Quantifying Phase Behaviour in Model Food Composites Using 3D Confocal Laser Scanning Microscopy

There is an increasing demand for the design of complex bio-composites with customized structural characteristics for use in processed food products. Phase behaviour of these mixtures determines textural properties, encouraging the pursue of a rapid technique that can accurately quantify it. The present work tests the efficacy of confocal laser scanning microscopy (CLSM) coupled with image analysis software (Imaris), for the quantification of phase behaviour in complex tertiary systems. In doing so, it develops phase separated gels of agarose and gelatin supporting inclusions of canola oil. The polysaccharide was replaced with whey protein isolate (WPI) and the topology of the tertiary dispersion with gelatin and canola oil was also examined. Reproducible phase volume estimates were obtained, including those of the lipid phase, which were a close match to the actual concentrations added to the hydrocolloid gel. The approach could offer an alternative to the rheological estimation, via theoretical blending law analysis, of phase volumes in bio-composites. Graphical Abstract

The Influence of Fed State Lipolysis Inhibition on the Intraluminal Behaviour and Absorption of Fenofibrate from a Lipid-Based Formulation

The bioavailability of lipophilic drugs may or may not be increased when administered with food due to increased solubilisation in fed state gastrointestinal (GI) fluids. The in vivo interplay between drug solubilisation, lipid phase digestion and drug absorption is complex and remains poorly understood. This study aimed to investigate the role of fed state GI lipolysis on the intraluminal behaviour and absorption of fenofibrate, formulated as the lipid-based formulation Fenogal. Therefore, a crossover study was performed in healthy volunteers using orlistat as lipase inhibitor. Fenofibrate concentrations were determined in the proximal jejunum and linked to simultaneously assessed systemic fenofibric acid concentrations. Inhibition of lipolysis by orlistat resulted in a faster onset of absorption in 4 out of 6 volunteers, reflected by a decrease in systemic Tmax between 20 and 140 min. In addition, the increase of undigested lipids present in the small intestine upon orlistat co-administration sustained drug solubilisation for a longer period, resulting in higher fenofibrate concentrations in the jejunum and improved absorption in 5 out of 6 volunteers (median AUC0–8h 8377 vs. 5832 μM.min). Sustaining drug solubilisation in the lipid phase may thus contribute to the absorption of lipophilic drugs. More research into the different mechanisms underlying lipophilic drug absorption from fed state media at different levels of digestion is warranted.

Solvent-Free Fabrication of Biphasic Lipid-Based Microparticles with Tunable Structure

Lipid-based biphasic microparticles are generally produced by long and complex techniques based on double emulsions. In this study, spray congealing was used as a solvent-free fabrication method with improved processability to transform water-in-oil non-aqueous emulsions into spherical solid lipid-based particles with a biphasic structure (b-MPs). Emulsions were prepared by melt emulsification using different compositions of lipids (Dynasan®118 and Compritol®888 ATO), surfactants (Cetylstearyl alcohol and Span®60) and hydrophilic carriers (PEGs, Gelucire®48/16 and Poloxamer 188). First, pseudo-ternary phase diagrams were constructed to identify the area corresponding to each emulsion type (coarse emulsion or microemulsion). The hydrophobicity of the lipid mostly affected the interfacial tension, and thus the microstructure of the emulsion. Emulsions were then processed by spray congealing and the obtained b-MPs were characterized in terms of thermal and chemical properties (by DSC and FT-IR), external and internal morphology (by SEM, CLSM and Raman mapping). Solid free-flowing spherical particles (main size range 200–355 µm) with different architectures were successfully produced: microemulsions led to the formation of particles with a homogeneous internal structure, while coarse emulsions generated “multicores-shell” particles consisting of variable size hydrophilic cores evenly distributed within the crystalline lipid phase. Depending on their composition and structure, b-MPs could achieve various release profiles, representing a more versatile system than microparticles based on a single lipid phase. The formulation and technological strategy proposed, provides a feasible and cost-effective way of fabricating b-MPs with tunable internal structure and release behavior.

Essential-Oil-Loaded Nanoemulsion Lipidic-Phase Optimization and Modeling by Response Surface Methodology (RSM): Enhancement of Their Antimicrobial Potential and Bioavailability in Nanoscale Food Delivery System

Nanoencapsulation is an attractive technique used for incorporating essential oils in foods. Thus, our main goal was to formulate a novel nanoemulsion (NE) with nanoscale droplet size and lowest interfacial tension in the oil–water interface, contributing positively to the stability and the enhancement of essential oil potential. Thereby, response surface methodology (RSM), with mixture design was used to optimize the composition of the NE lipid phase. The essential oil combinations were encapsulated through high-pressure homogenization (HPH) with the binary emulsifier system (Tween 80: Gum Arabic). Then, the electrophoretic and physical properties were evaluated. We also conducted a follow-up stability and antimicrobial study that examined the stabilization mechanism of optimal NE. Thereafter, the effect of nanoencapsulation on the essential oil composition was assessed. The RSM results were best fitted into polynomial models with regression coefficient values of more than 0.95. The optimal NE showed a nanometer-sized droplet (270 nm) and lower interfacial tension (~11 mN/m), favoring negative ζ-potential (−15 mV), showing good stability under different conditions—it synergistically enhances the antimicrobial potential. GC-MS analysis showed that the use of HPH affected the active compounds, consistent with the differences in linalool and 2-Caren-10-al content. Hence, the novel nanometric delivery system contributes to food industry fortification.

A unified model for the biogenesis of mitochondrial outer membrane multi-span proteins

The mitochondrial outer membrane (MOM) harbors proteins that traverse the membrane via several helical segments, so-called multi-span proteins. Two contradicting mechanisms were suggested to describe their integration into the MOM. The first proposes that the mitochondrial import (MIM) complex facilitates this process and functions as an insertase, whereas the second suggests that such proteins can integrate into the lipid phase without the assistance of import factors in a process that is enhanced by phosphatidic acid. To resolve this discrepancy and obtain new insights on the biogenesis of these proteins, we addressed this issue using yeast mitochondria and the multi-span protein Om14. Testing different truncation variants, we show that only the full-length protein contains all the required information that assure targeting specificity. Employing a specific insertion assay and several single and double deletion strains, we show that neither the import receptor Tom70 nor any other protein with a cytosolically exposed domain have a crucial contribution to the biogenesis process. We further demonstrate that Mim1 and Porin are required for optimal membrane integration of Om14 but none of them is absolutely required. Unfolding of the newly synthesized protein, its optimal hydrophobicity, as well as higher fluidity of the membrane dramatically enhanced the import capacity of Om14. Collectively, our findings suggest that MOM multi-span proteins can follow different biogenesis pathways in which proteinaceous elements and membrane behavior contribute to a variable extent to the combined efficiency.

Design and Evaluation of Efavirenz Loaded Solid Lipid Nanoparticle for Boosting Oral Bioavailability

Present work illustrates that efavirenz-loaded solid lipid nanoparticles were prepared with the objective of increasing bioavailability and protection of drugs due to biocompatible lipidic content. Efavirenz is generally used for the treatment of HIV. Selection of the suitable lipid phase, surfactant, and cosurfactant was done by individual screening method with the construction of pseudo-ternary phase study. The formulations were prepared by the microemulsion method followed by the lyophilization technique. EFV-SLN has shown a mean particle size of 55.73 ± 3.9 nm having a PDI of 0.153 ± 0.451. Zeta potential was found to be -9.98mV and the formulation was found stable. In vivo pharmaco-kinetic studies exhibited 5.41-fold enhancement in peak plasma concentration (

Diallyl Trisulfide, the Antifungal Component of Garlic Essential Oil and the Bioactivity of Its Nanoemulsions Formed by Spontaneous Emulsification

The aim of this study was to evaluate the chemical compounds of garlic essential oil (EO), and determine the antifungal efficacy of garlic EO and its major components, diallyl trisulfide and its nanoemulsions against wood-rotting fungi, Trametes hirsuta and Laetiporus sulphureus. GC-MS analysis revealed that the major constituents of garlic EO were diallyl trisulfide (39.79%), diallyl disulfide (32.91%), and diallyl sulfide (7.02%). In antifungal activity, the IC50 value of garlic EO against T. hirsuta and L. sulphureus were 137.3 and 44.6 μg/mL, respectively. Results from the antifungal tests demonstrated that the three major constituents were shown to have good antifungal activity, in which, diallyl trisulfide was the most effective against T. hirsuta and L. sulphureus, with the IC50 values of 56.1 and 31.6 μg/mL, respectively. The diallyl trisulfide nanoemulsions showed high antifungal efficacy against the examined wood-rotting fungi, and as the amount of diallyl trisulfide in the lipid phase increases, the antifungal efficacy of the nanoemulsions increases. These results showed that the nanoemulsions and normal emulsion of diallyl trisulfide have potential to develop into a natural wood preservative.