BioAFM Webinars

Performing Accurate Force Measurements on Biological and Soft Matter

Mastering force measurements with AFM: Insights from Prof. Andreas Janshoff

Explore the nanomechanical properties of cell membranes

Forces play a crucial role in biological mechanisms, such as cellular response, molecular interactions, and protein binding, and are essential for deriving the nanomechanical properties of a sample. AFM has emerged as a key platform for the precise measurement of interaction forces on the nanometer scale. AFM force spectroscopy is used to quantify forces and determine nanomechanical properties such as Young's modulus, cell adhesion, and viscoelastic properties, information that is invaluable for studying interaction-based and disease-related biomechanical changes. Prof. Janshoff will outline his work using AFM to investigate the biomechanical properties of cell membranes, and, in particular, the viscoelastic behavior of the cell cortex.

Webinar Highlights:

Key insights and proven strategies for achieving reliable results
Common pitfalls and practical tips for ensuring reproducible measurements
Q&A session with the team

Watch On-Demand Webinar Summary

Mechanical Properties of Biomembranes

The mechanical properties of cells are intricately linked to the architecture and dynamics of their viscoelastic cortex. This cortex comprises a contractile, cross-linked actin mesh that attaches to the plasma membrane via linker proteins. However, our understanding of cell mechanics has primarily focused on the upper, apical side of adherent, polarized epithelial cells due to their accessibility in culture dishes. Consequently, less is known about the viscoelastic properties of basal membranes. In our investigation, we explored the viscoelastic behavior of basolateral membranes derived from polarized MDCK II epithelial cells. These membranes were subjected to external deformation, and their response was compared to that of living cells probed at the apical side. To achieve this, MDCK II cells were cultured on porous surfaces until they formed a confluent layer. The upper cell body was then removed using a squirting-lysis protocol, leaving behind free-standing basal membranes. Through force indentation and relaxation experiments, I precisely assessed the cortical viscoelasticity of these membranes. Interestingly, when comparing the data to reconstituted neat lipid bilayers using giant liposomes and porespanning membranes in conjunction with atomic force microscopy, a significant difference emerged: basal membranes exhibited an absence of energy dissipation. However, we were able to rescue this behavior by artificially attaching an actin cortex to the bilayer. Furthermore, I developed a theoretical framework to describe force cycles and applied it to obtain the timedependent area compressibility modulus of biomembranes. When compared to the viscoelastic response of living cells, biomembranes derived from living cells were found to be substantially less fluid and stiffer. Nevertheless, they still adhered to the same universal scaling law, provided excess area was correctly accounted for. This research sheds light on the fascinating biomechanical properties of cell membranes and their implications in cell biology.

Find out more about the technology featured in this webinar or our other solutions for BioAFM:

Topic Input value is invalid.

The full-length recording of this presentation is available for on-demand viewing.

First Name Please enter your first name

Last Name Please enter your last name

Email Please enter your e-mail address

Phone Please enter a valid phone number

Company/Institution Please enter your Company/Institution

Country or Area Please select your Country

State/Province Please select your State

What best describes your current interest?

Learning: Expanding my knowledge Searching: Investigating technologies for my applications Investing: Buying in one year Purchasing: Actively in the buying process

Please add me to your email subscription list so I can receive webinar invitations, product announcements and events near me.

Opt-in

By submitting this form I confirm that I would like to be contacted by Bruker. I have taken note of the Bruker Website Privacy Notice and I agree to the Terms of Use of the Bruker website. Please accept the Terms and Conditions

^{Privacy Notice Terms of Use}

Note: Page will refresh upon submission; afterward, you may need to scroll down to see the video access link.

^{* Please fill out the mandatory fields.}

Webinar Recording is Now Available.

Click Here to Access the Viewing Page

Note: If you close or exit this page, you will not be able to reopen this confirmation window without re-submitting the form. Please save this access link to bypass the form in future visits.

Guest Speaker

Andreas Janshoff, Professor of Biophysical Chemistry, University of Goettingen

Prof. Dr. Andreas Janshoff is professor of biophysical chemistry at Georg-AugustUniversität Göttingen, Germany. He has a degree in chemistry from the University of Münster, where he also earned his Ph.D. in 1997. Following postdoctoral research at Scripps Research Institute, USA, and a habilitation at University of Münster, he became a full professor for Biophysical Chemistry in 2006. Prof. Janshoff’s research centers on biophysical chemistry, in particular, the mechanics and dynamics of cellular membranes and the cytoskeleton, and the viscoelastic nature of cellular components. A key focus of his work is on the mechanical properties of cells and how these relate to disease. Prof. Janshoff has published extensively in top-tier journals and collaborates widely in the fields of biophysics, nanotechnology, and biochemistry.

Past Webinars

BROWSE OUR BIOAFM WEBINARS