Phase behavior of aqueous dispersions of mixtures of N-palmitoyl ceramide and cholesterol: a lipid system with ceramide-cholesterol crystalline lamellar phases.

Ceramides are particularly abundant in the stratum corneum lipid matrix, where they determine its unusual mesostructure, are involved in the lateral segregation of lipid domains in biological cell membranes, and are also known to act as signaling agents in cells. The importance attributed to ceramides in several biological processes has heightened in recent years, demanding a better understanding of their interaction with other membrane components, namely, cholesterol. Structural data concerning pure ceramides in water are relatively scarce, and this is even more the case for mixtures of ceramides with other lipids commonly associated with them in biological systems.

Encapsulation of adenoviral vectors into chitosan-bile salt microparticles for mucosal vaccination.

The objective of this study is the incorporation of adenoviral vectors into a microparticulate system adequate for mucosal delivery. Microencapsulation of the vectors was accomplished by ionotropic coacervation of chitosan, using bile salts as counter-anion. The process was optimized in order to promote high encapsulation efficiency, with a minimal loss of viral infectivity.

Incorporation of a model protein into chitosan-bile salt microparticles.

In order to develop a mucosal delivery system based on biocompatible polymers, a new methodology for production of protein-loaded microparticles is developed. Chitosan anionic precipitation/coacervation is accomplished by the addition of sodium deoxycholate (DCA). These microparticles were prepared under mild conditions, where bovine serum albumin (BSA) and DCA were simply dipped into a chitosan solution under stirring.