Identification code Analytical method SdFFF* PCS° Cryo-TEM Mean diameter (nm) s.d. Mean diameter§ (nm) s.d. Mean diameter (nm) s.d. #SLN 44.6 3 166.1 5 113.7 9 #SLN-P80 32.0 2 169.3 4 112.6 2 #NLC 60.6 5 152.5 4 119.0 8 #NLC-P80 59.6 4 162.2 6 78.7 6 #SLN-CG 49.5 3 172.6 7 97.2 7 #SLN-P80-CG 32.9 2 183.4 11 88.7 7

*Sedimentation Field Flow Fractionation; °Photon Correlation Spectroscopy; #Cryogenic Transmission Electron Microscopy; §expressed as Z-Average; s.d.: standard deviation; data are the mean of 5 measurements

Table 3: Mean diameters of the nanoparticles used in the present study, as determined by SdFFF, PCS and Cryo-TEM.