Membrane Mechanics and Multiphysics Underlying Complex Electro-Chemo-Mechanical Response of Biomembranes

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Biomembranes play a critical role in the structure and organization of biological cells. Various biomembrane bound phenomena are central to the functioning of cells and play a key role in many disease conditions. Thus, an understanding of the physical interactions active on the surface of biomembranes is important to develop a deeper appreciation of cell functioning, and their implications on human health and disease conditions. This award supports research that will focus on the mechanical deformation aspects of biomembranes. The work aims to develop a novel theoretical formulation that models membrane deformation and its interactions with transport and electrochemical processes. The formulation will then be used to model various membrane bound phenomena. This research brings together several disciplines including mathematics, mechanics, chemistry and electrostatics. Since this project addresses important aspects of the mechanical evolution of cells, the research and learning obtained is of significant interest to researchers in biophysics and mechanics. Further, the formulation will be implemented into a computational framework. This computational framework will be made available as an open-source code to the scientific community at large. Theoretical and computational modeling of complex biomembrane mechanisms requires an integrated multiphysics approach to treat the coupled phenomena of mechanics, surface transport and electrochemistry. This project will develop a novel free-energy description of biomembrane mechanics - coupling viscoelasticity, surface transport of lipids, proteins and ions, and electrochemistry. This description will be implemented into a thin-shell mechanics framework to model mechano-chemical evolution of biomembranes. The mechanics treatment will be finite-strain visco-elasto-dynamics, and the numerical implementation will be a curvilinear-coordinates based coupled multiphysics framework. The numerical model will be used to model three important biomembrane phenomena: endocytosis, mechanoporation and strain-modulated neuronal electrical conduction. The model will be validated using experimental observations of neuronal membrane mechanoporation and electrical conduction. The distinguishing aspect of this work is the strong integration of multiphysics (membrane mechanics, surface transport and surface electrochemistry) to enable a unified treatment of various coupled phenomena in biomembranes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.