Hybrid lipid/block copolymer vesicles display broad phase coexistence region

The fluidity and polar environment of ~100 nm hybrid vesicles combining dipalmitoylphosphatidylcholine (DPPC) poly(1,2-butadiene)-block-polyethylene oxide (PBd-PEO, average molecular weight 950 g/mol) were studied upon vesicle heating using the fluorescence spectroscopy techniques DPH anisotropy laurdan generalized polarization (GP). These indicated PBd-PEO membranes are less ordered than solid DPPC, but slightly more fluid DPPC or dioleoylphosphatidylcholine (DOPC) membranes. We find values expected from additivity components' anisotropies in phase mixture PBd-PEO, inferring that strongly fluidizes PBd-PEO. use transitions GP to create a temperature/composition diagram for DPPC/PBd-PEO which we displays significantly broader solid/fluid coexistence region DPPC/DOPC, showing partitions readily into DOPC. existence broad is verified by Förster resonance energy transfer results visualization separation giant unilamellar containing up 95% single 100% at room temperature. add limited knowledge behavior diagrams vesicles, should be useful understanding tailoring membrane surface architecture toward biomedical applications such as drug delivery protein reconstitution.