Urea-Mediated Anomalous Diffusion in Supported Lipid Bilayers

TL;DR

This study demonstrates how urea can induce and tune anomalous subdiffusion in supported lipid bilayers, providing a controllable model to better understand complex diffusion behaviors in biological membranes.

Contribution

It introduces urea as a novel agent to modulate anomalous diffusion in supported lipid bilayers, extending previous lipid modification methods.

Findings

Urea induces anomalous subdiffusion in supported lipid bilayers.

Tuning urea concentration and incubation time controls diffusion behavior.

Model mimics diffusion characteristics observed in biological membranes.

Abstract

Diffusion in biological membranes is seldom simply Brownian motion; instead, the rate of diffusion is dependent on the timescale of observation and so is often described as anomalous. In order to help better understand this phenomenon, model systems are needed where the anomalous subdiffusion of the lipid bilayer can be tuned and quantified. We recently demonstrated one such model by controlling the excluded area fraction in supported lipid bilayers (SLBs) through the incorporation of lipids derivatised with polyethylene glycol. Here we extend this work, using urea to induce anomalous subdiffusion in SLBs. By tuning incubation time and urea concentration, we produce DCPC bilayers that exhibit anomalous behaviour on the same scale observed in biological membranes.