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

GRASSO, ERNESTO; RAFAEL GUSTAVO OLIVEIRA; MAGGIO, B.

JOURNAL OF COLLOID AND INTERFACE SCIENCE

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2016 vol. 464 p. 264 - 264

0021-9797

he molecular packing, thermodynamics and surface topography of binary Langmuir monolayers of Insulin and DPPC (dipalmitoylphosphatidylcholine) or POCP (palmitoyloleylphosphatidylcholine) at the air/water interface on Zn2+ containing solutions were studied. Miscibility and interactions were ascertained by the variation of surface pressure mean molecular area isotherms, surface compressional modulus and surface (dipole) potential with the film composition. Brewster angle microscopy was used to visualize the surface topography of the monolayers. Below 20 mN/m insulin forms stable homogenous films with DPPC and POPC at all mole fractions studied (except for films with XINS = 0.05 at 10 mN/m where domain coexistence was observed). Above 20 mN/m, a segregation process between mixed phases occurred in all monolayers without squeezing out of individual components. Under compression the films exhibit formation of a viscoelastic or kinetically trapped organization leading to considerable compos