# Curvature variation controls particle aggregation on fluid vesicles

## TL;DR

This study investigates how curvature variations on fluid vesicles influence particle aggregation, revealing that particles tend to cluster along regions of highest curvature, which could impact cellular processes and artificial vesicle division.

## Contribution

The paper demonstrates how membrane shape anisotropy directs particle interactions and aggregation patterns, providing insights into membrane-mediated processes in biological and synthetic systems.

## Key findings

- Particles attract each other on closed vesicles
- Particles align with the largest curvature direction
- Multiple particles form rings or arcs around vesicles

## Abstract

Cellular membranes exhibit a large variety of shapes, strongly coupled to their function. Many biological processes involve dynamic reshaping of membranes, usually mediated by proteins. This interaction works both ways: while proteins influence the membrane shape, the membrane shape affects the interactions between the proteins. To study these membrane-mediated interactions on closed and anisotropically curved membranes, we use colloids adhered to ellipsoidal membrane vesicles as a model system. We find that two particles on a closed system always attract each other, and tend to align with the direction of largest curvature. Multiple particles form arcs, or, at large enough numbers, a complete ring surrounding the vesicle in its equatorial plane. The resulting vesicle shape resembles a snowman. Our results indicate that these physical interactions on membranes with anisotropic shapes can be exploited by cells to drive macromolecules to preferred regions of cellular or intracellular membranes, and utilized to initiate dynamic processes such as cell division. The same principle could be used to find the midplane of an artificial vesicle, as a first step towards dividing it into two equal parts.