Spherical Nanovesicles Transform into a Multitude of Nonspherical Shapes

Area of Science:

• Biophysics
• Materials Science
• Computational Biology

Background:

• Nanovesicles, lipid bilayer structures (20-200 nm), exhibit diverse spherical and nonspherical shapes.
• Electron microscopy offers static snapshots, limiting dynamic morphological understanding.

Purpose of the Study:

• To investigate nanovesicle morphological transformations using molecular dynamics simulations.
• To understand how lipid distribution and membrane tension influence vesicle shape.
• To explore the relationship between vesicle volume, lipid asymmetry, and resulting shapes.

Main Methods:

• Molecular dynamics simulations of nanovesicle assembly and volume reduction.
• Analysis of lipid leaflet redistribution and its effect on membrane tension.
• Calculation of local spontaneous curvature from stress profiles.

Main Results:

• Spherical nanovesicles transform into various nonspherical shapes (oblates, stomatocytes, prolates, dumbbells) upon volume reduction.
• Lipid redistribution between leaflets controls vesicle polymorphism by altering mechanical tensions.
• Identified conditions for vanishing leaflet tensions and calculated spontaneous curvature.

Conclusions:

• Nanovesicle morphology is dynamically tunable via lipid leaflet tension.
• Simulation insights advance understanding of cellular nanovesicles like exosomes for biomarker and drug delivery applications.