Enhancing the antitumor activity of tea polyphenols encapsulated in biodegradable nanogels by macromolecular self-assembly

Toward function starch nanogels by self-assembly of polysaccharide and protein: From synthesis to potential for polyphenol delivery

Nanogels formed by self-assembly of natural proteins and polysaccharides have attracted great interest as potential carriers of bioactive molecules. Herein, we reported that carboxymethyl starch-lysozyme nanogels (CMS-Ly NGs) were prepared using carboxymethyl starch and lysozyme by green and facile electrostatic self-assembly, and the nanogels served as epigallocatechin gallate (EGCG) delivery systems. The dimensions and structure of the prepared starch-based nanogels (i.e., CMS-Ly NGs) were characterized by dynamic light scattering (DLS), ζ-potential, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA). FT-IR and 1H NMR spectra together confirmed the formation of CMS; FT-IR spectra confirmed the formation of CMS-Ly NGs; XRD spectra confirmed the disruption of the crystal structure of lysozyme after electrostatic self-assembly with CMS, and further confirmed the formation of nanogels. TGA demonstrated the thermal stability of nanogels. More importantly, the nanogels showed a high EGCG encapsulation rate of 80.0 ± 1.4 %. The CMS-Ly NGs encapsulated with EGCG exhibited regular spherical structure and stable particle size. Under the simulated gastrointestinal environmental conditions, CMS-Ly NGs encapsulated with EGCG showed the controlled release potential, which increased its utilization. Additionally, anthocyanins can also be encapsulated in CMS-Ly NGs and showed slow-release properties during gastrointestinal digestion in the same way. Cytotoxicity assay also demonstrated good biocompatibility between CMS-Ly NGs and CMS-Ly NGs encapsulated with EGCG. The findings of this research suggested the potential application of protein and polysaccharides-based nanogels in the delivery system of bioactive compounds.

A comparative study between two carboxymethylated polysaccharides/protein electrostatic and cross-linked nanogels constructed for caffeic acid and eugenol delivery

In response to the pressing demand for functional nanomaterials synthesis and applications, two polyelectrolyte complexes (PECs) [electrostatic and cross-linked nanogels (NGs)] loaded individually with caffeic acid (CafA) and eugenol (Eug) demonstrating multifunctionalities were proposed for the first time. Curdlan (Curd) and glucomannan (GM) were carboxymethylated (CMCurd and CMGM) successfully and polymeric ratios of 1:1 and 4:1 (v/v) for chitosan (Cs): CMCurd and lactoferrin (Lf): CMGM were selected for the synthesis of Cs/CMCurd and Lf/CMGM NGs. Due to the use of EDC/NHS, Cs/CMCurd/CafA and Lf/CMGM/Eug NGs possessed very uniform particles sizes of 177 ± 18 and 230 ± 17 nm with marked encapsulation efficiencies (EEs) of 76 ± 4 and 88 ± 3 %, respectively. The formation of a carbonyl-amide linkage in both cross-linked NGs was confirmed by FTIR. It should be noted, the self-assembly was not reliable in retaining enough of the encapsulated compounds. Owing to the excellent physicochemical characteristics of the loaded cross-linked NGs, they were prioritized over the electrostatic ones. Both Cs/CMCurd/CafA and Lf/CMGM/Eug NGs exhibited high colloidal stability over 12 weeks, elevated hemocompatibility, and in vitro serum stability. The generated NGs were also tailored to possess controlled release profiles for CafA and Eug over 72 h. Cs/CMCurd/CafA and Lf/CMGM/Eug NGs had promising antioxidant efficacies and could remarkably inhibit 4 bacterial pathogens at low 2-16 μg/mL concentration of encapsulated NGs compared to their unencapsulated counterparts. Interestingly, the respective NGs could significantly decline the IC₅₀ against colorectal cancer HCT-116 than conventional drugs. Based on these data, it was conferred that the investigated NGs could be promising candidates for functional foods and pharmaceutics.

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.

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.

Injectable Hydrogel Based on Protein-Polyester Microporous Network as an Implantable Niche for Active Cell Recruitment

Despite the potential of hydrogel-based localized cancer therapies, their efficacy can be limited by cancer recurrence. Therefore, it is of great significance to develop a hydrogel system that can provoke robust and durable immune response in the human body. This study has developed an injectable protein-polymer-based porous hydrogel network composed of lysozyme and poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide (PCLA) (Lys-PCLA) bioconjugate for the active recruitment dendritic cells (DCs). The Lys-PCLA bioconjugates are prepared using thiol-ene reaction between thiolated lysozyme (Lys-SH) and acrylated PCLA (PCLA-Ac). The free-flowing Lys-PCLA bioconjugate sols at low temperature transformed to immovable gel at the physiological condition and exhibited stability upon dilution with buffers. According to the in vitro toxicity test, the Lys-PCLA bioconjugate and PCLA copolymer were non-toxic to RAW 263.7 cells at higher concentrations (1000 µg/mL). In addition, subcutaneous administration of Lys-PCLA bioconjugate sols formed stable hydrogel depot instantly, which suggested the in situ gel forming ability of the bioconjugate. Moreover, the Lys-PCLA bioconjugate hydrogel depot formed at the interface between subcutaneous tissue and dermis layers allowed the active migration and recruitment of DCs. As suggested by these results, the in-situ forming injectable Lys-PCLA bioconjugate hydrogel depot may serve as an implantable immune niche for the recruitment and modification of DCs.

Theaflavin Chemistry and Its Health Benefits

Huge epidemiological and clinical studies have confirmed that black tea is a rich source of health-promoting ingredients, such as catechins and theaflavins (TFs). Furthermore, TF derivatives mainly include theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B), and theaflavin-3,3'-digallate (TF3). All of these TFs exhibit extensive usages in pharmaceutics, foods, and traditional medication systems. Various indepth studies reported that how TFs modulates health effects in cellular and molecular mechanisms. The available literature regarding the pharmacological activities of TFs has revealed that TF3 has remarkable anti-inflammatory, antioxidant, anticancer, antiobesity, antiosteoporotic, and antimicrobial properties, thus posing significant effects on human health. The current manuscript summarizes both the chemistry and various pharmacological effects of TFs on human health, lifestyle or aging associated diseases, and populations of gut microbiota. Furthermore, the biological potential of TFs has also been focused to provide a deeper understanding of its mechanism of action.

Recent insights on tea metabolites, their biosynthesis and chemo-preventing effects: A review

Tea manufactured from the cultivated shoots of Camellia sinensis (L.) O. Kuntze is the most commonly consumed nonalcoholic drink around the world. Tea is an agro-based, environmentally sustainable, labor-intensive, job-generating, and export-oriented industry in many countries. Tea includes phenolic compounds, flavonoids, alkaloids, vitamins, enzymes, crude fibers, protein, lipids, and carbohydrates, among other biochemical constituents. This review described the nature of tea metabolites, their biosynthesis and accumulation with response to various factors. The therapeutic application of various metabolites of tea against microbial diseases, cancer, neurological, and other metabolic disorders was also discussed in detail. The seasonal variation, cultivation practices and genetic variability influence tea metabolite synthesis. Tea biochemical constituents, especially polyphenols and its integral part catechin metabolites, are broadly focused on potential applicability for their action against various diseases. In addition to this, tea also contains bioactive flavonoids that possess health-beneficial effects. The catechin fractions, epigallocatechin 3-gallate and epicatechin 3-gallate, are the main components of tea that has strong antioxidant and medicinal properties. The synergistic function of natural tea metabolites with synthetic drugs provides effective protection against various diseases. Furthermore, the application of nanotechnologies enhanced bioavailability, enhancing the therapeutic potential of natural metabolites against numerous diseases and pathogens.

Recent progress in the preparation, chemical interactions and applications of biocompatible polysaccharide-protein nanogel carriers

Nanogel carriers are rapidly emerged as a major delivery strategy in the fields of food, biology and medicine for small particle size, excellent solubility, high loading, and controlled release. Natural polysaccharides and proteins are selected for the preparation of biocompatible, biodegradable, low toxic, and less immunogenic nanogels. Different polysaccharides and proteins form complex nanogels through different interaction forces (e.g., electrostatic interaction and hydrophobic interaction). The present review pursues three aims: 1) to introduce several well-known dietary polysaccharides (chitosan, dextran and alginate) and proteins (whey protein and lysozyme); 2) to discuss the types, preparation methods, chemical interactions and properties of various biocompatible complex carriers; 3) to present the application and prospect of polysaccharide-protein complex in bioactive ingredient delivery, nutrient encapsulation and flavor protection. We expect that the integration with nano-intelligent technology will improve the functional ingredient loading, recognition specificity and controlled release capabilities of polysaccharide-protein nanocomposites to generate new intelligent nanogels in the field of food industry in the future.

Strategies of confining green tea catechin compounds in nano-biopolymeric matrices: A review

Catechins are polyphenolic compounds which abundantly occur in the plants, especially tea leaves. They are widely used in nutraceutical and pharmaceutical formulations due to their capability of lowering the risk of developing various diseases. Nevertheless, low stability, loss of antioxidant and antimicrobial activities hinder the direct application of catechins in food formulations. To surmount this pervasive challenge, bioactive ingredients should be entrapped in a biopolymeric matrix. Thus, nanoencapsulation technology would be an appropriate strategy to improve the stability of these bioactive compounds and to protect them against degradation. Among different types of nanocarriers, biopolymer-based nanovehicles has captured a lot of attention in both industry and academia due to their safety and biocompatibility. This revision enlarges upon the various types of biopolymeric nanostructures used for accommodation of catechins, namely nanogels, nanotubes, nanofibers, nanoemulsions and nanoparticles. Last but not least, the applications of the entrapped catechins in the food industry are highlighted.

Nanonutraceuticals: The New Frontier of Supplementary Food

In the last few decades, the combination between nanotechnology and nutraceutics has gained the attention of several research groups. Nutraceuticals are considered as active compounds, abundant in natural products, showing beneficial effects on human health. Unfortunately, the uses, and consequently the health benefits, of many nutraceutical products are limited by their unsuitable chemico-physical features. For example, many nutraceuticals are characterized by low water solubility, low stability and high susceptibility to light and oxygen, poor absorption and potential chemical modifications after their administration. Based on the potential efficacy of nutraceuticals and on their limiting features, nanotechnology could be considered a revolutionary innovation in empowering the beneficial properties of nutraceuticals on human health, thus enhancing their efficacy in several diseases. For this reason, nanotechnology could represent a new frontier in supplementary food. In this review, the most recent nanotechnological approaches are discussed, focusing on their ability to improve the bioavailability of the most common nutraceuticals, providing an overview regarding both the advantages and the possible limitations of the use of several nanodelivery systems. In fact, although the efficacy of smart nanocarriers in improving health benefits deriving from nutraceuticals has been widely demonstrated, the conflicting opinions on the mechanism of action of some nanosystems still reduce their applicability in the therapeutic field.

Construction of thermally robust and porous shrimp ferritin crystalline for molecular encapsulation through intermolecular arginine-arginine attractions

Protein colloid crystals are considered as high porous soft materials, presenting great potentials in nutrients and drug encapsulation, but protein crystal fabrication usually needs precipitant and high protein concentration. Herein, an easy implemented approach was reported for the construction of protein colloid crystals in diluted solution with shimp ferritin as building blocks by taking advantage of the strength of multiple intermolecular arginine-arginine interactions. The X-ray single-crystal structure reveals that a group of exquisite arginine-arginine interactions between two neighboring ferritin enable them self-assembly into long-range ordered protein soft materials. The arginine-arginine interactions mediate crystal generation favored at pH 9.5 with 200 mM NaCl, and the resulting colloid crystals exhibit high thermal stability (90 °C for 30 min). Importantly, the interglobular cavity in colloid crystals is three times larger in volume than that of intrinsic ferritin cavity in each unit cell, which can be used for molecular encapsulation.

pH-Sensitive nanogels for drug delivery in cancer therapy

Compared to normal tissue, solid tumors exhibit a lower pH value. Such pH gradient can be used to design pH-sensitive nanogels for selective drug delivery. The acid-sensitive elements in the nanogel cause it to swell/degrade rapidly, followed by rapid drug release.

Preparation, Characterization and Antioxidant Activities of Kelp Phlorotannin Nanoparticles

Phlorotannins are a group of major polyphenol secondary metabolites found only in brown algae and are known for their bioactivities and multiple health benefits. However, they can be oxidized due to external factors and their bioavailability is low due to their low water solubility. In this study, the potential of utilizing nanoencapsulation with polyvinylpyrrolidone (PVP) to improve various activities of phlorotannins was explored. Phlorotannins encapsulated by PVP nanoparticles (PPNPS) with different loading ratios were prepared for characterization. Then, the PPNPS were evaluated for in vitro controlled release of phlorotannin, toxicity and antioxidant activities at the ratio of phlorotannin to PVP 1:8. The results indicated that the PPNPS showed a slow and sustained kinetic release of phlorotannin in simulated gastrointestinal fluids, they were non-toxic to HaCaT keratinocytes and they could reduce the generation of endogenous reactive oxygen species (ROS). Therefore, PPNPS have the potential to be a useful platform for the utilization of phlorotannin in both pharmaceutical and cosmetics industries.

Application of Polyphenol-Loaded Nanoparticles in Food Industry

Nanotechnology is an emerging field of science, and nanotechnological concepts have been intensively studied for potential applications in the food industry. Nanoparticles (with dimensions ranging from one to several hundred nanometers) have specific characteristics and better functionality, thanks to their size and other physicochemical properties. Polyphenols are recognized as active compounds that have several putative beneficial properties, including antioxidant, antimicrobial, and anticancer activity. However, the use of polyphenols as functional food ingredients faces numerous challenges, such as their poor stability, solubility, and bioavailability. These difficulties could be solved relatively easily by the application of encapsulation. The objective of this review is to present the most recent accomplishments in the usage of polyphenol-loaded nanoparticles in food science. Nanoparticles loaded with polyphenols and their applications as active ingredients for improving physicochemical and functional properties of food, or as components of active packaging materials, were critically reviewed. Potential adverse effects of polyphenol-loaded nanomaterials are also discussed.

Investigation of the blends of chitosan and tragacanth as potential drug carriers for the delivery of ibuprofen in the intestine

This study provides a new potential hydrogel for the intestinal delivery of ibuprofen.