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

Preparation, characterization, and application of chitosan preservation film doped with polyphenol-nanohydroxyapatite

Effective packaging is crucial for maintaining food quality, safety, and nutritional value. Chitosan (CS) films retard food oxidation by blocking oxygen and water vapor but lack sufficient antioxidant properties for long-term storage. To address this issue, this study investigated the properties of composite films prepared using CS and nanohydroxyapatite (nHAP) loaded with polyphenolic compounds (curcumin, epigallocatechin gallate [EGCG], and quercetin), and their impact on semi-dried golden pomfret (Trachinotus ovatus) freshness. The incorporation of nHAP substantially enhanced the mechanical strength, thermal stability, barrier properties, and oil adsorption capacity of the films. Fourier Transform Infrared Spectroscopy (FTIR) revealed that the incorporation of nHAP or polyphenol-nHAP carriers did not form a substantial number of new chemical bonds or intermolecular crosslinks. Instead, the carriers were continuously dispersed within the CS matrix. Electron microscopy further confirmed the good compatibility between the polyphenol-nHAP carrier and CS matrix. Furthermore, the in vitro drug release profile demonstrated that nHAP effectively controlled polyphenol release, minimizing loss. The composite film significantly reduced the total volatile base nitrogen (TVB-N) of semi-dried golden pomfret fish flesh, delayed protein and lipid oxidation, inhibited microbes, and maintained muscle water-holding capacity. In summary, CS-polyphenol-nHAP films offer a novel method for preserving aquatic products.

Alginate supramolecular for encapsulation of plant biocontrol bacteria: A review

This study investigates the transformative potential of supramolecular encapsulation of alginate in improving biological control strategies by increasing the stability and efficacy of beneficial microbial agents. With the increasing importance of sustainable agriculture, biological control measures have emerged as a promising alternative to chemical pesticides. Alginate, a naturally occurring biopolymer, serves as an ideal medium for the encapsulation of these microbial agents, ensuring their targeted release and sustained efficacy in the plant environment. The research addresses the mechanisms by which alginate encapsulation not only protects the viability of the microorganisms, but also enables better interaction with the host plants, which ultimately strengthens plant defenses. Furthermore, the results suggest that this innovative delivery system could significantly reduce dependence on synthetic pesticides and promote environmentally friendly agricultural practices. The study underscores the importance of interdisciplinary collaboration and further research to refine alginate-based formulations, opening the door to a new era of agriculture that balances productivity and environmental sustainability.

Hemoglobin-decorated metal polyphenol network platform featuring antibacterial, antioxidant, and oxygen carrying properties for promoting infected diabetic wound healing

Chronic wounds have emerged as a formidable challenge in diabetes management, leading to high morbidity and mortality. The diabetic wound healing is often impaired due to recurrent bacterial infections, excessive reactive oxygen species (ROS), and severe hypoxia. Thus, we developed a multifunctional nanoplatform that exhibited remarkable antibacterial activity, ROS scavenging and oxygen-carrying properties. Metal-phenol network (MPN) as core material was synthesized by assembling tannic acid (TA) with Fe2⁺ via coordination and hydrophobic interactions. Subsequently, hemoglobin (Hb) was decorated onto MPN surface through cation-π interactions. MPN protected Hb against oxidation and preserved its physiological function, facilitating oxygen transport. Moreover, MPN-Hb displayed robust and broad-spectrum antioxidant activity that can effectively scavenge ROS and reactive nitrogen species. Under near-infrared (NIR) irradiation, MPN-Hb demonstrated excellent bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), effectively eradicated biofilms through hyperthermia. In vivo studies have shown that MPN-Hb with good biocompatibility could effectively eliminate bacteria at the wound site, mitigate the inflammatory response, and promote collagen deposition and angiogenesis, thereby accelerating wound healing. Overall, this multifunctional nanoplatform offers a straightforward, safe, and efficient therapeutic strategy for treating chronic diabetic wounds.

Surface-functionalized bacteria: Frontier explorations in next-generation live biotherapeutics

Screening robust living bacteria to produce living biotherapeutic products (LBPs) represents a burgeoning research field in biomedical applications. Despite their natural abilities to colonize bio-interfaces and proliferate, harnessing bacteria for such applications is hindered by considerable challenges in unsatisfied functionalities and safety concerns. Leveraging the high degree of customization and adaptability on the surface of bacteria demonstrates significant potential to improve therapeutic outcomes and achieve tailored functionalities of LBPs. This review focuses on the recent laboratory strategies of bacterial surface functionalization, which aims to address these challenges and potentiate the therapeutic effects in biomedicine. Firstly, we introduce various functional materials that are used for bacterial surface functionalization involving organic, inorganic, and biological materials. Secondly, the methodologies for achieving bacterial surface functionalization are categorized into three primary approaches including covalent bonding, non-covalent interactions, and hybrid techniques, while various advantages and limitations of different modification strategies are compared from multiple perspectives. Subsequently, the current status of the applications of surface-functionalized bacteria in bioimaging and disease treatments, especially in the treatment of inflammatory bowel disease (IBD) and cancer is summarized. Finally, challenges and pressing issues in the development of surface-functionalized bacteria as LBPs are presented.

Design, fabrication, and performance evaluation of curcumin-loaded nanoparticles based on zein, hyaluronic acid, and tannic acid

Nanoparticles have attracted considerable attention as colloidal delivery systems. The performance of nanoparticles can be enhanced by assembling multiple structural components with different functional attributes. In this study, a model hydrophobic nutraceutical (curcumin) was encapsulated in nanoparticles assembled from zein, hyaluronic acid, and tannic acid to enhance its functionality. Specifically, curcumin was loaded into zein-hyaluronic acid-tannic acid (Cur-ZHT) nanoparticles prepared using anti-solvent precipitation. The optimized nanoparticle formulation had a relatively high encapsulation efficiency (92.11 ± 0.13 %), small mean particle diameter (307.40 ± 2.40 nm), and low polydispersity index (0.26 ± 0.01). Hydrophobic interactions and hydrogen bonding played an important role in the assembly of these nanoparticles. Curcumin in Cur-ZHT nanoparticles was protected against environmental stresses, including heating, light exposure, and storage for 30 days. The presence of tannic acid in the nanoparticles enhanced the chemical stability of the curcumin, which was attributed to its strong antioxidant properties. In vitro digestion studies showed that Cur-ZHT nanoparticles effectively protected curcumin from decomposition in gastric juice. Compared to the bioaccessibility of free curcumin (17.44 ± 0.32 %), that of Cur-ZHT nanoparticles was significantly improved to 50.44 ± 0.87 %. The multicomponent nanoparticles developed in this study are suitable for improving the solubility, stability, and bioavailability of hydrophobic bioactive compounds.

The in situ stability of nobiletin in green tea infusion regulating by the assembly of small molecules

Abandoning the traditional way of constructing delivery carriers with structural materials, the natural food system is used as the steady-state basis of functional factors. This study innovatively proposes directly using the original green tea infusion, rich in tea polyphenols, to construct a stable system, thereby achieving the efficient loading and long-term stability of nobiletin (NOB). Specifically, the concentration of NOB in the system reaches up to 1 mg/mL, with an encapsulation rate and loading rate exceeding 95 % and 75 %, respectively. Importantly, it is found that the assembly of key small molecules EGCG and caffeine achieves NOB homeostasis. Moreover, hydrogen bonding and electrostatic interaction are the main forces stabilizing the assembly, and the binding ratio of NOB to EGCG and Caffeine is 1:0.4 and 1:1.2, separately. The design strategy is expected to provide a new idea for the directional design of healthier future food.

Polyphenol and metal ion-reinforced supermolecular hydrogels incorporating nanofiber drug and peptide for annulus fibrosus regeneration

Rationale: Following the structural destruction of annulus fibrosus (AF), the early-stage damage manifests as symptoms such as an inflammatory phenotype and loss of mechanical support. The microenvironmental deterioration at the injury site, the limited population, and the inadequate differentiation of intrinsic stem/progenitor cells impede the efficient repair of AF. To address the aforementioned challenges, we developed a dual-drug-loaded hydrogel system to achieve systematic and functional annulus fibrosus tissue repair. Methods: A tannic acid-crosslinked gelatin-based hydrogel scaffold with the addition of Mn2+ was designed to work as a platform to provide mechanical support, antioxidant capacity, and immune-modulating function. The kartogenin-loaded nanofiber and SDF-1α mimic peptide were also incorporated into the hydrogel system to facilitate the recruitment of endogenous stem cells and direct AF tissue regeneration. Results: The resulting hydrogel scaffolds exhibit excellent biogenic properties while achieving mechanical properties similar to those of AF. The composite scaffold also enhances ROS clearance and promotes M2 polarization of macrophages to improve the inflammatory microenvironment during early-stage injury. Furthermore, the sustained release of kartogenin-loaded nanofiber and SDF-1α mimic peptide effectively enhances endogenous stem cell recruitment, promotes cartilage differentiation, and facilitates specific extracellular matrix deposition, thus meeting requirements for late-stage AF repair. Conclusion: The findings demonstrate the potential of a multifunctional, high-strength supramolecular hydrogel loaded with dual drugs for the functional regeneration of AF tissue.

Nanomedicine's shining armor: understanding and leveraging the metal-phenolic networks

Metal-phenolic networks (MPNs), which comprise supramolecular amorphous networks formed by interlinking polyphenols with metal ions, garner escalating interest within the realm of nanomedicine. Presently, a comprehensive synthesis of the cumulative research advancements and utilizations of MPNs in nanomedicine remains absent. Thus, this review endeavors to firstly delineate the characteristic polyphenols, metal ions, and their intricate interaction modalities within MPNs. Subsequently, it elucidates the merits and demerits of diverse synthesis methodologies employed for MPNs, alongside exploring their potential functional attributes. Furthermore, it consolidates the diverse applications of MPNs across various nanomedical domains encompassing tumor therapy, antimicrobial interventions, medical imaging, among others. Moreover, a meticulous exposition of the journey of MPNs from their ingress into the human body to eventual excretion is provided. Lastly, the persistent challenges and promising avenues pertaining to MPNs are delineated. Hence, this review offering a comprehensive exposition on the current advancements of MPNs in nanomedicine, consequently offering indirect insights into their potential clinical implementation.

Tannic acid coordination assembly enhances the interfacial properties of salted egg white gel particles

Tannic acid (TA) has attracted the attention of researchers as a promising organic ligand capable of forming metal-organic coordination networks with various metal ions at interfaces to impact surface properties. In this study, we innovatively reported a self-assembly method for surface decoration by depositing TA/Fe3+ coatings on the surface of desalted duck egg white nanoparticles (DEWN), further studying the oil/water interfacial properties of the modified particles. The results showed that the ratio and concentration of TA to Fe3+ could modulate interfacial properties. The modified DEWN has low interfacial tension, with TFe2 having near-neutral wettability (θo/w ∼ 90°) and stabilizing emulsions for over 60 days. Moreover, the emulsions stabilized by TFe1 and TFe2 formed stronger gel structures with better thixotropic recovery (98.82 % and 89.26 %). After further increasing the oil phase ratio, the increased layer assembly concentration improved the stability of the oil phase and formed a dense gel mesh structure. The effects of temperature and salt ion concentration on the emulsion were investigated under optimum conditions, both of which showed good stability. Overall, our research not only highlighted straightforward strategies for preparing emulsions with higher stability using green and sustainable raw materials, but also broadened the range of applications for metal-phenol decoration.

Tailoring carrier-free nanoparticles based on natural small molecule assembly for synergistic anti-tumor efficacy

Interfacial modular assemblies of versatile polyphenols have attracted widespread interest in surface and materials engineering. In this study, natural polyphenol (tannic acid, TA) and nobiletin (NOB) can directly form binary carrier-free spherical nanoparticles (NT NPs) through synergistically driven by a variety of interactions (such as hydrogen bonding, oxidative reactions, etc.). The synthesis involves polyphenolic deposition on hydrophobic NOB nanoaggregates, followed by in situ oxidative self-polymerization. Interestingly, the assembled NT NPs exhibit controllable and dynamic changes in particle size during the initial stage. Ultimately, uniform and spherical NT NPs appear stable, with high loading capability, enabling incorporated NOB to preserve their function. Furthermore, in vitro evaluations demonstrate that the rational combination of polyphenol module and NOB can induce apoptosis and inhibit tumor metastasis for both lung cancer H1299 and human fibrosarcoma HT1080 cell lines. Notably, the optimized NT48 NPs were then verified in vivo experiments to achieve a promising synergistic anti-tumor efficacy. These findings not only provide new opportunities for the streamlined and sensible engineering of future polyphenol-based biomaterials, but also open up new prospects for the design of small-molecule nature phytochemicals.

Tailored extracellular matrix-mimetic coating facilitates reendothelialization and tissue healing of cardiac occluders

Minimally invasive transcatheter interventional therapy utilizing cardiac occluders represents the primary approach for addressing congenital heart defects and left atrial appendage (LAA) thrombosis. However, incomplete endothelialization and delayed tissue healing after occluder implantation collectively compromise clinical efficacy. In this study, we have customized a recombinant humanized collagen type I (rhCol I) and developed an rhCol I-based extracellular matrix (ECM)-mimetic coating. The innovative coating integrates metal-phenolic networks with anticoagulation and anti-inflammatory functions as a weak cross-linker, combining them with specifically engineered rhCol I that exhibits high cell adhesion activity and elicits a low inflammatory response. The amalgamation, driven by multiple forces, effectively serves to functionalize implantable materials, thereby responding positively to the microenvironment following occluder implantation. Experimental findings substantiate the coating's ability to sustain a prolonged anticoagulant effect, enhance the functionality of endothelial cells and cardiomyocyte, and modulate inflammatory responses by polarizing inflammatory cells into an anti-inflammatory phenotype. Notably, occluder implantation in a canine model confirms that the coating expedites reendothelialization process and promotes tissue healing. Collectively, this tailored ECM-mimetic coating presents a promising surface modification strategy for improving the clinical efficacy of cardiac occluders.

Large Language Modeling to Assist Natural Polyphenols as Green Precipitants for Recycling Spent Batteries

The growing demand for energy storage batteries, driven by the need to alleviate global warming and reduce fossil fuel dependency, has led to environmental concerns surrounding spent batteries. Efficient recycling of these batteries is essential to prevent pollution and recover valuable metal ions such as nickel (Ni2+), cobalt (Co2+), and manganese (Mn2+). Conventional hydrometallurgical methods for battery recycling, while effective, often involve harmful chemicals and processes. Natural polyphenols offer a greener alternative due to their ability to coordinate with metal ions. However, optimizing polyphenol selection for efficient recovery remains a labor-intensive challenge. This study presents a strategy combining natural polyphenols as green precipitants with the power of GPT-4, a large language model (LLM), to enhance the precipitation and recovery of metal ions from spent batteries. By leveraging the capabilities of GPT-4 in natural language processing, we enable a dynamic, iterative collaboration between human researchers and the LLM, optimizing polyphenol selection for different experimental conditions. The results show that tannic acid achieved precipitation rates of 94.8, 96.7, and 96.7% for Ni2+, Co2+, and Mn2+, respectively, outperforming conventional methods. The integration of GPT-4 enhances both the efficiency and accuracy of the process, ensuring environmental sustainability by minimizing secondary pollution and utilizing biodegradable materials. This innovative strategy demonstrates the potential of combining artificial intelligence-driven analysis with green chemistry to address battery recycling challenges, paving the way for more sustainable and efficient methods.

Fluorescent poly(tannic acid)-based nanoprobes for selective and sensitive detection of bismuth ions

Herein, blue luminescent fluorescent poly(tannic acid) nanoparticles (FPTA NPs) were fabricated through chemical degradation of poly(tannic acid) large particles using H2O2, and the obtained FPTA NPs exhibited excellent water dispersibility, great fluorescence stability, and relatively high quantum yield. More importantly, based on the dynamic quenching and chelation enhanced quenching effect between FPTA NPs and bismuth ions (Bi3+), a fluorescence method for the rapid identification and detection of Bi3+ was developed. With the increase of Bi3+, the fluorescence of FPTA NPs could be quenched gradually; the linear range was 0.2-80 μM, R2 was 0.997, the detection limit was 13.54 nM, and the response time was as short as 10 s. The FPTA NP based nanoprobe was successfully applied for the determination of Bi3+ in water samples, and the recovery rate ranged from 98.18% to 105.89%, with a relative standard deviation of less than 3.48%, thereby confirming the feasibility of using FPTA NPs for detecting Bi3+ in real water samples.

A highly sensitive Photothermal Immunochromatographic test strip for detection of aflatoxin B1 based on CoS@TA Nanospheres

A novel photothermal immunochromatographic test strip (PITS) with tannic acid (TA) modified cobalt sulfide (CoS) nanospheres (CoS@TA) as immuno-probe element was developed for the detection of aflatoxin B1 (AFB1). CoS nanospheres (CoS NPs) with excellent photothermal conversion efficiency (η = 47.5 %) was synthesized and skillfully chelated with TA to improve its dispersion, biocompatibility, and chromatographic properties. After modification, the CoS@TA coupled with monoclonal antibody (mAb) against AFB1 (CoS@TA-mAb) by simple physical adsorption. The CoS@TA based PITS achieved highly sensitive detection of AFB1 with the limit of detection in photothermal signal (photothermal-LOD) of 0.00503 μg/L, which was 19.88-fold higher than the LOD in visual signal (visual-LOD, 0.1 μg/L). The application of TA in the modification of CoS provided ideas to improve the properties of functional nanomaterials such as dispersion and biocompatibility, and the application of CoS@TA in PITS construction laid a methodological foundation for further improving the detection sensitivity of trace targets.

Osteochondral Tissue Engineering: Scaffold Materials, Fabrication Techniques and Applications

Osteochondral damage, caused by trauma, tumors, or degenerative diseases, presents a major challenge due to the limited self-repair capacity of the tissue. Traditional treatments often result in significant trauma and unpredictable outcomes. Recent advances in bone/cartilage tissue engineering, particularly in scaffold materials and fabrication technologies, offer promising solutions for osteochondral regeneration. This review highlights the selection and design of scaffolds using natural and synthetic materials such as collagen, chitosan (Cs), and polylactic acid (PLA), alongside inorganic components like bioactive glass and nano-hydroxyapatite (nHAp). Key fabrication techniques-freeze-drying, electrospinning, and 3D printing-have improved scaffold porosity and mechanical properties. Special focus is placed on the design of multiphasic scaffolds that mimic natural tissue structures, promoting cell adhesion and differentiation and supporting the regeneration of cartilage and subchondral bone. In addition, the current obstacles and future directions for regenerating damaged osteochondral tissues will be discussed.

Recent advances in dietary polyphenols (DPs): antioxidant activities, nutrient interactions, delivery systems, and potential applications

Dietary polyphenols (DPs) have garnered growing interest because of their potent functional properties and health benefits. Nevertheless, the antioxidant capabilities of these substances are compromised by their multifarious structural compositions. Furthermore, most DPs are hydrophobic and unstable when subjected to light, heat, and varying pH conditions, restricting their practical application. Delivery systems based on the interactions of DPs with food constituents such as proteins, polypeptides, polysaccharides, and metal ions are being created as a viable option to improve the functional activities and bioavailability of DPs. In this review, the latest discoveries on the dietary sources, structure-antioxidant activity relationships, and interactions with nutrients of DPs are discussed. It also innovatively highlights the application progress of polyphenols and their green nutraceutical delivery systems. The conclusion drawn is that the various action sites and structures of DPs are beneficial for predicting and designing polyphenols with enhanced antioxidant attributes. The metal complexation of polyphenols and green encapsulation systems display promising outcomes for stabilizing DPs during food processing and in vivo digestion. In the future, more novel targeted delivery systems of DPs for nutrient fortification and intervention should be developed. To expand their usage in customized food products, they should meet the requirements of specific populations for personalized food and nutrition.

Nature-inspired adhesive systems

Many organisms in nature thrive in intricate habitats through their unique bio-adhesive surfaces, facilitating tasks such as capturing prey and reproduction. It's important to note that the remarkable adhesion properties found in these natural biological surfaces primarily arise from their distinct micro- and nanostructures and/or chemical compositions. To create artificial surfaces with superior adhesion capabilities, researchers delve deeper into the underlying mechanisms of these captivating adhesion phenomena to draw inspiration. This article provides a systematic overview of various biological surfaces with different adhesion mechanisms, focusing on surface micro- and nanostructures and/or chemistry, offering design principles for their artificial counterparts. Here, the basic interactions and adhesion models of natural biological surfaces are introduced first. This will be followed by an exploration of research advancements in natural and artificial adhesive surfaces including both dry adhesive surfaces and wet/underwater adhesive surfaces, along with relevant adhesion characterization techniques. Special attention is paid to stimulus-responsive smart artificial adhesive surfaces with tunable adhesive properties. The goal is to spotlight recent advancements, identify common themes, and explore fundamental distinctions to pinpoint the present challenges and prospects in this field.

Biomedical applications of stimuli-responsive nanomaterials

Nanomaterials have aroused great interests in drug delivery due to their nanoscale structure, facile modifiability, and multifunctional physicochemical properties. Currently, stimuli-responsive nanomaterials that can respond to endogenous or exogenous stimulus display strong potentials in biomedical applications. In comparison with conventional nanomaterials, stimuli-responsive nanomaterials can improve therapeutic efficiency and reduce the toxicity of drugs toward normal tissues through specific targeting and on-demand drug release at pathological sites. In this review, we summarize the responsive mechanism of a variety of stimulus, including pH, redox, and enzymes within pathological microenvironment, as well as exogenous stimulus such as thermal effect, magnetic field, light, and ultrasound. After that, biomedical applications (e.g., drug delivery, imaging, and theranostics) of stimuli-responsive nanomaterials in a diverse array of common diseases, including cardiovascular diseases, cancer, neurological disorders, inflammation, and bacterial infection, are presented and discussed. Finally, the remaining challenges and outlooks of future research directions for the biomedical applications of stimuli-responsive nanomaterials are also discussed. We hope that this review can provide valuable guidance for developing stimuli-responsive nanomaterials and accelerate their biomedical applications in diseases diagnosis and treatment.

Elution behavior of drugs in high-speed counter-current chromatography using on-column complexation with metal ions

In this study, determination of (nitrogen containing) drugs by on-column complexation with metal ions in high-speed counter-current chromatography (HSCCC) was investigated. Bromazepam (BMP) was strongly retained in the organic upper stationary phase (UP) of the two-phase solvent system composed of tert-butyl methyl ether-acetonitrile-water (2:2:3, v/v/v) by eluting the aqueous lower mobile phase (LP) at a flow rate of 2 mL min-1. On the other hand, BMP (200 µg mL-1) was eluted faster without retention to the organic UP with the two-phase system containing 100 μg mL-1 of copper ions (CuCl2) because a very polar BMP-Cu2+ complex was immediately formed in the aqueous LP. The dramatic change in the retention behavior of BMP resulted from on-column complexation. The on-column complexation in HSCCC was further investigated for five (nitrogen containing) drugs and seven metal ions. In the result, tizanidine and phentolamine formed complexes with Al3+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+, ambroxol formed complexes with Al3+, Fe2+, and Cu2+, but voriconazole formed no complexes with all metal ions tested.

Antioxidant Hydrogels: Antioxidant Mechanisms, Design Strategies, and Applications in the Treatment of Oxidative Stress-Related Diseases

Oxidative stress is a biochemical process that disrupts the redox balance due to an excess of oxidized substances within the cell. Oxidative stress is closely associated with a multitude of diseases and health issues, including cancer, diabetes, cardiovascular diseases, neurodegenerative disorders, inflammatory conditions, and aging. Therefore, the developing of antioxidant treatment strategies has emerged as a pivotal area of medical research. Hydrogels have garnered considerable attention due to their exceptional biocompatibility, adjustable physicochemical properties, and capabilities for drug delivery. Numerous antioxidant hydrogels have been developed and proven effective in alleviating oxidative stress. In the pursuit of more effective treatments for oxidative stress-related diseases, there is an urgent need for advanced strategies for the fabrication of multifunctional antioxidant hydrogels. Consequently, the authors' focus will be on hydrogels that possess exceptional reactive oxygen species and reactive nitrogen species scavenging capabilities, and their role in oxidative stress therapy will be evaluated. Herein, the antioxidant mechanisms and the design strategies of antioxidant hydrogels and their applications in oxidative stress-related diseases are discussed systematically in order to provide critical insights for further advancements in the field.

A pH responsive tannic acid/quaternized carboxymethyl chitosan/oxidized sodium alginate hydrogels for accelerated diabetic wound healing and real-time monitoring

Treatment of diabetic wounds is a major clinical issue. Diabetic wound dressings have higher requirements for anti-oxidant, antibacterial and wound monitoring properties compared to conventional wound dressings. In this study, a novel tannic acid (TA)/quaternized carboxymethyl chitosan (QCMCS)/oxidized sodium alginate (OSA)@carbon quantum dots (CQD) (TA/QCMCS/OSA@CQD) hydrogels for promoting diabetic wound healing and real-time monitoring have been developed. The TA/QCMCS/OSA@CQD hydrogels exhibited excellent self-healing, antibacterial and antioxidant properties. Besides, these hydrogels possessed good biocompatibility and effective hemostasis in a mouse liver injury model and significantly facilitated the healing process in a diabetic wound model. In addition, these hydrogels can reliable and timely measure the diabetic wound pH information by collecting image signals of hydrogels to monitor the healing status. Therefore, the pH responsive TA/QCMCS/OSA@CQD hydrogels could be utilized as wound dressing for promoting diabetic wound healing and real-time monitoring.

Lactoferrin-Anchored Tannylated Mesoporous Silica Nanomaterials-Induced Bone Fusion in a Rat Model of Lumbar Spinal Fusion

Lactoferrin (LF) is a potent antiviral, anti-inflammatory, and antibacterial agent found in cow and human colostrum which acts as an osteogenic growth factor. This study aimed to investigate whether LF-anchored tannylated mesoporous silica nanomaterials (TA-MSN-LF) function as a bone fusion material in a rat model. In this study, we created TA-MSN-LF and measured the effects of low (1 μg) and high (100 μg) TA-MSN-LF concentrations in a spinal fusion animal model. Rats were assigned to four groups in this study: defect, MSN, TA-MSN-LF-low (1 μg/mL), and TA-MSN-LF-high (100 μg/mL). Eight weeks after surgery, a greater amount of radiological fusion was identified in the TA-MSN-LF groups than in the other groups. Hematoxylin and eosin staining showed that new bone fusion was induced in the TA-MSN-LF groups. Additionally, osteocalcin, a marker of bone formation, was detected by immunohistochemistry, and its intensity was induced in the TA-MSN-LF groups. The formation of new vessels was induced in the TA-MSN-LF-high group. We also confirmed an increase in the serum osteocalcin level and the mRNA expression of osteocalcin and osteopontin in the TA-MSN-LF groups. TA-MSN-LF showed effective bone fusion and angiogenesis in rats. We suggest that TA-MSN-LF is a potent material for spinal bone fusion.

Multicolor Hair Dyeing with Biocompatible Dark Polyphenol Complex-Integrated Shampoo with Reactive Oxygen Species Scavenging Activity

Hair dyeing has become a prevalent lifestyle trend, especially within the fashion industry. However, it possesses disadvantages, such as containing carcinogenic and toxic materials. In this study, we developed a biocompatible hair-dyeing technology using a shampoo with a dark polyphenol complex (DPC), referred to as S-DPC. The DPC was formed from a mixture of gallic acid and [1,1'-biphenyl]-2,2',4,4',5,5'-hexol and used to enhance both the stability of the hair coating and its ability to scavenge reactive oxygen species (ROS). Colloidal DPC particles play a pivotal role in the coating process of various hair dyes, ensuring the uniform coloring of human hair through intermolecular interactions such as hydrogen bonding. Owing to the effect of a polyphenol complex on hair coating, we observed improved antistatic performance and enhanced mechanical strength, resulting in a substantial increase in elongation at the breaking point from 33.74% to 48.85%. The multicolor S-DPC exhibited antioxidant properties, as indicated by its ROS-scavenging ability, including 2,2-diphenyl-1-picrylhydrazyl inhibition (87-89%), superoxide radical scavenging (84-87%), and hydroxyl radical scavenging (95-98%). Moreover, the in vitro analysis of the DPC revealed nearly 100% cell viability in live and dead assays, highlighting the remarkable biocompatibility of the DPC. Therefore, considering its effectiveness and safety, this biomaterial has considerable potential for applications in hair dyeing.

Tannic Acid as a Versatile Template for Silica Monoliths Engineering with Catalytic Gold and Silver Nanoparticles

Tannic acid in alkaline solutions in which sol-gel synthesis is usually performed with tetraethoxysilane is susceptible to various modifications, including formation of reactive radicals, oxidation under the action of atmospheric oxygen, self-association, and self-polymerization. Here, a precursor with ethylene glycol residues instead of ethanol was used, which made it possible to synthesize bionanocomposites of tannic acid and silica in one stage in neutral media under normal conditions without the addition of acid/alkali and organic solvents. Silica was fabricated in the form of optically transparent monoliths of various shapes with 2-4 nm pores, the radius of which well correlated with the size of a tannic acid macromolecule in a non-aggregated state. Polyphenol, which was remained in pores of silica matrix, served then as reducing agent to synthesize in situ gold and silver nanoparticles. As shown, these Au@SiO₂ and Ag@SiO₂ nanocomposites possessed localized surface plasmon resonance and high catalytic activity.

Biopolymer coating for particle surface engineering and their biomedical applications

Surface engineering of particles based on a polymeric coating is of great interest in materials design and applications. Due to the disadvantages of non-biodegradability and undesirable biocompatibility, the application of petroleum-based synthetic polymers coating in the biomedical field has been greatly limited. In addition, there is lack of a universal surface modification method to functionalize particles of different compositions, sizes, shapes, and structures. Thus, it is imperative to develop a versatile biopolymeric coating with good biocompatibility and tunable biodegradability for the preparation of functional particle materials regardless of their surface chemical and physical structures. Recently, the natural polysaccharide polymers (e.g. chitosan and cellulose), polyphenol-based biopolymers (e.g. polydopamine and tannic acid), and proteins (e.g. amyloid-like aggregates) have been utilized in surface modification of particles, and applications of these modified particles in the field of biomedicine have been also intensively exploited. In this review, the preparation of the above three coatings on particles surface are summarized, and the applications of these materials in drug loading/release, biomineralization, cell immobilization/protection, enzyme immobilization/protection, and antibacterial/antiviral are exemplified. Finally, the challenges and the future research directions on biopolymer coating for particles surface engineering are prospected.

A J-aggregated nanoporphyrin overcoming phototoxic side effects in superior phototherapy with two-pronged effects

Phototherapy has been a promising therapeutic modality for pathological tissue due to its spatiotemporal selectivity and non-invasive characteristics. However, as a core component of phototherapy, a single photosensitizer (PS) nanoplatform integrating excellent therapeutic efficiency and minimal side effects remains an urgent but unmet need. Here, we construct a J-aggregated nano-porphyrin termed MTE based on the self-assembly of methyl-pheophorbide a derivative MPa-TEG (MT) and natural polyphenolic compound epigallocatechin gallate (EGCG). Due to the synergistic interaction between similar large π-conjugated structural EGCG and MT, MTE with small and uniform size is obtained by effectively hindering Ostwald ripening of MT. Noteworthily, MTE not only effectively avoids the inadvertent side effects of phototoxicity during transport thank to the ability of reactive oxygen species (ROS) scavenging, but also achieves two-pathway augmented superior phototherapy: (1) enhancing photodynamic therapy (PDT) via inhibiting the expression of anti-apoptosis protein surviving; (2) achieving adjuvant mild-temperature laser interstitial thermal therapy (LITT) via reducing the tumor thermoresistance on account that MTE inhibits the overexpression of HSP 70 and HSP 90. This research not only offers a facile strategy to construct multicomponent nanoplatforms but also provides a new pathway for efficient and low-toxicity phototherapy, which is beneficial to the future clinical application.

Preparation and Characterization of High Mechanical Strength Chitosan/Oxidized Tannic Acid Composite Film with Schiff Base and Hydrogen Bond Crosslinking

Chitosan-based composite films with good biodegradability, biocompatibility, and sustainability are extensively employed in the field of food packaging. In this study, novel chitosan/tannic acid (CTA) and chitosan/oxidized tannic acid (COTA) composite films with excellent mechanical and antibacterial properties were prepared using a tape casting method. The results showed that, when 20% tannic acid (TA) was added, the tensile strength of the CTA composite film was 80.7 MPa, which was 89.4% higher than that of the pure chitosan (CS) film. TA was oxidized to oxidized tannic acid (OTA) with laccase, and the phenolic hydroxyl groups were oxidized to an o-quinone structure. With the addition of OTA, a Schiff base reaction between the OTA and CS occurred, and a dual network structure consisting of a chemical bond and hydrogen bond was constructed, which further improved the mechanical properties. The tensile strength of 3% COTA composite film was increased by 97.2% compared to that of pure CS film. Furthermore, these CTA films with significant antibacterial effects against Escherichia coli (E. coli) are likely to find uses in food packaging applications.

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.

Tannic acid-reinforced zwitterionic hydrogels with multi-functionalities for diabetic wound treatment

Diabetic wounds remain one of the most prevalent hard-to-heal wounds in the clinic. The causative factors impeding the wound healing process include not only the elevated oxidative stress and bacterial infections but also the high and repetitive plantar stress (including compressive pressure and shear stress). Conventional hydrogel dressings are mechanically weak and fragile, limiting their applications in the high stress-loading conditions of diabetic foot ulcers. As such, mechanically tough hydrogel dressings with appropriate bioactivities are highly desirable for diabetic wound treatment. In this study, a mechanically reinforced hydrogel with multiple biofunctionalities was developed via a facile and straightforward strategy of incorporation of tannic acid (TA) in zwitterionic poly(sulfobetaine methacrylate) (polySBMA) hydrogel. The polySBMA hydrogel reinforced by TA showed excellent mechanical property, with the tensile stress and compressive stress up to 93.7 kPa and 18.4 MPa, respectively, and it could resist cyclic compressive stress at ∼200 kPa (maximum in-shoe plantar pressure) for up to 3500 cycles. The TA-reinforced zwitterionic hydrogel exhibited strong adhesion to skin tissue (20.2 kPa), which was expected to reduce the shear stress on the foot. The plantar pressure on the foot was significantly reduced by the application of the resilient hydrogel. Attributed to the antioxidant and antibacterial properties of TA, the hydrogel showed rapid radical scavenging capability and strong bactericidal efficacy against Gram-positive and Gram-negative bacteria. In vitro and in vivo studies confirmed that the hydrogel has good cytocompatibility and negligible skin irritation, and promoted healing of diabetic wounds in mice. Such tough and effective hydrogel with a straightforward preparation strategy holds great promise as wound dressings for diabetic wound treatment.

Preparation and application of pH-responsive drug delivery systems

Microenvironment-responsive drug delivery systems (DDSs) can achieve targeted drug delivery, reduce drug side effects and improve drug efficacies. Among them, pH-responsive DDSs have gained popularity since the pH in the diseased tissues such as cancer, bacterial infection and inflammation differs from a physiological pH of 7.4 and this difference could be harnessed for DDSs to release encapsulated drugs specifically to these diseased tissues. A variety of synthetic approaches have been developed to prepare pH-sensitive DDSs, including introduction of a variety of pH-sensitive chemical bonds or protonated/deprotonated chemical groups. A myriad of nano DDSs have been explored to be pH-responsive, including liposomes, micelles, hydrogels, dendritic macromolecules and organic-inorganic hybrid nanoparticles, and micron level microspheres. The prodrugs from drug-loaded pH-sensitive nano DDSs have been applied in research on anticancer therapy and diagnosis of cancer, inflammation, antibacterial infection, and neurological diseases. We have systematically summarized synthesis strategies of pH-stimulating DDSs, illustrated commonly used and recently developed nanocarriers for these DDSs and covered their potential in different biomedical applications, which may spark new ideas for the development and application of pH-sensitive nano DDSs.

Multifaceted tannin crosslinked bioinspired dECM decorated nanofibers modulating cell-scaffold biointerface for tympanic membrane perforation bioengineering

Tympanic membrane (TM) perforation leads to persistent otitis media, conductive deafness, and affects life quality. Ointment medication may not be sufficient to treat TM perforation due to the lack of an underlying tissue matrix and thus requiring a scaffold-based application. The engineering of scaffold biointerface close to the matrix via tissue-specific decellularized extracellular matrix (dECM) is crucial in instructing cell behaviour and regulating cell-material interaction in the bioengineering domain. Herein, polycaprolactone (PCL) and TM-dECM (from SD rats) were combined in a different ratio in nanofibrous form using an electrospinning process and crosslinked via tannic acid. The histological and biochemical assays demonstrated that chemical and enzymatic decellularization steps removed cellular/immunogenic contents while retaining collagen and glycosaminoglycan. The morphological, physicochemical, thermomechanical, contact angle, and surface chemical studies demonstrated that the tannin crosslinked PCL/dECM nanofibers fine-tune biophysical and biochemical properties. The multifaceted crosslinked nanofibers hold the tunable distribution of dECM moieties, assembled into a spool-shaped membrane, and could easily insert into perforated sites. The dECM decorated fibers provide a preferable biomimetic matrix for L929 fibroblast adhesion, proliferation, matrix adsorption, and f-actin saturation, which could be crucial for bioengineering. Overall, dECM patterning, surface hydrophilicity, interconnected microporosities, and multifaceted nanofibrous biosystem modulate cell-scaffold performance and could open opportunities to reconstruct TM perforation in a biomimetic fashion.

In situ silver nanoparticle coating of virions for quantification at single virus level

In situ labelling and encapsulation of biological entities, such as of single viruses, may provide a versatile approach to modulate their functionality and facilitate their detection at single particle level. Here, we introduce a novel virus metallization approach based on in situ coating of viruses in solution with silver nanoparticles (AgNP) in a two-step synthetic process, i.e. surface activation with a tannic acid - Sn(II) coordination complex, which subsequently induces silver ion (I) reduction. The metalic coating on the virus surface opens the opportunity for electrochemical quantification of the AgNP-tagged viruses by nano-impact electrochemistry on a microelectrode with single particle sensitivity, i.e. enable the detection of particles oherwise undetectable. We show that the silver coating of the virus particles impacting the electrode can be oxidized to produce distinct current peaks the frequency of which show a linear correlation with the virus count. The proof of the concept was done with inactivated Influenza A (H3N2) viruses resulting in their quantitation down to the femtomolar concentrations (ca. 5 × 10⁷ particles per mL) using 50 s counting sequences.

Inducing enantioselective crystallization with and self-assembly of star-shaped hybrid polymers prepared via "grafting to" strategy

Helical polymers present some interesting and distinctive properties, and one of the most distinguished applications of them is the chiral recognition and resolution of enantiomers. In this work, star-shaped hybrid helical poly (phenyl isocyanide) (PPI) with polyhedral oligomeric silsesquioxanes (POSS) as the core was designed and synthesized by "grafting to" strategy. The homoarm star-shaped hybrid POSS-(PPI)₈ was first obtained by the click reaction between azide-modified POSS (POSS-(N₃ )₈ ) and alkynyl-modified PPI (PPI-Alkynyl). The hybrid POSS-(PPI)₈ was with predominated left-handed helical conformation and exhibited excellent ability in the enantioselective crystallization of racemic compounds. In the meantime, heteroarm star-shaped hybrid (PEG)₄ -POSS-(PPI)₄ was prepared by the click reaction of POSS-(N₃ )₈ with PPI-Alkynyl and alkynyl-modified poly (ethylene glycol) (PEG-Alkynyl). The hybrid (PEG)₄ -POSS-(PPI)₄ was amphiphilic, and it could self-assemble to form spherical micelles in aqueous solutions.

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.

Tannic acid/Sr2+-coated silk/graphene oxide-based meniscus scaffold with anti-inflammatory and anti-ROS functions for cartilage protection and delaying osteoarthritis

Tissue engineering method provides a promising solution for meniscus repair and regeneration. However, the inflammatory environment that persists after meniscus injury in the knee joint impedes meniscus tissue regeneration. The purpose of this study was to investigate the applicability of silk/graphene oxide (GO)-based meniscus scaffold modified with tannic acid (TA)/Sr²⁺ coating for the elimination of inflammatory cytokines and reactive oxygen species (ROS) under osteoarthritis (OA) environment along with cartilage protection by using a rat model. The self-assembled coating composed of a series of TA-Sr²⁺ complex concentrations was formed by a facile, rapid, and efficient method on the scaffold. The phenolic hydroxyl groups on the coating endowed the meniscus scaffold with excellent anti-inflammatory and ROS scavenging capacities. We also found that the coating could promote cell migration in a mock wound model and could increase extracellular matrix secretion in vitro. Moreover, the coating components at a certain concentration played an effective role in delaying OA and providing cartilage protection in the rat model. The expression of inflammation cytokines (e.g., IL-6, IL-8, and MMPs) in rat knee tissue was significantly downregulated, and cartilage degeneration and OA damage were also inhibited according to tissue staining results and the OARSI (Osteoarthritis Research Society International) scoring system. Combining these performances, we suggest that this silk/GO-based scaffold modified with TA/Sr²⁺ coating could have broader application prospects by virtue of its effective and user-friendly properties. STATEMENT OF SIGNIFICANCE: The biological properties of the meniscus play a role in activating and regulating the metabolic and inflammatory responses that influence the homeostasis of joint health and ultimately lead to knee osteoarthritis (OA). The inflammation condition of the knee joint may exacerbate the degeneration of meniscus and cartilage. The present study aimed to develop a functional coating composed of tannic acid/Sr²⁺ complex on a silk/graphene oxide-based meniscus scaffold and to endow the scaffold with anti-inflammatory and ROS elimination capacities during the meniscus regeneration process to protect cartilage and delay OA development. The in vitro cytocompatibility study and the in vivo rat OA model study revealed that the coating was effective in promoting cell migration, facilitating ECM secretion, inhibiting inflammation, and delaying OA development.

Hybrid Metal-Phenol Nanoparticles with Polydopamine-like Coating for PET/SPECT/CT Imaging

The validation of metal-phenolic nanoparticles (MPNs) in preclinical imaging studies represents a growing field of interest due to their versatility in forming predesigned structures with unique properties. Before MPNs can be used in medicine, their pharmacokinetics must be optimized so that accumulation in nontargeted organs is prevented and toxicity is minimized. Here, we report the fabrication of MPNs made of a coordination polymer core that combines In(III), Cu(II), and a mixture of the imidazole 1,4-bis(imidazole-1-ylmethyl)-benzene and the catechol 3,4-dihydroxycinnamic acid ligands. Furthermore, a phenolic-based coating was used as an anchoring platform to attach poly(ethylene glycol) (PEG). The resulting MPNs, with effective hydrodynamic diameters of around 120 nm, could be further derivatized with surface-embedded molecules, such as folic acid, to facilitate in vivo targeting and multifunctionality. The prepared MPNs were evaluated for in vitro plasma stability, cytotoxicity, and cell internalization and found to be biocompatible under physiological conditions. First, biomedical evaluations were then performed by intrinsically incorporating trace amounts of the radioactive metals 111In or 64Cu during the MPN synthesis directly into their polymeric matrix. The resulting particles, which had identical physicochemical properties to their nonradioactive counterparts, were used to perform in vivo single-photon emission computed tomography (SPECT) and positron emission tomography (PET) in tumor-bearing mice. The ability to incorporate multiple metals and radiometals into MPNs illustrates the diverse range of functional nanoparticles that can be prepared with this approach and broadens the scope of these nanoconstructs as multimodal preclinical imaging agents.

Porphyrin and phthalocyanine-based metal organic frameworks beyond metal-carboxylates

Given the ubiquitous role of porphyrins in natural systems, these molecules and related derivatives such as phthalocyanines are fascinating building units to achieve functional porous materials. Porphyrin-based MOFs have been developed over the past three decades, yet chemically robust frameworks, necessary for applications, have been achieved much more recently and this field is expanding. This progress is partially driven by the development of porphyrins and phthalocyanines bearing alternative coordinating groups (phosphonate, azolates, phenolates…) that allowed moving the related MOFs beyond metal-carboxylates and achieving new topologies and properties. In this perspective article we first give a brief outline of the synthetic pathways towards simple porphyrins and phthalocyanines bearing these complexing groups. The related MOF compounds are then described; their structural and textural properties are discussed, as well as their stability and physical properties. An overview of the resulting nets and topologies is proposed, showing both the similarities with metal-carboxylate phases and the peculiarities related to the alternative coordinating groups. Eventually, the opportunities offered by this recent research topic, in terms of both synthesis pathways and modulation of pore size and shape, stability and physical properties, are discussed.

Lactoferrin-Anchored Tannylated Mesoporous Silica Nanomaterials for Enhanced Osteo-Differentiation Ability

In the present study, we created lactoferrin-anchored mesoporous silica nanomaterials with absorbed tannic acid (LF/TA-MSNs) and evaluated the effect of these LF/TA-MSNs on the in vitro osteo-differentiation ability of adipose-derived stem cells (ADSCs) by testing alkaline phosphatase (ALP) level, calcium accumulation, and expression of osteo-differentiation-specific genes, including osteocalcin (OCN) and osteopontin (OPN). Both bare MSNs and LF/TA-MSNs exhibited round nano-particle structures. The LF/TA-MSNs demonstrated prolonged LF release for up to 28 days. Treatment of ADSCs with LF (50 μg)/TA-MSNs resulted in markedly higher ALP level and calcium accumulation compared to treatment with LF (10 μg)/TA-MSNs or bare MSNs. Furthermore, LF (50 μg)/TA-MSNs remarkably increased mRNA levels of osteo-differentiation-specific genes, including OCN and OPN, compared to MSNs or LF (10 μg)/TA-MSNs. Together, these data suggest that the ability of LF/TA-MSNs to enhance osteo-differentiation of ADSCs make them a possible nanovehicle for bone healing and bone regeneration in patients with bone defect or disease.

Chitosan coordination driven self-assembly for effective delivery of curcumin

Self-assembly of metal-ligand coordination is of immense scientific interest in supramolecular construction of functional materials duo to their desirable functional properties. Herein, we investigated a designable coordination driven self-assembly to simultaneously enhance the water solubility and biological stability of curcumin (Cur). On the basis of amino group in chitosan (CS), it was chosen as the high-affinity anchors for coordination nanocomplexes, in which Cur were incorporated into the amino group by coordination bonding, forming a CS-metal-Cur architecture. The sizes of these nanocomplexes can be tuned by the feed concentrations of CS as well as the kind of metal ions. Time dependent absorption spectral measurements demonstrated the significant increase in hydrolytic stability of Cur after forming nanoparticles (NPs) especially for the CS-Cu-Cur NPs. Particularly, the formed CS-metal-Cur NPs can be efficiently triggered by pH, which was stable under physiological conditions while releasing encapsulated drugs under low pH conditions in a sustained manner. Based on cellular uptake study and cytotoxicity experiments, CS-metal-Cur NPs were shown to possess highly efficient internalization and an apparent cytotoxic effect. The high drug-loading capacities and responses to pH value, substantially enhanced antitumor activity of Cur provided this nanocomplex with promising properties for biomimetic and biomedical applications.

Metal-Phenolic Network Covering on Zein Nanoparticles as a Regulator on the Oil/Water Interface

Interfacial self-assembly has become a powerful force for regulating the amphipathy of Pickering emulsions on the oil/water interface. Herein, metal-phenolic supramolecular coatings, acting as a regulator on the oil/water interface, were fabricated on the surface of zein nanoparticles (NPs), as a consequence of which the prepared Pickering emulsions stabilized by the decorated zein NPs exhibited diverse properties, decided by different concentrations of zein, tannic acid (TA), and metal ions (Fe³⁺). Metal-phenolic network-decorated zein NPs named ZTFex NPs (ZTFe NPs represented zein/TA/Fe³⁺ NPs, and x represented different concentrations of compounds) exhibited increasing diameters of 100-110 nm. Three-phase contact angles also showed that the strong hydrophobicity of zein NPs could be decreased as a result of the formation of metal-phenolic networks. As for corresponding Pickering emulsions, the covering of TA-Fe³⁺ networks on zein NPs could enhance the stability of zein NP-based emulsion obviously, which might be due to the fact that ZTFex NPs revealed the ability to form strong films on the oil/water interfaces. ZTFe4 was selected as an optimal concentration because of its minimum size and excellent storage stability. Besides, it was also found that the diameter of ZTFe4-based emulsion enhanced with the increase in the oil phase. The rheological measurement results showed that both G' and G″ increased with the increase of x and the oil phase. In general, our paper not only highlighted a straightforward method for the interfacial nanofabrication of solid particles but also provided a novel and potential strategy in Pickering emulsion applications.

Characterization and Absorption Kinetics of a Novel Multifunctional Nanoliposome Stabilized by Sea Cucumber Saponins Instead of Cholesterol

Cholesterol was usually used to stabilize liposome, although there have been controversies on the relationship between dietary cholesterol and health. The present study aimed to prepare a novel multifunctional nanoliposomes stabilized by sea cucumber-derived saponins using ultrasound-assisted film dispersion method. A novel uniform liposome with a mass ratio of egg yolk lecithin/sea cucumber saponins at 75:25 was successfully prepared to encapsulate saponin, and the particle size was 164.8 ± 1.70 nm with a PDI value of 0.214 ± 0.022 and zeta potential of -15.97 ± 1.23 mV. The digestion and absorption results in vivo showed that the dietary saponins in liposome form could delay the peak time of saponins and prolong their residence time in the serum. Moreover, saponins were more easily converted into their corresponding metabolites after administration with saponins in the liposome form. The novel liposome as an efficient carrier with multiple functions had great potential in the development of functional food and biomedical applications.