Table 1.
Examples for the application areas of force-distance curves measured by FluidFM, collected from the literature.
| Application type | Experiment | Used InvOLS and k calibration | Rupture force | Reference |
|---|---|---|---|---|
| Grabbing the spread cells or bacteria with the FluidFM micropipette cantilevers and detaching them from the surface to measure adhesion forces | Measuring the effect of electric current on cellular adhesion using mouse myoblast (C2C12) cells. | InvOLS was recalibrated before all experiments on the substrate. Spring constant was calibrated with the Sader method. Exact values are not given. | The maximal adhesion force in control conditions on indium tin oxid coated glass slides was 520 nN ± 67,6 nN | 9 |
| Measuring cellular adhesion using mouse myoblast (C2C12) cells on different type of substrates. | Spring constant ranged between 1.7 and 2.3 Nm−1. InvOLS was calibrated before each measurement on a cell free spot. |
Median values on RGD presenting serum, covalent and non-covalent surfaces respectively: 236 nN, 409 nN, 425 nN; No detailed description of the measured errors. |
10 | |
| Detachment of individual cells and cells from monolayer from glass (L929 Fibroblasts) and gelatin coated glass (Human umbilical artery endothelial cells). | Spring constant was calibrated with the thermal noise method; InvOLS with Cytosurge’s built-in software. Exact values are not given. |
Individual cells (mean values): L929: 234 nN HUAECs: 805 nN Cells from monolayer (mean values): L929: 232 nN HUAECs: 1170 nN |
11 | |
| Measuring HeLa and HEK cells adhesion on glass and fibronectin in culture and room temperature environments. |
Spring constant was calibrated with the Sader method and ranged between 1.9 and 2.7 Nm−1. InvOLS calibration and values not presented. |
Mean values on glass: HeLa cells: 473 ± 127 nN HEK cells: 33 ± 9 nN Mean values on fibronectin: HeLa cells: 593 ± 70 nN HEK cells: 53 ± 15 nN |
12 | |
| Detachment of Escherichia coli and Streptococcus pyrogenes bacteria strains from polydopamin treated surface. |
Cantilevers with nominal spring constants of 2.5 and 0.2 Nm−1 were used. InvOLS calibration and values not presented. |
Force values are following a Gaussian distribution with mean values around 6–8 nN in the range of 0–14 nN. | 13 | |
| Detachment of neural cells from glass slides functionalized with fibronectin. | The details of spring constant and InvOLS calibration and not discussed. |
Force to detach neural cells: 1000 ± 300 nN |
15 | |
| Detachment of Human umbilical vein endothelial cells (HUVECs) from gelatin coated gratings with 100, 400 and 1000 nm depth and 1000 nm width. | The spring constant was determined to be around 1.8 Nm−1 with the Sader method. InvOLS calibration and exact values are not presented. |
Mean adhesion forces on substrates with different topology: Flat control surface −619 ± 70 nN 100 nm deep grating −1113 ± 86 nN 400 nm deep grating −860 ± 59 nN 1000 nm deep grating −598 ± 123 nN Treatment with myosin-II inhibitor Blebbistatin on the control surface resulted in the decrease of adhesion force: 295 ± 44 nN |
17 | |
| Application type | Experiment | Used InvOLS and k calibration | Reference | |
| Colloidal spectroscopy | Concanavalin-A coated colloidal particles were adsorbed on human embryonic kidney cells. The particles were detached from the cells, which enabled the measurement of the interacting forces between them. The adhesion force was ~60 nN between the particles and the cells, and individual cells showed ~20 nN adhesion force on the glass petri dish. | The spring constant was determined with the Sader method and resulted between 0.5 to 3 Nm−1. InvOLS was calibrated each time the medium of the experiment was changed. | 6 | |
| Reversible immobilization of functionalized silica beads onto the FluidFM cantilever, adhering bacteria and measuring hydrophobic interaction of the bacteria from leaves. 28 bacterial strains have been used for colloid particle-bacteria surface adhesion measurement. More than 700 FD-curves were recorded, the highest force values are around 50 nN of the members from Gammaproteobacteria. | The nominal spring constant value for micropipette cantilevers was used as 0.2 Nm−1. InvOLS was recalibrated after each bead exchange, but exact values are not given. | 33 | ||
| Force evaluation of different particle sizes grabbed by FluidFM micropipette and nanopipette cantilevers. Silica particles with diameters of 0.5 µm, 1 µm and 4.3 µm were used. | The nominal spring constant values were used for micropipette (0.3 and 2 Nm−1) and nanopipette (0.6 Nm−1) cantilevers. Exact k and InvOLS values are not given. | 7 | ||
| Polyanionic and polycathionic recombinant spider silk protein was used to prepare colloidal particles, for testing the biofunctionality of the material with FluidFM. | The nominal spring constant values were used for micropipette (0.2 Nm−1) cantilevers. “InvOLS was determined in a symmetric system between two silica particles.” Exact k and InvOLS values are not given. | 34 | ||
(A) Cellular adhesion experiments on different cell types and experimental conditions. (B) Colloidal spectroscopy and force analysis.