Behaviour of the model antibody fluid constrained by rigid spherical obstacles: effects of the obstacle-antibody binding

Abstract

We study a simplified model of monoclonal antibodies confined in a patchy random porous medium. Antibodies are represented as Y-shaped particles composed of seven tangential hard spheres with attractive patches on the terminal beads, while the matrix consists of randomly distributed hard-sphere obstacles bearing adhesive sites. The model captures antibody behavior in crowded biological environments with strong short-range antibody-matrix attractions. The theoretical approach combines Wertheim's multidensity thermodynamic perturbation theory, the Flory-Stockmayer theory of polymerization, and scaled particle theory for fluids in porous media. We analyze thermodynamic properties, percolation thresholds, and phase behavior, and compare the selected results with new computer simulations. The interplay between antibody-antibody and antibody-matrix interactions produces a complex phase behavior, including re-entrant phase separation with a closed-loop coexistence region at higher temperatures and conventional liquid-gas separation at lower temperatures.

12 pages, 8 figures

References in corpus (4)

• Theoretical and numerical study of the phase diagram of patchy colloids: ordered and disordered patch arrangements
• Phase diagrams of binary mixtures of patchy colloids with distinct numbers of patches: The network fluid regime
• Empty liquid state and re-entrant phase behavior of the patchy colloids confined in the porous media
• Phase Behavior of the Patchy Colloids Confined in the Patchy Porous Media