Impact of glycocalyx structure on red cell-red cell affinity in polymer suspensions

A theoretical framework based on macromolecular depletion has been utilized in order to examine the energetics of red blood cell interactions. Three different glycocalyx structures are considered and cell-cell affinities are calculated by superposition of depletion, steric and electrostatic interactions. The theoretical model predicts a non-monotonic dependence of the interaction energies on polymer size. Further, our results indicate that the glycocalyx segment distribution has a large impact on adhesion energies between cells: a linear segment distribution induces the strongest adhesion between cells followed by pseudo-tail and uniform distributions. Our approach confirms the concept of a depletion mechanism for RBC aggregation, and also provides new insights that may eventually help to understand and quantify cellular factors that control red blood cell interactions in health and disease.