Rheological properties of regular insulin and aspart insulin Langmuir monolayers at the air/water interface: Condensing effect of Zn2+ in the subphase

Alkyl esters of l-ascorbic acid: Stability, surface behaviour and interaction with phospholipid monolayers

“…(S1) and (S2)). Such phenomena are not often found in lipid films in the LE state, but have been reported for protein or lipid-protein and lipid-nanoparticles films [33][34][35] and for synthetic amphiphilic molecules able to establish intermolecular H-bonds [36,37].…”

Evaluating polymeric biomaterial–environment interfaces by Langmuir monolayer techniques

“…The investigation of interfacial rheology is applied to understand the viscoelastic properties, which provide the modulus and relaxation behaviour [190] and to gain information about the structure-rheology interplay. The two-dimensional properties for a variety of systems like synthetic (co)polymers [115,191,192], mixed protein layers [193], biomolecules [45,194,195] and low molecular weight molecules [196] have been performed. However, investigations on pure protein layers and their interaction with water-soluble molecules are still challenging.…”

Surface interactions, thermodynamics and topography of binary monolayers of Insulin with dipalmitoylphosphatidylcholine and 1-palmitoyl-2-oleoylphosphatidylcholine at the air/water interface

“…Also, it has been recently shown that the presence of Zn 2+ has a profound effect on the surface behavior of Insulin monolayers [32,24,20]. We recently described the rheological properties of regular Insulin and aspart Insulin in presence on Zn 2+ .…”

“…By oscillatory compressionexpansion cycles, we observed in all Insulin monolayers the development of a dilatational response to the surface perturbation, exhibiting a well-defined shear moduli in the presence of Zn 2+ , which was higher for regular Insulin compared to aspart Insulin. Development of a shear modulus indicates behavior resembling a nominal solid, suggesting formation of viscoelastic networks at the surface [20].…”

“…Comprehension of specific molecular interactions of Insulin with defined phospholipids, and their longer-range consequences on the surface organization is necessary in order to further understanding of such effects. With this aim, we studied in this work the surface behavior of mixed films of Insulin with DPPC and POPC, two major and well characterized constituents of egg and natural PCs, on Zn 2+ containing solutions (where Insulin molecules form hexamers showing well defined organization states and interesting viscoelastic properties [29,24,20]). Besides classical miscibility studies, we focused on the thermodynamics of the mixing process, on the presence of monolayer hysteresis and on exploring the surface topography of the films by Brewster Angle Microscopy.…”