The lumen of blood vessels is made of a cell monolayer called the endothelium. Under normal in vivo conditions, it is lined by a glycocalyx, a micrometer-thick layer of biomacromolecules that is directly exposed to blood flow. This glycocalyx is the primary gatekeeper that protects the vascular wall. It is thus expected to play a key role in controlling interactions with flowing blood cells.
In this context, a joint team of physicists from the LIPhy and biologists from the IAB (Institute for Advanced Biosciences) has developed a “microvasculature-on-a-chip” device : a network of microchannels whose inner walls are covered by a monolayer of endothelial cells. The team has shown for the first time that such a model in vitro endothelium displays a glycocalyx having the same thickness and uniformity as observed in vivo. Researchers have also been able to study how the presence of this glycocalyx affects the flow of red blood cells confined in these “endothelialized” microchannels. This work, published at the end of March in Scientific Reports provides an important insight into the physiological relevance of such microfluidic models recapitulating in vitro the nature and functions of the vascular walls.