Dipartimento di Scienze di Base e Applicate per l'Ingegneria

 

Endothelial cells in the cardiovascular system experience cyclic stretching due to pulsatile blood flow, leading to orientation changes that are crucial in vascular remodeling and related pathologies, such as hypertension. Traditional models often describe cell alignment as a deterministic drift toward energy-minimizing configurations. However, experimental observations reveal non-sharp distributions of orientations, with reduced spreading under increased strain amplitude. In recent work by Loy and Preziosi (Bull. Math. Biol., 2023) such spreading is modeled by augmenting the deterministic evolution equation with a noise term. This approach leads to a Fokker–Planck equation whose stationary solutions show qualitative agreement with experimental data. Building on that work, in this talk I adopt the framework of Stochastic Thermodynamics with Internal Variables (Leadbetter et al., PNAS Nexus, 2023) to derive a two-dimensional dynamical system governing the mean orientation and degree of alignment of the cells. Phase-plane analysis confirms that the effect of strain amplitude on the experimentally observed spreading phenomenon stems from the interplay between drift and noise.