Reversible photoswitching in a cell-sized vesicle

Area of Science:

• Soft matter physics
• Materials science
• Biophysics

Background:

• Amphiphilic molecules self-assemble into vesicles, forming structures with diverse applications.
• Controlling vesicle morphology dynamically is crucial for advanced material design and biological studies.
• Photosensitive molecules offer external control over material properties via light stimuli.

Purpose of the Study:

• To investigate the light-induced morphological changes in vesicles assembled from photosensitive amphiphilic molecules.
• To understand the mechanism behind reversible photoswitching of vesicle shape.
• To correlate molecular photoisomerization with macroscopic vesicle behavior.

Main Methods:

• Microscopic observation of vesicle morphology.
• Utilizing photosensitive amphiphilic molecules capable of photoisomerization.
• Analyzing changes in membrane fluctuation and shape transitions (ellipsoid to bud).
• Investigating the influence of initial vesicle asymmetry on shape response.

Main Results:

• Photosensitive amphiphilic molecules induced reversible shape changes in vesicles upon photoisomerization.
• Vesicle morphology transitioned between ellipsoid and bud shapes, dependent on initial asymmetry.
• Changes in membrane fluctuation behavior were observed.
• The mechanism was linked to alterations in the molecule's effective cross-sectional area.

Conclusions:

• Photosensitive amphiphilic molecules provide a mechanism for light-controlled vesicle morphology.
• The degree of initial shape asymmetry dictates the specific morphological response.
• This photoswitching behavior is driven by changes in molecular area upon photoisomerization, offering insights into soft material actuation.