Fabrication, characterization, physicochemical stability of zein-chitosan nanocomplex for co-encapsulating curcumin and resveratrol

Oxidized Chitin Nanocrystals Greatly Strengthen the Stability of Resveratrol-Loaded Gliadin Nanoparticles

Resveratrol (RES) is a natural polyphenol with a variety of health beneficial properties, but its application is greatly limited due to low aqueous solubility and poor bioavailability. This study aims to address these issues via gliadin nanoparticles stabilized with oxidized chitin nanocrystals (O-ChNCs) as a delivery system for RES. RES-loaded gliadin nanoparticles (GRNPs) were fabricated by an antisolvent method, and their formation mechanism was elucidated using zeta-potential, FTIR, XRD, and TEM. Furthermore, the effect of O-ChNCs on the colloidal stability and bioactiveness of GRNPs was discussed. The results demonstrate that O-ChNCs are adsorbed onto the surface of GRNPs through hydrogen bonding and electrostatic interactions, leading to the enhanced absolute potential and the improved hydrophobicity of the particles, which in turn facilitates the stability of the GRNPs. Furthermore, the changes in the release profile and antioxidant activity of RES in the simulated gastric and intestinal tracts indicate that the adsorption of O-ChNCs not only delays the release of RES but also has a protective effect on the antioxidant capacity of RES. This study provides significant implications for developing stable gliadin nanoparticles as delivery vehicles for bioactive substances.

Encapsulation of Bioactive Compounds for Food and Agricultural Applications

This review presents an updated scenario of findings and evolutions of encapsulation of bioactive compounds for food and agricultural applications. Many polymers have been reported as encapsulated agents, such as sodium alginate, gum Arabic, chitosan, cellulose and carboxymethylcellulose, pectin, Shellac, xanthan gum, zein, pullulan, maltodextrin, whey protein, galactomannan, modified starch, polycaprolactone, and sodium caseinate. The main encapsulation methods investigated in the study include both physical and chemical ones, such as freeze-drying, spray-drying, extrusion, coacervation, complexation, and supercritical anti-solvent drying. Consequently, in the food area, bioactive peptides, vitamins, essential oils, caffeine, plant extracts, fatty acids, flavonoids, carotenoids, and terpenes are the main compounds encapsulated. In the agricultural area, essential oils, lipids, phytotoxins, medicines, vaccines, hemoglobin, and microbial metabolites are the main compounds encapsulated. Most scientific investigations have one or more objectives, such as to improve the stability of formulated systems, increase the release time, retain and protect active properties, reduce lipid oxidation, maintain organoleptic properties, and present bioactivities even in extreme thermal, radiation, and pH conditions. Considering the increasing worldwide interest for biomolecules in modern and sustainable agriculture, encapsulation can be efficient for the formulation of biofungicides, biopesticides, bioherbicides, and biofertilizers. With this review, it is inferred that the current scenario indicates evolutions in the production methods by increasing the scales and the techno-economic feasibilities. The Technology Readiness Level (TRL) for most of the encapsulation methods is going beyond TRL 6, in which the knowledge gathered allows for having a functional prototype or a representative model of the encapsulation technologies presented in this review.

Zein-based nano-delivery systems for encapsulation and protection of hydrophobic bioactives: A review

Zein is a kind of excellent carrier materials to construct nano-sized delivery systems for hydrophobic bioactives, owing to its unique interfacial behavior, such as self-assembly and packing into nanoparticles. In this article, the chemical basis and preparation methods of zein nanoparticles are firstly reviewed, including chemical crosslinking, emulsification/solvent evaporation, antisolvent, pH-driven method, etc., as well as the pros and cons of different preparation methods. Various strategies to improve their physicochemical properties are then summarized. Lastly, the encapsulation and protection effects of zein-based nano-sized delivery systems (e.g., nanoparticles, nanofibers, nanomicelles and nanogels) are discussed, using curcumin as a model bioactive ingredient. This review will provide guidance for the in-depth development of hydrophobic bioactives formulations and improve the application value of zein in the food industry.

Polysaccharide-based nano-delivery systems for encapsulation, delivery, and pH-responsive release of bioactive ingredients

Polysaccharides are natural polymers isolated from plants, microorganisms, algae, and some animals they are composed of aldoses or ketoses linked by glycosidic bonds. Due to the affordability, abundance, safety, and functionality, polysaccharides are widely used in the foods and medicines to construct oral delivery systems for sensitive bioactive ingredients. In this article, the characteristics and applications of nanoscale polysaccharide-based delivery carriers are reviewed, including their ability to encapsulate, protect, and deliver bioactive ingredients. This review discusses the sources, characteristics, and functional properties of common food polysaccharides, including starch, pectin, chitosan, xanthan gum, and alginate. It also highlights the potential advantages of using polysaccharides for the construction of nano-delivery systems, such as nanoparticles, nanogels, nanoemulsions, nanocapsules, and nanofibers. Moreover, the application of delivery systems assembled from polysaccharides is summarized, with a focus on pH-responsive delivery of bioactives. There are some key findings and conclusions: Nanoscale polysaccharide delivery systems provide several advantages, including improved water-dispersibility, flavor masking, stability enhancement, reduced volatility, and controlled release; Polysaccharide nanocarriers can be used to construct pH-responsive delivery vehicles to achieve intestinal-targeted delivery and controlled release of bioactive ingredients; Polysaccharides can be used in combination with other biopolymers to form composite delivery systems with enhanced functional attributes.

Chitosan: Sources, Processing and Modification Techniques

Chitosan, a copolymer of glucosamine and N-acetyl glucosamine, is derived from chitin. Chitin is found in cell walls of crustaceans, fungi, insects and in some algae, microorganisms, and some invertebrate animals. Chitosan is emerging as a very important raw material for the synthesis of a wide range of products used for food, medical, pharmaceutical, health care, agriculture, industry, and environmental pollution protection. This review, in line with the focus of this special issue, provides the reader with (1) an overview on different sources of chitin, (2) advances in techniques used to extract chitin and converting it into chitosan, (3) the importance of the inherent characteristics of the chitosan from different sources that makes them suitable for specific applications and, finally, (4) briefly summarizes ways of tailoring chitosan for specific applications. The review also presents the influence of the degree of acetylation (DA) and degree of deacetylation (DDA), molecular weight (M_w) on the physicochemical and biological properties of chitosan, acid-base behavior, biodegradability, solubility, reactivity, among many other properties that determine processability and suitability for specific applications. This is intended to help guide researchers select the right chitosan raw material for their specific applications.

Loadings of lycopene in emulsion and sodium alginate-K-carrageenan composite systems: Preparation, characterization, bioaccessibility, and kinetics

This research aims to prepare capsules emulsion using gallic acid (GA), dextran (DEX), bovine serum albumin (BSA), sodium alginate, and K-carrageenan (K-Car) as the biological delivery system of lycopene. The stability and bioaccessibility of lycopene were further improved through encapsulation of covalent complex of sodium alginate and K-Car. The molecular weight distribution and secondary structure of the conjugates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR). The storage stability of the emulsion stabilized by conjugates was measured with Turbiscan stability index (TSI) and fluctuation of the particle size. The TSI value of ternary conjugates was 18.7 (37℃) with particle sizes ranging from 208 to 319 nm. Then, the changes of three-dimensional reticulate structures and physical properties of sodium alginate-K were analyzed by scanning electron microscopy (SEM) and TPA. The thermal stability of the sodium alginate-K-Car composite systems was increased compared with sodium alginate. The bioaccessibility of lycopene was significantly improved under the dual embedding of BSA-DEX-GA conjugate emulsion and sodium alginate-K-Car composite systems.

Fabrication and characterization of octenyl succinic anhydride modified pullulan micelles for encapsulating curcumin

BACKGROUND

Curcumin has become increasingly popular in functional foods and beverages field as a result of its high biological activity. Nevertheless, the application of curcumin is usually limited by its poor water solubility, low absorption, rapid metabolism and instability. Accordingly, the development of an appropriate wall material is crucial for its effective use. In the present study, curcumin-octenyl succinic anhydride modified pullulan (Cur-OSAP) micelles were successfully prepared by an anti-solvent co-precipitation method.

RESULTS

Octenyl succinic anhydride modified pullulan (OSAP) micelles exhibited the highest encapsulation efficiency (57.31%) and loading capacity (5.73%) of curcumin when the mass ratio of OSAP to curcumin was 10:1 and the degree of substitution of OSAP was 0.0469, at which point Cur-OSAP micelles formed via hydrogen binding and hydrophobic interactions, as confirmed by Fourier transform infrared and fluorescence techniques. The transmission electron microscopy results showed that the Cur-OSAP micelles were roughly spherical in shape with diameters in the approximate range 30-60 nm.

CONCLUSION

The encapsulation of OSAP greatly improved photostability and sustained release properties of curcumin in Cur-OSAP micelles. These findings suggest that OSAP can be used as a carrier to encapsulate and protect hydrophobic food ingredients. © 2021 Society of Chemical Industry.

Single-Step Self-Assembly of Zein–Honey–Chitosan Nanoparticles for Hydrophilic Drug Incorporation by Flash Nanoprecipitation

Zein- and chitosan-based nanoparticles have been described as promising carrier systems for food, biomedical and pharmaceutical applications. However, the manufacture of size-controlled zein and chitosan particles is challenging. In this study, an adapted anti-solvent nanoprecipitation method was developed. The effects of the concentration of zein and chitosan and the pH of the collection solution on the properties of the zein–honey–chitosan nanoparticles were investigated. Flash nanoprecipitation was demonstrated as a rapid, scalable, single-step method to achieve the self-assembly of zein–honey–chitosan nanoparticles. The nanoparticles size was tuned by varying certain formulation parameters, including the total concentration and ratio of the polymers. The zein–honey–chitosan nanoparticles’ hydrodynamic diameter was below 200 nm and the particles were stable for 30 days. Vitamin C was used as a hydrophilic model substance and efficiently encapsulated into these nanoparticles. This study opens a promising pathway for one-step producing zein–honey–chitosan nanoparticles by flash nanoprecipitation for hydrophilic compounds’ encapsulation.

Fabrication, characterization and in vitro cell exposure study of zein-chitosan nanoparticles for co-delivery of curcumin and berberine

For the first time, we synthesized the co-delivery nanopolymers using zein protein as the core and chitosan polysaccharide as the shell to deliver curcumin (Cur) and berberine (Ber) in MDA-MB-231 breast cancer cells. It has been shown that Cur and Ber altogether have synergistic effects on multiple cancers. Herein, the curcumin-zein-berberine-chitosan (Cur-Z-Ber-Ch) nanoparticles were fabricated and their organization procedure was reported. Physicochemical properties of synthesized nanoparticles were determined by Fourier transform infrared (FTIR) spectroscopy, XRD and fluorescence spectroscopy analyses. The nanoparticles included relatively small particles (d = 168.24 nm) with +36.76 mV zeta potential. The resulting nanoparticles had high entrapment efficiency (about 75%) for Cur and 60% for Ber. The Cur-Z-Ber-Ch nanoparticles represented ideal redispersibility and storage stability after 4 months. Drug release of the freeze-dried nanoparticles had pH-sensitive characteristic. In vitro cytoxicity assay demonstrated that Cur-Z-Ber-Ch nanoparticles induced elevated cytotoxic effect in MDA-MB-231 and A549 cancer cells. In vitro studies in MDA-MB-231 cells demonstrated that the Cur-Z-Ber-Ch nanoparticles could successfully increase cellular uptake and apoptosis with significant inhibition of IL-8 pro-inflammatory cytokines in comparison to the free Cur + Ber bioactive molecules. These bio-nanoparticles are the co-delivery vehicle for Cur and Ber which could be beneficial for participating them into pharmaceutical products.

Chitosan/zein films incorporated with essential oil nanoparticles and nanoemulsions: Similarities and differences

The purpose of this study was to prepare chitosan/zein (CS/Zein) edible films reinforced with Mosla chinensis essential oils (EOs) nanoemulsions (NEs) and nanoparticles (NPs) in order to compare their properties. NEs and NPs containing EOs could be used to fabricate films with functional properties, and the films were prepared using a casting method. The influence of EO concentration and mixing methods on the physical, mechanical, and functional properties of the films was investigated. The results indicated that the films formulated with EO NEs generated favorable fundamental and functional characteristics with excellent mechanical properties, moisture barrier capacity, and significant antioxidant and antibacterial activity. In addition, the use of NEs-based films improved the release of bioactive compounds, and the mechanism of EO release was found to follow a first order model. In summary, EO NEs were more effective in preserving the fundamental and functional properties of CS/Zein nanocomposite edible films than NP-based films. These differences may reflect different forms and methods of dispersing EOs in NEs and NPs. This study demonstrated that NEs reinforced films could be used to enhance the effectiveness of EOs in food products and develop new strategies for their delivery and application.

Delivery of Curcumin Using Zein-Gum Arabic-Tannic Acid Composite Particles: Fabrication, Characterization, and in vitro Release Properties

The application of curcumin (Cur) in fat-free food is limited due to its poor water solubility, stability, and bioaccessibility. In this study, zein-gum arabic-tannic acid (zein-GA-TA) composite particles with high physical stability were fabricated to deliver Cur (ZGT-Cur). Their stability and in vitro release properties were also evaluated. The results showed that the thermal and photochemical stability of Cur was improved after loading into composite particles. Meanwhile, the retention rate of Cur in ZGT-Cur composite particles was enhanced compared with Z-Cur or ZG-Cur particles. Fourier transform infrared (FTIR) spectroscopy confirmed that the hydrogen bond within the particles was greatly enhanced after the addition of tannic acid (TA). The in vitro antioxidant activity of Cur in ZGT-Cur composite particles was higher in terms of 2,2'-azino-bis (ABTS) (93.64%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) (50.41%) compared with Z-Cur or ZG-Cur particles. The bioaccessibility of Cur in ZGT-Cur composite particles was 8.97 times higher than that of free Cur. Therefore, the particles designed in this study will broaden the application of Cur in the food industry by improving its stability and bioaccessibility.

Co-encapsulation of vitamin D and rutin in chitosan-zein microparticles

There is a growing interest in co-encapsulating multiple species to harness potential synergy between them, enhance their stability and efficacy in various products. The aim of this work was to co-encapsulate vitamin D3 and rutin inside chitosan-zein microparticles using a simple and easily scalable process for food fortification. This was achieved via anti-solvent precipitation coupled with spray-drying. Free-flowing powders of spherical microparticles with wrinkled surface and particle size < 10 μm were obtained. The encapsulation efficiency was 75% for vitamin D3 and 44% for rutin and this could be attributed to their different molecular size and affinity to the aqueous phase. The physicochemical properties were characterized by X-Ray powder diffraction and Fourier transform infrared spectroscopy. The two crystalline bioactive compounds were present in the microparticles in amorphous form, which would allow for better bioavailability when compared to non-encapsulated crystalline solid. Therefore, the obtained microparticles would be suitable for use as food ingredient for vitamin D3 fortification, with the co-encapsulated rutin acting as stability and activity enhancer.

Biopolymer nanoparticles: a strategy to enhance stability, bioavailability, and biological effects of phenolic compounds as functional ingredients

Phenolic compounds are abundant in nature and have multiple beneficial effects on human health due to their antioxidant, anti-inflammatory, antithrombotic, antiallergenic, anticancer, and antiatherosclerotic properties. For this reason, phenolics are becoming relevant functional ingredients for several industries, mainly the food industry, derived from food consumer exigencies and regulations. However, the use of their beneficial properties still presents some limitations, such as chemical instability under environmental and processing conditions, which leads to structural changes and compromises their biological activities. They also present poor water solubility and sensitivity to pH changes, decreasing their bioavailability in the organism. The technologies for extraction and stabilization of these compounds have evolved rapidly in the development of different delivery systems to encapsulate sensitive active molecules. Biopolymeric nanoparticles are biodegradable polymer-based colloidal systems with sizes ranging from 1 to 1000 nm, and different techniques can be carried out to develop them. These systems have emerged as a green and effective alternative to improve stability, bioavailability, and biological effects of phenolic compounds. This comprehensive review aims to present an overview of recent advances in encapsulation processes of phenolic compounds within biopolymer nanoparticles as delivery systems and the impact on their physicochemical properties and biological effects after encapsulation. © 2021 Society of Chemical Industry.

Tremella polysaccharides-coated zein nanoparticles for enhancing stability and bioaccessibility of curcumin

The purpose of the present research was to examine the ability of Tremella polysaccharide (TP) to stabilize zein nanoparticles (zein NPs) and appraise the performance of zein/Tremella polysaccharide nanoparticles (zein/TP NPs) in terms of encapsulating and delivering curcumin. In this study, the zein/TP NPs were fabricated based on the anti-solvent precipitation method, which were used to protect and deliver curcumin. The results suggested that TP could be deposited on the surface of zein NPs by virtue of electrostatic interaction, so as to improve the hydrophilicity of zein, provide better protection for curcumin and assemble more stable nanoparticles. Compared with zein NPs (54.73%), the zein/TP NPs exhibited higher encapsulation efficiency of curcumin (93.34%) and excellent re-dispersibility. Furthermore, the retention rate of curcumin encapsulated in zein/TP NPs reached 80.78% and 90.74% after UV irradiation and 80 °C heat treatment for 2 h, respectively, which proved that the addition of TP significantly improved the stability of curcumin. Meanwhile, in vitro digestion study demonstrated that the bioaccessibility of curcumin encapsulated in zein/TP NPs increased by 37.36% compared with in zein NPs. Therefore, the zein/TP NPs may be served as an effective and potential carrier for the delivery of nutraceuticals.

•

Zein/tremella polysaccharide nanoparticles (zein/TP NPs) were fabricated via anti-solvent deposition method.

•

Deposition of TP on zein nanoparticles improved the encapsulation efficiency of curcumin.

•

The mass ratio of zein to TP influenced physicochemical stabilities of nanoparticles.

•

Curcumin loaded in zein/TP NPs showed superior photostability and thermal stability.

•

Zein/TP NPs enhanced the bioaccessibility of curcumin in vitro gastrointestinal fluids.

Fabrication and Characterization of Quercetagetin-Loaded Nanoparticles Based on Shellac and Quaternized Chitosan: Improvement of Encapsulation Efficiency and Acid and Storage Stabilities

Shellac can be used as an ideal delivery vehicle to deliver and protect the hydrophobic quercetagetin; the barriers such as low acid stability and encapsulation efficiency, however, heavily impede the application of shellac. The purpose of this work is to prepare quercetagetin-loaded shellac-quaternized chitosan nanoparticles (Que-Sh-QCS NPs) to overcome these challenges. Herein, quaternized chitosan, with 14% degree of substitution, was successfully synthesized via a quaternization modification. The concentration of quaternized chitosan over 0.05% can prevent the aggregation of shellac nanoparticles at the acid. The encapsulation efficiency of quercetagetin obviously increased from 37.92 to 65.48% with the concentration of QCS varying from 0 to 0.05%. Meanwhile, Que-Sh-QCS_0.05 NPs possessed good storage stability, antioxidant property, biocompatibility, and controlled release. Therefore, quaternized chitosan can improve the encapsulation efficiency and acid and storage stabilities of nutraceutical-loaded shellac nanoparticles, providing a new insight into the application of shellac in cosmetics, pharmaceuticals, and food.

Encapsulation of curcumin in CD-MOFs: promoting its incorporation into water-based products and consumption

Curcumin has received considerable interest in functional food areas due to its variety of biological effects. However, its utilization is often limited by its insolubility and instability in aqueous solutions. Herein, curcumin was encapsulated in γ-cyclodextrin metal-organic frameworks (CD-MOFs) to achieve immediate release and rapid dissolution in water just by gentle stirring due to the dissociation of CD-MOFs. The released curcumin exhibited remarkably enhanced stability compared to its free form in aqueous solutions due to the inclusion effects of cyclodextrins. Besides, the impacts of temperature, light and gastrointestinal pH on the chemical stability of curcumin released from basic and neutral CD-MOFs were compared. The molar ratios of curcumin : γ-CD in basic CD-MOFs and neutral CD-MOFs were 1 : 1.7 and 1 : 9.8, respectively. Neutral CD-MOFs were more effective in retarding thermal and gastrointestinal degradation of curcumin because all curcumin molecules can form inclusion complexes with cyclodextrin. Basic CD-MOFs were more conducive to prolonging the half-life time of curcumin during photodegradation since its alkalinity darkened the color of curcumin solution causing lower light transmittance. Moreover, CD-MOFs exhibited higher loading and stability of curcumin due to their unique host-guest structure, than their pure cyclodextrin inclusion complex. Curcumin-loaded CD-MOFs having a fast-dissolving ability accompanied by the improved amorphous form stability of curcumin hold great potential as functional additives in instant food.

Surface tailored zein as a novel delivery system for hypericin: Application in photodynamic therapy

Zein is an FDA-approved maize protein featured by its manipulative surface and the possibility of fabrication into nanomaterials. Although extensive research has been carried out in zein-based technology, limited work is available for the application of zein in the field of cancer photodynamic therapy (PDT). In this work, we report zein as a carrier for the natural photosensitizer hypericin in the PDT of hepatocellular carcinoma in vitro. Zein was modified through chemical PEGylation to form PEGylated zein micelles that were compared with two zein nanoparticle formulations physically stabilized by either the lecithin/pluronic mixture or sodium caseinate. FT-IR, ¹HNMR and HP-SEC MALS approaches were employed to confirm the chemical PEGylation of zein. Our developed zein nanoparticles and micelles were further characterized by photon correlation spectroscopy (PCS) and atomic force microscopy (AFM). The obtained results showed relatively smaller sizes and higher encapsulation of hypericin in the micellar zein than the nanoparticle-based formulations. Phototoxicity on hepatocellular carcinoma (HepG2 cells) manifested a dose-dependent toxicity pattern of all designed zein formulations. However, superior cytotoxicity was prominent for the hypericin-based micelles, which was influenced by the higher cellular uptake profile. Consequently, the treated HepG2 cells manifested a higher level of intracellular generated ROS and disruption of mitochondrial membrane potential, which induced apoptotic cell death. Comparatively, the designed hypericin formulations indicated lower phototoxicity profile in murine fibroblast L929 cells reflecting their safety on normal cells. Our investigations suggested that the surface-modified zein could be employed to enhance the delivery of the hydrophobic hypericin in PDT and pave the way for future in vivo and clinical applications in cancer treatment.

Improving Physicochemical Stability of Quercetin-Loaded Hollow Zein Particles with Chitosan/Pectin Complex Coating

Hollow nanoparticles are preferred over solid ones for their high loading capabilities, sustained release and low density. Hollow zein particles are susceptible to aggregation with a slight variation in the ionic strength, pH and temperature of the medium. This study was aimed to fabricate quercetin-loaded hollow zein particles with chitosan and pectin coating to improve their physicochemical stability. Quercetin as a model flavonoid had a loading efficiency and capacity of about 86–94% and 2.22–5.89%, respectively. Infrared and X-ray diffraction investigations revealed the interaction of quercetin with zein and the change in its physical state from crystalline to amorphous upon incorporation in the composite particles. The chitosan/pectin coating improved the stability of quercetin-loaded hollow zein particles against heat treatment, sodium chloride and in a wide range of pH. The complex coating protected quercetin that was encapsulated in hollow zein particles from free radicals in the aqueous medium and enhanced its DPPH radical scavenging ability. The entrapment of quercetin in the particles improved its storage and photochemical stability. The storage stability of entrapped quercetin was enhanced both at 25 and 45 °C in hollow zein particles coated with chitosan and pectin. Therefore, composite hollow zein particles fabricated with a combination of polysaccharides can expand their role in the encapsulation, protection and delivery of bioactive components.

Surface-Tailored Zein Nanoparticles: Strategies and Applications

Plant-derived proteins have emerged as leading candidates in several drug and food delivery applications in diverse pharmaceutical designs. Zein is considered one of the primary plant proteins obtained from maize, and is well known for its biocompatibility and safety in biomedical fields. The ability of zein to carry various pharmaceutically active substances (PAS) position it as a valuable contender for several in vitro and in vivo applications. The unique structure and possibility of surface covering with distinct coating shells or even surface chemical modifications have enabled zein utilization in active targeted and site-specific drug delivery. This work summarizes up-to-date studies on zein formulation technology based on its structural features. Additionally, the multiple applications of zein, including drug delivery, cellular imaging, and tissue engineering, are discussed with a focus on zein-based active targeted delivery systems and antigenic response to its potential in vivo applicability.

Nanocomplexes of curcumin and glycated bovine serum albumin: The formation mechanism and effect of glycation on their physicochemical properties

Bovine serum albumin (BSA) and BSA-glucose conjugates (GBSAⅠ and GBSAⅠI) with different extent of glycation were complexed with curcumin (CUR). The formation mechanism of BSA/GBSA-CUR complexes and the effect of glycation on their physicochemical properties were investigated. Fluorescence quenching and FTIR analysis indicated that the BSA/GBSA-CUR nanocomplexes were formed mainly by hydrophobic interactions. XRD analysis demonstrated that CUR was present in an amorphous state in the nanocomplexes. BSA with a greater extent of glycation (BSA < GBSAⅠ<GBSAⅠI) displayed a higher binding affinity for CUR. The highest CUR encapsulation efficiency (86.77%) and loading capacity (7.81 mg/g) were obtained in the GBSAⅠI-CUR nanocomplex. The zeta-potential varied from -17.45 to -27.65 mV, depending on the extent of glycation. Furthermore, the physicochemical stability of BSA/GBSA-CUR nanocomplexes increased with the increasing extent of glycation of BSA. Thus, the obtained GBSAⅠI have the potential to become new delivery carriers for encapsulating hydrophobic food components.

Partition and stability of folic acid and caffeic acid in hollow zein particles coated with chitosan

The carriers for hydrophobic bioactives have been extensively studied, while those for hydrophilic bioactives are still challenging. The partition of bioactives in the particles depends greatly on their solubility, interaction with carrier materials, as well as structure of carriers. In this study, chitosan-coated hollow zein particles using calcium phosphate as a sacrificing template (CS-HZ) were fabricated to co-encapsulate folic acid (FA) and caffeic acid (CA). Partition, photostability, and antioxidant capacity of bioactive compounds were also studied. The size, polydispersity index and ζ-potential of optimized CS-HZ were 176.3 nm, 0.14 and +39.3 mV, respectively, indicating their small and uniform dimension with excellent colloidal stability. FA interacted with chitosan to form complexes and then coated on the zein particles where CA was encapsulated. After co-encapsulation in CS-HZ, the photostability of both FA and CA was improved in comparison with encapsulation of single compound, with 85% of FA remaining after 240 min of UVA irradiation, and 90% of CA remaining after 80 min. Antioxidant activity of CA decreased upon encapsulation, but significantly increased after irradiation. Findings in this study shed some light on the design of carriers for co-delivery of hydrophilic compounds in acidic condition.

Stability and bioaccessibility improvement of capsorubin using bovine serum albumin-dextran-gallic acid and sodium alginate

This study attempted to prepare ternary conjugate emulsion from bovine serum albumin (BSA), dextran (DEX) and gallic acid (GA) to improve the stability of conjugate emulsion and the bioaccessibility of capsorubin. The release of capsorubin was further delayed by sodium alginate capsules in the intestinal phase. First, protein formed new functional groups and covalent bonds was analyzed by Fourier transform infrared (FTIR) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Next, the stability of the ternary conjugate showed distinct pH correlation and the higher stability near the isoelectric point. Finally, the bioaccessibility of capsorubin embedded in sodium alginate emulsion was higher than that of ternary conjugate emulsion (65% and 34%).

Chitosan-based nanocarriers for encapsulation and delivery of curcumin: A review

To overcome the poor aqueous solubility and bioavailability of curcumin, emphasize its functional features, and broaden its applications in the food and pharmaceutical industries, many nanoscale systems have been widely applied for its encapsulation and delivery. Over many decades, chitosan as a natural biopolymer has been extensively studied due to its polycationic nature, biodegradability, biocompatibility, non-toxicity, and non-allergenic. Various chitosan-based nanocarriers with unique properties for curcumin delivery, including but not limited to, self-assembled nanoparticles, nanocomposites, nanoemulsions, nanotubes, and nanofibers, have been designed. This review focuses on the most-recently reported fabrication techniques of different types of chitosan-based nanocarriers. The functionalities of chitosan in each formulation which determine the physicochemical properties such as surface charge, morphology, encapsulation driving force, and release profile, were discussed in detail. Moreover, the current pharmaceutical applications of curcumin-loaded chitosan nanoparticles were elaborated. The role of chitosan in facilitating the delivery of curcumin and improving the therapeutic effects on many chronic diseases, including cancer, bacterial infection, wound healing, Alzheimer's diseases, inflammatory bowel disease, and hepatitis C virus, were illustrated. Particularly, the recently discovered mechanisms of action of curcumin-loaded chitosan nanoparticles against the abovementioned diseases were highlighted.

Preparation of dextran-casein phosphopeptide conjugates, evaluation of its calcium binding capacity and digestion in vitro

In order to construct a novel and efficient calcium delivery system, a dextran- casein phosphopeptide (CPP) conjugates as calcium carrier was prepared by Maillard reaction of CPP and dextran. The preparation of the conjugates, construction of calcium delivery system and digestion in vitro were studied. The grafting rate of conjugates, which was confirmed by migration and intensity changes in the characteristic peaks using ultraviolet-visible and Fourier transform infrared spectroscopy, reached 48.88%. The microscopy showed CPP was coated with dextran, the conjugates with a kind of "shell-core" structure had excellent stability. Compared with CPP, the chelating rate of conjugates increased from 6.0% to 13.87%, and the calcium retention rate improved from 1.09% to 7.90% in vitro digestion. The calcium binding capacity and effect of controlled release of the conjugates were superior to those of CPP. Therefore, the conjugates could be used as an effective carrier for new calcium supplements.

Development of curcumin-loaded zein nanoparticles for transport across the blood-brain barrier and inhibition of glioblastoma cell growth

Glioblastoma (GBM) is a devastating primary brain tumor resistant to conventional therapies. A major obstacle to GBM treatment is the blood-brain barrier (BBB), or blood-glioma barrier, which prevents the transport of systemically administered (chemotherapeutic) drugs into the tumor. This study reports the design of dodecamer peptide (G23)-functionalized polydopamine (pD)-coated curcumin-loaded zein nanoparticles (CUR-ZpD-G23 NPs) that efficiently traversed the BBB, and delivered curcumin to glioblastoma cells. The NPs enhanced the cellular uptake of curcumin by C6 glioma cells compared to free curcumin, and showed high penetration into 3D tumor spheroids. Functionalization of the NPs with G23 stimulated BBB crossing and tumor spheroid penetration. Moreover, the NPs markedly inhibited proliferation and migration and induced cell death in liquid and soft agar models of C6 glioma cell growth. Fluorescence microscopy and flow cytometry studies showed that the CUR-ZpD-G23 NPs increased cellular ROS production and induced apoptosis of C6 glioma cells. Following in vivo intravenous injection in zebrafish, ZpD-G23 NPs demonstrated the ability to circulate, which is a first prerequisite for their use in targeted drug delivery. In conclusion, zein-polydopamine-G23 NPs show potential as a drug delivery platform for therapy of GBM, which requires further validation in in vivo glioblastoma models.

Development and characterization of soybean protein isolate and fucoidan nanoparticles for curcumin encapsulation

Curcumin (Cur) is a natural polyphenol with beneficial biological and pharmacological activities; however, it has limited applications owing to its low solubility and light sensitivity. The protein-polysaccharide complex can effectively embed lipid-soluble drugs to increase their stability and dispensability in aqueous solutions. Soybean protein isolate (Spi) and fucoidan (Fuc) were used as a polymer matrix, and core-shell nanoparticles were prepared to encapsulate Cur via electrostatic interaction under acidic and neutral conditions. The structure of the Spi-Fuc nanoparticles was studied via Fourier-transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy. Concurrently, we evaluated the efficacy of the nanoparticles based on stability, drug loading rate, and simulated release. Our results showed that the Spi-Fuc nanoparticles (size, approximately 236.56 nm) had a spherical, core-shell structure and that they could effectively load Cur with an embedding efficiency of >95%; moreover, the system had long-term dispersion stability. Thus, we provide a simple method for Cur delivery, which can also be potentially used for delivering lipid-soluble active ingredients.