High-throughput label-free cell interaction studies
z-Movi™ is a breakthrough technology for research and development of personalized therapies, including immunotherapy. It is the first platform able to directly measure the strength of interaction, or avidity, between cells with specific targets and sort cells of interest, in a high throughput and label-free manner.
The core of the z-Movi technology consists of a glass microfluidic chip with a piezo element that generates resonant acoustic waves (ultrasound). These resonant acoustic waves are used to exert forces on cells. The platform can be easily integrated with a microscope to enable cell imaging, while the dedicated z-Movi software offers a full solution for real-time cell counting.
The illustration at the right shows multiple cells interacting with targets. These targets can be adherent cells — such as tumor cells — or ligands coated to the surface of a chip.
z-Movi quantitively queries the interaction strength of cells with their cognate binding partners. Quantification of the cell-target interaction strength, or avidity, is possible by exerting forces on thousands of cells in parallel and measuring the rupture force at the single-cell level.
Cells interacting with the targets require a certain amount of force to detach from their partners. The higher the avidity between the cells and their targets, the higher the force one needs to apply in order to separate them.
Avidity-based sorting of cells can be achieved by gradually increasing the force while flushing out and collecting the consequently detaching cells. In this way, it is possible to sort subpopulations of cells based on their avidity with the specific target.
z-Movi workflow: First (1), target cells or ligands are immobilized on the surface of the chip and left to incubate with cells of interest. By applying varying levels of forces (2), the cells of interest can be distinguished based on avidity (3): low avidity cells require less force to be separated from their interacting targets, while high avidity cells remain bound. Repeating this process with a gradually increasing force allows screening and sorting cells based on their avidity.
Screening & sorting of potent lymphocytes
In this example, researchers cultured an adherent cell line inside the z-Movi chip. Next, they flushed into the chip a mix of two different lymphocyte populations. The cells fluorescently labeled in red had the capacity to specifically bind to the adherent target cells, while the cells labeled green did not. Next, the chip was incubated to allow recognition between the binding partners to occur.
Following this, they turned on the acoustic forces to a low force setting. This resulted in the separation of the non-specific lymphocytes from the target cells, which acoustically levitated upwards. Gentle flushing of the chip allowed the collection of the unbound cells, resulting in an enriched target-specific lymphocyte population in the chip. By repeating the experiment at increasing applied acoustic forces it was possible to screen and sort lymphocytes based on their target cell avidity. Subsequently, the target-specific lymphocytes can be collected.
Cell incubation: an adherent cell line is cultured inside the z-Movi flow cell and introduced to a population of non-specific lymphocytes (green) and target-specific lymphocytes (red).
Avidity-based sorting: After applying acoustic forces, the non-specific lymphocytes separated from the target cells and were subsequently flushed out and collected. This resulted in an enriched target-specific lymphocyte population in the chip.
Quantification of interaction forces
The z-Movi can measure and monitor over time the interaction strength between the binding partners.
The figure at the right shows the total number of two types of lymphocytes bound to target cells under increasing applied acoustic forces. As the target-specific lymphocytes bind to the target cell antigens with higher efficiency than the non-specific lymphocytes, they need more force to detach from their target. Weakly bound cells and the non-specific lymphocytes exhibit no attachment and come right off as seen by the sharp drop in the graph.
Percentage of target-specific (blue) and non-specific (red) lymphocytes bound to target cells, plotted against applied separation force.
The z-Movi™ Set-up
The core of the z-Movi platform is the microfluidic glass chip with integrated piezo transducers that create an acoustic force field. This acoustic field effectively applies forces on the cells of interest without the need for any labeling or alteration of those cells.
Automated Force Field Generator
For the controlled application of highly-precise pulling forces:
• Applied acoustic forces are non-invasive
• Cell fractions can be isolated and collected for further experimental use
Automated Microfluidics and Cell Sorting
• Up to 10 different channels, individually controlled to create different gradients
• Highly-controlled fluid- and temperature environment
• Option for gas-conditioned fluidics
• Effective cell incubation and experimentation
• Introduction of multiple cells and/or components within one experiment
• Fast switching between different collection tubes for the isolation of cell fractions based on their target-specific avidity
• Real-time software-controlled cell counting