pp. 317-325. (doi: 10.1016/j.actbio.2023.04.039) (PMID:37137402)

Abstract

Microrheology, the study of fluids on micron length-scales, promises to reveal insights into cellular biology, including mechanical biomarkers of disease and the interplay between biomechanics and cellular function. Here a minimally-invasive passive microrheology technique is applied to individual living cells by chemically binding a bead to the surface of a cell, and observing the mean squared displacement of the bead at timescales ranging from milliseconds to 100s of seconds. Measurements are repeated over the course of hours, and presented alongside analysis to quantify changes in the cells’ low-frequency elastic modulus, G′0, and the cell’s dynamics over the time window ∼10−2s to 10s. An analogy to optical trapping allows verification of the invariant viscosity of HeLa S3 cells under control conditions and after cytoskeletal disruption. Stiffening of the cell is observed during cytoskeletal rearrangement in the control case, and cell softening when the actin cytoskeleton is disrupted by Latrunculin B. These data correlate with conventional understanding that integrin binding and recruitment triggers cytoskeletal rearrangement. This is, to our knowledge, the first time that cell stiffening has been measured during focal adhesion maturation, and the longest time over which such stiffening has been quantified by any means.

• Item Type: Articles
• Additional Information: This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) under grants EP/S0214334/1, EP/L016052/1, EP/R035067/1, EP/R035563/1, EP/R035156/1 ”Experiencing the microworld: a cell’s perspective”, the Oxford and Nottingham Biomedical Imaging (ONBI) CDT and the University of Nottingham.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Tassieri, Dr Manlio
• Authors: Hardiman, W., Clark, M., Friel, C., Huett, A., Pérez-Cota, F., Setchfield, K., Wright, A. J., and Tassieri, M.
• College/School: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Journal Name: Acta Biomaterialia
• Publisher: Elsevier
• ISSN: 1742-7061
• ISSN (Online): 1878-7568
• Published Online: 01 May 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Acta Biomaterialia 166:317-325
• Publisher Policy: Reproduced under a Creative Commons license

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
301441		Experiencing the micro-world - a cell's perspective	Manlio Tassieri	Engineering and Physical Sciences Research Council (EPSRC)	EP/R035067/1	ENG - Biomedical Engineering