“…Like lipid GUVs, PGUVs were able to fuse to hydrophilic glass and PDMS substrates and form patches with distinct heart or circular shapes (Figure ). The effective vesicle–substrate interaction, which is the sum of the van der Waals attraction, the hydration repulsion, and the entropic repulsion arising from thermal membrane undulations, is sufficient to increase the membrane tension above a critical value leading to vesicle rupture and fusion. ,,,, However, polymer vesicles needed some additional adjustments to fuse to glass and PDMS. These included (1) baking the plasma-oxidized glass at 200 °C to reduce the hydration repulsion force or (2) subjecting the vesicles to hypo-osmotic shock, which swells them and increases their membrane tension, as well as reducing the undulation repulsion with the substrate .…”