Paper Number
RI3 

Session
Rheology and Mobility at Interfaces

Title
High throughput assessment of shear surface viscosity of bilayer membranes

Presentation Date and Time
October 12, 2021 (Tuesday) 4:35

Track / Room
Track 6 / Ballroom 1

Authors (Click on name to view author profile)

  1. Faizi, Hammad A. (Northwestern University)
  2. Dimova, Rumiana (Max Planck Institute of Colloids and Interfaces, Department of Theory and Biosystems)
  3. Vlahovska, Petia M. (Northwestern University, Engineering Sciences and Applied Mathematics)

Author and Affiliation Lines (in printed abstract book)
Hammad A. Faizi1, Rumiana Dimova2 and Petia M. Vlahovska3
1Northwestern University, Evanston, IL 60208; 2Department of Theory and Biosystems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany; 3Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208

Speaker / Presenter 
Faizi, Hammad A.

Keywords
experimental methods; applied rheology; biological materials; interfacial mobility; interfacial rheology; rheology methods; surfactants

Text of Abstract
The shear surface viscosity of lipid bilayer membranes plays an important role in dictating the function of embedded biomolecules. In this study, we devise a high throughput and probe-independent method to measure shear surface viscosity of bilayer membranes based on transient vesicle electrodeformation. We simplify the existing theory from Vlahovska et al. BJ 96, 4789-4803 (2009) with facile design considerations to fit for membrane viscosity as the only fitting parameter in the deformation regime. Our method is probe-free and sensitive enough to allow for robust measurement of membrane viscosity of single-and multi-component lipid vesicles and polymersomes. We find good match of the viscosity values with the existing methods in the literature. Surprisingly, we find that shear surface viscosity depends on the surface charges of the membrane. This has important implications for biomolecular transport of native cell membranes that are intrinsically charged with a transmembrane potential across.