The new tool can be used to study the complex biological mechanisms in cells, those responsible for cancer spread, wound healing, biofilm formation and other fluid-based processes.
The masterpieces that came out under the hands of Rembrandt, Van Gogh and other great artists often started by making a rainbow of varied colors on a coloring board. Similarly, researchers from the US National Institute of Standards and Technology (NIST) developed an innovative device known as a "microfluidic color palette" to create stable and multiple chemical "waterfalls" - gradual changes in concentration along the length of an area - in a tiny cell the diameter of a pinhead.
The new tool can be used to study the complex biological mechanisms in cells, those responsible for cancer spread, wound healing, biofilm formation and other fluid-based processes.
The advantage of the new facility, as described in a recently published article, is that the cascades of changes are produced by flutter - the light movement of material from one point to another by random molecular movement. Microfluidic systems mix liquids more actively, using pumps and flow paths. Butterfly cascades allow examining cells that remain in the microchamber without the risk of their loss outside. Pulpation also allows chemical particles to move in and out of the cells normally and without the risk of large pressures, which are often obtained in flow systems - pressures that could cause the cells to burst or act in an unexpected way.
The innovative system overcomes these bumps through an intelligent piping structure. The key component of the system is a microcell, a tiny board-like area with a diameter of only 1.5 millimeters anchored to the center of a piece of glass. Tiny nozzles around the perimeter of this chamber – three in the prototype, but more can be built – allow various liquid mixtures to flow into the chamber. Below the cell, each port is connected to a Y-shaped long-tailed channel that in turn is connected to a second layer. These channels pass through them different chemicals into the cell. Fluid flows in and out of the short arms of each of these Y-arms at constant pressure ensuring a uniform flow of "fresh" chemicals. Since the internal pressure in the cell is balanced by initially filling it with a buffer solution (buffer), the chemicals that move through the channels into the cell do so almost entirely through pulsation. Therefore, as long as there is a steady stream of flow in the channels, the cascades in the cell can be maintained, almost irreversibly. limited.
In order to demonstrate how the state-of-the-art system works, the researchers injected dyes of the three basic colors - red, yellow and blue - separately through the three nozzles of the cell. For each separate color, its own constant concentration gradient is maintained, as long as the flow rate into the cell does not change. As a result of mixing the three color cascades, a mixture of color concentrations is obtained in which the combination of colors at one point is completely different from any other point.
Similarly, if three different drugs were injected into a cell containing cell cultures, individual cells in different locations would be exposed to different combinations of drug concentrations. In a single experiment, the effects of a wide range of drug mixture concentrations on the same cell type can be easily studied.
Another possible application of the microfluidic system is in the study of the field called chemotaxis - the movement of cells in a cascade of substance concentrations, a biological phenomenon that takes an active part in the spread of tumors (metastasis), wound healing, inflammation and the carbon cycle in days.
