Deformable cell-cell and cell-substrate interactions in semi-infinite domain.

Leukocyte movement through blood vessels during inflammation involves complex adhesion processes. Prior research has shown that selectins and ligands mediate initial cell interactions. However, modeling these interactions remains challenging due to fluid dynamics at the microscale. Existing models often simplify cell behavior or ignore mechanical compliance. This gap motivated the development of a more comprehensive simulation framework. The need to capture both cell-cell and cell-substrate interactions is critical for accurate representation. Current approaches struggle with large domains of influence in Stokes flow. This paper introduces a novel method to address these limitations. The new approach integrates contact forces and deformable particle mechanics.

The study aims to develop a simulation framework for leukocyte adhesion dynamics. Researchers sought to model multiple steps of the leukocyte adhesion cascade (LAC). They focused on interactions between cells and surfaces in a semi-infinite domain. The goal was to incorporate contact and lubrication forces into the model. The team built upon prior models of rolling interactions and deformable particles. They aimed to demonstrate the model's applicability to cell collisions and adhesion. The study also sought to analyze how cell compliance affects rolling velocity. By addressing these factors, the researchers aimed to improve computational accuracy.

The simulation integrates contact and lubrication forces with fluid dynamics. The model extends prior work from Hammer and Apte (1992) on single-particle rolling. It builds on King and Hammer’s (2001a) multiparticle interactions framework. Gee and King’s (2006) deformable particle model was also incorporated. The approach uses Hertzian contact mechanics to describe cell-substrate interactions. The model was tested for cell-cell collisions near a planar substrate. Adhesive interactions between cells and surfaces were simulated. The framework accounts for deformability and its impact on rolling behavior.

The model successfully simulated cell-cell collisions and adhesive interactions. Hertzian contact mechanics showed increased interfacial contact area. This increase may enhance rolling interactions due to cell-cell collisions. Rolling velocity decreased significantly for compliant cells compared to rigid ones. The simulation confirmed the role of contact formulation in adhesion dynamics. Deformability altered the mechanical response at the cell-substrate interface. The model demonstrated how compliance affects leukocyte rolling behavior. These findings suggest that cell compliance is a key factor in adhesion processes.

The study presents a novel simulation framework for leukocyte adhesion dynamics. The model captures cell-cell and cell-substrate interactions in Stokes flow. Hertzian contact mechanics contribute to increased contact area during adhesion. Rolling velocity decreases when cells are compliant rather than rigid. The model confirms that deformability influences adhesion and rolling behavior. These findings align with prior work on cell mechanics and fluid dynamics. The simulation offers a new perspective on leukocyte trafficking during inflammation. The approach may improve future modeling of microvascular adhesion processes.