Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

Ultrasound-assisted preparation of wax-based composite gelator: Structural characterisation, in vitro antioxidant activity and application in oleogels

In recent years, the development of zero-trans fatty acid products instead of traditional hydrogenated and high-unsaturated fatty acid animal and vegetable oils has been an increasing interest in the field of food. This paper focused on the ultrasound-assisted preparation of a novel wax-based composite gelator loaded with natural antioxidant to prepare oleogels with good storage oxidation stability. The preparation of the wax-based composite gelator was to first form the anthocyanin (ACNs) and soyabean lecithin (SL) complex, and then homogenized with beeswax (BW). A complex maximum association efficiency of 86.43 % was achieved when the combination was performed for 50 min at 40 °C and 270 W ultrasonic power, and exhibited higher lipophilicity. Moreover, structural analysis results revealed that ultrasonic-assisted treatment accelerated the formation of ACNs and SL ultrasonic complexes (ASUC) by the hydrogen bonding. The results of gelators indicated the ASUC-BW composite gelator showed the highest ACNs embedding rate of 72.91 % and better antioxidant activity. XRD analysis and thermogravimetric analysis demonstrated that ASUC-BW composite gelator maintained β' crystal structure and had higher thermal stability due to physical interactions between ASUC and beeswax. Accelerated storage tests at 60 °C revealed that oleogels prepared by ASUC-BW composite gelator (ALO) had significantly lower peroxide values (PV) (14.0 mmol/kg) and thiobarbituric acid reactive substances (TBARS) (1.8 mg/kg). Overall, this paper demonstrates ultrasonic-assisted treatment is an effective way to improve dispersion and availability of ANCs in food rich in oil and can be further applied to developing novel high stability fatty food systems.

Preferential localization of Escherichia coli in dairy emulsions: Influence of milk lipid droplets surface composition on bacterial adhesion

In food emulsions such as raw milk, the lipid droplets exhibit an interfacial layer possibly the site of interactions with bacteria, including the shiga toxin-producing Escherichia coli (STEC). Some pathogenic E. coli strains can adhere to intestinal cells after ingestion or to ligands that could modulate their pathogenicity such as those present at the surface of emulsion lipid droplets. The objectives of this study were to investigate the preferential localization of E. coli cells, AEEC 4315-A strain belonging to the O26:H11 serotype, as a function of the surface composition of emulsion lipid droplets i.e. milk fat globule membrane (MFGM) surrounding raw milk fat globules, milk polar lipids or whole milk proteins. The emulsions were artificially spiked with E. coli from an overnight culture in Brain Heart Infusion broth. Then, the E. coli cells were enumerated in the lipid droplet enriched creams and in the skimmed phases recovered after centrifugation. The localization of the E. coli cells in the creams was observed by confocal laser scanning microscopy (CLSM). This study revealed the role played by the surface properties of dairy lipid droplets on the adhesion of E. coli. For milk fat globules, the concentrations of E. coli in the creams were about 10 times higher than in the aqueous phase. In the processed emulsions, E. coli cells were concentrated in the aqueous phase. The CLSM images showed the adhesion of E. coli to the MFGM containing glycoproteins and their mobility as a function of time in the aqueous phase surrounding lipid droplets. This study provided additional scientific information supporting a specific affinity of E. coli for the MFGM of raw milk fat globules.

Review on novel targeted enzyme drug delivery systems: enzymosomes

The goal of this review is to present enzymosomes as an innovative means for site-specific drug delivery. Enzymosomes make use of an enzyme's special characteristics, such as its capacity to accelerate the reaction rate and bind to a particular substrate at a regulated rate. Enzymosomes are created when an enzyme forms a covalent linkage with a liposome or lipid vesicle surface. To construct enzymosomes with specialized activities, enzymes are linked using acylation, direct conjugation, physical adsorption, and encapsulation techniques. By reducing the negative side effects of earlier treatment techniques and exhibiting efficient medication release, these cutting-edge drug delivery systems improve long-term sickness treatments. They could be a good substitute for antiplatelet medication, gout treatment, and other traditional medicines. Recently developed supramolecular vesicular delivery systems called enzymosomes have the potential to improve drug targeting, physicochemical characteristics, and ultimately bioavailability in the pharmaceutical industry. Enzymosomes have advantages over narrow-therapeutic index pharmaceuticals as focusing on their site of action enhances both their pharmacodynamic and pharmacokinetic profiles. Additionally, it reduces changes in normal enzymatic activity, which enhances the half-life of an enzyme and accomplishes enzyme activity on specific locations.

Differential effects of the lipidic and ionic microenvironment on NPP1's phosphohydrolase and phosphodiesterase activities

Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) is an enzyme present in matrix vesicles (MV). NPP1 participates on the regulation of bone formation by producing pyrophosphate (PPi) from adenosine triphosphate (ATP). Here, we have used liposomes bearing dipalmitoylphosphatidylcholine (DPPC), sphingomyelin (SM), and cholesterol (Chol) harboring NPP1 to mimic the composition of MV lipid rafts to investigate ionic and lipidic influence on NPP1 activity and mineral propagation. Atomic force microscopy (AFM) revealed that DPPC-liposomes had spherical and smooth surface. The presence of SM and Chol elicited rough and smooth surface, respectively. NPP1 insertion produced protrusions in all the liposome surface. Maximum phosphodiesterase activity emerged at 0.082 M ionic strength, whereas maximum phosphomonohydrolase activity arose at low ionic strength. Phosphoserine-Calcium Phosphate Complex (PS-CPLX) and amorphous calcium-phosphate (ACP) induced mineral propagation in DPPC- and DPPC:SM-liposomes and in DPPC:Chol-liposomes, respectively. Mineral characterization revealed the presence of bands assigned to HAp in the mineral propagated by NPP1 harbored in DPPC-liposomes without nucleators or in DPPC:Chol-liposomes with ACP nucleators. These data show that studying how the ionic and lipidic environment affects NPP1 properties is important, especially for HAp obtained under controlled conditions in vitro.

Lipid-based nanoparticles as drug delivery systems for cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have shown remarkable success in cancer treatment. However, in cancer patients without sufficient antitumor immunity, numerous data indicate that blocking the negative signals elicited by immune checkpoints is ineffective. Drugs that stimulate immune activation-related pathways are emerging as another route for improving immunotherapy. In addition, the development of nanotechnology presents a promising platform for tissue and cell type-specific delivery and improved uptake of immunomodulatory agents, ultimately leading to enhanced cancer immunotherapy and reduced side effects. In this review, we summarize and discuss the latest developments in nanoparticles (NPs) for cancer immuno-oncology therapy with a focus on lipid-based NPs (lipid-NPs), including the characteristics and advantages of various types. Using the agonists targeting stimulation of the interferon genes (STING) transmembrane protein as an exemplar, we review the potential of various lipid-NPs to augment STING agonist therapy. Furthermore, we present recent findings and underlying mechanisms on how STING pathway activation fosters antitumor immunity and regulates the tumor microenvironment and provide a summary of the distinct STING agonists in preclinical studies and clinical trials. Ultimately, we conduct a critical assessment of the obstacles and future directions in the utilization of lipid-NPs to enhance cancer immunotherapy.