(282c) Phase Behavior of Lipid/Copolymer/Protein Hybrid Biomembranes

Recent studies of hybrid biomembranes combining block copolymers and phospholipids will be discussed. The chemical diversity afforded by inclusion of block copolymers is particularly relevant to the formation of stealth liposomes or stimuli-responsive membranes (e.g. pH- or thermo-responsive systems), which can aid in the control of drug retention and release. However, the phase behavior of these hybrid biomembranes has not been methodically explored. To this end, we have studied small (~100 nm) vesicles, copolymer-stabilized nanodiscs, and giant vesicles with membranes made of polybutadiene-block-polyethylene oxide (PBd-PEO) and dipalmitoylphosphatidylcholine (DPPC) using fluorescence spectroscopy and by fluorescence microscopy. Efforts to incorporate proteins into these hybrid biomembranes will also be mentioned.