Supramolecular design of coordination bonding architecture on zein nanoparticles for pH-responsive anticancer drug delivery

Pickering emulsion gel of polyunsaturated fatty acid-rich oils stabilized by zein-tannic acid green nanoparticles for storage and oxidation stability enhancement

HYPOTHESIS

Poor storage stability and oxidative deterioration are the common drawbacks of edible oils rich in polyunsaturated fatty acids (PUFAs). We hypothesized that the natural zein/tannic acid self-assembly nanoparticles (ZT NPs) could be employed as stabilizers to anchor at the oil-water interface, thus constructing Pickering emulsion gel (PKEG) system for three types of PUFA-rich oils, soybean oil (SO), fish oil (FO) and cod liver oil (CLO), to improve the storage and oxidation stability.

EXPERIMENTS

ZT NPs were prepared by the anti-solvent coprecipitation method, and the three-phase contact angle, FT-IR, and XRD were mainly characterized. To observe the shell-core structure and oil-water interface details of SO/FO/CLO PKEGs by confocal laser scanning microscope and cryo-scanning electron microscope. Accelerated oxidation of FO was performed to assess the protective effect of PKEG on lipids.

FINDINGS

The SO, FO, and CLO PKEGs stabilized by 2 % ZT NPs, with oil fraction (φ = 0.5-0.6), were obtained. PKEGs show high viscoelasticity, clear shell-core structure spatial network structure, and ideal storage stability. Under accelerated oxidation, the degree of oxidative rancidity of FO PKEG was obviously lower than that of free FO. Overall, this work opens up new possibilities for using natural PKEG to prevent oxidative deterioration and prolong the shelf-life of PUFA-rich oils.

Synergistic improvement of antioxidant and antibacterial properties of carbon quantum complexes with zinc doping and chlorogenic acid for longan preservation

The deterioration of fruit could reduce the shelf life, decreased marketability and substantial economic value. Thus, a safe, simple, economical and environmentally friendly preservation technology for fruit is of great significance. Here, the postharvest preservation technology was investigated with zinc-doped carbon quantum dots and chlorogenic acid (Zn-CQDs/CGA) composite. Zn-CQDs/CGA composite were synthesized, which exhibits superior antioxidant and antibacterial activities. The binding mechanism of the Zn-CQDs/CGA composite was investigated, which revealed that the bindings of two components were mainly driven by hydrogen bonding and van der Waals forces to create a novel composite. The Zn-CQDs/CGA composite was applied to longan preservation and was found to significantly reduce the incidence of mildew spot, browning of fruit endocarp and pulp, as well as the degree of degradation of quality indexes. These results suggest that the Zn-CQDs/CGA composite has the potential for inhibiting browning and preserving the quality of longan during storage.

Revolutionizing Cancer Treatment: The Promising Horizon of Zein Nanosystems

Various nanomaterials have recently become fascinating tools in cancer diagnostic applications because of their multifunctional and inherent molecular characteristics that support efficient diagnosis and image-guided therapy. Zein nanoparticles are a protein derived from maize. It belongs to the class of prolamins possessing a spherical structure with conformational properties similar to those of conventional globular proteins like ribonuclease and insulin. Zein nanoparticles have gained massive interest over the past couple of years owing to their natural hydrophilicity, ease of functionalization, biodegradability, and biocompatibility, thereby improving oral bioavailability, nanoparticle targeting, and prolonged drug administration. Thus, zein nanoparticles are becoming a promising candidate for precision cancer drug delivery. This review highlights the clinical significance of applying zein nanosystems for cancer theragnostic─moreover, the role of zein nanosystems for cancer drug delivery, anticancer agents, and gene therapy. Finally, the difficulties and potential uses of these NPs in cancer treatment and detection are discussed. This review will pave the way for researchers to develop theranostic strategies for precision medicine utilizing zein nanosystems.

Development and characterization of cellulose nanofiber reinforced hydroxypropyl methylcellulose films functionalized with propolis-loaded zein nanoparticles and its application for cheddar cheese storage

Cellulose nanofiber (CNF) reinforced hydroxypropyl methylcellulose (HPMC) films were functionalized with propolis-loaded zein nanoparticles (ZNP) to develop active, printable, and heat-sealable films. The films with 0, 0.10, 0.25, 0.50, or 0.75 mg/mL propolis-loaded ZNP, named 0ZNP, 0.10ZNP, 0.25ZNP, 0.50ZNP, and 0.75ZNP, respectively, were characterized for their mechanical, physicochemical, structural, functional and optical properties and antioxidant activity. The addition of propolis-loaded ZNP did not change tensile strength (P > 0.05), but increased elongation at break (from 24.72 to 36.58 %) (P < 0.05) for 0.25ZNP film. A water contact angle increased significantly (P < 0.05) for 0.50ZNP (~45 %) and 0.75ZNP (~137 %) films. The 0.25ZNP and 0.75ZNP films were evaluated for packaging cheddar cheese under refrigerated storage for 30 days, and resulted in comparable water activity, pH, titratable acidity, and lipid oxidation (P > 0.05) with those packaged by LDPE film and vacuum package. The developed films can function as eco-friendly alternatives to single-use plastic food packaging.

Recent Advances in Zein-Based Nanocarriers for Precise Cancer Therapy

Cancer has emerged as a leading cause of death worldwide. However, the pursuit of precise cancer therapy and high-efficiency delivery of antitumor drugs remains an enormous obstacle. The major challenge is the lack of a smart drug delivery system with the advantages of biodegradability, biocompatibility, stability, targeting and response release. Zein, a plant-based protein, possesses a unique self-assembly ability to encapsulate anticancer drugs directly or indirectly. Using zein as a nanotherapeutic pharmaceutic preparation can protect anticancer drugs from harsh environments, such as sunlight, stomach acid and pepsin. Moreover, the surface functionalization of zein is easily realized, which can endow it with targeting and stimulus-responsive release capacity. Hence, zein is an ideal nanocarrier for the precise delivery of anticancer drugs. Combined with our previous research experiences, we attempt to review the current state of the preparation of zein-based nanocarriers for anticancer drug delivery. The challenges, solutions and development trends of zein-based nanocarriers for precise cancer therapy are discussed. This review will provide a guideline for precise cancer therapy in the future.

Double network hydrogel based on curdlan and flaxseed gum with photothermal antibacterial properties for accelerating infectious wound healing

The healing of infected wounds has always been a clinical challenge. With the increasing threat of drug resistance due to antibiotic overuse, it is imperative to improve antibacterial wound dressings. In this study, we designed a double network (DN) hydrogel via a "one pot method" with antibacterial activity, and natural polysaccharides with the potential to promote skin wound healing were used. That is, a DN hydrogel matrix was formed by the hydrogen bond crosslinking of curdlan and the covalent crosslinking of flaxseed gum under the action of borax. We added ε-polylysine (ε-PL) as a bactericide. Tannic acid/ferric ion (TA/Fe³⁺) complex was also introduced into the hydrogel network as a photothermal agent to induce photothermal antibacterial properties. The hydrogel had fast self-healing, tissue adhesion, mechanical stability, good cell compatibility and photothermal antibacterial activity. In vitro studies of hydrogel showed its ability to inhibit S. aureus and E. coli. In vivo experiments also demonstrated the significant healing effect of hydrogel when used to treat wounds infected by S. aureus by promoting collagen deposition and accelerating the formation of skin appendage. This work provides a new design for the preparation of safe antibacterial hydrogel wound dressings and demonstrates great potential for promoting wound healing of bacterial infections.

Advances and Prospects of Prolamine Corn Protein Zein as Promising Multifunctional Drug Delivery System for Cancer Treatment

Zein is a type of prolamine protein that is derived from corn, and it has been recognized by the US FDA as one of the safest biological materials available. Zein possesses valuable characteristics that have made it a popular choice for the preparation of drug carriers, which can be administered through various routes to improve the therapeutic effect of antitumor drugs. Additionally, zein contains free hydroxyl and amino groups that offer numerous modification sites, enabling it to be hybridized with other materials to create functionalized drug delivery systems. However, despite its potential, the clinical translation of drug-loaded zein-based carriers remains challenging due to insufficient basic research and relatively strong hydrophobicity. In this paper, we aim to systematically introduce the main interactions between loaded drugs and zein, administration routes, and the functionalization of zein-based antitumor drug delivery systems, in order to demonstrate its development potential and promote their further application. We also provide perspectives and future directions for this promising area of research.

Tannic acid: a versatile polyphenol for design of biomedical hydrogels

Tannic acid (TA), a natural polyphenol, is a hydrolysable amphiphilic tannin derivative of gallic acid with several galloyl groups in its structure. Tannic acid interacts with various organic, inorganic, hydrophilic, and hydrophobic materials such as proteins and polysaccharides via hydrogen bonding, electrostatic, coordinative bonding, and hydrophobic interactions. Tannic acid has been studied for various biomedical applications as a natural crosslinker with anti-inflammatory, antibacterial, and anticancer activities. In this review, we focus on TA-based hydrogels for biomaterials engineering to help biomaterials scientists and engineers better realize TA's potential in the design and fabrication of novel hydrogel biomaterials. The interactions of TA with various natural or synthetic compounds are deliberated, discussing parameters that affect TA-material interactions thus providing a fundamental set of criteria for utilizing TA in hydrogels for tissue healing and regeneration. The review also discusses the merits and demerits of using TA in developing hydrogels either through direct incorporation in the hydrogel formulation or indirectly via immersing the final product in a TA solution. In general, TA is a natural bioactive molecule with diverse potential for engineering biomedical hydrogels.

Influence of polyphenol-metal ion-coated ovalbumin/sodium alginate composite nanoparticles on the encapsulation of kaempferol/tannin acid

In this research, ovalbumin (OVA) and sodium alginate (SA) were used as the materials to prepare OVA-SA composite carriers, which protected and encapsulated the hydrophobic kaempferol (KAE) and the hydrophilic tannic acid (TA). To achieve the purpose of targeted delivery, the TA-Fe³⁺ coating film was prepared. Results showed that the observation of small diffraction peaks in carriers proved the formation of TA/Fe³⁺ coating film on the surface of four composite nanoparticles (pOVA, pOVA-SA, pOVA-KAE-SA, and pOVA-KAE-TA-SA). The protein structure of the composite nanoparticles coated with TA/Fe³⁺ changed, and the order of the changes was pOVA-KAE > pOVA > pOVA-KAE-SA > pOVA-KAE-TA-SA > pOVA-SA. This phenomenon is due to the fact that the chromophore -C=O and the auxo-chromophore -OH are in the opposite position in the benzene ring of TA, and the two substituents have opposite effects and synergize, resulting in the different degrees of redshift of the composite nanoparticle λ_max. Additionally, pOVA-SA had the highest α-helix content and the lowest random coils, conferring the protein structure the strongest stability. The coating of TA/Fe³⁺ increased the system stability and the thermal stability of the composite nanoparticles. Additionally, the carriers were endowed with antioxidant activity, and their antibacterial ability against Staphylococcus aureus and Escherichia coli was pOVA-KAE-TA-SA > pOVA-KAE-SA > pOVA-KAE > pOVA-SA > pOVA based on the difference in antibacterial diameter (D, mm) and square (S, mm²). pOVA-KAE-TA-SA had the strongest antioxidant activity and antibacterial ability, which improved the bioavailability of TA/KAE. These results provide a theoretical basis for the application of OVA-SA composite nanoparticles in the delivery of bioactive compounds.

Elaborated survey in the scope of nanocarriers engineering for boosting chemotherapy cytotoxicity: A meta-analysis study

Cancer is the prime cause of mortality throughout the world. Although the conventional chemotherapeutic agents damage the cancerous cells, they exert prominent injury to the normal cells owing to their lack of specificity. With advances in science, many research studies have been established to boost the cytotoxic effect of the chemotherapeutic agents via innovating novel nano-formulations having different variables. In the current meta-analysis study, combined data from different research articles were gathered for the evidence-based proof of the superiority of drug loaded nanocarriers over their corresponding conventional solutions in boosting the cytotoxic effect of chemotherapy in terms of IC50 values. The meta-analysis was subdivided into three subgroups; nanoparticles versus nanofibers, surface functionalized nanocarriers versus naked ones, and protein versus non-protein-based platforms. The different subgroups interestingly showed distinct scoring outcome data paving the road for cytotoxicity enhancement of the anti-cancer drugs in an evidence-based manner.

Zein as a versatile biopolymer: different shapes for different biomedical applications

In recent years, the interest regarding the use of proteins as renewable resources has deeply intensified. The strongest impact of these biomaterials is clear in the field of smart medicines and biomedical engineering. Zein, a vegetal protein extracted from corn, is a suitable biomaterial for all the above-mentioned purposes due to its biodegradability and biocompatibility. The controlled drug delivery of small molecules, fabrication of bioactive membranes, and 3D assembly of scaffold for tissue regeneration are just some of the topics now being extensively investigated and reported in the literature. Herein, we review the recent literature on zein as a biopolymer and its applications in the biomedical world, focusing on the different shapes and sizes through which it can be manipulated.

Zein a versatile biomaterial in the biomedical field. Easy to chemically functionalize with good emulsification properties, can be employed in drug delivery, fabrication of bioactive membranes and 3D scaffolds for tissue regeneration.

Gold-Protein Composite Nanoparticles for Enhanced X-ray Interactions: A Potential Formulation for Triggered Release

Drug-delivery vehicles have been used extensively to modulate the biodistribution of drugs for the purpose of maximizing their therapeutic effects while minimizing systemic toxicity. The release characteristics of the vehicle must be balanced with its encapsulation properties to achieve optimal delivery of the drug. An alternative approach is to design a delivery vehicle that preferentially releases its contents under specific endogenous (e.g., tissue pH) or exogenous (e.g., applied temperature) stimuli. In the present manuscript, we report on a novel delivery system with potential for triggered release using external beam radiation. Our group evaluated Zein protein as the basis for the delivery vehicle and used radiation as the exogenous stimulus. Proteins are known to react with free radicals, produced during irradiation in aqueous suspensions, leading to aggregation, fragmentation, amino acid modification, and proteolytic susceptibility. Additionally, we incorporated gold particles into the Zein protein matrix to create hybrid Zein-gold nanoparticles (ZAuNPs). Zein-only nanoparticles (ZNPs) and ZAuNPs were subsequently exposed to kVp radiation (single dose ranging from 2 to 80 Gy; fractionated doses of 2 Gy delivered 10 times) and characterized before and after irradiation. Our data indicated that the presence of gold particles within Zein particles was correlated with significantly higher levels of alterations to the protein, and was associated with higher rates of release of the encapsulated drug compound, Irinotecan. The aggregate results demonstrated a proof-of-principle that radiation can be used with gold nanoparticles to modulate the release rates of protein-based drug-delivery vehicles, such as ZNPs.

Multifaceted role of phyto-derived polyphenols in nanodrug delivery systems

As naturally occurring bioactive products, several lines of evidence have shown the potential of polyphenols in the medical intervention of various diseases, including tumors, inflammatory diseases, and cardiovascular diseases. Notably, owing to the particular molecular structure, polyphenols can combine with proteins, metal ions, polymers, and nucleic acids providing better strategies for polyphenol-delivery strategies. This contributes to the inherent advantages of polyphenols as important functional components for other drug delivery strategies, e.g., protecting nanodrugs from oxidation as a protective layer, improving the physicochemical properties of carbohydrate polymer carriers, or being used to synthesize innovative functional delivery vehicles. Polyphenols have emerged as a multifaceted player in novel drug delivery systems, both as therapeutic agents delivered to intervene in disease progression and as essential components of drug carriers. Although an increasing number of studies have focused on polyphenol-based nanodrug delivery including epigallocatechin-3-gallate, curcumin, resveratrol, tannic acid, and polyphenol-related innovative preparations, these molecules are not without inherent shortcomings. The active biochemical characteristics of polyphenols constitute a prerequisite to their high-frequency use in drug delivery systems and likewise to provoke new challenges for the design and development of novel polyphenol drug delivery systems of improved efficacies. In this review, we focus on both the targeted delivery of polyphenols and the application of polyphenols as components of drug delivery carriers, and comprehensively elaborate on the application of polyphenols in new types of drug delivery systems. According to the different roles played by polyphenols in innovative drug delivery strategies, potential limitations and risks are discussed in detail including the influences on the physical and chemical properties of nanodrug delivery systems, and their influence on normal physiological functions inside the organism.

Multifunctional Tannic Acid-Alendronate Nanocomplexes with Antioxidant, Anti-Inflammatory, and Osteogenic Potency

In the current study, we fabricated tannic acid-alendronate (TA-ALN) nanocomplexes (NPXs) via self-assembly. These TA-ALNs were characterized by dynamic light scattering, zeta potential, transmission electron microscopy, and FT-IR spectroscopy. The TA-ALNs were evaluated for antioxidant, anti-inflammatory, and osteogenesis-accelerating abilities in osteoblast-like cells (MC3T3-E1 cells). All TA-ALNs displayed nano-sized beads that were circular in form. Treatment with TA-ALN (1:0.1) efficiently removed reactive oxygen species in cells and protected osteoblast-like cells from toxic hydrogen peroxide conditions. Moreover, TA-ALN (1:0.1) could markedly decrease the mRNA levels of pro-inflammatory mediators in lipopolysaccharide-stimulated cells. Furthermore, cells treated with TA-ALN (1:1) exhibited not only significantly greater alkaline phosphatase activity and calcium collection, but also outstandingly higher mRNA levels of osteogenesis-related elements such as collagen type I and osteocalcin. These outcomes indicate that the prepared TA-ALNs are excellent for antioxidant, anti-inflammatory, and osteogenic acceleration. Accordingly, TA-ALN can be used latently for bone renovation and regeneration in people with bone fractures, diseases, or disorders.

Properties and Applications of Nanoparticles from Plant Proteins

Nanoparticles from plant proteins are preferred over carbohydrates and synthetic polymeric-based materials for food, medical and other applications. In addition to their large availability and relatively low cost, plant proteins offer higher possibilities for surface modifications and functionalizing various biomolecules for specific applications. Plant proteins also avoid the immunogenic responses associated with the use of animal proteins. However, the sources of plant proteins are very diverse, and proteins from each source have distinct structures, properties and processing requirements. While proteins from corn (zein) and wheat (gliadin) are soluble in aqueous ethanol, most other plant proteins are insoluble in aqueous conditions. Apart from zein and gliadin nanoparticles (which are relatively easy to prepare), soy proteins, wheat glutenin and proteins from several legumes have been made into nanoparticles. The extraction of soluble proteins, hydrolyzing with alkali and acids, conjugation with other biopolymers, and newer techniques such as microfluidization and electrospraying have been adopted to develop plant protein nanoparticles. Solid, hollow, and core-shell nanoparticles with varying sizes and physical and chemical properties have been developed. Most plant protein nanoparticles have been used as carriers for drugs and as biomolecules for controlled release applications and for stabilizing food emulsions. This review provides an overview of the approaches used to prepare nanoparticles from plant proteins, and their properties and potential applications. The review's specific focus is on the preparation methods and applications, rather than the properties of the proteins, which have been reported in detail in other publications.

Promotion of the anticancer activity of curcumin based on a metal-polyphenol networks delivery system

Curcumin (Cur), a hydrophobic active pharmaceutical ingredient with high anticancer activity, has poor water solubility and low bioavailability. Although many delivery systems have been developed to improve their bioavailability, some limitation such as low drug loading efficiency and poor stability are still remained. The metal-polyphenol networks (MPNs) delivery system designed in this subject solved above problems and effectively improved the anticancer activity of Cur. The synthesized Cur@EGCG-Fe(III) is consisting of epigallocatechin gallate (EGCG), iron chloride (FeCl₃) and Cur, and the well-designed structure endow Cur@EGCG-Fe(III) high loading efficiency, good water solubility and stability. After the Cur@EGCG-Fe(III) nanoparticles were internalized by MCF-7 cells, the Cur could be released in endo/lysosomal microenvironment (pH = 5.0), and the Cur delivery in the deep tumor could be realized. The distribution of Cur@EGCG-Fe(III) in MCF-7 cells was analyzed by laser confocal, and Cur@EGCG-Fe(III) could effectively deliver more Cur into MCF-7 cells in comparison with free Cur. In addition, the results of flow cytometry and western blot further indicated that Cur@EGCG-Fe(III) had a stronger ability to induce apoptosis than free Cur. Transwell cell migration and invasion experiments showed that Cur and EGCG-Fe(III) had a synergistic effect in inhibiting MCF-7 cell migration and invasion. In vitro hemolysis and in vivo experiments showed that the Cur@EGCG-Fe(III) had negligible effect on the blood environment and a great tumor-inhibition efficacy, indicating that the MPNs delivery system had a good blood compatibility and antitumor activity. Our results indicated that MPNs-coated Cur nanoparticle could be a new form of Cur delivery system for anticancer application.

Tuning of Molecular Interactions between Zein and Tannic Acid to Modify Sunflower Sporopollenin Exine Capsules: Enhanced Stability and Targeted Delivery of Bioactive Macromolecules

There are multiple obstacles for the storage and digestion of orally administered bioactive macromolecules. This study developed a low-cost and sustained-release delivery system (sporopollenin exine capsules with zein/tannic acid modification) of proteins with excellent storage stability, and at the same time provided insights into the sustained-release mechanism through exploring the interaction between zein and tannic acid (TA). β-Galactosidase (β-Gal) was utilized as a model protein and loaded into sporopollenin exine capsules (SECs), which were then coated with the zein/TA system. Under the optimized zein/TA conditions, the zein/TA system showed better performance than the zein alone system in the sustained release of β-Gal, with the residual activity of about 70.26% after 24 h of simulated digestion. Evaluation of the storage stability demonstrated a β-Gal residual activity of nearly 90% for 28 days at 25 °C. Additionally, FTIR analysis demonstrated that the stability of the zein/TA system depends on both hydrogen bonding and certain covalent bonding through the Schiff-base reaction, and the sustained release is regulated by the bonding strength.

Natural Polyphenol-Vanadium Oxide Nanozymes for Synergistic Chemodynamic/Photothermal Therapy

The selection of suitable nanozymes with easy synthesis, tumor specificity, multifunction, and high therapeutics is meaningful for tumor therapy. Herein, a facile one-step assembly approach was employed to successfully prepare a novel kind of natural polyphenol tannic acid (TA) hybrid with mixed valence vanadium oxide nanosheets (TA@VO_x NSs). In this system, VO_x is assembled with TA through metal-phenolic coordination interaction to both introduce superior peroxidase-like activity and high near infrared (NIR) absorption owing to partial reduction of vanadium from V⁵⁺ to V⁴⁺ . The presence of mixed valence vanadium oxide in TA@VO_x NSs is proved to be the key for the catalytic reaction of hydrogen peroxide (H₂ O₂ ) to ^. OH, and the corresponding catalytic mechanism of H₂ O₂ by TA@VO_x NSs is proposed. Benefitting from such peroxidase-like activity of TA@VO_x NSs, the overproduced H₂ O₂ of the tumor microenvironment allows the realization of tumor-specific chemodynamic therapy (CDT). As a valid supplement to CDT, the NIR absorption enables TA@VO_x NSs to have NIR light-mediated conversion ability for photothermal therapy (PTT) of cancers. Furthermore, in vitro and in vivo experiments confirmed that TA@VO_x NSs can effectively inhibit the growth of tumors by synergistic CDT/PTT. These results offer a promising way to develop novel vanadium oxide-based nanozymes for enhanced synergistic tumor-specific treatment.

Porous Inorganic and Hybrid Systems for Drug Delivery: Future Promise in Combatting Drug Resistance and Translation to Botanical Applications

BACKGROUND

Porous micro- and nanoparticles have the capacity to encapsulate a large quantity of therapeutics, making them promising delivery vehicles for a variety of applications. This review aims to highlight the latest development of inorganic and hybrid (inorganic/ organic) particles for drug delivery with an additional emphasis on combatting drug resistant cancer. We go one step further and discuss delivery applications beyond medicinal delivery, as there is generally a translation from medicinal delivery to botanic delivery after a short lag time.

METHODS

We undertook a search of relevant peer-reviewed publications. The quality of the relevant papers was appraised using standard tools. The characteristics of the papers are described herein, and the relevant material and therapeutic properties are discussed.

RESULTS

We discuss 4 classes of porous particles in terms of drug delivery and theranostics. We specifically focus on silica, calcium carbonate, metal-phenolic network, and metalorganic framework particles. Other relevant biomedically relevant applications are discussed and we highlight outstanding therapeutic results in the relevant literature.

CONCLUSION

The findings of this review confirm the importance of studying and utilizing porous particles for therapeutic delivery. Moreover, we show that the properties of porous particles that make them promising for medicinal drug delivery also make them promising candidates for agro-industrial applications.

A pH-sensitive carrier based-on modified hollow mesoporous carbon nanospheres with calcium-latched gate for drug delivery

A novel nanocarrier based-on hollow mesoporous carbon nanospheres (HMCNs) with primary amines on its surface, a large cavity, and good hydrophilicity was synthesized by a hydrothermal reaction. The primary amine functionalities on the mesoporous carbon were used as the initiation sites for growing poly (epichlorohydrin) (PCH) chains. The chlorine groups in the side chain of PCH were replaced with imidazole as the pendant groups. Calcium chloride (CaCl₂) was applied as a capping agent. The coordination bonding was formed between pendant imidazole groups and calcium ions. Doxorubicin (DOX) was selected as a model of hydrophilic anticancer drug and was loaded onto the nanocarrier and released through the cleavage of the pH-sensitive coordination bonding. The gating mechanism enables the nanocarrier to store and release the calcium ions and the DOX molecules trapped in the pores. MTT assay toward HeLa cells indicated that the nanocarrier had low toxicity because of the surface modification with the oxygen-rich polymer. The cellular uptake of the pH-sensitive nanocarrier for HeLa cancer cell lines was confirmed by CLSM images and flow cytometry. So, the novel pH-sensitive nanocarrier can be applicable to carry and release both DOX drug and calcium ions for cancer treatment.

Co-encapsulation of Epigallocatechin Gallate (EGCG) and Curcumin by Two Proteins-Based Nanoparticles: Role of EGCG

In this study, a novel plant-protein-based nanoparticle delivery system was developed to encapsulate and stabilize curcumin and epigallocatechin gallate (EGCG) with different polarities. The strongly hydrophobic curcumin was embedded within the hydrophobic cores of zein nanoparticles using an antisolvent method, while the weakly hydrophobic EGCG was adsorbed to the region between the zein core and caseinate shell. The physicochemical properties, structure, and stability of the core-shell particles were characterized using dynamic light scattering, particle electrophoresis, fluorescence spectroscopy, and Fourier transform infrared spectroscopy. The bioaccessibility of curcumin in the core-shell nanoparticles was determined using a simulated gastrointestinal tract. Mean particle diameters around 100-200 nm could be produced by modulating the mass ratio of curcumin to zein. The encapsulation efficiency of curcumin in the core-shell nanoparticles was higher (96.2%) in the presence of EGCG than in its absence (77.9%). Moreover, the water dispersibility and 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity of the nanoparticles were significantly improved in the presence of EGCG. The simulated gastrointestinal tract experiments indicated that curcumin had a high bioaccessibility in the optimized core-shell nanoparticles. Overall, our findings suggest that EGCG can be used to improve the functional properties of curcumin-loaded zein-caseinate nanoparticles, which may increase their use in food, cosmetics, and pharmaceutical applications.

Supramolecular design and applications of polyphenol-based architecture: A review

Polyphenol-based materials are of wide-spread interest because of the unique properties of the polyphenol itself. Tannic acid, contains high level of galloyl groups, could be coordinated to a range of metal ions to generate robust mental ion-TA films on substrate or even forming hollow capsules. These films or capsules can be used in the field of sensing, separation and catalysis, most importantly in drug/nutraceutical delivery, allowing for the high loading efficiency, high mechanical and thermal stability, pH-responsive disassembly and fluorescence behavior. Additionally, such coating could also provide protection of the sensitive molecules and cells. With the numerous carbonyl and phenolic functional groups, TA has also been demonstrated to form strong hydrogen bonded multilayers with various non-ionic polymers. The properties of the hydrogen-bonded system were highly influenced by the chemical structure of the polymers, which will change the behavior of pH-, temperature- or ionic strength-responsive release of the loading molecules. Additionally, the ionization of galloyl phenol group was attributed to the interaction between TA and other ionic polymers by electrostatic interaction. The electrostatic interaction/hydrogen bonding derived TA/polyme$$%r complexes could deposit on glass slides, microcores or even forming hollow capsules, promising in their applicability to nutraceutical encapsulation, delivery and depot. Notably, polyphenols self-polymerizing could also deposit coatings on different substrates without any exogenous additives, while the comprehensive undertanding about the self-polymerizing mechenism remains unclear. This review provides a promising prospect for utilizing polyphenol-based materials to design versatile architecture in different system, used in the field of chemistry and materials science.

Tannic Acid Cross-linked Polysaccharide-Based Multifunctional Hemostatic Microparticles for the Regulation of Rapid Wound Healing

Hemostatic microparticles (HMs) have been widely used in surgery. To improve the comprehensive performance of HMs, multifunctional HMs named HM₁₅ and HM₁₅ ' are prepared from starch, carboxymethyl chitosan, hyaluronic acid, and tannic acid. Herein, tannic acid is used as an effective cross-linker. A 3D network structure for cell growth and wound repair can be formed by secondary cross-linking. Through synergistic effect of these natural materials, the process of wound healing can be regulated controllably. HM₁₅ and HM₁₅ ' have the ability of rapid hemostasis. Moreover, HM₁₅ ' shows excellent properties in antibacteria and wound healing acceleration. Blood clotting time treated with different HMs is shortened obviously from 436.8 s to 126 s. Compared with Celox, HM₁₅ and HM₁₅ ' exhibited better broad spectrum antibacterial activity against both Escherichia coli and Staphylococcus aureus. Notably, the wound can be repaired rapidly by HM₁₅ ' in 14 days. These multifunctional HMs might have an important prospect in clinical application.

Engineering Multifunctional Coatings on Nanoparticles Based on Oxidative Coupling Assembly of Polyphenols for Stimuli-Responsive Drug Delivery

In this study, zein nanoparticles (NPs) with novel multifunctional coatings based on oxidative coupling assembly of polyphenols were synthesized for the first time. This coating was formed by oxidative self-polymerization of the organic ligands (polyphenols) in an alkaline condition, which could be biodegraded by acidic pH, as a result, impacting the pH-responsive property of the system. More importantly, the high level of intracellular glutathione (GSH) could induce the biodegradation of the polyphenol coatings, resulting in a fast release of trapped anticancer drugs in the cells. Based on confocal laser scanning microscopy (CLSM) and cytotoxicity experiments, drug-loaded and polyphenol-coated zein NPs were shown to possess highly efficient internalization and an apparent cytotoxic effect on HeLa cells. Notably, the CLSM observation illustrated that coated zein NPs showed delayed drug release compared with free drug or DOX-loaded zein NPs without coatings, resulting from the pH-responsive release of loaded drug in the extra/intracellular environment. Additionally, the short-time cytotoxicity and morphology observation also confirmed the delayed drug release behavior of coated NPs. These highly biocompatible and biodegradable polyphenol-coated zein NPs may be promising vectors in the field of controlled-release biomedical applications and cancer therapy.

Electrochemical Behavior and Redox-Dependent Disassembly of Gallic Acid/FeIII Metal-Phenolic Networks

Metal-phenolic networks (MPNs) are a versatile class of organic-inorganic hybrid systems that are generating interest for applications in catalysis, bioimaging, and drug delivery. These self-assembled MPNs possess metal-coordinated structures and may potentially serve as redox-responsive platforms for triggered disassembly or drug release. Therefore, a comprehensive study of the reduction and oxidation behavior of MPNs for evaluating their redox responsiveness, specific conditions required for their disassembly, and the kinetics of metal ion release, is necessary. Using a representative MPN gallic acid-iron (GA/Fe^III) system, we conducted electrochemical studies to provide fundamental insights into the redox behavior of these MPNs. We demonstrate that GA/Fe^III is redox active, and evaluate its electrochemical reversibility, identify the oxidation state of the redox-active species, and provide information regarding the stability of the networks toward reductive stimuli and specific redox conditions required for the "on-off" or continuous release of Fe^III. Overall, through studying the redox properties of GA/Fe^III films, we advance the understanding of multifunctional iron-containing MPN platforms that may have practical significance for biologically relevant applications.

Structural characterization, formation mechanism and stability of curcumin in zein-lecithin composite nanoparticles fabricated by antisolvent co-precipitation

Curcumin (Cur) exhibits a range of bioactive properties, but its application is restrained due to its poor water solubility and sensitivity to environmental stresses. In this study, zein-lecithin composite nanoparticles were fabricated by antisolvent co-precipitation technique for delivery of Cur. The result showed that the encapsulation efficiency of Cur was significantly enhanced from 42.03% in zein nanoparticles to 99.83% in zein-lecithin composite nanoparticles. The Cur entrapped in the nanoparticles was in an amorphous state confirmed by differential scanning calorimetry and X-ray diffraction. Fourier transform infrared analysis revealed that hydrogen bonding, electrostatic interaction and hydrophobic attraction were the main interactions among zein, lecithin, and Cur. Compared with single zein and lecithin nanoparticles, zein-lecithin composite nanoparticles significantly improved the stability of Cur against thermal treatment, UV irradiation and high ionic strength. Therefore, zein-lecithin composite nanoparticles could be a potential delivery system for water-insoluble bioactive compounds with enhanced encapsulation efficiency and chemical stability.

Folate-functionalized assembly of low density lipoprotein/sodium carboxymethyl cellulose nanoparticles for targeted delivery

In this study, well-defined folate (FA)-functionalized low density lipoproteins (LDL)/sodium carboxymethyl cellulose (CMC) nanoparticles (NP) were first formulated, utilized in tumor targeting and pH-triggered drug release. CMC was modified with FA before the preparation of NP. A model anti-tumor drug, doxorubicin (DOX), was effectively loaded into the LDL/CMC-FA NP by ionic bonding and hydrophobic interactions. To enhance non-covalent encapsulation stability, self-assembly of DOX-loaded LDL/CMC-FA NP (NP-DOX) was cross-linked by multivalent cations such as Ca²⁺ (Ca²⁺-NP-DOX). The active targeting efficiency of NP-DOX and Ca²⁺-NP-DOX was tested against KB cells (FA-receptor over-expressing cells, FR+) and A549 cells (FA-receptor negative-expressing cells, FR-), using FA non-modified DOX-loaded LDL/CMC NP (NG-DOX) as control. The competition assay proved that free FA molecules prevented the cellular uptake of the NP by competitive binding to the FA receptors on the surface of KB cells. This new pH-responsive and FA-targeted nanocarrier may be a promising efficient drug delivery system for potential cancer therapy.

Tailoring stimuli-responsive delivery system driven by metal-ligand coordination bonding

In this study, a novel coordination bonding system based on metal-tannic acid (TA) architecture on zein/carboxymethyl chitosan (CMCS) nanoparticles (NPs) was investigated for the pH-responsive drug delivery. CMCS has been reported to coat on zein NPs as delivery vehicles for drugs or nutrients in previous studies. The cleavage of either the "metal-TA" or "NH2-metal" coordination bonds resulted in significant release of guest molecules with high stimulus sensitivity, especially in mild acidic conditions. The prepared metal-TA-coated zein/CMCS NPs (zein/CMCS-TA/metal NPs) could maintain particle size in cell culture medium at 37°C, demonstrating good stability compared with zein/CMCS NPs. In vitro release behavior of doxorubicin hydrochloride (DOX)-loaded metal-TA film-coated zein/CMCS NPs (DOX-zein/CMCS-TA/metal NPs) showed fine pH responsiveness tailored by the ratio of zein to CMCS as well as the metal species and feeding concentrations. The blank zein/CMCS-TA/metal NPs (NPs-TA/metal) were of low cytotoxicity, while a high cytotoxic activity of DOX-zein/CMCS-TA/metal NPs (DOX-NPs-TA/metal) against HepG2 cells was demonstrated by in vitro cell assay. Confocal laser scanning microscopy (CLSM) and flow cytometry were combined to study the uptake efficiency of DOX-NPs or DOX-NPs-TA/metal. This system showed significant potential as a highly versatile and potent platform for drug delivery.

Synthesis and Characterization of Chlorpyrifos/Copper(II) Schiff Base Mesoporous Silica with pH Sensitivity for Pesticide Sustained Release

The salicylaldehyde-modified mesoporous silica (SA-MCM-41) was prepared through a co-condensation method. Through the bridge effect from the copper ion, which also acts as the nutrition of the plant, the model drug chlorpyrifos (CH) was supported on the copper(II) Schiff base mesoporous silica (Cu-MCM-41) to form a highly efficient sustained-release system (CH-Cu-MCM-41) for pesticide delivery. The experimental results showed that the larger the concentration of the copper ion, the more adsorption capacity (AC) of Cu-MCM-41 for chlorpyrifos and the smaller its release rate. The results confirmed the existence of a coordination bond between SA-MCM-41 and copper ions as well as a coordination bond between Cu-MCM-41 and chlorpyrifos. The AC of SA-MCM-41 is 106 mg/g, while that of Cu-MCM-41 is 295 mg/g. The as-synthesized system showed significant pH sensitivity. Under the condition of pH ≤ 7, the release rate of chlorpyrifos decreased with increasing pH, whereas its release rate in weak base conditions was slightly larger than that in weak acid conditions. Meanwhile, the drug release rate of the as-synthesized system was also affected by the temperature. Their sustained-release curves can be described by the Korsmeyer-Peppas equation.

Nanogels fabricated from bovine serum albumin and chitosan via self-assembly for delivery of anticancer drug

In this study, bovine serum albumin (BSA) and chitosan (CS) were used to prepare BSA-CS nanogels by a simple green self-assembly technique. Then the nanogels were successfully used to entrap doxorubicin hydrochloride (DOX) with an entrapment ratio of 46.3%, aiming to realize the slow-release effect and lower the cytotoxicity of DOX. The IC50 values of DOX-loaded BSA-CS (DOX-BSA-CS) and free DOX obtained by MTT assay in SGC7901 cells were 0.22 and 0.05μg/mL, respectively. The cytotoxicity of DOX significantly decreased within 24h after encapsulation by the nanogels, indicating that the loaded drug could slowly release within 24h and the BSA-CS was a good slow release system. The cellular uptake experiments indicated DOX-BSA-CS diffused faster into the cancer cell than the bare drug. The flow cytometry and TUNEL assay proved DOX-BSA-CS could induce a larger apoptosis proportion of gastric cancer cells 7901 than the bare drug and it is promising to be used for curing gastric cancer.

Inherently antioxidant and antimicrobial tannic acid release from poly(tannic acid) nanoparticles with controllable degradability

From a natural polyphenol, Tannic acid (TA), poly(TA) nanoparticles were readily prepared using a single step approach with three different biocompatible crosslinkers; trimethylolpropane triglycidyl ether (TMPGDE), poly(ethylene glycol) diglycidyl ether (PEGGE), and trisodium trimetaphosphate (STMP). P(TA) particles were obtained with controllable diameters between 400 to 800nm with -25mV surface charge. The effect of synthesis conditions, such as the emulsion medium, pH values of TA solution, and the type of crosslinker, on the shape, size, dispersity, yield, and degradability of poly(Tannic Acid) (p(TA)) nanoparticles was systematically investigated. The hydrolytic degradation amount in physiological pH conditions of 5.4, 7.4, and 9.0 at 37.5°C were found to be in the order TMPGDE<PEGGE<STMP. Furthermore, the degradation amounts of TA from p(TA) nanoparticles can be controlled by the appropriate choice of crosslinker, and the pH of releasing media. The highest TA release, 600mg/g, was obtained for TMPGDE-crosslinked p(TA) particles in intestinal pH conditions (pH 9) over 3 days; whereas, a slow and linear TA release profile over almost 30 days was obtained by using PEGGE-crosslinked p(TA) in body fluid pH conditions (pH 7.4). The total phenol content of p(TA) particles was calculated as 70±1μgmL(-1) for 170μgmL(-1) p(TA), and the trolox equivalent antioxidant capacity was found to be 2027±104mM trolox equivalent g(-1). Moreover, p(TA) nanoparticles demonstrated strong antimicrobial effects against common bacterial strains. More interestingly, with a higher concentration of p(TA) particles, higher blood clotting indices were obtained.

Engineering functional alginate beads for encapsulation of Pickering emulsions stabilized by colloidal particles

Pickering emulsions are widely used as delivery systems in food, cosmetics, and pharmaceutical industries for the encapsulation and sustained release of hydrophilic compounds.

Coordination-driven multilayer of phosvitin-polyphenol functional nanofibrous membranes: antioxidant and biomineralization applications for tissue engineering

The layer-by-layer (LBL) deposition technique has been widely used to decorate the nanofibers formed from polymer pairs with complementary functional groups.

pH-Degradable antioxidant nanoparticles based on hydrogen-bonded tannic acid assembly

Hydrogen-bonded polyphenol-based assemblies have attracted increasing interest for biomedical applications.