title: Cavity Orientation Regulated by Mixture Composition and Clustering of Amphiphilic Cyclodextrins in Phospholipid Monolayers.
abstract: Artificial supramolecular-hierarchical structures that emulate nature represent an overcoming alternative for the design of new drug delivery systems. Thermodynamic and topographic properties of films formed by a monoacylated amphiphilic β-cyclodextrin (βCD-C16) with the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) at the air/water interface were studied. βCD-C16 formed stable mixed films with POPC at several proportions when spread together at the air/water interface. The orientation of βCD-C16 cavity at the interface depends on its mole fraction in the film as reveled by the analysis of partial mean molecular areas as a function of composition. Furthermore, βCD-C16 was able to penetrate POPC preformed films in a broad range of initial surface pressures, including that near the collapse pressure of the phospholipid. These results demonstrated the strong tendency of βCD-C16 to be inserted into this lipid matrix commonly used in liposome formulations. Topography studies show that βCD-C16 segregate from POPC forming clusters enriched in βCD-C16. Segregation of βCD-C16 was especially noticeable when βCD-C16 were incorporated by themselves into a preformed POPC matrix leading to ordered and highly birefringent structures that suggest the formation of hierarchical stacked βCD-C16 arrangement at the interface.
authors.affiliation: Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC-UNC-CONICET), Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria , X5000HUA Córdoba, Argentina.
authors.forename: John J
authors.initials: JJ
authors.lastname: Pinzón Barrantes
authors.affiliation: Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC-UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria , X5000HUA Córdoba, Argentina.
authors.forename: Bruno
authors.initials: B
authors.lastname: Maggio
authors.affiliation: Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC-UNC-CONICET), Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria , X5000HUA Córdoba, Argentina.
authors.forename: Rita H
authors.initials: RH
authors.lastname: de Rossi
authors.affiliation: Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC-UNC-CONICET), Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria , X5000HUA Córdoba, Argentina.
authors.forename: Raquel V
authors.identifier: 0000-0002-1982-8823
authors.initials: RV
authors.lastname: Vico
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D008968:Molecular Conformation; D010316:Particle Size; D010743:Phospholipids / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D003505:Cyclodextrins; D010743:Phospholipids; D013501:Surface-Active Agents