Fig. 2. Ternary GUVs can act as a platform for user-defined, thermoresponsive content release. (A) DOPC : DPPC : Chol 1 : 1 : 3 ternary vesicles containing Lo/Ld domains can release their cargo when taken through the vesicle Tmix (∼32 °C), as shown through application of multiple heat cycles and compared to domain-free DOPC GUVs. Error bars = 1 S.D., n = 5. (B) Fluorescence and phase contrast images highlighting calcein-free ternary GUVs after applying a heat cycle. Vesicles that leaked lost contrast during phase contrast imaging (arrows) as their internal and external content equilibrated. White dotted circles represent outlines of vesicles that have leaked scale bar = 30 μm. (C) Graph of content release after 20 thermal cycles, showing ternary GUVs underwent almost complete content release. Error bars = 1 S.D., n = 5. (D) Visualisation of ternary GUVs after 20 cycles with superimposed bright-field and fluorescence channels, showing the majority of vesicles released dye cargo. Scale bar = 50 μm. (E) Image of ternary DOPC : EggSM : Chol 1 : 1 : 3 vesicles successfully formed via phase transfer, showing the same Lo/Ld domain formation. Scale bar = 50 μm. (F) Graph showing that vesicle Tmix defines the release temperature, as shown by the release of content from DOPC : DPPC : Chol (Tmix ∼ 32 °C) when cycled to 40 °C, whilst DOPC : EggSM : Chol vesicles (Tmix ∼ 45 °C) only release their content when cycled to 50 °C. Error bars = 1 S.D., n = 5.
