Impact of red blood cell rigidity on in vivo flow dynamics and lingering in bifurcations

The distribution of red blood cells in the microcirculation is a critical factor that determines how oxygen and essential solutes are delivered to tissues. This process relies heavily on the partitioning of red blood cells at successive bifurcations throughout the microvascular network. In this study we quantify how the microscopic behaviour of cell lingering affects this partitioning, through combined in vivo experiments and in silico simulations.

Lingering refers to the phenomenon where cells temporarily reside near the apex of a bifurcation with a significantly diminished velocity. We demonstrate that this lingering behaviour correlates strongly with deviations from the established empirical predictions for the phase separation process.

Furthermore, we reveal how the specific geometry of a bifurcation and the rigidity of the cell membrane affect the lingering behaviour of red blood cells. Rigid cells, for example, tend to linger less than softer cells. This points to an important mechanism for understanding microcirculatory blood flow, particularly in diseases associated with abnormal cell rigidity such as malaria and sickle cell anaemia.