Structural characterization of the poly(ethylene glycol) layer of sterically stabilized liposomes by means of FTIR spectroscopy

► ATR-FTIR analysis of the PEG-layer of sterically stabilized liposomes is presented. ► PEG hydration is described by the ratio of the trans and gauche configurations. ► Minimum hydration of the polymer layer is found at ∼6 mol% PEG-lipid molar ratio.