Jump to main content
Jump to site search

Issue 39, 2018
Previous Article Next Article

Standardized microgel beads as elastic cell mechanical probes

Author affiliations


Cell mechanical measurements are gaining increasing interest in biological and biomedical studies. However, there are no standardized calibration particles available that permit the cross-comparison of different measurement techniques operating at different stresses and time-scales. Here we present the rational design, production, and comprehensive characterization of poly-acrylamide (PAAm) microgel beads mimicking size and overall mechanics of biological cells. We produced mono-disperse beads at rates of 20–60 kHz by means of a microfluidic droplet generator, where the pre-gel composition was adjusted to tune the beads’ elasticity in the range of cell and tissue relevant mechanical properties. We verified bead homogeneity by optical diffraction tomography and Brillouin microscopy. Consistent elastic behavior of microgel beads at different shear rates was confirmed by AFM-enabled nanoindentation and real-time deformability cytometry (RT-DC). The remaining inherent variability in elastic modulus was rationalized using polymer theory and effectively reduced by sorting based on forward-scattering using conventional flow cytometry. Our results show that PAAm microgel beads can be standardized as mechanical probes, to serve not only for validation and calibration of cell mechanical measurements, but also as cell-scale stress sensors.

Graphical abstract: Standardized microgel beads as elastic cell mechanical probes

Back to tab navigation

Supplementary files

Article information

30 May 2018
16 Aug 2018
First published
04 Sep 2018

J. Mater. Chem. B, 2018,6, 6245-6261
Article type

Standardized microgel beads as elastic cell mechanical probes

S. Girardo, N. Träber, K. Wagner, G. Cojoc, C. Herold, R. Goswami, R. Schlüßler, S. Abuhattum, A. Taubenberger, F. Reichel, D. Mokbel, M. Herbig, M. Schürmann, P. Müller, T. Heida, A. Jacobi, E. Ulbricht, J. Thiele, C. Werner and J. Guck, J. Mater. Chem. B, 2018, 6, 6245
DOI: 10.1039/C8TB01421C

Social activity

Search articles by author