We report on studies of lipid transfer rates between different morphology nanoparticles and lipids with different lengths of acyl chains. The lipid transfer rate of dimyristoyl phosphatidylcholine (di-C14, DMPC) in discoidal "bicelles" (0.156 h(-1)) is two orders of magnitude greater than that of DMPC vesicles (ULVs) (1.1 x 10(-3) h(-1)). For both bicellar and ULV morphologies, increasing acyl chain length by two carbons [going from di-C14 DMPC to di-C16, dipalmitoyl phosphatidylcholine (DPPC)], causes lipid transfer rates to decrease by more than two orders of magnitude. Results from small angle neutron scattering (SANS), differential scanning calorimetry (DSC), and fluorescence correlation spectroscopy (FCS) are in good agreement with each other. The present studies highlight the importance of lipid dynamic processes taking place in different morphology biomimetic membranes.