Ca-mediated electroformation of cell-sized lipid vesicles

Area of Science:

• Biophysics
• Materials Science
• Cell Biology

Background:

• Giant unilamellar vesicles (GUVs) mimic cell structures but their formation is poorly understood, leading to size variability.
• Conventional electroformation methods produce polydisperse GUVs, limiting their utility in controlled biological studies.

Purpose of the Study:

• To develop a novel strategy for producing giant unilamellar vesicles (GUVs) with controlled size distributions.
• To investigate the role of calcium in mediating GUV formation during electroformation.
• To enhance the understanding of lipid self-assembly for cell-like vesicle construction.

Main Methods:

• Electroformation of GUVs utilizing calcium ion (Ca(2+)) adsorption layers on lipid films.
• Electroformation using in situ formed calcium carbonate (CaCO3) mineral layers on lipid films.
• Analysis of calcium's effect on electroosmotic flow and GUV fusion/growth dynamics.

Main Results:

• Calcium ion adsorption layers induced electroosmotic flow, confining GUV growth and yielding uniform vesicle sizes.
• Direct use of calcium carbonate layers further improved GUV uniformity, resulting in narrow polydispersity.
• Demonstrated a novel biological function of calcium in the controlled formation of cell-like lipid vesicles.

Conclusions:

• Calcium mediation offers a precise method for controlling GUV size distribution during electroformation.
• The findings provide new insights into the physics of lipid vesicle self-assembly.
• This approach may aid in constructing advanced models for elucidating cellular development processes.