An Overview of Mechanobiology with FluidFM


Learn more about the basic principle of mechanobiology and the use of the FluidFM technology for mechanobiology applications. 

What is mechanobiology?

Mechanobiology - the definition 

The term "mechanobiology" refers to "A field at the interface of biology, physics, and bioengineering, which focuses on how cell/tissue mechanics and physical forces influence cell behavior, cell and tissue morphogenesis, and diseases related to these processes." [1]

Why is mechanobiology so important?

Cells feel and respond to various mechanical signals from their surroundings. The mechanical stiffness of the extracellular matrix strongly determines cell function, stem cell differentiation and tissue homeostasis [2-6]. Oppositely, changes in the matrix stiffness can support the development and spreading of diseases, such as cancer and fibrosis [4]. In addition, cells are often subjected to shear stress due to several physiological processes. In a nutshell, cells are highly sensitive to external forces. Given their central importance in cell function and human health, the literature accumulated has showed that these forces are ubiquitous in vivo. As a result, mechanobiology has emerged as a new and growing field that attracts researchers from various disciplines. The field of mechanobiology comprises a range of field of applications and tools to perform force measurements between various systems and in different environments (air, liquid).

How does mechanobiology with FluidFM work?

Mechanobiology applied - single-cell force spectroscopy with the FluidFM technology

Traditionally, in Single-Cell Force Spectroscopy (SCFS) assays, the object of interest is glued to an AFM cantilever resulting in complex handling and low throughput.  The FluidFM systems solve this issue by reversibly immobilizing a cell to a FluidFM probe via suction, and subsequent release with a pressure pulse or brief washing.

This gentle exchange of the cell allows the cantilever to be re-used for several measurements, saves time and costs, and results in a 10 times higher throughput compared to traditional methods. Consequently, both throughput and efficiency of measurements are increased, drastically reducing the time required to obtain statistically relevant data compared to conventional methods. [7] Hence, this technology broadens the possibilities for highly reproducible single-cell adhesion measurements for a broad range of applications. 

FluidFM Mechanobiology - Single cell force spectroscopy

Benefits & Features of FluidFM for Mechanobiology

The FluidFM OMNIUM platform is a semi-automated system for measuring up to 200 single cells a day. Get reproducible, direct force measurements in high quality and with sound statistics.

High Throughput

Measure up to 200 cells a day using semi-automated workflows.

Many Cell Types & Colloids

For mammalian cells, microbes, and colloids

Broad Force Range

Direct force measurement from pN to µN

 
 
10x faster measurements compared to standard methods

As objects like cells or colloids can be quickly exchanged through reversible immobilization, measurement throughput is increased more than 10-fold. Up to 200 individual objects can be analyzed in a single day.

FluidFM Mechanobiology - Working principle of single-cell force spectroscopy with FluidFM

Working principle of single cell force spectroscopy with FluidFM.

Simple - no glue needed

The suction method of immobilizing the objects onto the FluidFM cantilever makes it reversible and avoids any glue: Pick. Measure. Release. Repeat.

 
 

Fast & easy. In this video, three micrometer colloids are attracted from suspension with a vacuum, held briefly, and then released again with a pressure pulse.

Switch the probe anytime or reuse to save money

Whether due to degradation, contamination or a required change of probe geometry or chemistry – you can switch the probe at any time. Just release the object, change the probe, and take up the object again. Our FluidFM Probes typically last for several force spectroscopy measurement days allowing the analysis of several hundred cells.

Many cell types and colloids supported

Cells and colloids come in a wealth of shapes and sizes. FluidFM single-cell force spectroscopy works with adherent or suspension mammalian cells, spheric or rod-shaped microbes, and with colloids, bubbles, and droplets from 0.5 to 100 µm particle size. FluidFM can handle them whether they are hundreds of nm or dozens of µm in diameter. Customers have even analyzed non-colloidal E.coli cells.

 

Cells Microbes Colloids

FluidFM Mechanobiology - Cell

FluidFM Mechanobiology - Microbe

FluidFM Mechanobiology - Colloid

Adherent or suspension cells Spheric or rod shaped. Algae, bacteria, protozoa, and fungi.
Colloids from 0.5 to 100 µm particle size. Also for bubbles, droplets.
Self-centering – means reproducibility

The position of the object on the FluidFM cantilever is given by the position of the aperture. Thus, every colloidal probe will be centered automatically and at the same position – as long as the same FluidFM Probe is used. This results in highly reproducible positioning. 

FluidFM Mechanobiology - Single cell force spectroscopy

1) cell is selected 2) Cell is detached from surface 3) Resulting force spectroscopy. Image courtesy of Bruker.

10x higher force range

The various stiffnesses and opening diameters of FluidFM Probes enable to measure forces from tens of pN up to µN.

Pick from substrate or attract from solution, or even air

Pick-up cells directly from a substrate or attract them from a solution via liquid influx to the aperture of the FluidFM Probe. This method is also recommended when the long-term adhesion of a microbe to a substrate is too strong to quantify, and hence shorter-term interactions are studied. Researchers have also performed particle and microbe measurements in air.

FluidFM Mechanobiology - Single cell force spectroscopy

S. Cerevisiae, also known as baker’s yeast, are picked-up from medium, measured and then deposited in a line with a FluidFM Micropipette. The cells stay fully viable through this procedure. Image courtesy of P. Dörig, ETH Zurich.

Mechanobiology applications with the FluidFM technology

Study of tumor progression and metastasis with cell-cell adhesion forces 

Study with a Nanosurf Flex-FPM by Dr. Noa Cohen, group of Prof. Tanya Konry, Northeastern University in Boston, on cell-cell adhesion forces to gain more insights into tumor progression and metastasis (Cohen et al., 2017):

Optical images showing:

A) a single cell to be picked up by a FluidFM Probe
B) the cell aspired to the cantilever and
C) the FluidFM Probe with aspired cell during a cell-cell adhesion measurement.

FluidFM Mechanobiology - Single cell force spectroscopy
  Data/image courtesy of Tanya Konry group, Northeastern University, Boston, USA.


A) Typical force curves between a MCF7 cell aspired to the cantilever and non-cancerous, fibroblast (HS5) on the substrate at different contact times.
B) Development of the force with contact time between the cells.

FluidFM Mechanobiology - Single cell force spectroscopy

  Data/image courtesy of Tanya Konry group, Northeastern University, Boston, USA.

Curious about Automated Single Cell Force Spectroscopy with FluidFM?

Related Resources

Instrument / Probes

FluidFM ADD-ON FluidFM OMNI­UM
Description Convenient solution to add FluidFM functionality to existing AFM systems
Versatile, automated, stand-alone FluidFM system, optimized for life science applications with large manipulation range
Pre-existing require­ments Needs a compat­ible AFM from third party supplier
No require­ments
Hard­ware FluidFM module as add-on to existing AFM systems
Stand­alone FluidFM system with inte­grated micro­scope and force-control unit
Software Exten­sion to software of AFM supplier
Stand­alone software with dedi­cated work­flows and automa­tion
Automation Limited and depending on AFM system
Automated workflows available as well as full manual control if needed
Compat­ible probes Full range of FluidFM Nano­syringes, Nano­pipettes, and Micro­pipettes
More on FluidFM probes & technology
Probe replace­ment Easy click-fix mount of probe pre-assem­bled on adaptor, no tools needed
Automated probe exchange process
Incuba­tor for CO2 and temper­ature control Available (from AFM supplier)
Available, specially tailored to the FluidFM OMNIUM
Compat­ibility Nanosurf (CoreAFM, FlexAFM and DriveAFM), Bruker (Bio­scope Resolve), JPK (Nano­wizard, CellHesion and ForceRobot families)
n.a. (stand­alone system)


Mechanobiology relevant specifications

FluidFM ADD-ON FluidFM OMNI­UM
Work­flow automa­tion
Operator guided mea­surement for each cell.
Limited automa­tion available depend­ing on AFM supplier software.
Operator selects cells of interest in software.
Auto­mated mea­surement and release of selected cells.
Auto­mated probe washing proce­dure between two cells.
Through­put
Up to 20 adherent cells per day
Up to 100 adherent cells per day
Force sensitiv­ity and resolu­tion
< 100 pN
< 1 nN
Force range
100 pN to 1 µN
1 nN to 1 µN
Force mapping 
Available as sup­ported by specific AFM
Not available
AFM imaging modes
All modes as sup­ported by specific AFM
Not available
Z-move­ment resolu­tion
< 0.1 nm
< 5 nm
Z- measure­ment range
10 µm to 200 µm (depend­ing on AFM system)
5 cm
Accessi­ble XY-range during one measure­ment
100 µm x 100 µm (depend­ing on AFM system)
240 mm x 74 mm (two well plates)
XY-automa­tion
Yes, depend­ing on AFM model
Yes
Culture plate/ slide compat­ibility
Depend­ing on AFM model, typically low-profile dishes (50mm or 35 mm), not compat­ible with standard well plates.
Compat­ible with standard plates (6, 12, 24-well), petri-dishes, glass slides and more.


Selected Publications
Generating & functionalizing bubbles

Publication showing how FluidFM can be used to generate and functionalize bubbles of constant size for exploring their interaction with biological surfaces. The ability to engineer bubbles will advance various applications, including drug delivery and cell separation. I. Demi et al., Probing the interactions between air bubbles and (bio)interfaces at the nanoscale using FluidFM technology. (2021). Journal of Colloid and Interface Science.


Assessing mature intercellular adhesion forces

This study introduces FluidFM as tool for the assessment of mature intercellular adhesion forces in a physiological setting that will be of relevance to biological processes in developmental biology, tissue regeneration and diseases like cancer and fibrosis.

A. Sancho et al., A new strategy to measure intercellular adhesion forces in mature cell-cell contacts.  (April 2017) Scientific Reports, 7(46152) 


Optimizing drugs

Researchers from both the University Hospital Würzburg and the University Würzburg found a new potential approach to overcome resistance to the recently approved Midostaurin drug and even increase the drug activity, also with help of FluidFM cell measurements. A. Garitano-Trojaola et al., RAC1 Inhibitor EHT1864 and Venetoclax overcome Midostaurin resistance in Acute Myeloid Leukemia. (2019) Blood. doi: 10.1182/blood-2019-129762


Optimizing stents

In this publication research groups from ETH Zurich investigate stent design optimization by measuring cell adhesion to its surface with FluidFM. E. Potthoff et al., Toward a rational design of surface textures promoting endothelialization. (2014) Nano Letters, 14(2), 1069 — 1079. doi:10.1021/nl4047398


Quantify and optimize bacterial adhesion

In this study researchers from the University of Kaiserslautern apply FluidFM to study bacterial adhesion to typical reactor material such as stainless steel. Not only do they present a new method how to optimize the measurement parameters, they also show that using FluidFM leads to comparable results as with traditional SCFS, where a cell is glued to an AFM probe. L. Hofherr et al., FluidFM as a tool to study adhesion forces of bacteria - Optimization of parameters and comparison to conventional bacterial probe Scanning Force Spectroscopy. (2020). PLOS ONE. doi: 10.1371/journal.pone.0227395


Quantify bacterial adhesion with colloids

Scientist at ETH Zurich quantified the hydrophobic adhesion properties of 28 bacteria strains taken from leaf isolates. They developed a modular FluidFM approach where colloidal, hydrophobic probes were brought in contact with the isolated bacteria on a PLL coated glass substrate. With 700 individual bacteria measured, this very extensive single cell force spectroscopy study allowed to observe cell-cell heterogeneity. The differences between the strains regarding hydrophobic interactions covered 3 orders of magnitude and correlated well with bacteria retention in planta. M. Mittelviehfhaus et al., A modular atomic force microscopy approach reveals a large range of hydrophobic adhesion forces among bacterial members of the leaf microbiota. (2019) The ISME Journal. doi: 10.1038/s41396-019-0404-1


Characterizing soft material

3D printing has become prevalent in many fields, especially in tissue engineering. Yet so far it was not possible to melt-electrowrite (MEW) hydrogels, limiting print architecture and resolution of this important material in biomedicine. Researchers from The Julius Maximilians University of Würzburg and the University Hospital Würzburg have discovered a way unlocking MEW with promising implications to directly print soft, yet resilient tissues. FluidFM helped to characterize the printed material with its fast colloidal probe technique. D. Nahm et al., A versatile biomaterial ink platform for the melt electrowriting of chemically-crosslinked hydrogels. (2019) Materials Horizon. Doi:10.1039/C9MH01654F

References

[1] Jansen, Karin A., et al. "A guide to mechanobiology: Where biology and physics meet." Biochimica et Biophysica Acta (BBA)-Molecular Cell Research 1853.11 (2015): 3043-3052.

[2] Engler, Adam J., et al. "Matrix elasticity directs stem cell lineage specification." Cell 126.4 (2006): 677-689.

[3] Orr, A. Wayne, et al. "Mechanisms of mechanotransduction." Developmental cell 10.1 (2006): 11-20.

[4] Lu, Pengfei, Valerie M. Weaver, and Zena Werb. "The extracellular matrix: a dynamic niche in cancer progression." Journal of cell biology 196.4 (2012): 395-406.

[5] Eyckmans, Jeroen, et al. "A hitchhiker's guide to mechanobiology." Developmental cell 21.1 (2011): 35-47.

[6] Wang, J. H-C., and B. P. Thampatty. "An introductory review of cell mechanobiology." Biomechanics and modeling in mechanobiology 5.1 (2006): 1-16.

[7] Dehullu, Jérôme, et al. "Fluidic force microscopy captures amyloid bonds between microbial cells." Trends in microbiology 27.9 (2019): 728-730.