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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Thursday Speaker Abstracts
40
Phases and Fluctuations in Biological Membranes and Possible Implications for General Anesthesia
Sarah L. Veatch
.
University of Michigan, Ann Arbor, MI, USA.
The thermodynamic properties of plasma membrane lipids play a vital role in many functions at
the mammalian cell surface. Some functions are thought to occur, at least in part, because plasma
membrane lipids have a tendency to separate into two distinct liquid phases. We propose that
these lipid mediated functions occur because plasma membrane composition is tuned close to a
miscibility critical point at physiological temperature. This hypothesis is supported by our
observations of micron-sized and dynamic critical composition fluctuations in isolated plasma
membranes near room temperature. In this talk, I will discuss some of our ongoing efforts to
probe for the existence and consequences of criticality in the plasma membranes of intact cells
using super-resolution imaging of intact cellular membranes and functional studies of lipid
mediated processes. I will focus on recent results showing a striking correlation between the
effects of compounds on critical temperatures in isolated plasma membrane vesicles and their
function as general anesthetics in cells and organisms. I will present our current thinking of how
at least some aspects of anesthetic functions could be attributed to lipid heterogeneity.