Influence of the particle size of encapsulated chia oil on the oil release and bioaccessibility during in vitro gastrointestinal digestion

Bioaccessibility of chlorogenic acid and curcumin co-encapsulated in double emulsions with the inner interface stabilized by functionalized silica nanoparticles

The aim of this study was to evaluate the bioaccessibility of chlorogenic acid (CA) and curcumin co-encapsulated in Pickering double emulsions (DEs) with the inner interface stabilized by hydrophobically modified silica nanoparticles with myristic acid (SNPs-C14) or tocopherol succinate (SNPs-TS). Both SNPs-C14 and SNPs-TS showed contact angles > 90°. Pickering W1/O emulsions were formulated with 4 % of both types of SNPs. Pickering DEs showed higher creaming stability (5-7 %, day 42) and higher CA encapsulation efficiency (EE; 80 %) than control DE. The EE of curcumin was > 98 % in all the DEs. CA was steadily released from Pickering DEs during digestion, achieving bioaccessibility values of 58-60 %. Curcumin was released during the intestinal phase (∼80 % bioaccessibility in all DEs). Co-loaded DEs showed similar bioaccessibility for CA and curcumin than single-loaded. SNPs-C14 and SNPs-TS were suitable to stabilize the W1:O interface of DEs as co-delivery systems of bioactive compounds with health-promoting properties.

Bioaccessibility, Intestinal Absorption and Anti-Inflammatory Activity of Curcuminoids Incorporated in Avocado, Sunflower, and Linseed Beeswax Oleogels

Beeswax oleogels (OGs), with a mechanical strength similar to pork backfat, were formulated with avocado (A), sunflower (S), and linseed (L) oils, applying a central composite design plus star point, and were evaluated as oral delivery vehicles of curcuminoids (OGACur, OGSCur, OGLCur). The incorporation of curcumin into the OG matrix significantly delayed both the formation of peroxides and conjugated trienes (K268 values), and the degradation rate of curcumin decreased with the increase of the oil polyunsaturated fatty acids (PUFA) content. The oil structuring did not affect the bioaccessibility of curcuminoids (>55% in all the OGs, regardless of the oil type), but it did reduce the release of fatty acids (~10%) during in vitro gastrointestinal digestion. The intestinal absorption, evaluated in Caco-2 cell monolayers, was higher for the micelle-solubilized curcumin from the digested OG than from unstructured oils, and it showed high anti-inflammatory potential by inhibiting the tumor necrosis factor-α (TNF-α) production compared to the positive control, both before and after the stimulation of ThP-1 cells with LPS. Regardless of the oil type, these beeswax-based OGs with gel-like behavior designed as fat replacers may be promising vehicles for the oral delivery of curcuminoids.

Design and advanced characterization of quercetin-loaded nano-liposomes prepared by high-pressure homogenization

Quercetin-loaded nano-liposomes were prepared by high-pressure homogenization (HPH) at different pressures (up to 150 MPa) and number of passes (up to 3) to define the best processing conditions allowing the lowest particle size and the highest encapsulation efficiency (EE). The process at 150 MPa for 1 pass was the best, producing quercetin-loaded liposomes with the lowest particle size and 42% EE. Advanced techniques (multi-detector asymmetrical-flow field flow fractionation and analytical ultracentrifugation combined with transmission electron microscopy) were further used for the characterization of the liposomes which were oblong in shape (ca. 30 nm). Results highlight the need for several techniques to study nano-sized, polydisperse samples. The potential of quercetin-loaded liposomes against colon cancer cells was demonstrated. Results prove that HPH is an efficient and sustainable method for liposome preparation and highlight the remarkable role of process optimisation as well as the powerfulness of advanced methodologies for the characterisation of nano-structures.

The presence of propylene glycol alginate increased the stability and intestine-targeted delivery potential of carboxymethyl starch-stabilized emulsions

Propylene glycol alginate (PGA) was added to improve the stability and delivery performance of carboxymethyl starch (CMS)-stabilized emulsion. In the first instance, the CMS/PGA complexes were characterized, which proved that the formation of CMS/PGA complexes mainly depended on hydrogen bonding, and the CMS/PGA complexes showed porous networks. The CMS/PGA complexes were more hydrophobic than CMS, and the interaction of CMS with PGA enhanced the thermal stability of CMS. Next, the effects of CMS/PGA complexes on the properties of emulsions were investigated, and the intestine-targeted delivery potential of emulsions was evaluated through the in vitro release study as well. The droplet size of CMS/PGA complex-stabilized emulsions gradually decreased and the encapsulation efficiency (EE) improved with increasing the PGA content in CMS/PGA complexes. The addition of PGA also greatly improved the physical stability of emulsions, including anti-flocculation and anti-coalescence stabilities. All emulsions exhibited non-Newtonian pseudoplastic properties. Furthermore, the emulsions stabilized by CMS/PGA complexes showed reduced curcumin (Cur) release in the simulated gastric fluid (SGF), whereas exhibited sustained release in the α-amylase-containing simulated intestinal fluid (SIF). These results demonstrated that the emulsion stabilized by CMS/PGA complex was able to control and modulate the release of Cur in the gastrointestinal tract, and was therefore a promising intestine-targeted delivery system for Cur.