Thermotropic and structural study of sphingolipids mixtures

HEREDIA V; DUPUY F.; MAGGIO B; BELTRAMO D.

Otro; XLII Reunion Anual de la Sociedad Argentina de Biofísica; 2013

Paclitaxel (Ptx) is an antitumoral drug that inhibit microtubule depolymerization. However, its low water solubility (less than 1 μg.ml−1) is a drawback in treatment of cancer patients. Recently, we demonstrated that paclitaxel (Ptx) can be loaded into GM1 ganglioside micelles, to render a stable water soluble formulation that increase the drug solubility up to 6.3 mg.ml-1 (a). In order to get insights of the membrane interaction of Ptx, we studied the interfacial behavior of the drug in the absence and in the presence of GM1 by means of the monolayer technique at air-water interfase. Gibbs absorption experiments and compression isotherms were carried out in a Langmuir balance, equipped with surface potential meter and Brewster angle microscopy, in order to evaluate the affinity of Ptx towards GM1, the lateral packing of the mixtures and the topography and molecular arrangement of the molecules at the film. The results indicate that Ptx became stabilized at the interface in the presence of the ganglioside, being the GM1/Ptx mixed monolayers at air-water interface stable at surface pressure values higher than pure Ptx.