Fluid membranes can drive linear aggregation of adsorbed spherical nanoparticles

TL;DR

This study uses computer simulations to demonstrate that fluid membranes can induce linear aggregation of spherical nanoparticles, contrasting with isotropic clustering seen in other systems, and provides a phase diagram and energy analysis.

Contribution

It reveals a novel mechanism where lipid membranes promote linear nanoparticle aggregation, supported by phase diagrams and free energy calculations.

Findings

Membranes mediate linear aggregation of nanoparticles.

Linear aggregation occurs across various membrane rigidities.

Free energy barriers differ for linear versus isotropic aggregation.

Abstract

Using computer simulations we show that lipid membranes can mediate linear aggregation of spherical nanoparticles binding to it for a wide range of biologically relevant bending rigidities. This result is in net contrast with the isotropic aggregation of nanoparticles on fluid interfaces or the expected clustering of isotropic insertions in biological membranes. We present a phase diagram indicating where linear aggregation is expected, and compute explicitly the free energy barriers associated with linear and isotropic aggregation. Finally, we provide simple scaling arguments to explain this phenomenology.