Generating forces in confinement via polymerization

TL;DR

This study investigates how self-assembling polymers can generate forces and deform soft compartments, revealing key parameters like monomer release rate and multivalent particle interactions that influence force production.

Contribution

The paper introduces a computational model demonstrating force generation by self-assembling polymers in soft shells, highlighting the importance of monomer dynamics and multivalent particles.

Findings

Polymerization can induce shell deformation via spontaneous bundling.

Monomer release rate critically affects deformation capability.

Multivalent particles can enhance or hinder polymer performance.

Abstract

Understanding how to produce forces using biomolecular building blocks is essential for the development of adaptive synthetic cells and living materials. Here we ask whether a dynamic polymer system can generate deformation forces in soft compartments by pure self-assembly, motivated by the fact that biological polymer networks like the cytoskeleton can exert forces, move objects, and deform membranes by simply growing, even in the absence of molecular motors. We address this question by investigating polymer force generation by varying the release rate, the structure, and the interactions of self-assembling monomers. First, we develop a toy computational model of polymerization in a soft elastic shell that reveals the emergence of spontaneous bundling which enhances shell deformation. We then extend our model to account more explicitly for monomer binding dynamics. We find that the rate at which monomers are released into the interior of the shell is a crucial parameter for achieving deformation through polymer growth. Finally, we demonstrate that the introduction of multivalent particles that can join polymers can either improve or impede polymer performance, depending on the amount and on the structure of the multivalent particles. Our results provide guidance for the experimental realization of polymer systems that can perform work at the nanoscale, for example through rationally designed self-assembling proteins or nucleic acids.