Stabilization of Lipid Lamellar Bilayer Structure of Stratum Corneum Modulated by Poly (2-methacryloyloxyethyl phosphorylcholine) in Relation to Skin Hydration and Skin Protection

One crucial factor in skin tissue engineering is to understand the hydration and barrier property of skin. We investigated the skin hydration and stabilization strategy of inter-lamellar structure of stratum corneum (SC) using poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC). The unique hydration and stabilization potency of PMPC on the barrier function of the SC examined using freshly excised hairless mouse skin as a model membrane and the relationship between the stabilization of the lipid lamellar bilayer (LLB) and its enhanced water holding capacity was established. Differential scanning calorimeter based on the phase-transition temperature of lipid domain of SC demonstrated that PMPC stabilized the LLB. The ratio of the heat of lipid phase transition (△H) of SC exposed to water and PMPC for 24 h was 1.51. X-ray crystallography showed the presence of well- organized lipids in intercellular membranes exhibiting short and long periodicity of lamellar phases. The peak at 4.4 nm attributed to the long periodicity phase (LPP) was missing in water-treated SC, where, the presence of 4.2- 4.4 nm peak in PMPC treated SC indicated that PMPC stabilized LPP. Transmission electron microscopy study demonstrated that the LLB structure became more rigid and orderly in PMPC treated SC. The unique ion paired structure of PMPC enhances the barrier function of the SC by stabilizing LLB structure and hydration by inducing weakly bound water. The unique hydration state and stabilization effect from extended water exposure could provide a valuable information to prepare reliable artificial skin matrix and skin tissue.