(634c) The Structure and Elasticity of Lipid Vesicles Interacting with End-Phosphorylated Polyethylene Glycol

Yu, J., University of Chicago
Tirrell, M. V., University of Chicago

The structure and dynamics of lipid membranes in the presence of extracellular macromolecules is critical for cell membrane functions and many pharmaceutical applications. End phosphorylation of a triblock polyethylene glycol, ABAPEG 11K, greatly changes the interactions between the polymer and vesicle membranes, preventing PEG induced vesicle phase separation. SANS shows Pi-ABAPEG 11K weakly interacts with DMPC vesicle membranes but does not significantly change the structure of DMPC unilamellar vesicles at 37oC. Neutron spin-echo results show that the adsorption of Pi-ABAPEG 11K on DMPC vesicle membranes increases the membrane bending modulus . X ray reflectivity measurements confirm the weak adsorption of Pi-ABAPEG 11K on DMPC monolayer resulting in a more compacted DMPC monolayer structure.