IIBYT   23944
INSTITUTO DE INVESTIGACIONES BIOLOGICAS Y TECNOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
The rheological properties of lipid monolayers modulate the incorporation of L-ascorbic acid alkyl esters
Autor/es:
ZULUETA DIAZ, YENISLEIDY DE LAS MERCEDES; MOTTOLA, MILAGRO; VICO, VIVIANA RAQUEL; FANANI, MARÍA LAURA
Revista:
LANGMUIR
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2015 vol. 32 p. 587 - 595
ISSN:
0743-7463
Resumen:
In this work, we tested the hypothesis that the incorporation of amphiphilic drugs into lipid membranes may be regulated by their rheological properties. For this purpose two members of the L-ascorbic acid alkyl esters family (ASCn) wereselected: ASC16 and ASC14, which have different rheological properties whenorganized at the air/water interface. They are lipophilic forms of vitamin C used in topical pharmacological preparations. The effect of the phase state of the host lipid membranes on ASCn incorporation was explored using Langmuir monolayers. Films of pure lipids with known phase states have been selected, showing liquidexpanded,liquid-condensed and solid phases as well as pure cholesterol films in liquid-ordered state. We also tested ternary and quaternary mixed films that mimic the properties of cholesterol containing membranes and of the stratum corneum.The compressibility and shear properties of those monolayers were assessed in order to define its phase character. We found that the length of the acyl chain of theASCn compounds induces differential changes in the rheological properties of thehost membrane, and subtly regulates the kinetics and extent of the penetrationprocess. The capacity for ASCn uptake was found to depend on the phase state ofthe host film. The increase in surface pressure resultant after amphiphileincorporation appears to be a function of the capacity of the host membrane toincorporate such amphiphile as well as the rheological response of the film. Hence, monolayers that show a solid phase state responded with a larger surface pressure increase to the incorporation of a comparable amount of amphiphile than liquidexpanded ones. The cholesterol- containing films, including the mixture that mimics stratum corneum, allowed a very scarce ASCn uptake independently of the membrane diffusional properties. This suggests an important contribution of Cho on the maintenance of the barrier function of stratum corneum.