Courant Institute of Mathematical Sciences
New York University
November 20, 2012
A discrete model of the red blood cell cytoskeleton and its use in Immersed Boundary method simulations
The red cell cytoskeleton, which is anchored to the lipid bilayer membrane, is an elastic structure that helps the cell recover from the large deformations it experiences while circulating through the body. The cytoskeleton can be thought of as a graph of spectrin polymers (edges) connected at actin-based junctional complexes (nodes). In this talk, we discuss an algorithm to generate a random graph on the surface of a model red blood cell with the physiologically observed statistical properties, such as the distributions of edge length and the number of neighbors of a given node. To model the network elasticity, we treat these edges as entropic springs. We show that the spring constant obtained from a well-known model of entropic springs is in reasonable agreement with the experimentally determined shear modulus of the continuum model of the cytoskeleton. Lastly, we present results from Immersed Boundary simulations of the red cell under shear flow, including the discrete cytoskeleton and its ~40,000 nodes. This is joint work with Alejandra Leo-Macias, David Stokes, and Charles Peskin.