Nanoscale Nutrient Delivery Systems for Food Applications: Improving Bioactive Dispersibility, Stability, and Bioavailability

Zein Beta-Cyclodextrin Micropowders for Iron Bisglycinate Delivery

Given the limited number of materials available to design delivery platforms for nutrients, the rational combination of raw materials already approved as food ingredients and their processing through nano-micro technology can offer a unique tool for innovation. Here, we propose a nano-in-micro strategy to produce powders based on the hydrophobic protein zein, useful for the oral delivery of a hydrophilic iron source (iron bisglycinate) in anaemic patients. Iron-loaded powders were prepared through a two-step strategy consisting in the formation of a zein pseudolatex followed by a spray-drying step. To extend the manipulation space for zein and entrap iron bisglycinate, β-cyclodextrin (βCD) was selected as helping excipient. Addition of βCD allowed iron loading in the pseudolatex and greatly increased product yields after the drying process as compared to zein alone. Iron-loaded micro-sized powders were characterised by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to elucidate the role of βCD as a compatibilizer for the zein-iron system. Remarkably, micropowders released only 20% of FeBIS in a simulated gastric fluid, whereas release in a simulated intestinal fluid was almost completed in 7 h. In summary, βCD association to zein is a novel strategy to expand applications in the oral delivery of iron bisglycinate and, prospectively, to micronutrient chelates.

Impact of curcumin delivery system format on bioaccessibility: nanocrystals, nanoemulsion droplets, and natural oil bodies

Curcumin, a hydrophobic yellow-orange crystalline substance derived from plants, is claimed to exhibit a broad range of biological activities. Its application in functional foods and beverages is often limited by its low solubility in aqueous media, chemical instability, and low bioavailability. Previously, we have shown that curcumin can be successfully loaded into emulsions using the pH-shift method. In this study, we compared the efficacy of curcumin crystals dispersed in water (control) with three delivery systems produced using the pH-shift method: curcumin nanocrystals; curcumin-loaded nanoemulsions; and curcumin-loaded soy oil bodies. The nanoemulsions and oil bodies formed creamy yellow dispersions that were stable to creaming, whereas the nanocrystals formed a cloudy yellow-orange suspension that was prone to sedimentation. The gastrointestinal fate of the delivery systems was assessed using a static in vitro digestion model consisting of mouth, stomach, and small intestine phases. The nanoemulsions and oil bodies were rapidly and fully digested, while the nanocrystals were not. All three systems were relatively stable to chemical transformation in the in vitro digestion model. The nanocrystals gave a low bioaccessibility but the other two systems gave a high bioaccessibility, which was attributed to their ability to form mixed micelles to solubilize the curcumin. These results have important implications for the creation of more effective delivery systems for curcumin.

The role of the intestinal-protein corona on the mucodiffusion behaviour of new nanoemulsions stabilised by ascorbyl derivatives

Nanoemulsions are vesicular systems with great potential for the delivery of drugs, which significantly depends on the appropriate selection of the components that constitute them. In this sense, the use of materials with adequate toxicity profiles for the oral route provides additional advantages in terms of safety concerns avoidance. This work describes the formulation of novel two-component nanoemulsions constituted by α-tocopherol and ascorbyl-palmitate derivatives. Among them, ascorbyl-dipalmitate allowed the formation of nanoemulsions with size values around 170 nm and negative charge; additionally, they showed strong antioxidant capacity. These nanoemulsions are proposed to the oral route, so their behaviour in intestinal conditions was evaluated by incubating the nanoemulsion in simulated intestinal fluid. This process led to the formation of an intestinal-protein corona (I-PC) at the colloidal surface that determined the interaction with the mucus barrier. The I-PC displaced the immobile-hindered particles towards a subdiffusive-diffusive population. These studies report for the first time the effect of the I-PC on the mucodiffusion behaviour of vesicular systems, a finding that may help to comprehend the performance of nanocarriers under intestinal conditions.

A heat-stable microparticle platform for oral micronutrient delivery

Micronutrient deficiencies affect up to 2 billion people and are the leading cause of cognitive and physical disorders in the developing world. Food fortification is effective in treating micronutrient deficiencies; however, its global implementation has been limited by technical challenges in maintaining micronutrient stability during cooking and storage. We hypothesized that polymer-based encapsulation could address this and facilitate micronutrient absorption. We identified poly(butylmethacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methylmethacrylate) (1:2:1) (BMC) as a material with proven safety, offering stability in boiling water, rapid dissolution in gastric acid, and the ability to encapsulate distinct micronutrients. We encapsulated 11 micronutrients (iron; iodine; zinc; and vitamins A, B2, niacin, biotin, folic acid, B12, C, and D) and co-encapsulated up to 4 micronutrients. Encapsulation improved micronutrient stability against heat, light, moisture, and oxidation. Rodent studies confirmed rapid micronutrient release in the stomach and intestinal absorption. Bioavailability of iron from microparticles, compared to free iron, was lower in an initial human study. An organotypic human intestinal model revealed that increased iron loading and decreased polymer content would improve absorption. Using process development approaches capable of kilogram-scale synthesis, we increased iron loading more than 30-fold. Scaled batches tested in a follow-up human study exhibited up to 89% relative iron bioavailability compared to free iron. Collectively, these studies describe a broad approach for clinical translation of a heat-stable ingestible micronutrient delivery platform with the potential to improve micronutrient deficiency in the developing world. These approaches could potentially be applied toward clinical translation of other materials, such as natural polymers, for encapsulation and oral delivery of micronutrients.

Impact of Site-Specific Bioconjugation on the Interfacial Activity of a Protein Biosurfactant

Biosurfactants are surface active molecules that can be produced by renewable, industrially scalable biologic processes. DAMP4, a designer biosurfactant, enables the modification of interfaces via genetic or chemical fusion to functional moieties. However, bioconjugation of addressable amines introduces heterogeneity that limits the precision of functionalization as well as the resolution of interfacial characterization. Here, we designed DAMP4 variants with cysteine point mutations to allow for site-specific bioconjugation. The DAMP4 variants were shown to retain the structural stability and interfacial activity characteristic of the parent molecule, while permitting efficient and specific conjugation of polyethylene glycol (PEG). PEGylation results in a considerable reduction on the interfacial activity of both single and double mutants. Comparison of conjugates with one or two conjugation sites shows that both the number of conjugates as well as the mass of conjugated material impact the interfacial activity of DAMP4. As a result, the ability of DAMP4 variants with multiple PEG conjugates to impart colloidal stability on peptide-stabilized emulsions is reduced. We suggest that this is due to steric constraints on the structures of amphiphilic helices at the interface. Specific and efficient bioconjugation permits the exploration and investigation of the interfacial properties of designer protein biosurfactants with molecular precision. Our findings should therefore inform the design and modification of biosurfactants for their increasing use in industrial processes and nutritional and pharmaceutical formulations.

Development of microemulsion of tamsulosin and dutasteride for benign prostatic hyperplasia therapy

Benign prostatic hyperplasia (BPH) is a condition characterized by a benign enlargement of the prostate that interferes with the normal flow of urine. This disease is treated with the oral administration of combination therapy comprising α-blockers (tamsulosin) and 5α-reductase inhibitors (dutasteride). However, these compounds have low bioavailability. Thus, transdermal microemulsions aimed at promoting permeation and efficient targeted drug delivery through the skin are used. The objectives of this study were to obtain microemulsions of the combined doses of dutasteride and tamsulosin and evaluate their anti-hyperplastic activity in vivo. A phase diagram (4:1) was obtained for the choice of microemulsions. The microemulsions were characterized in terms of the droplet size, rheology, pH, conductivity, refractive index, in vitro release profile, and antihyperplastic effect in vivo. A method for the simultaneous quantification of drugs was developed using UV-vis spectroscopy. The microemulsions had an average size less than 116 nm, an acidic pH and low viscosity. The conductivity ranged from 6.18 to 185.2 μS/cm. The in vitro release profile was sustained for 6 h. Microemulsions promoted the reduction in the size of testosterone-dependent organs (prostate and seminal vesicles). Transdermal formulations for the treatment of BPH were obtained as a therapeutic alternative to conventional treatments.

Characterization of the behavior of carotenoids from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) during microemulsion production and in a dynamic gastrointestinal system

Uncommon tropical fruits are emerging as raw-material for new food products with health benefits. This work aimed at formulating and processing microemulsions from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) fruits, since they are very rich in carotenoids (particularly lycopene and β-carotene), in order to encapsulate and increase carotenoids' bioaccessibility. Pitanga and buriti microemulsions were produced by applying a direct processing (high-speed homogenization at 15,000 rpm and ultrasound with 20 kHz probe at 40% amplitude) of the whole pulp together with surfactant (Tween 80 or Whey Protein Isolate at 2%) and corn oil (5%). All treatments (HSH-US for 0-4, 4-0, 4-4, 4-8 min-min) applied were able to increase the amount of carotenoid released. However, the processing also decreased the total amount of carotenoids in the whole pulp of studied fruits. The impact of processing during microemulsion production was not severe. The overall data suggest that the presence of surfactant and oil during processing may protect the carotenoids in fruits and microemulsions. Final recovery of total carotenoids, after passing the samples through a dynamic gastrointestinal system that simulates the human digestion, was higher for microemulsions than for whole pulps. High losses of total carotenoids in buriti and β-carotene and lycopene in pitanga occurred during jejunum and ileum phases. The present work confirms that it is possible to increase β-carotene and lycopene bioaccessibility from fruits by directly processing microemulsions (p < 0.01).

Improving the Physical and Oxidative Stability of Emulsions Using Mixed Emulsifiers: Casein-Octenyl Succinic Anhydride Modified Starch Combinations

This study aims to investigate the influence of casein and octenyl succinic anhydride modified starch (OSAS) combinations on the physical and oxidative stability of fish oil-in-water emulsions. The interaction between casein and OSAS was manifested in changes in protein structure and hydrogen-bonding interaction. Casein-OSAS combinations could effectively inhibit droplet aggregation at pH 4 and attenuate droplet growth at a high CaCl2 concentration of 0.2 mol/L, compared with casein as an emulsifier. Nanoemulsions stabilized by casein-OSAS combinations or casein showed better oxidative stability compared with OSAS-stabilized emulsions. Therefore, casein-OSAS combinations can improve some physical properties of protein-based emulsions and oxidative stability of modified starch-based emulsions, suggesting protein-modified starch combinations are more promising in the emulsion-based food industry compared to each of the two emulsifiers alone.

Nano-encapsulation of curcumin using soy protein hydrolysates - tannic acid complexes regulated by photocatalysis: a study on the storage stability and in vitro release

Purpose: To evaluate the feasibility of soy protein hydrolysates (SPH)-tannic acid (TA) complex nanoparticle obtained by photocatalysis (SPH-T (P)) to construct curcumin (Cur) delivery vehicles. Methods: The interaction behaviour of SPH-T (P) was investigated using Fourier transform infra-red, X-ray diffraction and differential scanning calorimeter analyzes. Formation and stability of the complexes were characterised by particle size, morphology, zeta potential, and in vitro release. Results: Negatively charged Cur-loaded complex with small size (<100 nm), spherical cluster shape and uniform size distribution were formed through the driving force of electrostatic attraction, followed by hydrogen bonding. The presence of photocatalysis in the complexes significantly improved the storage stability and in vitro sustained release of curcumin by enhancing the hydrogen bonding, hydrophobic effects and π-π stacking interactions between SPH and TA. Conclusion: SPH-T (P) would be a useful and promising delivery vehicle for encapsulating, protecting, and delivering hydrophobic nutraceuticals.

Core-Shell Nanoencapsulation of α-Tocopherol by Blending Sodium Oleate and Rebaudioside A: Preparation, Characterization, and Antioxidant Activity

Nanoencapsulation of α-tocopherol (α-TOC) by blending sodium oleate (NaOl) and rebaudioside A (RebA) was successfully prepared by self-assembly method under mild conditions. The optimized nanoemulsion showed the loading capacity of α-TOC was 30 wt% of sodium oleate. FTIR analysis suggested that hydrogen bonds and hydrophobic interactions were the major forces in α-TOC-NaOl/RebA complexes that were spherical and possessed well-distinguishable core-shell structures. The freeze-dried α-TOC-NaOl/RebA complexes had great stability under ambient conditions. The release profile of α-TOC showed a first-order kinetics reaching around 67.9% after 90 h at 25 °C. Nanoencapsulation improved dispersibility and greatly increased the antioxidant activity of α-TOC. Therefore, the stable α-TOC-NaOl/RebA core-shell complexes prepared from “generally recognized as safe” (GRAS) ingredients have great potential to supplement α-TOC in food and cosmetic products.

Soy genistein administered in soluble chitosan microcapsules maintains antioxidant activity and limits intestinal inflammation

We used water-soluble Chitosan obtained by Maillard reaction with glucosamine to microencapsulate soy genistein (Ge) and preserve its biological activity for oral administration. Release of Ge was pH dependent with a super Case II mechanism at pH 1.2 and an anomalous transport with non-Fickian kinetics at pH 6.8. Microencapsulated Ge retained its antioxidant properties in vitro and its daily administration to mice attenuated clinical signs of acute colitis, limited inflammatory reaction and reduced oxidative stress and tissue injury as well. Remarkably, after feeding microencapsulated Ge the production of IL-10 in colonic tissue was restored to levels of untreated controls. According to statistical multivariate analysis, this cytokine was the parameter with the highest influence on the inflammatory/oxidative status. Microencapsulation of Ge with derivatized Chitosan becomes an interesting alternative to develop therapeutic approaches for oxidative inflammatory diseases; our findings suggest that the soy isoflavone could be incorporated into any functional food for application in intestinal inflammation.

Enhanced Oral Bioavailability of Chlormadinone Acetate through a Self-Microemulsifying Drug Delivery System for a Potential Dose Reduction

Chlormadinone acetate (CMA) is a derivative of the naturally secreted hormone progesterone and exhibits reliable contraceptive and non-contraceptive benefits. Although the marketed product of CMA as oral tablets under the trade name Belara® has been highly successful, there is still room for further improvements in oral bioavailability and a reduction in the clinical dose to decrease related adverse effects. In the current study, a CMA-based self-microemulsifying drug delivery system (SMEDDS) was developed using 32% ethyl oleate as an oil phase, 40% Tween-80 as a surfactant, and 12% Transcutol P combined with 16% PEG400 as a cosurfactant, resulting in spherical droplets with a z-average particle size of 38.92 nm and an average zeta potential of - 3.18 mv. The in vitro release rate of CMA from CMA-SMEDDS in different media (distilled water, HCl solution at pH 1.2, phosphate buffers at pH 4.5 and pH 6.8) was significantly faster than that from Belara® in the first 15 min. A pharmacokinetic study in rats showed that the C_max and AUC of CMA-SMEDDS were significantly higher (P < 0.01) than those of Belara®, with a 1.98-fold increase in oral bioavailability. In comparison with Belara®, the developed CMA-SMEDDS showed promising release profiles both in vitro and in vivo, which could potentially be useful in enhancing oral bioavailability and reducing the clinical dose of CMA.

An Overview of Nanotechnology in Food Science: Preparative Methods, Practical Applications, and Safety

As the researches to utilize nanotechnology in food science are advanced, applications of nanotechnology in various fields of the food industry have increased. Nanotechnology can be applied to the food industry for production, processing, storage, and quality control of foods. Nanomaterials, unlike conventional microscale materials, having novel characteristics can improve sensory quality of foods by imparting novel texture, color, and appearance. Nanotechnology has been used to design nanosensors for detection of harmful components in foods and a smart packaging system enabling to recognize food contamination very rapidly and sensitively. Nanoencapsulation is the most significant technology in food science, especially for bioactive compounds and flavors. Targeted delivery systems designed with nanoencapsulation can enhance bioavailability of bioactive compounds after oral administration. In addition, nanoencapsulation enables to control the release of flavors at the desired time and to protect the degradation of flavors during processing and storage. In this review, current applications of nanotechnology in food science including flavor control, enhancement of bioavailability of bioactive compounds, and detection of deleterious substances in foods are presented. Furthermore, this article overviews classification, preparative methods, and safety issues of nanomaterials for food science. This review will be of help to provide comprehensive information for newcomers utilizing nanotechnology to the food sector.

Neuroprotective Natural Molecules, From Food to Brain

The prevalence of neurodegenerative disorders is increasing; however, an effective neuroprotective treatment is still remaining. Nutrition plays an important role in neuroprotection as recently shown by epidemiological and biochemical studies which identified food components as promising therapeutic agents. Neuroprotection includes mechanisms such as activation of specific receptors, changes in enzymatic neuronal activity, and synthesis and secretion of different bioactive molecules. All these mechanisms are focused on preventing neuronal damage and alleviating the consequences of massive cell loss. Some neuropathological disorders selectively affect to particular neuronal populations, thus is important to know their neurochemical and anatomical properties in order to design effective therapies. Although the design of such treatments would be specific to neuronal groups sensible to damage, the effect would have an impact in the whole nervous system. The difficult overcoming of the blood brain barrier has hampered the development of efficient therapies for prevention or protection. This structure is a physical, enzymatic, and influx barrier that efficiently protects the brain from exogenous molecules. Therefore, the development of new strategies, like nanocarriers, that help to promote the access of neuroprotective molecules to the brain, is needed for providing more effective therapies for the disorders of the central nervous system (CNS). In order both to trace the success of these nanoplatforms on the release of the bioactive cargo in the CNS and determinate the concentration at trace levels of targets biomolecules by analytical chemistry and concretely separation instrumental techniques, constitute an essential tool. Currently, these techniques are used for the determination and identification of natural neuroprotective molecules in complex matrixes at different concentration levels. Separation techniques such as chromatography and capillary electrophoresis (CE), using optical and/or mass spectrometry (MS) detectors, provide multiples combinations for the quantitative and qualitative analysis at basal levels or higher concentrations of bioactive analytes in biological samples. Bearing this in mind, the development of food neuroprotective molecules as brain therapeutic agents is a complex task that requires the intimate collaboration and engagement of different disciplines for a successful outcome. In this sense, this work reviews the new advances achieved in the area toward a better understanding of the current state of the art and highlights promising approaches for brain neuroprotection.

In vitro intestinal epithelium responses to titanium dioxide nanoparticles

Titanium dioxide (TiO₂) is enclosed in many consumer products including pharmaceuticals, cosmetics, and foods. TiO₂ (E171) is daily ingested as mixed nano- and submicron-sized particles since it is approved as a white colorant in Europe in a wide variety of food products, Noteworthy, the relevant risk assessment has never been satisfactorily concluded and growing alarms for human hazards deriving from TiO₂ exposure are incrementally reported. The objective of the present study was to establish conceivable mechanisms by which nano-sized TiO₂ particles affect physiological function of the intestinal epithelium layer. The well-established Caco-2 cell line differentiated for 21 days on permeable supports was used as a predictive model of the human intestinal mucosa to identify the biological response triggered by TiO₂ particles. Exposure to 42 μg/mL TiO₂ nanoparticles disrupted the tight junctions-permeability barrier with a prompt effect detectable after 4 h incubation time and wide effects on barrier integrity at 24 h. Transport and ultrastructural localization of TiO₂ nanoparticles were determined by ICP-OES, TEM and ESI/EELS analysis, respectively. Nano-sized particles were efficiently internalized and preferentially entrapped by Caco-2 monolayers. Storage of TiO₂ nanoparticles inside the cells affected enterocytes viability and triggered the production of pro-inflammatory cytokines, including TNF-α and IL-8. Taken together these data indicate that nano-sized TiO₂ particles exert detrimental effects on the intestinal epithelium layer.

Nanoemulsions in drug delivery: formulation to medical application

Nanoscale oil-in-water emulsions (NEs), heterogeneous systems of two immiscible liquids stabilized by emulsifiers or surfactants, show great potential in medical applications because of their attractive characteristics for drug delivery. NEs have been explored as therapeutic carriers for hydrophobic compounds via various routes of administration. NEs provide opportunities to improve drug delivery via alternative administration routes. However, deep understanding of the NE manufacturing and functionalization fundamentals, and how they relate to the choice of administration route and pharmacological profile is still needed to ease the clinical translation of NEs. Here, we review the diversity of medical applications for NEs and how that governs their formulation, route of administration, and the emergence of increasing sophistication in NE design for specific application.

The effect of sterol derivatives on properties of soybean and egg yolk lecithin liposomes: Stability, structure and membrane characteristics

The effects of three kinds of sterols (cholesterol, β-sitosterol and ergosterol) on the stability, microstructure and membrane properties of soybean and egg yolk lecithin liposomes were investigated by light scattering, transmission electron microscope (TEM), atomic force microscope (AFM), fluorescence and Fourier transform infrared spectroscopy (FTIR). The vesicle size of cholesterol or β-sitosterol incorporated liposomes was higher than that of the control and ergosterol incorporated ones, while the zeta-potential was similar when the same lecithin was used. Due to the excellent emulsifying capacity, Tween-80 was introduced into the system and which could obviously maintain the liposomal vesicle size in fetal bovine serum. According to TEM and AFM, the phenomena of membrane fusion and deformation were observed respectively in ergosterol-incorporated liposomes. Results of fluorescence probe spectra revealed the most compact membrane structure was found in cholesterol-incorporated liposomes, which was in accordance with the strongest intermolecular interaction in bilayers obtained by FTIR results. Conversely, the membrane of ergosterol-incorporated liposomes was the most fragile and fluid, which was also identified with the lowest physical stability obtained by Turbiscan. These results systematically illustrated the relationship between the structure of sterols and the liposomal membrane stability, and provided some meaningful information on the choice of sterols and lecithin in preparation of liposomes for different purposes.

Protein-Based Delivery Systems for the Nanoencapsulation of Food Ingredients

Many proteins possess functional attributes that make them suitable for the encapsulation of bioactive agents, such as nutraceuticals and pharmaceuticals. This article reviews the state of the art of protein-based nanoencapsulation approaches. The physicochemical principles underlying the major techniques for the fabrication of nanoparticles, nanogels, and nanofibers from animal, botanical, and recombinant proteins are described. Protein modification approaches that can be used to extend their functionality in these nanocarrier systems are also described, including chemical, physical, and enzymatic treatments. The encapsulation, retention, protection, and release of bioactive agents in different protein-based nanocarriers are discussed. Finally, some of the major challenges in the design and fabrication of protein-based delivery systems are highlighted.

In vitro digestion models suitable for foods: Opportunities for new fields of application and challenges

In vitro digestion assays simulate the physiological conditions of digestion in vivo and are useful tools for studying and understanding changes, interactions, as well as the bioaccessibility of nutrients, drugs and non-nutritive compounds. The technique is widely used in fields such as nutrition, pharmacology and food chemistry. Over the last 40 years, more than 2500 research articles have been published using in vitro digestion assays (85% of which have been published in the last two decades) to elucidate multiple aspects such as protein digestibility, nutrient interactions or the viability of encapsulated microorganisms. The most recent trend in the use of this technique involves the determination of the antioxidant activity of bioactive compounds after digestion. However, the inability to reproduce certain in vivo digestion events, as well as the multiple models of in vitro digestion, point to a need to optimize and validate the method with in vivo assays to determine its limitations and uses. The purpose of this paper is to provide an overview of the current state of the art of in vitro digestion models through an analysis of how they have evolved in terms of the development of digestion models (parameters, protocols, guidance) and taking into consideration the boom in new fields of application.

In Vitro Bioavailability, Cellular Antioxidant Activity, and Cytotoxicity of β-Carotene-Loaded Emulsions Stabilized by Catechin-Egg White Protein Conjugates

Previously, it was shown that catechin-egg white protein (CT-EWP) conjugates were effective antioxidant emulsifiers that could form and stabilize emulsions, and also inhibit the degradation of encapsulated carotenoids. The objective of the current study was to evaluate the impact of conjugation on the in vitro bioavailability, cellular antioxidant activity, and cytotoxicity of β-carotene-loaded emulsions. Lipid droplets coated with EWP or with CT-EWP conjugates exhibited quite similar behavior when they were passed through a simulated gastrointestinal tract. The β-carotene encapsulated in emulsions stabilized by CT-EWP conjugates exhibited a higher overall in vitro bioavailability, which was attributed to a greater stability of the carotenoids to chemical transformation. The emulsions stabilized by CT-EWP conjugates also exhibited greater ability in inhibiting oxidation in a cell-based assay (dichlorofluorescein diacetate). Cytotoxicity analysis suggested that β-carotene emulsions stabilized by CT-EWP conjugates only exhibited a slight cytotoxicity when used at high concentrations. These results suggest that CT-EWP conjugates can be used to formulate emulsion-based delivery systems for chemically labile hydrophobic bioactives with enhanced antioxidant activity and bioavailability.

Interfacial Antioxidants: A Review of Natural and Synthetic Emulsifiers and Coemulsifiers That Can Inhibit Lipid Oxidation

There has been strong interest in developing effective strategies to inhibit lipid oxidation in emulsified food products due to the need to incorporate oxidatively labile bioactive lipids, such as ω-3 fatty acids, conjugated linoleic acids, or carotenoids. Emulsifiers or coemulsifiers can be utilized to inhibit lipid oxidation in emulsions. Both of these molecular types can adsorb to droplet surfaces and inhibit lipid oxidation, but emulsifiers can also stabilize droplets against aggregation whereas coemulsifiers cannot. There are a host of existing emulsifiers, covalent conjugates, or physical complexes that have the potential to inhibit lipid oxidation by a variety of mechanisms. Existing emulsifiers with antioxidant potential consist of surfactants, phospholipids, proteins, polysaccharides, and colloidal particles. Conjugates and complexes are typically formed by covalently or physically linking together a surface-active molecule with an antioxidant molecule. This article reviews the molecular and physicochemical basis for the surface and antioxidant activities of emulsifiers and coemulsifiers, highlights the important properties of interfacial layers that can be engineered to control lipid oxidation, and outlines different kinds of existing emulsifiers, conjugates, and complexes that can be used to inhibit oxidation.

Applications of nanoparticle systems in drug delivery technology

The development of nanoparticle-based drug formulations has yielded the opportunities to address and treat challenging diseases. Nanoparticles vary in size but are generally ranging from 100 to 500 nm. Through the manipulation of size, surface characteristics and material used, the nanoparticles can be developed into smart systems, encasing therapeutic and imaging agents as well as bearing stealth property. Further, these systems can deliver drug to specific tissues and provide controlled release therapy. This targeted and sustained drug delivery decreases the drug related toxicity and increase patient's compliance with less frequent dosing. Nanotechnology has proven beneficial in the treatment of cancer, AIDS and many other disease, also providing advancement in diagnostic testing.

Interaction of cruciferin-based nanoparticles with Caco-2 cells and Caco-2/HT29-MTX co-cultures

The objective of this work was to assess the potential of Cruciferin/Calcium (Cru/Ca) and Cruciferin/Chitosan (Cru/Cs) nanoparticles for oral drug delivery. For this purpose, Cru/Ca and Cru/Cs nanoparticles were developed through cold gelation of Cruciferin, a major canola protein, and in interaction with calcium and chitosan, respectively. The extent and rate of particle uptake in Caco-2 cells and Caco-2/HT29 co-culture was then evaluated by fluorescence spectroscopy as well as flow cytometry. Through pre-incubation of Caco-2 cell monolayer with specific endocytosis inhibitors, the mechanism of cell uptake was investigated. Our results showed that the uptake of negatively-charged Cru/Ca particles to be ∼3 times higher than positively-charged Cru/Cs ones by Caco-2 cells. Presence of mucus secreted by HT29 cells in their co-culture with Caco-2 had negligible influence on the uptake and transport of both particles. In contrast to Cru/Ca particles which were dissociated in the simulated gastrointestinal conditions, digestion of Cru/Cs particles resulted in 6- and 2-fold increase in the cellular uptake and transport of encapsulated coumarin in the latter particles, respectively. While the presence of mucus in Caco-2/HT29 co-culture caused 40-50% decrease of cellular uptake and transport for coumarin encapsulated in digested Cru/Cs particles, it had no significant effect on the cell uptake and transport of coumarin associated with Cru/Ca particles after digestion. Energy-dependent mechanisms were the dominant mechanism for uptake of both undigested and digested particles. Therefore, in Caco-2/HT29 co-culture which closely simulated intestinal epithelial cells, undigested Cru/Ca and Cru/Cs particles had the ability to penetrate mucus layers, while digested Cru/Cs particles showed mucoadhesive property, and digested Cru/Ca particles were dissociated. Our results points to a potential for cruciferin based nanoparticles for oral drug delivery.

STATEMENT OF SIGNIFICANCE

The long-term objective of this research is to investigate the potential of edible and safe biopolymer in enhanced oral delivery of drugs and/or vaccines. Here, we investigated the potential application of nanoparticles based on a protein extracted from Canola seeds, i.e., cruciferin, for oral delivery of a model small molecule, i.e., coumarin, through cells representing gastrointestinal epithelium, Caco-2 and Caco-2/HT29 cell monolayer. This study was completed for intact cruciferin nanoparticles and cruciferin coated chitosan nanoparticles, before and after digestion with gastric or intestine simulating fluids. This comparison was useful to understand the fate the cruciferin based particles in digestive mucosal tissues and their potential mucoadhesive and/or mucus-penetrating property.

Interfacial rheological properties of self-assembling biopolymer microcapsules

Tuning the mechanical properties of microcapsules through a cost-efficient route of fabrication is still a challenge. The traditional method of layer-by-layer assembly of microcapsules allows building a tailored composite multi-layer membrane but is technically complex as it requires numerous steps. The objective of this article is to characterize the interfacial rheological properties of self-assembling biopolymer microcapsules that were obtained in one single facile step. This thorough study provides new insights into the mechanics of these weakly cohesive membranes. Firstly, suspensions of water-in-oil microcapsules were formed in microfluidic junctions by self-assembly of two oppositely charged polyelectrolytes, namely chitosan (water soluble) and phosphatidic fatty acid (oil soluble). In this way, composite membranes of tunable thickness (between 40 and 900 nm measured by AFM) were formed at water/oil interfaces in a single step by changing the composition. Secondly, microcapsules were mechanically characterized by stretching them up to break-up in an extensional flow chamber which extends the relevance and convenience of the hydrodynamic method to weakly cohesive membranes. Finally, we show that the design of microcapsules can be 'engineered' in an extensive way since they present a wealth of interfacial rheological properties in terms of elasticity, plasticity and yield stress whose magnitudes can be controlled by the composition. These behaviors are explained by the variation of the membrane thickness with the physico-chemical parameters of the process.

Morphology and Structural Properties of Novel Short Linear Glucan/Protein Hybrid Nanoparticles and Their Influence on the Rheological Properties of Starch Gel

Starch nanoparticles were potential texture modifiers. However, they have strong tendency to aggregate and poor water dispersibility, which limited their application. The interaction between glucan (prepared from starch by enzymatic modification) and protein could significantly improve the dispersity of starch nanoparticles and, thus, enhance the rheological properties of food gels. In this work, glucan/protein hybrid nanoparticles were successfully developed for the first time using short linear glucan (SLG) and edible proteins [soy protein isolate (SPI), rice protein (RP), and whey protein isolate (WPI)]. The results showed that the SLG/SPI hybrid nanoparticles exhibited hollow structures, of which the smallest size was approximately 10-20 nm when the SLG/SPI ratio was 10:5. In contrast, SLG/RP nanoparticles displayed flower-like superstructures, and SLG/WPI nanoparticles presented stacked lamellar nanostructures with a width of 5-10 nm and a length of 50-70 nm. In comparison to bare SLG nanoparticles, SLG/SPI and SLG/WPI hybrid nanoparticles had higher melting temperatures. The addition of all nanoparticles greatly increased the storage modulus of corn starch gels and decreased loss tangent values. Importantly, the G' value of starch gels increased by 567% with the addition of flower-like SLG/RP superstructures.

Modulation of Lipid Digestion Profiles Using Filled Egg White Protein Microgels

Colloidal delivery systems are required to encapsulate, protect, and release active food ingredients, such as vitamins, nutraceuticals, and minerals. In this study, lipid droplets were encapsulated within biopolymer microgels fabricated from egg white proteins using an injection-gelation process. Confocal fluorescence microscopy indicated that lipid droplets were dispersed within a network of cross-linked proteins within the microgels. The properties of the lipid-loaded microgels were compared to those of simple oil-in-water emulsions stabilized by egg white proteins. Light scattering and microscopy measurements indicated that both delivery systems exhibited good stability under acid conditions (pH 3-5) but aggregated at higher pH values as a result of a reduction in electrostatic repulsion. Simulated gastrointestinal tract studies indicated that lipid droplets encapsulated within protein microgels were digested more slowly than free lipid droplets. Our results therefore suggest that egg white protein microgels may be useful for encapsulation and controlled release of hydrophobic bioactive agents.