TY  - JOUR
AU  - Fedosov, D.A.
AU  - Pan, W.
AU  - Caswell, B.
AU  - Gompper, G.
AU  - Karniadakis, G.E.
TI  - Predicting human blood viscosity in silico
JO  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 108
SN  - 0027-8424
CY  - Washington, DC
PB  - Academy
M1  - PreJuSER-15941
SP  - 11772 - 11777
PY  - 2011
N1  - This work was supported by National Institutes of Health Grant R01HL094270 and simulations were performed on the Cray XT5 at the National Science Foundation-National Institute for Computational Science and at the Julich Supercomputing Center in Germany.
AB  - The viscosity of blood has long been used as an indicator in the understanding and treatment of disease, and the advent of modern viscometers allows its measurement with ever-improving clinical convenience. However, these advances have not been matched by theoretical developments that can yield a quantitative understanding of blood's microrheology and its possible connection to relevant biomolecules (e.g., fibrinogen). Using coarse-grained molecular dynamics and two different red blood cell models, we accurately predict the dependence of blood viscosity on shear rate and hematocrit. We explicitly represent cell-cell interactions and identify the types and sizes of reversible rouleaux structures that yield a tremendous increase of blood viscosity at low shear rates. We also present the first quantitative estimates of the magnitude of adhesive forces between red cells. In addition, our simulations support the hypothesis, previously deduced from experiments, of yield stress as an indicator of cell aggregation. This non-Newtonian behavior is analyzed and related to the suspension's microstructure, deformation, and dynamics of single red blood cells. The most complex cell dynamics occurs in the intermediate shear rate regime, where individual cells experience severe deformation and transient folded conformations. The generality of these cell models together with single-cell measurements points to the future prediction of blood-viscosity anomalies and the corresponding microstructures associated with various diseases (e.g., malaria, AIDS, and diabetes mellitus). The models can easily be adapted to tune the properties of a much wider class of complex fluids including capsule and vesicle suspensions.
KW  - Blood Viscosity
KW  - Cell Adhesion: physiology
KW  - Computer Simulation
KW  - Humans
KW  - Models, Biological
KW  - Molecular Dynamics Simulation
KW  - Rheology: methods
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:21730178
C2  - pmc:PMC3141939
UR  - <Go to ISI:>//WOS:000292876900019
DO  - DOI:10.1073/pnas.1101210108
UR  - https://juser.fz-juelich.de/record/15941
ER  -