Without prior incubation with AMPs, the vesicles exhibit significant deformation that correlates with the salt concentration as depicted in Figures and. This outcome, replicating the textbook example of semipermeable vesicles or cells in a hypertonic solution, is unsurprising. Since the membrane largely blocks ions while allowing water to pass, the substantial solute concentration difference across the membrane generates significant osmotic pressure, leading to the vesicle deformation. At 20 °C, the membrane is in gel phase, and the deformation only becomes apparent at high osmotic pressures, as can be seen from top curve in figure . However, at 37 °C, the same membrane is in the fluid phase and consequently much softer. In this case, the deformation is more dramatic and readily apparent even at the lowest salt concentration, as seen in figure . However, when the vesicles have been incubated with AMPs prior to salt addition, the outcome is entirely different, as can be readily observed in figures 2B and 2C for indolicidin and LL-37, respectively, at 20 degrees and similarly with figures 2E and 2F at 37 °C. In this case, salt addition does not result in deformation as indicated by the lack of significant changes in the scattering curves. This holds true for both the gel and fluid phase membranes, even at very high initial salt gradients, and shows that the AMP-incubated vesicles are not subjected to the same osmotic pressure.