When studying diseases or testing potential drug therapies, researchers usually turn to cultured cells on Petri dishes or experiments with lab animals, but recently, researchers have been developing a different approach: small, organ-on-a-chip devices that mimic the functions of human organs, serving as potentially cheaper and more effective tools.
Now, researchers have built a new device that’s especially good for modeling atherosclerosis — the constriction of blood vessels that’s the leading cause of heart attacks and strokes. In a paper appearing this week in APL Bioengineering, from AIP Publishing, researchers illustrate how the new device can be used to study important inflammatory responses in cells that line the vessel in ways that could not be done in animal models. The research team also explains how this organ-on-a-chip could improve blood testing for patients.
“Atherosclerosis is a very important and complex disease,” said Han Wei Hou, a biomedical engineer at Nanyang Technological University in Singapore. It develops when fat, cholesterol and other substances in the blood form plaque that accumulates on the inside walls of arteries. This buildup constricts the blood vessel, causing cardiovascular diseases.
Understanding what regulates this abnormal vessel constriction is crucial to studying and treating vessel disease and preventing acute cardiac arrest. While researchers have previously developed organ-on-a-chip models of blood vessels, those devices focused more on recreating the vessel’s biological complexity than on its shape and geometry — which are key factors in atherosclerosis, Hou said. “It involves not just the biological aspect of endothelial dysfunction, but also the biomechanics of blood flow.”
To address blood flow, the researchers built a device that fits on a single square-inch chip, consisting of two stacked chambers separated by a thin and flexible polymer membrane. The bottom contains air while the top contains a flowing fluid similar in mechanical properties to blood.