Controlled deformation of vesicles by flexible structured media

Area of Science:

• Soft Matter Physics
• Materials Science
• Biophysics

Background:

• Biological liquid crystalline (LC) networks like actin and tubulin influence cell shape.
• Replicating these active, anisotropic behaviors in synthetic systems is a key challenge.
• Giant vesicles in LCs offer a model system to study these interactions.

Purpose of the Study:

• To reproduce cell-shape deformation using synthetic liquid crystals and giant vesicles.
• To investigate the formation of topological defects and resulting vesicle shapes.
• To establish a foundation for creating active, anisotropic hybrid systems.

Main Methods:

• Utilized a coupled particle-continuum model for deformable networks in nematic LCs.
• Employed Landau-de Gennes free energy functional for LC representation.
• Experimental observation of giant unilamellar vesicles in LCs.

Main Results:

• Liquid crystals deform vesicles into equilibrium anisotropic shapes based on elastic properties.
• Perpendicular anchoring results in a Saturn ring defect and oblate vesicle shape.
• Degenerate planar anchoring leads to boojum defects and elongated spheroidal vesicle shapes.
• Vesicle curvature increases, causing topological defect volume to shrink.
• Experimental observations confirm spindle-like shapes for planar anchoring.
• Vesicle tension suppresses deformation; anchoring strength and elastic constants promote anisotropy.

Conclusions:

• Synthetic LCs can actively deform suspended vesicles, creating anisotropic shapes.
• Defect formation and vesicle shape are tunable via anchoring conditions and material properties.
• This work provides insights into designing functional hybrid soft matter systems.