Phase Behavior of the Bilayers Containing Hydrogenated Soy Lecithin and β-Sitosteryl Sulfate

Modulating edible-oleogels physical and functional characteristics by controlling their microstructure

The influence of co-oleogelators like lecithin or hydrogenated lecithin together with the addition of dispersed water droplets to modulate the microstructure and thus the physical properties of glyceryl stearate (GS)-corn oil oleogels was investigated by thermal profile, microstructure, hardness, and oil binding capacity (OBC). The addition of β-carotene (βC) was also assessed. With lecithin, crystallization and melting temperatures were reduced, resulting in less-ordered crystal networks with a lower hardness and OBC, while with hydrogenated lecithin, the opposite effect was observed. In the presence of water, oleogels became harder but more brittle. Finally, βC acted as a crystal modifier increasing the hardness and OBC in the presence of lecithin, but decreased these parameters in hydrogenated lecithin-containing and water-filled oleogels. This study provides a better understanding on how the composition of GS-based oleogels can affect their physical properties.

Structural Changes in Liposomal Vesicles in Association with Sodium Taurodeoxycholate

Liposomes composed of soy lecithin (SL) have been studied widely for drug delivery applications. The stability and elasticity of liposomal vesicles are improved by incorporating additives, including edge activators. In this study, we report the effect of sodium taurodeoxycholate (STDC, a bile salt) upon the microstructural characteristics of SL vesicles. Liposomes, prepared by the thin film hydration method, were characterized by dynamic light scattering (DLS), small-angle neutron scattering (SANS), electron microscopy, and rheological techniques. We noticed a reduction in the size of vesicles with the incremental addition of STDC. Initial changes in the size of spherical vesicles were ascribed to the edge-activating action of STDC (0.05 to 0.17 µM). At higher concentrations (0.23 to 0.27 µM), these vesicles transformed into cylindrical structures. Morphological transitions at higher STDC concentrations would have occurred due to its hydrophobic interaction with SL molecules in the bilayer. This was ascertained from nuclear magnetic resonance observations. Whereas shape transitions underscored the deformability of vesicles in the presence of STDC, the consistency of bilayer thickness ruled out any dissociative effect. It was interesting to notice that SL-STDC mixed structures could survive high thermal stress, electrolyte addition, and dilution.

Polymerized phosphonium ionic liquid functionalized silica microspheres as mixed-mode stationary phase for liquid chromatographic separation of phospholipids

There is a large and growing demand for the vigorous development of new high performance liquid chromatography stationary phases in order to solve complex phospholipids separation. Herein, phosphonium-based ionic liquid trioctyl(allyl)phosphonium bromide ([P_888Allyl]Br) was first synthesized with trioctylphosphine and allyl bromide. With [P_888Allyl]Br as the polymerizable monomer, polymerized phosphonium ionic liquid functionalized silica microsphere (PIL@SiO₂) was further synthetized via click chemistry reaction. Significantly, based on the inherent amphiphilic nature of the introduced [P_888Allyl]Br, the packed PIL@SiO₂ column displayed hydrophilic/hydrophobic mixed-mode retention mechanisms. The PIL@SiO₂ column can achieve separation of nucleic acid bases and nucleosides, sulfonamides, amides and anilines with excellent selectivity in a shorter separation time. The column efficiency reached 109,700 N/m for 2-iodoacetamide. One of the important characteristics of the PIL@SiO₂ column is that both phospholipid classes and species can be efficiently separated via the same column, outperforming that of the commercial amino column. Furthermore, the application potential of the PIL@SiO₂ column was further verified via separation of phospholipids extracted from soy lecithin. The proposed PIL@SiO₂ column provides a promising candidate for separation of complex phospholipid samples.

Liposomes: Structure, Biomedical Applications, and Stability Parameters With Emphasis on Cholesterol

Liposomes are essentially a subtype of nanoparticles comprising a hydrophobic tail and a hydrophilic head constituting a phospholipid membrane. The spherical or multilayered spherical structures of liposomes are highly rich in lipid contents with numerous criteria for their classification, including structural features, structural parameters, and size, synthesis methods, preparation, and drug loading. Despite various liposomal applications, such as drug, vaccine/gene delivery, biosensors fabrication, diagnosis, and food products applications, their use encounters many limitations due to physico-chemical instability as their stability is vigorously affected by the constituting ingredients wherein cholesterol performs a vital role in the stability of the liposomal membrane. It has well established that cholesterol exerts its impact by controlling fluidity, permeability, membrane strength, elasticity and stiffness, transition temperature (Tm), drug retention, phospholipid packing, and plasma stability. Although the undetermined optimum amount of cholesterol for preparing a stable and controlled release vehicle has been the downside, but researchers are still focused on cholesterol as a promising material for the stability of liposomes necessitating explanation for the stability promotion of liposomes. Herein, the prior art pertaining to the liposomal appliances, especially for drug delivery in cancer therapy, and their stability emphasizing the roles of cholesterol.

Novel Environmentally Friendly Waterborne Epoxy Coating with Long-Term Antiscaling and Anticorrosion Properties

Metal pipes in industrial production are exposed to various corrosive ions. The combined action of these ions with oxygen in water causes corrosion and contamination of the metal pipes and equipment. In addition, metallic ions in water react with anions to form scale on the surface of the metal, which significantly reduces the service life of the metal and equipment, resulting in safety hazards. Waterborne coatings have attracted tremendous attention due to the less negative impact on the environment, but their practical applications are severely restricted by poor barrier properties and poor mechanical durability. Herein, the barrier properties of water-based coatings are successfully improved by adding functional slow-release nanofillers, and the fillers also endow the coating with excellent antiscaling properties. A functional slow-release nanofiller (lecithin/SiO₂/HEDP) was prepared using HEDP (etidronic acid) as the scale inhibitor active material and SiO₂ as the carrier, combined with a phospholipid membrane with slow-release permeability. With the addition of slow-release fillers, compared with the EP coating, the impedance modulus of composite coatings increases about 1 order of magnitude, the scale inhibition rate is as high as 80.7%, and the antiscaling life is double that of the coating without the phospholipid-coated filler. Thus, this study is expected to provide a new perspective for the preparation of new slow-release fillers and high-efficiency scale inhibitor coatings.

Impact of Doping a Phytosteryl Sulfate on the Properties of Liposomes Made of Saturated and Unsaturated Phosphatidylcholines

The size, dispersibility, and fluidity of DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine), POPC (1-palmitoy-2-oleoyl-sn-glycero-3-phosphocholine), and DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) liposomes doped with β-sitosteryl sulfate (PSO₄) were comparatively studied. In all three types of liposomes, PSO₄ reduced sizes and enhanced the negative values of the ζ-potential. However, the effect on sizes quantitatively differed in the three cases in a manner dependent on their phase behaviors. PSO₄ rigidified each type of membrane in its liquid crystalline phase and fluidized the gel phase. It enhanced the glucose trapping efficiency (TE) of both DPPC and DOPC liposomes. The TE of DPPC first increased with the increasing concentration of PSO₄, then decreased gradually. On the other hand, in the case of DOPC, the TE increased significantly upon addition of PSO₄, then remained nearly constant. Though the exact dependence of TE on the PSO₄ concentration differed in the two cases, its effect, in each case, was more than the effect of β-sitosterol (POH). The ability of PSO₄ for reducing the size and enhancing dispersibility and TE of liposomes can be useful for preparing cosmetics and pharmaceutical formulations.