Project Details
Projekt
B3 Pulsating flows in the microcirculation
Applicant
Professor Dr. Stephan Gekle
Subject Area
Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 349558021
The microcirculatory network contains the smallest blood vessels with diameters between 5 and 100 microns. It represents that region in a living organism where the particulate nature of blood as a suspension of red blood cells is most relevant. On the one hand, it is relevant for biological function such as oxygen exchange or drug delivery. On the other hand, the particulate nature also determines the flow behavior of blood at these scales. A striking example in the latter area is the creation of highly pulsatile flow patterns. Such flows can appear when red blood cells temporarily get stuck at the apex of bifurcations and are then suddenly released back into the flow. This and many other related phenomena are still not fully understood.In the present project, we will use Lattice-Boltzmann-Immersed-Boundary computer simulations to elucidate the origin of pulsatility in the microcirculation but also its consequences on the flow behavior of red blood cells. For this, we will start by considering a single red blood cell in a straight channel under externally imposed pulsating flow. Based on our recent investigations together with the group of Christian Wagner we aim to understand if and how pulsatily can influence the fragile dynamic modes of motion of a single red blood cell such as slippers or parachutes. Subsequently, we will investigate how the interplay of many red blood cells in microvascular networks, starting from simple two-node bifurcations and then moving to realistic in-vivo geometries, can lead to pulsating flow patterns even under steady external boundary conditions. This will be connected to in-vitro and in-vivo measurements. Finally, we aim to understand how margination, i.e. the well-known near-wall migration of stiff particles such as leucocytes or drug delivery agents, can be affected by pulsating flows. In the long run, we will also include the influence of the glycocalix, a thin polymer layer coating the wall of a blood vessel, which may significantly influence red blood cell dynamics especially under pulsating flow conditions.Our overall goal in this project is to reach a systematic mechanistic understanding of the two-way-coupling between pulsating flow and red blood cell dynamics in the microcirculation.
DFG Programme
Research Units
