Controlling lipid nanoemulsion digestion using nanolaminated biopolymer coatings

Evaluation of a mucoadhesive auto-nanoemulsifying drug delivery system (SNEDDS) for oral insulin administration

This study investigated the potential of self-nanoemulsifying drug delivery systems (SNEDDS) to optimize the oral bioavailability of insulin. Insulin complexes with phospholipids and enzymatically-modified phospholipids were developed and incorporated into the SNEDDS using Lauroglycol FCC as the oily phase and Cremophor EL and Labrafil M1944CS as the surfactant and co-surfactant, respectively. Additionally, mucoadhesive polysaccharides (sodium alginate and guar gum) were added further to enhance the bioavailability of insulin in these systems. The objective was to increase the bioavailability and bioactivity of an insulin-modified phosphatidylcholine complex by incorporating mucoadhesives into the SNEDDS. After polymer inclusion, the resulting nanoemulsions exhibited droplet diameters ranging from 57 to 83 nm. Cytotoxicity and apparent permeability tests were conducted on Caco-2 and NIH 3 T3 cell lines, revealing that toxicity was related to the concentrations of insulin and surfactant in the nanosystems-formulations containing guar gum as a mucoadhesive showed better tolerance to cell death in the Caco-2 line. In a murine diabetes model, the SNEDDS were observed to reduce glucose levels by up to 61.63 %, with a relative bioavailability of 2.25 % compared to subcutaneously administered insulin. These results suggest that SNEDDS incorporating mucoadhesives could represent a promising strategy for improving oral insulin delivery.

Effect of gelation technique on lipid digestibility of emulsion-loaded alginate microparticles: a systematic review and meta-analysis

Alginate microparticles fabricated via calcium gelation or layer-by-layer assembly are commonly used for encapsulating emulsions. In this study, the impact of these two gelation methods on the lipid digestibility of emulsions was reviewed through a systematic screening of relevant studies. From the literature search (Scopus, PubMed, and Web of Science databases), 604 records were screened and 25 articles were included in the analysis. The fold change of free fatty acid release rate at the end of in vitro digestion process between alginate-encapsulated emulsion and emulsions not encapsulated by alginate was calculated for calcium gelation (weighted mean of response ratio 0.64, 95% CI 0.54-0.75) and layer-by-layer assembly (weighted mean of response ratio 0.89, 95% CI 0.81-0.98). Alginate-calcium hydrogels showed stronger inhibition of the extent of lipid digestion than alginate-coated multilayer emulsions. The structural and particle size differences between alginate microparticles acquired using different techniques may contribute to this phenomenon.

Enhancing the Gastrointestinal Stability of Curcumin by Using Sodium Alginate-Based Nanoemulsions Containing Natural Emulsifiers

Curcumin presents interesting biological activities but low chemical stability, so it has been incorporated into different emulsion-based systems in order to increase its bioaccessibility. Many strategies are being investigated to increase the stability of these systems. Among them, the use of polysaccharides has been seen to highly improve the emulsion stability but also to modulate their digestibility and the release of the encapsulated compounds. However, the effect of these polysaccharides on nanoemulsions depends on the presence of other components. Then, this work aimed to study the effect of alginate addition at different concentrations (0-1.5%) on the gastrointestinal fate and stability of curcumin-loaded nanoemulsions formulated using soybean lecithin or whey protein as emulsifiers. Results showed that, in the absence of polysaccharides, whey protein was more effective than lecithin in preventing curcumin degradation during digestion and its use also provided greater lipid digestibility and higher curcumin bioaccessibility. The addition of alginate, especially at ≥1%, greatly prevented curcumin degradation during digestion up to 23% and improved the stability of nanoemulsions over time. However, it reduced lipid digestibility and curcumin bioaccessibility. Our results provide relevant information on the use of alginate on different emulsifier-based nanoemulsions to act as carriers of curcumin.

Influence of fish skin gelatin-sodium alginate complex stabilized emulsion on benzyl isothiocyanate stability and digestibility in vitro and in vivo

BACKGROUND

An emulsion delivery system for benzyl isothiocyanate (BITC) was prepared using fish skin gelatin (FSG) and sodium alginate (Alg). The effects of the FSG-Alg complex on the emulsion stability and BITC release pattern from the emulsion were investigated in vitro and in vivo.

RESULTS

The storage stability and embedding rate of the 10 g kg^-1 FSG and 2.5 g kg^-1 Alg (FSG-Alg) emulsion were the highest among all samples. The FSG-Alg complex provided BITC a better protection during in vitro digestion. The microstructure of the FSG-Alg emulsions was more stable during in vitro digestion, and the bioaccessibility and retention rate of BITC were much higher compared to those of the FSG emulsion. The results of the ex vivo everted gut sac of rat intestine study showed that the FSG-Alg emulsion significantly increased the BITC absorption rate in the duodenum.

CONCLUSION

The FSG-Alg emulsion delivery system is a highly stable system for the delivery of BITC that improves the bioaccessibility of BITC and promotes its absorption in the duodenum. © 2022 Society of Chemical Industry.

Lipid oxidation and aldehyde formation during in vitro gastrointestinal digestion of roasted scallop (Patinopecten yessoensis) - the role of added antioxidant of bamboo leaves

This study investigated lipid oxidation and aldehyde formation in roasted scallop during in vitro gastrointestinal digestion, and the effects of co-digestion of antioxidant of bamboo leaves (AOB) on this process. The results showed that the contents of lipid hydroperoxides (LOOH), conjugated dienes (CD), and Schiff bases (SB) were increased during gastrointestinal digestion. Besides, malondialdehyde (MDA) levels and total aldehyde formation decreased initially at the gastric stage but increased at the intestinal stage. The results of HPLC-ESI-MS/MS analysis showed that the contents of hexanal (HEX), trans, trans-2,4-octadienal (ODE), trans, trans-2,4-decadienal (DDE), 4-hydroxyhexenal (HHE) and 4-hydroxynonenal (HNE) in the digestive juices were all initially decreased and then increased during gastrointestinal digestion. Meanwhile, the content of acrolein, propanal, and trans-2-pentenal at the end of intestinal digestion was lower than that in the initial stage of gastric digestion. Additionally, the digestion of roasted scallop caused significant oxidation of polyunsaturated fatty acids (PUFAs) and release of free fatty acids (FFA) in the intestinal phase, which were positively related to aldehyde production. However, co-digestion of AOB significantly reduced lipid oxidation and formation of lipid oxidation products (LOOH, CD, SB, and aldehyde) during gastrointestinal digestion, indicating that the addition of AOB was effective in reducing gastrointestinal lipid oxidation.

Cell surface nucleolin as active bait for nanomedicine in cancer therapy: a promising option

Conventional chemotherapy used against cancer is mostly limited due to their non-targeted nature, affecting normal tissue and causing undesirable toxic effects to the affected tissue. With the aim of improving these treatments both therapeutically and in terms of their safety, numerous studies are currently being carried out using nanoparticles (NPs) as a vector combining tumor targeting and carrying therapeutic tools. In this context, it appears that nucleolin, a molecule over-expressed on the surface of tumor cells, is an interesting therapeutic target. Several ligands, antagonists of nucleolin of various origins, such as AS1411, the F3 peptide and the multivalent pseudopeptide N6L have been developed and studied as therapeutic tools against cancer. Over the last ten years or so, numerous studies have been published demonstrating that these antagonists can be used as tumor targeting agents with NPs from various origins. Focusing on nucleolin ligands, the aim of this article is to review the literature recently published or under experimentation in our research team to evaluate the efficacy and future development of these tools as anti-tumor agents.

Improving the bioavailability of oil-soluble vitamins by optimizing food matrix effects: A review

The potency of oil-soluble vitamins (vitamins A, D, E and K) in fortified foods can be improved by understanding how food matrices impact their bioavailability. In this review, the major food matrix effects influencing the bioavailability of oil-soluble vitamins are highlighted: oil content, oil composition, particle size, interfacial properties, and food additives. Droplet size and aggregation state in the human gut impact vitamin bioavailability by modulating lipid digestion, vitamin release, and vitamin solubilization. Vitamins in small isolated oil droplets typically have a higher bioavailability than those in large or aggregated ones. Emulsifiers, stabilizers, or texture modifiers can therefore affect bioavailability by influencing droplet size or aggregation. The dimensions of the hydrophobic domains in mixed micelles depends on lipid type: if the domains are too small, vitamin bioavailability is low. Overall, this review highlights the importance of carefully designing food matrices to improve vitamin bioavailability.

Chitosan reduces vitamin D bioaccessibility in food emulsions by binding to mixed micelles

Consumption of sufficiently high quantities of dietary fibers has been linked to a range of health benefits. Recent research, however, has shown that some dietary fibers interfere with lipid digestion, which may reduce the bioavailability of oil-soluble vitamins and nutraceuticals. For this reason, we examined the impact of a cationic polysaccharide (chitosan) on the bioaccessibility of vitamin D using the standardized INFOGEST in vitro digestion model. The vitamin D was encapsulated within an emulsion-based delivery system that contained whey protein-coated corn oil droplets. Our results showed that chitosan promoted severe droplet flocculation in the small intestine and reduced the amount of free fatty acids detected using a pH-stat method. However, a back-titration of the digested sample showed that the lipids were fully digested at all chitosan levels used (0.1-0.5%), suggesting that chitosan may have bound some of the free fatty acids released during lipid digestion. The presence of the chitosan decreased the bioaccessibility of vitamin D by about 37%, but this effect did not depend strongly on chitosan concentration (0.1-0.5%). It was hypothesized that chitosan bound to the vitamin-loaded mixed micelles and promoted their precipitation. The knowledge gained in this study might provide useful insights in designing emulsion-based delivery systems with high vitamin bioaccessibility.

Improving oxidative stability and release behavior of docosahexaenoic acid algae oil by microencapsulation

BACKGROUND

Spray-dried docosahexaenoic acid algae oil (DHA AO) microcapsules were prepared using whey protein isolate and glucose syrup (WPI + GS), or sodium starch octenylsuccinate and glucose syrup (SSOS + GS), or whey protein isolate and lactose (WPI + L). The effect of the formulations on encapsulation properties, oxidative protection and in vitro oil release pattern of the resulting microencapsulates was investigated.

RESULTS

A high encapsulation efficiency of over 98% of DHA AO was obtained for microcapsules with all three wall materials. Among the wall materials, SSOS + GS exhibited a better micro-particulation ability reflected by more uniform size and smoother surface of the formed microcapsules and no agglomerates. DHA AO microcapsules with all the wall materials showed good protection of the oil from oxidation during storage with an increasing order of WPI + GS, SSOS + GS and WPI + L. Moreover, microencapsulation significantly increased the release of DHA AO in the intestinal phase of the in vitro digestion process with an increasing order of SSOS + GS, WPI + GS and WPI + L, indicating the increased stability of the oil in the highly acidic gastric environment and the enhanced lipid digestibility in the small intestine.

CONCLUSIONS

The results suggest that it is possible to transform a highly oxidizable liquid functional food ingredient such as DHA AO into a stable and easy-to-handle solid powder through spray drying with properly selected wall materials. © 2020 Society of Chemical Industry.

Designing biopolymer-coated Pickering emulsions to modulate in vitro gastric digestion: a static model study

The aim of this study was to restrict the degree of gastric destabilization of Pickering emulsions by using electrostatic deposition of a biopolymeric layer at the proteinaceous particle–laden oil–water interface.

Maillard Conjugation of Sodium Alginate to Whey Protein for Enhanced Resistance to Surfactant-Induced Competitive Displacement from Air-Water Interfaces

Whey protein adsorbed to an interface forms a viscoelastic interfacial film but is displaced competitively from the interface by a small-molecule surfactant added afterward. The present study evaluated the impact of the covalent conjugation of high- or low-molecular-weight sodium alginate (HA or LA) to whey protein isolate (WPI) via the Maillard reaction on the ability of whey protein to resist surfactant-induced competitive displacement from the air-water interface. Surfactant added after the pre-adsorption of conjugate to the interface increased surface pressure. At a given surface pressure, the WPI-LA conjugate showed a significantly higher interfacial area coverage and lower interfacial film thickness compared to those of the WPI-HA conjugate or unconjugated WPI. The addition of LA to the aqueous phase had little effect on the interfacial area and thickness of pre-adsorbed WPI. These results suggest the importance of the molecular weight of the polysaccharide moiety in determining interfacial properties of whey protein-alginate conjugates.

Ultrastable Liquid-Liquid Interface as Viable Route for Controlled Deposition of Biodegradable Polymer Nanocapsules

Liquid-liquid interfaces are highly dynamic and characterized by an elevated interfacial tension as compared to solid-liquid interfaces. Therefore, they are gaining an increasing interest as viable templates for ordered assembly of molecules and nanoparticles. However, liquid-liquid interfaces are more difficult to handle compared to solid-liquid interfaces; their intrinsic instability may affect the assembly process, especially in the case of multiple deposition. Indeed, some attempts have been made in the deposition of polymer multilayers at liquid-liquid interfaces, but with limited control over size and stability. This study reports on the preparation of an ultrastable liquid-liquid interface based on an O/W secondary miniemulsion and its possible use as a template for the self-assembly of polymeric multilayer nanocapsules. Such polymer nanocapsules are made of entirely biodegradable materials, with highly controlled size-well under 200 nm-and multi-compartment and multifunctional features enriching their field of application in drug delivery, as well as in other bionanotechnology fields.

Understanding solid-state properties of triglycerides used in pharmaceutical and food microencapsulation

Hydrophobic materials, in particular hydrogenated vegetable oils, HVO, are extensively used as coating materials in food and pharmaceutical systems. Correct application of these coatings requires an evaluation of their behaviour as a function of various parameters such as melting temperature, solubility, concentration and/or pH. The purpose of this study was to assess the physico-chemical properties of an HVO in terms of composition, crystallisation, phase transition and polymorphism using a variety of analytical techniques, such as electrospray mass spectrometry (ESI-MS), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). High-resolution ESI-MS allowed establishment of the HVO main composition of long-chain triglycerides (average molecular weight 1183 Da). DSC results showed that thermal history determines the formation of at least two polymorphs of HVO, namely two different crystal forms, assigned as form α, melting point (m.p.) 48 °C, and form β', m.p. 60 °C. A third polymorph, the more thermodynamically stable β-form, having a melting point at 62 °C, is obtained by solution-mediated re-crystallisation. Phase transformation paths were investigated by isothermal DSC experiments, which evidenced that the α-form is kinetically stable at temperatures lower than 25 °C. These data are of particular interest in practical applications such as spray freezing or pan coating where significant heat transfer phenomena are involved.

Enhanced oral absorption and therapeutic effect of acetylpuerarin based on D-α-tocopheryl polyethylene glycol 1000 succinate nanoemulsions

Background

Acetylpuerarin (AP), because of its lower water solubility, shows poor absorption that hinders its therapeutic application. Thus, the aim of this study was to prepare nanoemulsions for AP, enhance its oral bioavailability, and thus improve the therapeutic effect.

Methods

The nanoemulsions stabilized by D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were prepared by high-pressure homogenization and characterized in terms of particle size, drug loading, morphology, and in vitro drug release. A lipid digestion model was used to predict in vivo drug solubilization in the gastrointestinal environment. The pharmacokinetics of AP formulations were performed in rats; meanwhile, a chylomicron flow-blocking rat model was used to evaluate the lymphatic drug transport. Moreover, the therapeutic effects of AP nanoemulsions on the model of focal cerebral ischemia-reperfusion for brain injury were also assessed.

Results

The nanoemulsions with a droplet size of 150 nm were well stabilized by TPGS and showed a high loading capacity for AP. In the digestion model, the distribution of AP in aqueous phase/pellet phase was about 90%/10% for nanoemulsions and 5%/95% for oil solution, indicating that the drug encapsulated in nanoemulsions would present in solubilized form after transportation into the gastrointestinal tract, whereas drug precipitation would occur as the oil solution was orally administered. The area under the curve value of AP nanoemulsions was 5.76±0.56 μg·hour·mL⁻¹, or was about 2.6 and 1.7 times as great as that of suspension and oil solution, respectively, indicating enhanced drug absorption and thus achieving a better neuroprotection effect on cerebral ischemic reperfusion injury. The values of peak plasma concentration and area under the curve from the blocking model were significantly less than those of the control model, suggesting that the lymphatic transport performed a very important role in absorption enhancement.

Conclusion

Enhanced oral bioavailability in nanoemulsions was achieved via the mechanism of the maintenance of drug solubilization in the gastrointestinal tract and the enhancement of lymphatic transport, which resulted in therapeutic improvement of cerebral ischemic reperfusion injury.

Edible lipid nanoparticles: digestion, absorption, and potential toxicity

Food-grade nanoemulsions are being increasingly used in the food and beverage industry to encapsulate, protect, and deliver hydrophobic functional components, such as oil-soluble flavors, colors, preservatives, vitamins, and nutraceuticals. These nanoemulsions contain lipid nanoparticles (radius <100 nm) whose physicochemical characteristics (e.g., composition, dimensions, structure, charge, and physical state) can be controlled by selection of appropriate ingredients and fabrication techniques. Nanoemulsions have a number of potential advantages over conventional emulsions for applications within the food industry: higher stability to particle aggregation and gravitational separation; higher optical transparency; and, increased bioavailability of encapsulated components. On the other hand, there are also some risks associated with consumption of lipid nanoparticles that should be considered before they are widely utilized, such as their ability to alter the fate of bioactive components within the gastrointestinal tract and the potential toxicity of some of the components used in their fabrication (e.g., surfactants and organic solvents). This article provides an overview of the current status of the biological fate and potential toxicity of food-grade lipid nanoparticles suitable for utilization within the food and beverage industry.