Thermodynamic Approach to Phase Coexistence in Ternary Phospholipid-Cholesterol Mixtures

Jean Wolff (1) , Carlos Marques (1) , Fabrice Thalmann (1)

1 ICS - Institut Charles Sadron

We introduce a simple and predictive model for determining the phase stability of ternary phospholipid-cholesterol mixtures. Assuming that competition between the liquid and gel order of the phospholipids is the main driving force behind lipid segregation, we derive a Gibbs free-energy of mixing, based on the thermodynamic properties of the lipids main transition. A numerical approach was devised that enable the fast and efficient determination of the ternary diagrams associated with our Gibbs free-energy. The computed phase coexistence diagram of DOPC/DPPC/cholesterol reproduces well known features for this system at 10°C, as well as its evolution with temperature.

Mots clés: phase; theoretical; lipids; transition; cholesterol; ternary; coexistence

Domaines: Matière Molle [cond-mat.soft]

Jean Wolff, Carlos Marques, Fabrice Thalmann. Thermodynamic Approach to Phase Coexistence in Ternary Phospholipid-Cholesterol Mixtures. Physical Review Letters, 2011, 106, pp.128104. ⟨10.1103/PhysRevLett.106.128104⟩. ⟨hal-00581246⟩