Spatio-temporal dynamics of M1and M2macrophages in a multiphase model of tumor growth

This study investigates the complex dynamics of vascular tumors and their interplay with macrophages, key agents of the innate immune response. We model the tumor microenvironment as a multiphase fluid, with each cellular population treated as a distinct, non-mixing phase. The framework also incorporates diffusible species that are critical for processes such as nutrient transport, angio-genesis, chemotaxis, and macrophage activation. Numerical simulations of our model show how phenotypic and spatial heterogeneity in the macrophage population arises and how such heterogeneity impacts a tumor’s growth dynamics. Finally, we propose an immunotherapeutic strategy based on the experimental agent vactosertib which promotes an anti-tumor macrophage phenotype. Our simulations demonstrate an increased density of anti-tumor macrophages over the period of a few months, followed by a relapse period where the tumor regains its original dynamics.