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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Poster Abstracts
76
8-POS
Board 4
Large Area Model Biomembranes (LAMBs) to Understand Membrane Mechanics,
Structure, and Function
Peter J. Beltramo
, Nicole Schai, Jan Vermant.
ETH Zürich, Zürich, Switzerland.
The development of model cellular membranes is crucial for fundamental investigations of
biological phenomena, ranging from antimicrobial peptide pore formation and biomolecule
transport to bilayer elasticity and lipid raft formation. In this talk, a versatile platform to generate
free-standing, planar, phospholipid bilayers with millimeter scale areas will be introduced. The
technique relies on an adapted thin-film balance apparatus allowing for the dynamic control of
the nucleation and growth of a planar black lipid membrane in the center of an orifice surrounded
by microfluidic channels. A unique advantage in this system for the study of membrane
mechanics is control of the membrane tension in a planar geometry, which is demonstrated by
measuring the elasticity modulus of bilayers with varying composition. Simultaneous
fluorescence microscopy enables monitoring the lateral heterogeneity in ternary lipid mixtures
undergoing phase separation. In particular, the the effect of interdigitation on phase separation in
mixtures containing hybrid lipids (“linactants”) is shown by comparing bilayer to monolayer
experiments. Independent control of the solution conditions on either side of the bilayer allows
for mimicking the response of biological membranes to external stimuli, such as the introduction
of antimicrobial peptides. In this realm, the destabilizing effect of a model antimicrobial peptide,
magainin 2, due to pore formation and altered membrane tension on bilayers reconstituted from
bacterial cell lipids is analyzed. Together, the results demonstrate a new paradigm for studying
the mechanics, structure, and function of model biomembranes.