Evaluation of alginate-biopolymers (protein, hydrocolloid, starch) composite microgels prepared by the spray aerosol technique as a carrier for green tea polyphenols

Fabrication, characterization, and bioactivity of self-assembled carrier-free colloidal dispersions from Citrus × Limon 'Rosso' essential oil and tea polyphenols

Carrier-free nanodelivery systems are fully self-assembled from active ingredients through interactions, offering the advantages of green, safe, and large-scale manufacturing. To improve the dispersion of Citrus × limon 'Rosso' peel essential oil (CEO) in water and boost the biological activity of CEO and tea polyphenols (TP), self-assembled CEO-TP colloidal dispersions (CEO-TP Colloids) were fabricated through sonication without surfactants or carriers. The optimal CEO and TP concentrations in the CEO-TP Colloids were determined to be 10.0 and 20.0 mg/mL by particle size and stability analyzer, respectively. The CEO self-assembled with TP to form spherical nanoparticles through hydrophobic and hydrogen-bonding interactions, whereas the CEO in CEO-TP Colloids weakened TP intramolecular aggregation. Meanwhile, the CEO-TP Colloids showed synergistic effects with better antibacterial, cellular antioxidant, and anti-inflammatory activities than single components. This study opens up the possibility of carrier-free co-delivery of hydrophobic and hydrophilic active components developed into food-grade formulations with multiple bioactivities.

Preparation, characterization and drug release properties of pH sensitive Zingiber officinale polysaccharide hydrogel beads

The aim of this study was to prepare a drug carrier that could deliver oral insulin to the intestine. A hydrogel beads composed of sodium carboxymethyl cellulose (CMC), Zingiber offtcinale polysaccharide (ZOP) and chitosan (CS) were prepared by ionic gel method as insulin carrier. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and thermogravimetric (TGA) showed that the hydrogel was formed by metal ion coordination between ZOP and CMC and Fe3+, and CS was coated on the surface of the hydrogel ball in the form of non covalent bond. The results showed that the swelling process of hydrogel spheres has significant pH sensitivity. In addition, the hydrogel beads successfully coated insulin, and the drug loading rate (DL) of (ZOP/CMC-Fe3+)@CS could reach 69.43 ± 7.32 mg/g, and the entrapment efficiency (EE) could reach 66.94 ± 7.43 %. In vitro release experiments, the release rate of (CMC/ZOP-Fe3+)@CS in simulated gastric fluid (SGF) for 2 h was <20 %, and the cumulative release rate of insulin after 9 h in simulated intestinal fluid (SIF) reached over 90 %. The results showed that the hydrogel beads prepared in this work could be used as a potential carrier for delivering oral insulin.

Preparation and characterization of particle-filled microgels by chemical cross-linking based on zein and carboxymethyl starch for delivering the quercetin

This work aimed to develop novel particle-filled microgels based on zein and carboxymethyl starch for delivering quercetin (Que). The anti-solvent precipitation and chemical cross-linking methods were combined to produce the zein-carboxymethyl starch particle-filled microgels (SM-Z). The critical finding of the study was that adding zein nanoparticles significantly improved the strength, water holding capacity, and thermal stability of carboxymethyl starch microgel (SM). Besides, SM-Z had good biodegradability, and the particle size was about 44-61 μm. SM-Z successfully encapsulated Que with a high encapsulation efficiency of 86.7 %. Que-loaded SM-Z (Q/SM-Z) significantly enhanced 30 d storage and UV light stability (up to 89.4 % retention rate) of Que than the Que-loaded SM (Q/SM). Q/SM-Z exhibited pH-responsive swelling behavior, and the swelling was greatest in the simulated intestinal fluid (pH = 7). Besides, the Q/SM-Z showed good stability in simulated gastric fluids and sustained release of Que in simulated intestinal fluids, 72.5 % Que was released at 8 h. During Que transport in Caco-2 cell monolayers, Q/SM (5.8 %) and Q/SM-Z (9.7 %) were significantly higher than free Que (1.93 %). Therefore, as an oral delivery system for hydrophobic active substances, SM-Z possesses good biodegradability and pH-responsive intestinal-targeted delivery capability, providing a new strategy for designing starch-based encapsulation materials.

Multifaceted Applications of Ferritin Nanocages in Delivering Metal Ions, Bioactive Compounds, and Enzymes: A Comprehensive Review

Ferritin, a distinctive iron-storage protein, possesses a unique cage-like nanoscale structure that enables it to encapsulate and deliver a wide range of biomolecules. Recent advances prove that ferritin can serve as an efficient 8 nm diameter carrier for various bioinorganic nutrients, such as minerals, bioactive polyphenols, and enzymes. This review offers a comprehensive summary of ferritin's structural features from different sources and emphasizes its functions in iron supplementation, calcium delivery, single- and coencapsulation of polyphenols, and enzyme package. Additionally, the influence of innovative food processing technologies, including manothermosonication, pulsed electric field, and atmospheric cold plasma, on the structure and function of ferritin are examined. Furthermore, the limitations and prospects of ferritin in food and nutritional applications are discussed. The exploration of ferritin as a multifunctional protein with the capacity to load various biomolecules is crucial to fully harnessing its potential in food applications.

Determination of the critical pH for unfolding water-soluble cod protein and its effect on encapsulation capacities

Hydrophobic polyphenols, with a variety of physiological activities, are often practically limited due to their low water solubility and chemical instability, among which curcumin (Cur) is a representative hydrophobic polyphenol. To improve Cur, the cod protein (CP)-Cur composite particles (CP-Cur) were successfully prepared using the pH-shift method, but this pH-shift method (7-12-7) required a higher pH, which limited application and increased cost. The critical pH of CP structure unfolding during pH-shift and its encapsulation effect on Cur were investigated in this paper. During the pH-shift process, the critical pH of the structural unfolding of CP was pH 10, and the degree of protein structure unfolding was higher, which was attributed to the increasing electrostatic repulsion, and the weakened hydrogen bond and hydrophobic interaction. The encapsulation efficiency of CP-Cur formed after pH 10-shift was higher than that formed after pH 9.8-shift, which increased by 22.17 %. At pH 9.8, the binding sites in CP reached saturation at the molar ratio of 10, while at pH 10 and 10.2, the binding sites in CP both reached saturation at the molar ratio of 14, also indicating that the protein treated with critical pH could bind more Cur. The binding between Cur and CP was mostly hydrophobic interaction, accompanied by hydrogen bonding and electrostatic interactions. The above results verified the necessity of critical pH in the experiment, indicating that critical pH could indeed improve the encapsulation effect and obtain a higher encapsulation efficiency. This work will help improve the large-scale application of hydrophobic functional substances in production.

Efficient Utilization of Tea Resources through Encapsulation: Dual Perspectives from Core Material to Wall Material

With the high production and consumption of tea around the world, efficient utilization of tea byproducts (tea pruning, tea residues after production, and drinking) is the focus of improving the economy of the tea industry. This review comprehensively discusses the efficient utilization of tea resources by encapsulation from the dual perspectives of core material and wall material. The core material is mainly tea polyphenols, followed by tea oils. The encapsulation system for tea polyphenols includes microcapsules, nanoparticles, emulsions, gels, conjugates, metal-organic frameworks, liposomes, and nanofibers. In addition, it is also diversified for the encapsulation of tea oils. Tea resources as wall materials refer to tea saponins, tea polyphenols, tea proteins, and tea polysaccharides. The application of the tea-based delivery system widely involves functionally fortified food, meat preservation, film, medical treatment, wastewater treatment, and plant protection. In the future, the coencapsulation of tea resources as core materials and other functional ingredients, the precise targeting of these tea resources, and the wide application of tea resources in wall materials need to be focused on. In conclusion, the described technofunctional properties and future research challenges in this review should be followed.

Ferritin nanocage based delivery vehicles: From single-, co- to compartmentalized- encapsulation of bioactive or nutraceutical compounds

Bioactive or nutraceutical ingredients have been widely used in pursuit of health and well-being. However, the environmental instability, poor solubility and bioavailability, and unspecific delivery highly limited their practical values. By virtue of the unique shell-like structure, definite disassembly/reassembly behavior, and excellent safety profile of ferritin protein, it stands out among of various nano-materials and is emerging as one of the most promising vehicles for the encapsulation and delivery of bioactive ingredients or drugs. In this review, we present a systematic overview of recent advances of ferritin-based delivery systems from single-encapsulation, co-encapsulation, to compartmentalized-encapsulation of bioactive ingredients or drugs. Different encapsulation strategies for cargo loading as well as their advantages and drawbacks have been critically reviewed. This study emphasized the importance of the construction of compartmentalized delivery systems through the usage of ferritin nanocages, which exhibit great potential for facilitating the synergistic functionality of different types of cargos. Lastly, the applications of ferritin nanocages for physicochemical improvements and functionality achievements of loaded cargos are summarized. In conclusion, ferritin protein nanocages not only are excellent nanocarriers, but also can act as"multi-seated" vehicles for co-encapsulation and compartmentalized encapsulation of different cargos simultaneously.

Multifunctional Gel Films of Marine Polysaccharides Cross-Linked with Poly-Metal Ions for Wound Healing

The development of an efficient and convenient material to improve skin tissue regeneration is a major challenge in healthcare. Inspired by the theory of moist wound healing, portable chitooligosaccharide (COS)/sodium alginate (SA) dual-net gel films containing multiple metal ions were prepared by a casting and in-situ spray method, which can be used to significantly promote wound healing without the use of therapeutic drugs. A variety of divalent cations was introduced in this experiment to improve the advantages of each metal ion by forming metal ion chelates with COS. Moreover, the physicochemical properties and antioxidant properties of nIon²⁺-COS/SA gel films were systematically characterized and evaluated by in vitro experiments. The gel films showed good antibacterial activity against Gram-negative and Gram-positive bacteria. In addition, the gel films showed good cytocompatibility in cellular experiments, and the gel films with Zn²⁺ and Sr²⁺ addition significantly accelerated wound healing in whole skin defect model experiments. Therefore, this nIon²⁺-COS/SA gel film is an ideal candidate material for wound dressing.