Local well-posedness for a novel nonlocal model for cell-cell adhesion via receptor binding
Mabel Lizzy Rajendran, Anna Zhigun
TL;DR
The paper develops a rigorous local well-posedness theory for a novel nonlocal cell-adhesion model coupling a degenerate porous-medium diffusion–advection equation with a nonlinear nonlocal receptor-binding integral equation. The authors decouple the system and solve each part via Banach fixed point arguments, introducing the Kantorovich-Rubinstein norm to handle measure-valued inputs in the integral equation. They establish local well-posedness for the integral equation with measure parameters, prove well-posedness for the diffusion-adhesion PDE with degenerate diffusion and fixed advection, and then treat the coupled system by iterative fixed point arguments, ensuring stability and non-explosion of the support for small times. The results provide a mathematically robust framework for macroscopic models that encode microscopic receptor binding dynamics within cell-cell adhesion, with potential implications for upscaling and biological interpretation of early invasion dynamics.
Abstract
Local well-posedness is established for a highly nonlocal nonlinear diffusion-adhesion system for bounded initial values with small support. Macroscopic systems of this kind were previously obtained by the authors through upscaling in [32] and can account for the effect of microscopic receptor binding dynamics in cell-cell adhesion. The system analysed here couples an integro-PDE featuring degenerate diffusion of the porous media type and nonlocal adhesion with a novel nonlinear integral equation. The approach is based on decoupling the system and using Banach's fixed point theorem to solve each of the two equations individually and subsequently the entire system. The main challenge of the implementation lies in selecting a suitable framework. One of the key results is the local well-posedness for the integral equation with a Radon measure as a parameter. The analysis of this equation utilizes the Kantorovich-Rubinstein norm, marking the first application of this norm in handling a nonlinear integral equation.
