Photomanipulation of Minimal Synthetic Cells: Area Increase, Softening, and Interleaflet Coupling of Membrane Models Doped with Azobenzene‐Lipid Photoswitches

• Published in: Advanced science Vol. 10; no. 31; p. e2304336
• Main Authors: Aleksanyan, Mina, Grafmüller, Andrea, Crea, Fucsia, Georgiev, Vasil N., Yandrapalli, Naresh, Block, Stephan, Heberle, Joachim, Dimova, Rumiana
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.11.2023; John Wiley and Sons Inc; Wiley
• Subjects: atomic force microscopy (AFM); azo‐PC; bending rigidity; Drug delivery systems; Drug dosages; giant vesicles; Light; Lipids; Mechanical properties; membrane capacitance; Membranes; Microscopy; molecular dynamics simulations; Morphology; Simulation
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202304336

Light can effectively interrogate biological systems in a reversible and physiologically compatible manner with high spatiotemporal precision. Understanding the biophysics of photo-induced processes in bio-systems is crucial for achieving relevant clinical applications. Employing membranes doped with the photolipid azobenzene-phosphatidylcholine (azo-PC), a holistic picture of light-triggered changes in membrane kinetics, morphology, and material properties obtained from correlative studies on cell-sized vesicles, Langmuir monolayers, supported lipid bilayers, and molecular dynamics simulations is provided. Light-induced membrane area increases as high as ≈25% and a ten-fold decrease in the membrane bending rigidity is observed upon trans-to-cis azo-PC isomerization associated with membrane leaflet coupling and molecular curvature changes. Vesicle electrodeformation measurements and atomic force microscopy reveal that trans azo-PC bilayers are thicker than palmitoyl-oleoyl phosphatidylcholine (POPC) bilayers but have higher specific membrane capacitance and dielectric constant suggesting an increased ability to store electric charges across the membrane. Lastly, incubating POPC vesicles with azo-PC solutions results in the insertion of azo-PC in the membrane enabling them to become photoresponsive. All these results demonstrate that light can be used to finely manipulate the shape, mechanical and electric properties of photolipid-doped minimal cell models, and liposomal drug carriers, thus, presenting a promising therapeutic alternative for the repair of cellular disorders.