Mechanical Instabilities of Biological Tubes

TL;DR

This paper provides a theoretical analysis of how mechanical instabilities in biological tubes, caused by abnormal cell growth and tissue properties, lead to various pathological shapes, offering insights into underlying causes and potential genetic regulation.

Contribution

It introduces a phase diagram of tubular instabilities based on mechanical parameters, linking tissue mechanics to pathological shapes in biological tubes.

Findings

Different pathological shapes are linked to specific mechanical parameters.

Uncontrolled cell growth induces buckling instabilities in biological tubes.

A phase diagram predicts shape outcomes based on tissue properties.

Abstract

We study theoretically the shapes of biological tubes affected by various pathologies. When epithelial cells grow at an uncontrolled rate, the negative tension produced by their division provokes a buckling instability. Several shapes are investigated : varicose, enlarged, sinusoidal or sausage-like, all of which are found in pathologies of tracheal, renal tubes or arteries. The final shape depends crucially on the mechanical parameters of the tissues : Young modulus, wall-to-lumen ratio, homeostatic pressure. We argue that since tissues must be in quasistatic mechanical equilibrium, abnormal shapes convey information as to what causes the pathology. We calculate a phase diagram of tubular instabilities which could be a helpful guide for investigating the underlying genetic regulation.