To generate different hybrid vesicle compositions, relative volumes of POPC (32 mM) and the polymer (6.57 mM) in chloroform were measured using a Hamilton syringe into a glass vial. The solutions were dried in a vacuum desiccator to give a lipid/polymer film and then rehydrated with 1.0 mL of aqueous solution of 40 mM HEPES and 20 mM sodium chloride buffered to pH 7.4. The films were incubated at 50 °C for 5 minutes and vortexed for 1 minute. The suspensions were then frozen in liquid nitrogen, thawed in a 60 °C water bath and vortexed for 10 seconds. This cycle was repeated 5 times. Suspensions were extruded 11 times at room temperature through 100 nm polycarbonate membrane filter using a LiposoFast Basic Extruder. The samples were then kept at 4