Cubic and Hexagonal Mesophases for Protein Encapsulation: Structural Effects of Insulin Confinement

Abstract

Monoolein-based cubic and hexagonal mesophases were investigated as matrices for insulin loading, at low pH, as a function of temperature and in the presence of increasing amounts of oleic acid, as a structural stabilizer for the hexagonal phase. Synchrotron small angle X-ray diffraction, rheological measurements, and attenuated total reflection-Fourier transform infrared spectroscopy were used to study the effects of insulin loading on the lipid mesophases and of the effect of protein confinement in the 2D- and 3D-lipid matrix water channels on its stability and unfolding behavior. We found that insulin encapsulation has only little effects both on the mesophase structures and on the viscoelastic properties of lipid systems, whereas protein confinement affects the response of the secondary structure of insulin to thermal changes in a different manner according to the specific mesophase: in the cubic structure, the unfolding toward an unordered structure is favored, while the prevalence of parallel β-sheets, and nuclei for fibril formation, is observed in hexagonal structures.

Nanostructured liquid-crystalline polymer films for ionic actuators: self-assembly of photopolymerizable ionic itaconate with an ionic liquid

“…The Cub bi sample has been found to exhibit the highest G 0 value of about 10 6 Pa. The G 0 value is comparable to that of aqueous lyotropic Cub bi liquid crystals 33,34 and supramolecular hydrogels. 35,36 In addition, the G 0 value of the Col h phase (B10 5 Pa) was higher than that of the Sm phase (B10 3 Pa).…”

Structural Entities Associated with Different Lipid Phases of Plant Thylakoid Membranes—Selective Susceptibilities to Different Lipases and Proteases

“…Further candidates include lipocalin enzyme zeaxanthin-epoxidase [ 72 ], components of the large stroma-side protruding subunits of PSI [ 83 ], and the tightly bound ferredoxin:NADP + oxidoreductase [ 84 , 85 ], as well as the NAD(P)H–dehydrogenase complex [ 80 ]. In general, hydrophobic peptides have been shown to be capable of forming peptide-rich H II lipid phases [ 86 , 87 ], and water-soluble proteins can also be encapsulated in different non-bilayer phases [ 88 , 89 ]. In this context, it is interesting to recall that water-soluble respiratory electron-transport chain protein cytochrome c has been shown to promote the formation of the H II phase in model membranes containing cardiolipin, the main non-bilayer lipid of the IMMs [ 90 , 91 , 92 ].…”

Coencapsulation of Gemcitabine and Thymoquinone in Citrem–Phosphatidylcholine Hexosome Nanocarriers Improves In Vitro Cellular Uptake in Breast Cancer Cells

“…Brixadi will be available in the U.S. healthcare setting in September 2023. Hence, various formulations of inverse hexagonal (H 2 ) and inverse bicontinuous cubic (V 2 ) nanodispersions have provided novel insights and suggest their potential for clinical translation in drug delivery applications and/or theranostics. − …”