  The glycocalyx is a complex layer of carbohydrate and protein molecules that
surrounds the cell membrane of many types of mammalian cells. It serves several
important functions, including cell adhesion and communication, and maintain
cell shape and stability, especially in the case of erythrocytes. Alteration of
glycocalyx composition represents a cardiovascular health threatening. For
example, in diabetes mellitus glycocalyx of erythrocytes and of endothelial
cells is known to be impaired, a potential source of blood occlusion in
microcirculation, which may lead to blindness, and renal failure of patients.
The impact of glycocalyx impairment on erythrocyte aggregation remains a
largely unexplored research area. We conduct here in vitro-experiments in
microfluidic devices in order to investigate erythrocytes aggregation incubated
with amylase, an enzyme that partially breaks down glycocalyx molecules. It is
found that incubation of erythrocytes by amylase leads to a dramatic increase
of their aggregation and stability and alters the aggregates morphologies.
Confocal microscopy analysis reveals a significant degradation of the
glycocalyx layer, correlated with enhanced erythrocytes aggregation. An
increased erythrocyte aggregation in vivo should affect oxygen and other
metabolites delivery to organs and tissues. This study brings new elements
about elucidation of microscopic origins of erythrocyte aggregation and their
potential impact on cardiovascular pathologies.
