On-Chip Precisely Controlled Preparation of Uniform Core-Shell Salmon Byproduct Protein/Polysaccharide Microcapsules for Enhancing Probiotic Survivability in Fruit Juice

The increasing demand for probiotic-fortified fruit juices stems from the dietary requirements of individuals with dairy allergies, lactose intolerance, and vegetarian diets. However, a notable obstacle arises from the degradation of probiotics in fruit juices due to their low pH levels and harsh gastrointestinal conditions. In response, this study proposes an innovative approach utilizing a microfluidic chip to create core-shell microcapsules that contain Lactobacillus plantarum Lp90. This method, based on internal-external gelation, forms highly uniform microcapsules that fully enclose the core, which consists of oil-in-water Pickering emulsions stabilized by salmon byproduct protein and sodium alginate. These emulsions remain stable for up to 72 h at a 1% sodium alginate concentration. The shell layer incorporates kelp nanocellulose and sodium alginate, thus improving the thermal properties. Furthermore, compared to free probiotics, the multilayer structure of the core-shell microcapsules provides a robust barrier, resulting in significantly enhanced probiotic stability. These findings introduce a novel strategy for augmenting probiotic delivery in functional fruit juice beverages, promising solutions to the challenges encountered during their development.

Lego-Inspired Glass Capillary Microfluidic Device: A Technique for Bespoke Microencapsulation of Phase Change Materials

We report a Lego-inspired glass capillary microfluidic device capable of encapsulating both organic and aqueous phase change materials (PCMs) with high reproducibility and 100% PCM yield. Oil-in-oil-in-water (O/O/W) and water-in-oil-in-water (W/O/W) core-shell double emulsion droplets were formed to encapsulate hexadecane (HD, an organic PCM) and salt hydrate SP21EK (an aqueous PCM) in a UV-curable polymeric shell, Norland Optical Adhesive (NOA). The double emulsions were consolidated through on-the-fly polymerization, which followed thiol-ene click chemistry for photoinitiation. The particle diameters and shell thicknesses of the microcapsules were controlled by manipulating the geometry of glass capillaries and fluid flow rates. The microcapsules were monodispersed and exhibited the highest encapsulation efficiencies of 65.4 and 44.3% for HD and SP21EK-based materials, respectively, as determined using differential scanning calorimetry (DSC). The thermogravimetric (TGA) analysis confirmed much higher thermal stability of both encapsulated PCMs compared to pure PCMs. Polarization microscopy revealed that microcapsules could sustain over 100 melting-crystallization cycles without any structural changes. Bifunctional microcapsules with remarkable photocatalytic activity along with thermal energy storage performance were produced after the addition of 1 wt % titanium dioxide (TiO₂) nanoparticles (NPs) into the polymeric shell. The presence of TiO₂ NPs in the shell was confirmed by higher opacity and whiteness of these microcapsules and was quantified by energy dispersive X-ray (EDX) spectroscopy. Young's modulus of HD-based microcapsules estimated using micromanipulation analysis increased from 58.5 to 224 MPa after TiO₂ incorporation in the shell.

All-Aqueous Electrosprayed Emulsion for Templated Fabrication of Cytocompatible Microcapsules

Encapsulation of biomolecules and cells in hydrogel capsules via emulsion templating frequently induces an irreversible loss of bioactivity, because of the use of nonaqueous solvents. Here, we introduce an all-aqueous electrospray (AAE) approach to generate aqueous two-phase emulsion droplets, and we use them as templates to fabricate microcapsules with preserved cell viability. The approach allows formation of monodisperse microparticles with tunable sizes, variable compositions, and interior architectures in a mild gelation process. This technique potentially benefits a variety of new biomedical applications, such as delivery of bioactive proteins, transplantation of living cells, and assembly of cell-mimicking structures.