Wolde-Kidan, AmanuelAmanuelWolde-KidanPham, Quoc DatQuoc DatPhamSchlaich, AlexanderAlexanderSchlaichLoche, PhilipPhilipLocheSparr, EmmaEmmaSparrNetz, Roland R.Roland R.NetzSchneck, EmanuelEmanuelSchneck2025-04-022025-04-022019Physical Chemistry Chemical Physics 21 (31): 16989-17000 (2019)https://hdl.handle.net/11420/55136The influence of the co-solutes TMAO, urea, and NaCl on the hydration repulsion between lipid membranes is investigated in a combined experimental/simulation approach. Pressure-hydration curves obtained via sorption experiments reveal that the repulsion significantly increases when the membranes are loaded with co-solutes, most strongly for TMAO. As a result, the co-solutes retain additional water molecules and therefore provide membranes with a fluid and more physiological environment. The experimental data are quantitatively reproduced in complementary solvent-explicit atomistic molecular dynamics simulations, which yield the chemical potential of water. Simulation analysis reveals that the additional repulsion arises from the osmotic pressure generated by the co-solutes, an effect which is maximal for TMAO, due to its unfavorable interactions with the lipid headgroup layer and its extraordinarily high osmotic coefficient.en1463-9084|||1463-90762019311698917000The Royal Soc. of ChemistryTechnology::620: EngineeringJournal Article10.1039/c9cp01953gJournal Article