Accurate coarse-grained modeling of red blood cells.

We develop a systematic coarse-graining procedure for modeling red blood cells (RBCs) using arguments based on mean-field theory. The three-dimensional RBC membrane model takes into account the bending energy, in-plane shear energy, and constraints of fixed surface area and fixed enclosed volume. The coarse-graining procedure is general, it can be used for arbitrary level of coarse-graining and does not employ any fitting parameters. The sensitivity of the coarse-grained model is investigated and its behavior is validated against available experimental data and in dissipative particle dynamics (DPD) simulations of RBCs in capillary and shear flows.