Phase Transition Induced Fission in Lipid Vesicles

TL;DR

This study shows that a first-order phase transition in lipid vesicles can trigger membrane fission, with potential implications for understanding cellular processes and designing vesicle-based systems.

Contribution

It demonstrates that phase transition-driven fission in giant unilamellar vesicles can be controlled and characterized, revealing new insights into membrane dynamics.

Findings

Phase transition induces vesicle fission and budding.

Cooling through the phase transition causes rupture and division.

Increasing viscosity reduces vesicle size without affecting fission.

Abstract

In this work we demonstrate how the first order phase transition in giant unilamellar vesicles (GUVs) can function as a trigger for membrane fission. When driven through their gel-fluid phase transition GUVs exhibit budding or pearl formation. These buds remain connected to the mother vesicle presumably by a small neck. Cooling these vesicles from the fluid phase (T>Tm) through the phase transition into the gel state (T<Tm), leads to complete rupture and fission of the neck, while the mother vesicle remains intact. Pearling tubes which formed upon heating break-up and decay into multiple individual vesicles which then diffuse freely. Finally we demonstrate that mimicking the intracellular bulk viscosity by increasing the bulk viscosity to 40cP does not affect the overall fission process, but leads to a significant decrease in size of the released vesicles.