Mechanobiology and Microscale devices - Eugene Cheong
Effect of Pressure on Cells
Every cell in the human body experiences some form of pressure. From the bone cells, which experience immense weight to keep our bodies upright to the blood cells, which experience large amounts of hydro-static pressure every time out heart beats. Yet, pressure is often overlooked in studies involving cells and cell culture. Therefore, in the field of mechanobiology, researchers aim to study the effect of pressure on cells. Most of these studies involve the use of big and expensive bioreactors that cam modulate the pressure of the entire system to ensure that all the cells are experiencing the same pressure equally. Though there is a lot to find out from these studies, almost of of these studies focus on a few aspects of the cells. These are the cell morphology, the rate of diffusion of substances such as growth media and oxygen and the growth rate of the cells.
Effect of Pressure on the Morphology of the Cell
When under immense pressure, the cell will often attempt to counteract the outside pressure by increasing the internal pressure of the cell. Should this not happen, the cell will collapse on itself and die. With this balancing of the pressure, the cell will often take on an elongated morphology.
Effect of Pressure on the Cell Membrane
Under immense pressure, the surface membrane of the cell will most definitely be affected. There are many other components to the cell membrane that are often overlooked by researchers when designing such experiments. For example, the exertion of pressure could affect the protein channels within the cell membrane such as aquaporin that ultimately affects the diffusion of water into the cell. Another aspect of the cell membrane pressure could affect are the ion channels within the cell membrane, effectively influencing the cell's ability to transmit neural signals or synthesize ATP.
Using Microfluidic Devices to Study The Effects of Pressure on Cells
It is important to note that the use of large bioreactors is a more than viable way of pressurizing a cell culture system and provides the most control over the range of pressures available. As such they are still in use for studies today. However, the use of a microfluidic device could bring just about the same amount of control while consuming less space and resources.
One example of this is the study dine by Liu et al. where they created a microfluidic device that has a built-in electrofluidic pressure sensor to study endothelial cells under shear stress as well as hydrostatic pressure. Similarly, Ho et al. created an advanced microfluidic device that exerts a cyclic hydrostatic pressure on the cells. Thus allowing for the study of cyclic compression on adherent cells, mimicking the environment experienced by cells in the blood vessels.