This small marvel of technical ingenuity has become a milestone in cell analysis and diagnostics. Whereas cells in a medium in a (Petri) dish used to grow statically, the medium now uniformly and continuously flows through the cell area. For the first time, the ibidi Pump System simulates the situation of many blood and immune cells within a few centimeters, with very simple handling and at a reasonable price. The cells need this flow of the medium also over a long period as a mechanical stimulus to behave as they do in the body.

“When developing our pump system, we always followed the ibidi motto ‘cells in focus’,” summarizes Dr Valentin Kahl. He heads the jointly founded company with Dr Roman Zantl.

"Our focus was on providing cells with a permanent feel-good package of temperature and gas mixture/ pH-value as well as constant flow. We also wanted to enable a sterile, antibiotic-free experimental setting and live microscopy in a high-tech environment. I am very proud that we have succeeded in doing this so smartly!"

Structure of the ibidi Pump System

The ibidi Pump System consists of three elements: an electric pump, a software-controlled fluidic unit and a slide with a small channel. Thin tubes connect the elements, positioning the channel slide between the two liquid reservoirs on the microscope, with the electric pump standing beside it. All together it is smaller than a toaster and is easy to operate. Computer-controlled, the pump compresses air, which moves the liquid through the attached channel slide. Because it is a closed system, the flow direction can be predetermined by the sophisticated geometry of the device – always in the same direction, as is found in the vessels of the circulatory system. A total volume of just 10 ml is sufficient, due to the clever design, to supply the cells with everything they need to survive for several weeks.

In addition, the innovative valve concept generates different fluid profiles, allowing the fluid to flow over the cells in various ways and speeds. It creates pulsatile profiles for differently timed start/stop/start rhythms, oscillating profiles for defined directional changes, and unidirectional profiles for continuous flow in the same direction. By changing the flow velocity, a wide range of conditions can be simulated: from gentle flow in tissue, supplying it with nutrients and transporting waste products, to medium flow velocities in kidneys or veins, up to strong flows in arteries or even injured blood vessels.

A particularly noteworthy feature is that the pump system can be operated directly in the cell culture incubator. Usually, electrical devices massively change the balanced ratio of heat and gas mixture/pH-value, causing the cells to suffer or be destroyed and the device to corrode. However, in the ibidi Pump System, the pressure generation and boost are decoupled. This means that the electric pump is located outside the incubator, while the liquid thrust is transferred inside via air pressure. Meaning, the cell culture and the electrical device both remain intact.

The ongoing experiment can be observed in real time using standard microscopy. The ibidi channel slides, in which the cells grow so beautifully, are of high optical quality, they transmit light without interference. High optical quality in combination with an ideal environment are usually a contradiction, but the ibidi founders knew how to combine them with many patent-protected innovations. Therefore, the view of living cell nuclei, organelles, and the interaction of several cells is unobstructed, even in high-resolution microscopy, while applying flow.

“We have just sent the 1000th Pump System to Athens – and our first ones are still running stably!”, says a delighted Wolfgang Oeffner, who cleverly designed the electric pump. Since then, the ibidi Pump System has enabled many pioneering cell experiments. The best results appear in internationally renowned scientific journals (as so-called ‘papers’) to promote progress in human and animal biology, medicine, and pharmacy.

An Example of Changes Induced in Cells Under Flow

Endothelial cells line the inner walls of blood vessels. They react noticeably when the initially resting liquid above them is suddenly set in motion. The flow exerts a mechanical stimulus on them in the form of shear stress. Under the new demands, they quickly change their morphology, i.e. their appearance and structure, as their cytoskeleton aligns itself in the direction of flow. However, the mechanical force of the flow has a much deeper effect and influences the biochemical function of the cell. As soon as the cell’s ‘external antennas’ (the receptors) sense the flow of its environment, they motivate the cell’s own genes to produce endothelial cell-specific building blocks. As a result, the cell develops particularly efficient ‘anchoring feet’ (adhesion molecules) allowing it to cling to the surface and resist the forces of the flow. Many other processes and mechanisms can be observed from the altered gene expression and protein synthesis of cells under flow.

Steps into the Future

The properties of the ibidi Pump System are in high demand. 3D Cell biology is currently striving to develop good cell-based models of spheroids and organoids, i.e. miniature spatial laboratory moulds with body-like organ functions. The ibidi Pump System is also being used here. Unlike the static cell culture of the (Petri) dish, it has already solved the most urgent problem, the constant supply of nutrients to living cells and cell clusters. To add to this, many creative ibidi slides are now available, which offer researchers every possibility for cell experiments – with different surfaces, in several channels and planes, with active ingredient reservoirs and computer-controlled conditional changes. One pump system can even control four different parallel experiments.

"We see ourselves as pioneers, helping to close gaps in knowledge with our product innovations. The Pump System is one of these – its success is motivating! We are currently expanding the functional scope of the pump system with the aim of supplying three-dimensional cell cultures with nutrients over very long periods of time. This transition to the third dimension makes it possible to replicate human organs or even tumours to carry out biomedical research without animal testing under conditions typical of the human body,” predicts Dr Roman Zantl.

More About the Fluid System with the ibidi Pump:
More information about the ibidi Pump System can be found on our website.