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Membrane Sealing by Polymers
Author(s) -
MASKARINEC STACEY A.,
WU GUOHUI,
LEE KA YEE C.
Publication year - 2006
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1363.018
Subject(s) - polymer , chemistry , membrane , biochemistry , organic chemistry
A bstract : An intact cell membrane serves as a barrier, controlling the traffic of materials going into and out of the cell. When the integrity of the membrane is compromised, its transport barrier function is also disrupted, leaving the cell vulnerable to necrosis. It has been shown that triblock copolymer surfactants can help seal structurally damaged membranes, arresting the leakage of intracellular materials. Using model lipid monolayers along with concurrent Langmuir isotherm and fluorescence microscopy measurements as well as surface X‐ray scattering techniques, the nature of the interaction between lipids and a particular family of triblock copolymers in the form poly(ethylene oxide)‐poly(propylene oxide)‐poly(ethylene oxide) is examined. The polymer is found to selectively insert into membranes where the lipid packing density is below that of an intact cell membrane, thus localizing its sealing effect on damaged portions of the membrane. The inserted polymer is “squeezed out” of the lipid film when the lipid packing density is increased, suggesting a mechanism for the cell to be rid of the polymer when the membrane integrity is restored.