Incorporation of aromas in nanostructured monolinolein-based miniemulsions: A structural investigation

Small-angle X-ray and neutron scattering applied to lipid-based nanoparticles: Recent advancements across different length scales

Lipid-based nanoparticles (LNPs), ranging from nanovesicles to non-lamellar assemblies, have gained significant attention in recent years, as versatile carriers for delivering drugs, vaccines, and nutrients. Small-angle scattering methods, employing X-rays (SAXS) or neutrons (SANS), represent unique tools to unveil structure, dynamics, and interactions of such particles on different length scales, spanning from the nano to the molecular scale. This review explores the state-of-the-art on scattering methods applied to unveil the structure of lipid-based nanoparticles and their interactions with drugs and bioactive molecules, to inform their rational design and formulation for medical applications. We will focus on complementary information accessible with X-rays or neutrons, ranging from insights on the structure and colloidal processes at a nanoscale level (SAXS) to details on the lipid organization and molecular interactions of LNPs (SANS). In addition, we will review new opportunities offered by Time-resolved (TR)-SAXS and -SANS for the investigation of dynamic processes involving LNPs. These span from real-time monitoring of LNPs structural evolution in response to endogenous or external stimuli (TR-SANS), to the investigation of the kinetics of lipid diffusion and exchange upon interaction with biomolecules (TR-SANS). Finally, we will spotlight novel combinations of SAXS and SANS with complementary on-line techniques, recently enabled at Large Scale Facilities for X-rays and neutrons. This emerging technology enables synchronized multi-method investigation, offering exciting opportunities for the simultaneous characterization of the structure and chemical or mechanical properties of LNPs.

Inverse ISAsomes in Bio-Compatible Oils—Exploring Formulations in Squalane, Triolein and Olive Oil

In contrast to their more common counterparts in aqueous solutions, inverse ISAsomes (internally self-assembled somes/particles) are formulated as kinetically stabilised dispersions of hydrophilic, lyotropic liquid-crystalline (LC) phases in non-polar oils. This contribution reports on their formation in bio-compatible oils. We found that it is possible to create inverse hexosomes, inverse micellar cubosomes (Fd3m) and an inverse emulsified microemulsion (EME) in excess squalane with a polyethylene glycol alkyl ether as the primary surfactant forming the LC phase and to stabilise them with hydrophobised silica nanoparticles. Furthermore, an emulsified -phase and inverse hexosomes were formed in excess triolein with the triblock-copolymer Pluronic® P94 as the primary surfactant. Stabilisation was achieved with a molecular stabiliser of type polyethylene glycol (PEG)-dipolyhydroxystearate. For the inverse hexosomes in triolein, the possibility of a formulation without any additional stabiliser was explored. It was found that a sufficiently strong stabilisation effect was created by the primary surfactant alone. Finally, triolein was replaced with olive oil which also led to the successful formation of inverse hexosomes. As far as we know, there exists no previous contribution about inverse ISAsomes in complex oils such as triolein or plant oils, and the existence of stabiliser-free (i.e., self-stabilising) inverse hexosomes has also not been reported until now.

Cubosomes and Hexosomes as Novel Nanocarriers for Bioactive Compounds

Cubosomes and hexosomes are nanostructured liquid crystalline particles, known as biocompatible nanocarriers for drug delivery. In recent years, there has been good interest in using cubosomes and hexosomes for the delivery of bioactive compounds in functional foods. These systems feature thermodynamic stability, encapsulate both hydrophobic and hydrophilic substances, and have a high tolerance to environmental stresses and potential for controlled release. This review outlines the recent advances in cubosomes and hexosomes in the food industry, focusing on their structure, composition, formation mechanisms, and factors influencing phase transformation between cubosomes and hexosomes. The potential applications especially for the bioactive delivery are presented. The integration of cubosomes and hexosomes with other emerging encapsulation technologies such as surface coating, gelation, and incorporation of polymers are also discussed.

Citrem–phosphatidylcholine nano-self-assemblies: solubilization of bupivacaine and its role in triggering a colloidal transition from vesicles to cubosomes and hexosomes

In concentration- and lipid composition-dependent manners, bupivacaine triggers lamellar–nonlamellar phase transitions in citrem/soy phosphatidylcholine nanodispersions.

Influence of γ-Lactones on Monolinolein/Water Bulk and Emulsified Mesophases

The emulsification of two flavor compounds of the γ-lactone type with monolinolein liquid crystalline submicron particles is reported. The stabilization is ensured by the copolymer F127. γ-Nonalactone can be loaded in bicontinuous cubic monolinolein particles at a larger level (up to 20 wt %) than γ-decalactone (less than 15 wt %). The phase behavior of the ternary monolinolein/water/γ-nonalactone system was studied. The large γ-nonalactone content solubilized into cubosomes was corroborated by the observation of a wide cubic V₂ range in the ternary phase diagram. Surprisingly, no inverted hexagonal phase was found in the system. On the contrary, the incorporation of γ-decalactone in the lipid particles gave rise to a dispersion of inverted hexagonal phase, which corresponds to a classical behavior of an oily additive. We finally determined the internal phase of particles including 10 wt % of γ-nonalactone upon increasing the F127 content. We thus found that γ-nonalactone restricts very significantly the interaction of the emulsifier with the cubosomes' interior.