The intensity difference (ΔI) between the inside and outside of each GUV was calculated; a positive value defining a positive delivery event, a negative value indicating no calcein delivery. Intensity differences were plotted for each cubosome size class in the histogram shown in Figure . The distribution of ΔI was assumed to be a function in variation in size between giant vesicles (generally between 8 -20 μm). A total of around 10 GUVs for each LLC size class was analysed, and repeated in triplicate (histogram shows 64 GUVs in total). A marked difference was noted between size classes. Particles at 130 nm were seen to deliver calcein, whereas 310 nm particles did not.