Applications of tannic acid in membrane technologies: A review

Application of green waste polyphenols in natural antimicrobial materials for the environmental fields: A review

In recent years, green waste polyphenols (GWPs) have attracted global attention due to their abundant renewable resources and excellent antibacterial properties. We analyzed the research progress on the antimicrobial properties of natural polyphenol composites (including polyphenol-metal nanoparticles, polyphenol nanofiber membranes, polyphenol-polymer membranes, and polyphenol hydrogels) in environmental applications. The waste sources of polyphenols and the latest extraction technologies were systematically summarized, and a universal hydrodynamic cavitation-integrated membrane technology combined with polyphenol extraction and purification process was initially constructed. The inhibitory effects of GWPs on pathogenic bacteria and the antibacterial properties of polyphenol composites in the environmental field were systematically analyzed. These composites exhibited outstanding antimicrobial performance, effectively inhibiting E. coli and S. aureus by up to 100%, especially in water treatment and air filtration. In addition, the advantages, challenges, and prospects for the application of green waste polyphenol antibacterial materials (GWPAMs) in the environmental field are discussed. With high efficiency, low toxicity, antimicrobial resistance, and sustainable antimicrobial properties, GWPs exhibit significant application potential in the "resource recycling-pollution control-ecological restoration" synergistic system within the environmental field. Future work should focus on the green synthesis of polyphenol composites, conducting systematic and thorough investigations on their antibacterial mechanisms, and enhancing their antibacterial properties in agriculture, waste treatment, and soil remediation, to improve their environmental adaptability and sustainable application value.

A multifunctional semi-interpenetrating polymer network hydrogel dressing for wound healing

Hydrogels have exhibited significant application potential in the field of new wound dressings due to their unique physicochemical properties and biological functions. However, traditional hydrogels possess limitations regarding mechanical properties, adhesion, and the promotion of wound healing. Herein, a multifunctional polyvinyl alcohol-tannic acid/polyacrylamide-polydopamine (PVA-TA/PAM-PDA) hydrogels are developed. By combining an amide-rich crosslinked polyacrylamide (PAM) network with a hydroxyl-rich linear polyvinyl alcohol (PVA) structure, a semi-interpenetrating polymer network (semi-IPN) is formed, which serves as a scaffold to enhance mechanical properties. The incorporation of tannic acid (TA) and polydopamine (PDA) into the semi-IPN framework can enhance cell affinity and tissue adhesiveness. This multifunctional composite hydrogel demonstrates outstanding physical and mechanical properties, including excellent elasticity and toughness, stable rheological properties, and favorable swelling properties. It also exhibits strong adhesive properties to various materials and skin, and can promote tissue regeneration and wound healing. This study offers novel ideas for the development and application of multifunctional composite hydrogel wound dressings, and the PVA-TA/PAM-PDA hydrogel shows great promise for clinical applications as an innovative wound dressing.

Interfacial Stabilization of Green and Food-Safe Emulsions through Complexation of Tannic Acid and Nanochitins

Nanochitins exhibit unique structural attributes that confer distinct physical properties to multiphase systems. Amphiphilic tannic acid (TA) serves as an excellent candidate for interfacial modification via electrostatic adsorption and complexation with nanochitin. In this study, we developed green and food-safe strategies to enhance the stabilizing and functional performance of complexes formed through the coassembly of chitin nanofibers (ChNF) and TA. Their interactions were systematically investigated using spectroscopy, rheological measurements, and molecular simulations, all confirming strong interfacial binding primarily through hydrogen bonding. X-ray diffraction analysis further revealed TA-induced changes in ChNF crystallinity. The resulting ChNF-TA complexes effectively stabilized high internal phase Pickering emulsions (HIPPEs), which exhibited long-term stability and were successfully applied in direct ink writing. The exceptional stability of the HIPPEs was attributed to the synergistic effects of electrostatic charge neutralization and interfacial tension reduction. Quartz crystal microgravimetry demonstrated rapid complexation, with TA binding to ChNF thin films at a level of approximately 450 ng/cm2. The resulting HIPPEs remained stable for at least two months and readily formed cryogels upon freeze-drying. Owing to their enhanced stability and viscoelastic properties, HIPPEs stabilized with ChNF-TA complexes offer a promising platform for the development of sustainable emulsions, with the potential for customization in personalized food and related fields.

Preparation and Performance of Biomimetic Zebra-Striped Wood-Based Photothermal Evaporative Materials

An efficient solar water evaporator is an important strategy for addressing the problem of water shortage. Constructing high-performance solar interfacial evaporators through bionic design has become a crucial approach for performance enhancement. Through the study of zebra patterns, it has been found that the black-and-white alternating patterns generate vortices on the surface of the zebra's skin, thereby reducing the temperature. By utilizing the vortices brought about by the temperature difference, the design of a solar water evaporator is created based on the bionic zebra pattern, so as to improve its water evaporation performance. In this work, green and sustainable wood is used as the base of the evaporator, and the bionic design of zebra stripes is adopted. Meanwhile, the following research is conducted: The wood is cut into thin slices with dimensions of 30 × 30 × 5 mm3, and a delignification treatment is performed. Tannic acid-Fe ions are used as the photothermal material for functionalization. A series of stable patterned water evaporators based on delignification wood loaded with tannic acid-Fe ion complex (TA-Fe3+) are successfully prepared. Among them, the wood-based solar water evaporator with 3 mm zebra stripes exhibits excellent photothermal water evaporation performance, achieving a water evaporation rate of 1.44 kg·m-2·h-1 under the illumination intensity of one sun. Its water evaporation performance is significantly superior to that of other coating patterns, proving that the bionic design of zebra patterns is effective and can improve water evaporation efficiency. This work provides new insights into the development of safe and environmentally friendly solar interfacial water evaporation materials through bionic design.

Bionic polydopamine in-situ functionalized keratin double network gel with adsorption and self-adaptability: promoting uranium entrapment from seawater

Adsorption behavior driven by surface charge is a challenge for uranyl extraction from seawater (UES), so it is attractive to design uranium adsorbents with charge and environment self-adaptability. In this paper, polyphenolamine (PPA) with a dopamine-like structure was synthesized by a one-step method using tannic acid (TA) and polyethyleneimine (PEI) as raw materials. The PPA with different isoelectric points are obtained by adjusting the ratios of TA and PEI, which enables the charge regulation of PPA within pH 6-9. Then, based on the excellent adhesion of PPA, a novel double network PPA-HK aerogel was constructed by the spatial crosslinking strategy between PPA and keratin peptides. It not only realizes the transformation of PPA from dispersed to condensed state, but also endows PPA-HK with the charge-driven regulable adsorption behavior. When the ratio of TA and PEI was 1:2, the maximum adsorption capacity of PPA-HK (265 mg g-1) was achieved at pH = 8 which was exactly the pH of natural seawater. The saturated adsorption capacity of PPA-HK reached 8.05 mg g-1 after 25 days of adsorption in natural seawater, as well as it exhibited excellent recyclability and antibacterial performance (with an antibacterial rate of over 90 %). What is more important is that it still maintains high mechanical strength. The in-situ spatial crosslinking strategy is used in the modification of keratin by using polydopamine-like PPA for the first time. This study not only endues the adsorbent multi properties, but also expands the application potential of keratin in uranium extraction.

Hydratable Janus Membranes with Robust Antiwetting Pores for Stable Membrane Distillation of Saline Oily Wastewater

Janus membranes, composed of a hydrophilic surface layer and a hydrophobic substrate, are potential candidates for membrane distillation (MD) to prevent organic substance induced wetting in saline oily wastewater treatments. However, owing to insufficient hydrophobicity of pore surfaces, traditional hydrophobic substrates suffer from pore wetting and limited MD performance stability when saline water penetrates through the hydrophilic layer. Herein, we present a Janus polyvinylidene fluoride (PVDF) nanocomposite membrane with robust pore surface antiwettability for stable MD desalination of saline oily wastewater. Hydrophobic silica (SiO2) nanoparticles are used to build nanostructures on pore surfaces to significantly enhance their hydrophobicity for preventing pore wetting. The superhydrophilic tannic acid/Fe (TA/Fe) layer provides a hydratable surface to promote water molecule absorption, facilitate the evaporation rate, and effectively impede oil/surfactant/gypsum contaminants. As a result, the TA/Fe-PVDF/SiO2 Janus membrane shows stable desalination (32 h) with a high flux of 25.2 kg m-2 h-1 and salt rejection (>99.9%) for saline oily solution. This work provides a promising approach to develop high-performance Janus membranes with antiwetting ability for stable saline oily wastewater treatment.

Epitope molecularly imprinted polymers based on host-guest interaction: specific recognition of CD59

The detection of CD59 is of great clinical importance since it is an important glycoprotein that can serve as a biomarker related to kinds of cancers. In this work, we prepared host-guest interaction based oriented epitope molecularly imprinted polymer (hg-EMIP) for the immobilization of CD59 N-terminal epitopes. Cucurbit[7]uril (CB[7]) and l-phenylalanine (L-phe) were employed as the host and guest; and tannic acid (TA) with abundant hydroxyl groups and diethylenetriamine (DETA) were chosen as the functional monomer and crosslinking agent, respectively. The obtained hg-EMIP can specifically recognize CD59 with the adsorption capacity of 88.2 mg/g and imprinting factor of 5.63, and possesses high reusability. The hg-EMIP-based method possesses a wide linear range (1 ng/mL - 1 μg/mL) and low limit of detection (0.44 ng/mL), and can be successfully used for the detection of CD59 in human serum sample. This study provides a scheme for the preparation of host-guest based epitope molecularly imprinted polymers for helping to identify potential disease biomarkers efficiently.

Tannic acid as a multifunctional additive in polysaccharide and protein-based films for enhanced food preservation: A comprehensive review

Fossil-based polymers continue to dominate the market for single-use food packaging, despite increasing concerns about their sustainability. In response, natural and renewable polymers, such as proteins and polysaccharides, are gaining attention as potential alternatives due to their biodegradability and biocompatibility. However, their broader adoption is hindered by the need to improve their mechanical, barrier, and thermal properties. Tannic acid (TA) has emerged as a particularly effective additive for biopolymer-based films, offering strong antioxidant and antimicrobial properties. It also enhances mechanical and barrier characteristics through physical and/or covalent crosslinking. As a result, TA shows great potential as an additive for bioplastics, improving food packaging performance and extending product shelf life, while benefiting both the environment and the food industry. Despite the promising applications of TA, comprehensive reviews that focus on recent developments in its performance and bioactive properties remain limited. This review aims to highlight the effectiveness of TA as both an active ingredient and a crosslinking agent in various biopolymer films, offering valuable insights into its role in sustainable food packaging solutions by critically examining the latest advancements.

Multifunctional poly(lactic acid) membrane assisted by coal-based carbon dots for efficient separation of oil-in-water emulsions and dyes

Superhydrophilic separation membranes have broad application prospects in oil-water separation and wastewater purification. However, the accumulation of pollutants on the membrane surface and the secondary environmental pollution caused by waste membranes remain inevitable challenges. In this study, a superhydrophilic self-cleaning multifunctional membrane was fabricated by hydrolytic co-deposition of carbon dots, tetrabutyl titanate (TBT), and tannic acid on the surface of a degradable poly(lactic acid) (PLA) membrane for efficient separation of dye/oil/water emulsions. The results indicate that the superhydrophilic crosslinking network is formed on the surface of PLA-based membranes through co-deposition of TA-based coating, enabling the multifunctional membrane to possess a stable and ultra-strong oleophobic hydrophilic layer. As a result, the membrane exhibits strong underwater oil resistance and excellent performance in the separation of oil-in-water emulsions (rejection rate > 99%). More importantly, the surface of the superhydrophilic crosslinking network is negatively charged, which facilitates the selective removal of positively charged organic soluble substances in water through electrostatic adsorption. For instance, the removal rate of cationic dye MB and amphoteric dye RhB can reach as high as 99.93%. Additionally, with the catalysis of TiO2, the organic pollutants on the membrane surface can be decomposed under UV irradiation, indicating the ideal self-cleaning property of the multifunctional membrane. This novel strategy for constructing a multifunctional surface deposition layer is expected to provide broader prospects for the application of superhydrophilic membranes in oil-water separation and wastewater purification.

Distinct responses of Caenorhabditis elegans to polyethylene microplastics and plant secondary metabolites

Soil worms are among the most abundant and functionally diverse soil animals. However, they have been largely overlooked in studies on microplastic (MP) toxicity. MPs and plant secondary metabolites (PSMs) are ubiquitous in soil due to plant litter decomposition and heavy MP contamination, inevitably interacting and exerting combined toxicity on soil organisms. However, little research has been conducted on their joint effects. This study investigates the individual and combined toxic effects of polyethylene (PE) MPs and three PSMs (glycyrrhizic acid, tannic acid, and matrine) on the model organism Caenorhabditis elegans. Physiological and biochemical responses were assessed using fluorescence microscopy, image analysis, and statistical methods. After 42 h of exposure to PE MPs and/or PSMs, worm growth and development were negatively impacted. Under experimental conditions, matrine and PE MPs synergistically inhibited worm growth, exacerbated neurological damage, and induced oxidative stress. In contrast, glycyrrhizic acid and tannic acid alleviated PE MP-induced growth inhibition, mitigated oxidative stress, and demonstrated antioxidant properties that counteracted oxidative damage. This study offers new insights into the combined effects of MPs and PSMs in soil ecosystems, contributing to ecological risk assessments and pollution management strategies.

Development of faba protein-tannic acid conjugate via free radical grafting: Evaluation of interaction mechanisms and antioxidative properties

A soluble fraction of faba bean protein was conjugated with tannic acid via the free-radical grafting method using a mixture of ascorbic acid and hydrogen peroxide. Surface plasmon resonance showed a strong bonding between them, while the free amino and thiol group measurements indicated tannic acid's bonding with the amino groups and cysteine residues on the proteins. Structural analysis using intrinsic fluorescence and surface hydrophobicity demonstrated tannic acid's interaction with the aromatic and hydrophobic amino acids of the protein. The conjugate showed about 77 % DPPH, 89 % ABTS, and 83 % hydroxyl radical scavenging activities and superior ferric-reducing ability compared to the protein alone and the mixture of protein and tannic acid. Electron paramagnetic resonance (EPR) spectroscopy revealed 97.8 % radical scavenging ability of the conjugate, comparable to the pure tannic acid. The exceptional antioxidative properties of conjugate can be utilized to delay lipid oxidation in protein-stabilized oil-in-water emulsions.

Unlocking the potential of plant polyphenols: advances in extraction, antibacterial mechanisms, and future applications

Plant polyphenols are widely distributed in most higher plants, garnering significant attention from researchers due to their remarkable antioxidative, antibacterial, anticancer, and anti-radiation properties. They also offer multiple health benefits for various lifestyle-related diseases and oxidative stress. While there has been considerable research on the extraction and antibacterial application of plant polyphenols, developing a rapid and efficient extraction method remains a persistent challenge. Furthermore, the introduction of novel technologies is imperative to enhance the bioavailability of polyphenolic compounds. This comprehensive review synthesizes recent research findings pertaining to the extraction, antibacterial mechanisms, and applications of plant polyphenols. This research highlights the prevalent issues of low extraction rates of plant polyphenols and the ambiguous antibacterial mechanisms in current research. To address these challenges, this research proposes innovative directions for improving extraction technology and expanding antibacterial applications. Additionally, this review outlines promising future research avenues within the realm of plant polyphenols.

Graphical abstract

Magnetic Field-Driven Ion Selectivity Boosts LiF-Rich SEI Formation for Enhanced Lithium Metal Battery Performance Across Temperatures

Lithium metal anodes are considered highly promising electrode materials due to their exceptional theoretical capacity and low reduction potential. However, their path to large-scale commercialization has been obstructed by significant challenges such as uncontrolled volume expansion, severe side reactions, and dendrite formation. To tackle these issues, our study introduces a covalent modification of separators using tannic acid (TA) and Co2+, coupled with the application of an external magnetic field. This innovative approach promotes the adsorption of CO32- ions while inhibiting the uptake of F- ions on the TA-Co/PP separators, leading to the formation of a LiF-rich solid electrolyte interface on the anode surface. Such modifications significantly enhance the electrochemical performance of lithium metal batteries. Remarkably, with the aid of the magnetic field, batteries featuring these modified separators maintained a Coulombic efficiency of 90% over 650 cycles at 1 mA cm-2. Additionally, under challenging conditions at 60 °C and 4 mA cm-2, the polarization voltage of Li symmetric cells utilizing TA-Co/PP separators is maintained at just 20 mV. This successful demonstration underlines the potential of our method to catalyze the broader adoption and commercialization of lithium metal batteries across varied temperature spectra.

Unlocking the Potential of Gallic Acid-Based Metal Phenolic Networks for Innovative Adsorbent Design

Metal phenolic networks (MPNs) have attracted significant attention due to their environmentally benign nature, broad compatibility, and universal adhesive properties, making them highly effective for modifying adsorbent surfaces. These supramolecular complexes are formed through the coordination of metal ions with natural phenolic ligands, resulting in stable structures while retaining the active adsorption sites of the ligands, thereby enhancing the adsorption performance of unmodified substrates. Among various MPNs, metal ion gallic acid (GA) networks are particularly well-known for their exceptional stability, biological activity, and superior adsorption ability. This review offers a comprehensive examination of GA-based MPN adsorbents, focusing on their formation chemistry, characterization techniques, and applications. The coordination chemistry underlying the stability of GA-metal complexes is analyzed through equilibrium studies, which are critical for understanding the robustness of MPNs. The main analytical methods for assessing metal ligand interactions are discussed, along with additional characterization techniques for evaluating adsorbent properties. This review also explores various synthesis and performance enhancement strategies for GA-based MPN adsorbents, including stand-alone MPNs, MPN-mediated mesoporous materials, MPN-MOF composites, and MPN-coated substrates. By consolidating current advancements in MPN-based adsorbents and offering fundamental insights into their chemistry and characterization, this review serves as a valuable resource for researchers seeking to develop stable, functional metal-organic materials. It aims to drive innovation in sustainable and efficient adsorbent technologies for diverse environmental and industrial applications.

Nanocapsuled Neutrophil Extracellular Trap Scavenger Combating Chronic Infectious Bone Destruction Diseases

Chronic infectious bone destruction diseases, such as periodontitis, pose a significant global health challenge. Repairing the bone loss caused by these chronic infections remains challenging. In addition to pathogen removal, regulating host immunity is imperative. The retention of neutrophil extracellular traps (NETs) in chronic infectious niches is found to be a barrier to inflammation resolution. However, whether ruining the existing NETs within the local infectious bone lesions can contribute to inflammation resolve and bone repair remains understudied. Herein, a nanocapsuled delivery system that scavenges NETs dual-responsively to near-infrared light as a switch and to NETs themselves as a microenvironment sensor is designed. Besides, the photothermal and photodynamic effects endow the nanocapsules with antibacterial properties. Together with the ability to clear NETs, these features facilitate the restoration of the normal host response. The immunocorrective properties and inherent pro-osteogenic effects finally promote local bone repair. Together, the NET scavenging nanocapsules address the challenge of impaired bone repair in chronic infections due to biased host response caused by excessive NETs. This study provides new concepts and strategies for repairing bone destruction attributable to chronic infections via correcting biased host responses in chronic infectious diseases.

Room-temperature and recyclable preparation of cellulose nanofibers using deep eutectic solvents for multifunctional sensor applications

Cellulose nanofibers (CNFs) have gained increasing attention due to their robust mechanical properties, favorable biocompatibility, and facile surface modification. However, green and recyclable CNF production remains challenging. Herein, a green, low-cost and room-temperature strategy was developed to exfoliate CNFs using deep eutectic solvents. A high average yield (~90 %) of CNFs was achieved during the recycling process. The resultant CNFs delivered favorable dispersion in water with an average length of ~5.3 μm and an average diameter of ~44 nm. The application of the resultant CNFs for multifunctional sensors was explored by fabricating the composite films of poly(vinyl alcohol) (PVA), tannic acid-decorated CNFs (CNF@TA) and Ag nanoparticles (AgNPs). As a stretchable strain sensor, the PVA/CNF@TA/AgNPs sample exhibited superior sensitivity (GF = 46.42), low detection limit (<1 %) and fast response (80 ms). This sensor possessed excellent temperature sensing performance with good accuracy (0.1 °C), high TCR (29.84/°C) in the body temperature region of 34-42 °C and desirable linearity (R2 = 0.981). In addition, the sensor could be used to monitor real-time skin moisture information. This simple and economical preparation strategy may facilitate potential applications of CNFs in the development of multifunctional sensors for wearable electronic devices.

Lattice Reconstruction Engineering Boosts the Extreme Fast Charging/Discharging Performance of Nickel-Rich Layered Cathodes

The low specific capacity and the poor capacity retention at extreme fast charging/discharging limit the nickel-rich layered cathode commercialization in electric vehicles, and the root causes are interface instability and capacity loss induced by birth defects and irreversible phase transition. In this work, we propose a lattice reconstruction strategy combining polyvinylpyrrolidone-assisted wet chemistry and calcination to prepare the aluminum-modified LiNi0.83Co0.11Mn0.06O2 (ANCM). Our method offers distinct advantages in tailoring birth defects (residual alkali and rocksalt phase), reducing Li vacancies and oxygen vacancies, exhibiting gradient Ni concentration distribution, suppressing the Li/Ni intermixing defects, lowering the lattice strain before and after recycling, and inhibiting the microcracks. The ANCM constructs robust crystal lattices and delivers an initial discharge capacity of 155.3 mAh/g with 89.2% capacity retention after 200 cycles at 5 C. This work highlights the importance of synthesis design and structural modification for cathode materials.

Enhancing Waterproof Food Packaging with Janus Structure: Lotus Leaf Biomimicry and Polyphenol Particle Technology for Vegetable Preservation

With the increasing demand for improved food preservation, conventional waterproof food packaging has proven inadequate because of its limited functionality. Although incorporating features such as antibacterial and antioxidant properties into packaging enhances protection, it can compromise the hydrophobicity of the involved material, thereby increasing the risk of contamination from external sources. To address this challenge, a robust and reliable barrier capable of simultaneously integrating multiple protective functions is required. This research synthesizes polyphenol particles via metal ion coordination and multiple hydrogen bondings to enhance antioxidant and antimicrobial properties. In addition, inspired by the asymmetric wettability of Janus-structured lotus leaves, this study develops biomimetic multifunctional Janus electrospun fibers via electrostatic spinning. These fibers exhibit exceptional properties, including superhydrophobic, antifouling, ultraviolet-blocking, pH sensitivity, antioxidation, antimicrobial, and freshness retention properties. Experiments and mesoscopic capillary flow simulations elucidate the waterproofing ability and underlying mechanisms of the Janus electrospun fibers, demonstrating their function as hydrophobic shields for preventing water penetration. Overall, this study provides a reference for high-performance waterproof food packaging to enhance vegetable preservation.

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.

Polyphenol-mediated assembly of toll-like receptor 7/8 agonist nanoparticles for effective tumor immunotherapy

Toll-like receptor (TLR) 7/8 agonists have shown significant potential in tumor immunotherapy. However, the limited pharmacokinetic properties and systemic toxicity resulting from off-target effects limits their biomedical applications. We here report the polyphenol-mediated assembly of resiquimod (R848, a TLR7/8 agonist) nanoparticles (RTP NPs) to achieve tumor-selective immunotherapy while avoiding systemic adverse effects. Upon intravenous administration, the prepared RTP NPs are effectively accumulated at tumor sites, which increase their bioavailability and reduce systemic inflammation. RTP NPs can trigger a potent antitumor immune response in a mouse tumor model to inhibit tumor growth. Additionally, after subcutaneous injection at the tail base, RTP NPs efficiently migrate to the lymph nodes, where they elicit immune memory to prevent tumorigenesis. This study underscores the potential application of polyphenol-mediated assembly in developing nanomedicines with reduced toxicity for tumor-specific immunotherapy. STATEMENT OF SIGNIFICANCE: Toll-like receptor agonist (R848) nanoparticles for tumor-selective immunotherapy were synthesized through polyphenol-mediated assembly, a method that simplifies preparation process and minimizes potential side effects. Intravenously administered these nanoparticles effectively extended circulation time, enhanced tumor enrichment, and reduced systemic inflammation, thus augmenting the bioavailability and minimizing the side effects of R848. The nanoparticles significantly inhibited tumor growth by triggering a potent antitumor immune response, including dendritic cell maturation, macrophage polarization, T-cell infiltration, and cytokine secretion. Moreover, after subcutaneous injection at the tail base, they can elicit immune memory to prevent tumorigenesis.

Supramolecular Reconstruction of Self-Assembling Photosensitizers for Enhanced Photocatalytic Hydrogen Evolution

Natural photosynthetic systems require spatiotemporal organization to optimize photosensitized reactions and maintain overall efficiency, involving the hierarchical self-assembly of photosynthetic components and their stabilization through synergistic interactions. However, replicating this level of organization is challenging due to the difficulty in efficiently communicating supramolecular nano-assemblies with nanoparticles or biological architectures, owing to their dynamic instability. Herein, we demonstrate that the supramolecular reconstruction of self-assembled amphiphilic rhodamine B nanospheres (RN) through treatment with metal-phenolic coordination complexes results in the formation of a stable hybrid structure. This reconstructed structure enhances electron transfer efficiency, leading to improved photocatalytic performance. Due to the photoluminescence quenching property of RN and its electronic synergy with tannic acid (T) and zirconium (Z), the supramolecular complexes of hybrid nanospheres (RNTxZy) with Pt nanoparticles or a biological workhorse, Shewanella oneidensis MR-1, showed marked improvement in photocatalytic hydrogen production. The supramolecular hybrid particles with a metal-phenolic coordination layer showed 5.6- and 4.0-fold increases, respectively, in the productivities of hydrogen evolution catalyzed by Pt (Pt/RNTxZy) and MR-1 (M/RNTxZy), respectively. These results highlight the potential for further advancements in the structural and photochemical control of supramolecular nanomaterials for energy harvesting and bio-hybrid systems.

High-Performance Triple-Network Hydrogels Derived from Chrome Leather Scraps: Ultrahigh Compressive Strength, Adhesion, and Self-Recovery

The development of engineered hydrogels with high strength, self-recovery, and adhesion is essential for applications requiring resistance to large deformations and cyclic loading. Herein, a triple-network (TN) hydrogel with ultrahigh compressive strength, strong adhesion, and good self-recovery was constructed by using tannic acid-modified chrome leather scrap hydrolysate as the first network, polyacrylamide as the second network, and poly-2-propenamide-2-methylpropanesulfonic acid as the third network. The ultrahigh (70 MPa compressive strength and 95% compression deformation) TN hydrogels were effectively created, which is attributed to the synergy of the three networks. The TN hydrogels display adhesion (adhesion strength > 20 kPa) ascribed to the introduction of phenolic hydroxyl groups in tannic acid. Intriguingly, the TN hydrogels exhibit excellent self-recovery performance (93.6% dissipated energy recovery at 70 °C) and shape memory performance (restored to the original shape in 20 s). These properties are essential for the development of high-performance hydrogels and promote the resource utilization of leather waste.

Application of an Injectable Thermosensitive Hydrogel Drug Delivery System for Degenerated Intervertebral Disc Regeneration

Intervertebral disc degeneration is characterized by a localized, chronic inflammatory response leading to a synthesis/catabolism imbalance within the nucleus pulposus (NP) and progressive functional impairment within the NP. Polyphenol molecules have been widely used in anti-inflammatory therapies in recent years; therefore, we designed an injectable, temperature-sensitive hydrogel PLGA-PEG-PLGA-based drug delivery system for local and sustained delivery of two drugs tannic acid (TA) and resveratrol (Res), with the hydrogel carrying TA directly and Res indirectly (carried directly by inflammation-responsive nanoparticles). The delivery system presents good injectability at room temperature and forms a gel in situ upon entering the intervertebral disc. The delivery system can rapidly release TA and sustain Res release. In vitro and in vivo experiments have shown that this hydrogel drug delivery system is effective in anti-inflammation of degenerated intervertebral discs and promotes the regeneration of extracellular matrix in the NP.

Modulating the Interactions of Peptide-Polyphenol for Supramolecular Assembly Coatings with Controllable Kinetics and Multifunctionalities

Polyphenols and peptides represent two fundamental building blocks in the kingdom of supramolecular assembly (SA) coatings, which have recently attracted considerable interest. Regulating the assembly kinetics of SA coatings is critical to controlling the performance of SA coatings, but this area is still in its infancy, especially in the SA coating of peptide-polyphenol. Herein, a library of oligopeptides with rich diversity, numerous polyphenols, and modulators are explored to reveal their roles in the formation and regulation of SA coating. Citric acid (CA) is an effective regulator of interaction between the polyphenols and peptides to produce peptide-polyphenol coatings, TCP. The electrostatic interaction between tannic acid (TA) and cationic peptide drives the formation of TCP, while the multiple hydrogen bonds between CA and TA and peptide dominate the assembly kinetics. With optimized assembly pH and the mass ratio of TA, CA, and peptide, the thickness of TCP coating deposits onto diverse substrates (glass, silica, titanium, polystyrene) is ≈400 nm with controllable kinetics. The multifunctional TCP coatings are endowed via peptide-coupled functional units, including enhanced cellular adhesion, elevated osteogenic capacity, anti-protein adsorption, and antimicrobial. This work contributes to the understanding of the assembly kinetics and functionalization of peptide-polyphenol coatings.

Self-expanding cellulose sponge with enhanced hemostatic ability by tannic acid/metal ion composite coating for highly effective hemostasis of difficult-to-control bleeding wounds

Refractory bleeding presents a critical, life-threatening challenge, and the goal of medical professionals and researchers has always been to achieve safe and effective hemostasis for bleeding wounds. In this study, we utilized the benefits of a self-expanding cellulose sponge to control incompressible bleeding, which is achieved this by creating a tannic acid/metal ion coating on the surface and within the pores of the sponge to improve its hemostatic effectiveness. The effects of various types and concentrations of metal ions (calcium, magnesium, iron, and zinc) on hemostatic efficiency and biosafety is systematically investigated. The results from bacteriostasis and in vitro coagulation experiments identified 0.3 wt% Fe3+ as the optimal metal ion coating. Scanning electron microscope energy spectrum analysis confirmed the uniform distribution of Fe3+ within the cellulose sponge. Furthermore, the in vivo and in vitro results demonstrated that the prepared tannic acid/Fe3+ coated composite hemostatic sponge exhibits excellent coagulation ability and biocompatibility. Both the bleeding time and theblood loss in two bleeding models are significantly reduced, showing promising potential for treating extensive surface bleeding and deep penetrating wounds. Furthermore, the straightforward preparation method for this composite hemostatic sponge facilitates additional research towards market application.

Amyloid Proteins Adhesive for Slippery Liquid-Infused Porous Surfaces

Biomimetic slippery liquid-infused porous surfaces (SLIPS) have emerged as a promising solution to solve the limitations of superhydrophobic surfaces, such as inadequate durability in corrosion protection and a propensity for frosting. However, the challenge of ensuring strong, lasting adhesion on diverse materials to enhance the durability of the lubricant layer remains. The research addresses this by leveraging amyloid phase-transitioned lysozyme (PTL) as an adhesive interlayer, conferring stable attachment of SLIPS across a variety of substrates, including metals, inorganics, and polymers. The silica-textured interface robustly secures the lubricant with a notably low sliding angle of 1.15°. PTL-mediated adhesion fortifies the silicone oil attachment to the substrate, ensuring the retention of its repellent efficacy amidst mechanical stressors like ultrasonication, water scrubbing, and centrifugation. The integration of robust adhesion, cross-substrate compatibility, and durability under stress affords the PTL-modified SLIPS exceptional anti-fouling, anti-icing, and anti-corrosion properties, marking it as a leading solution for advanced protective applications.

Leveraging Interfacial Electric Field for Smart Modulation of Electrode Surface in Nitrate to Ammonia Conversion

The efficiency of nitrate reduction reaction (NO3RR) at low nitrate concentration is predominantly hindered by the poor affinity of nitrate ions and competitive hydrogen evolution reaction (HER), particularly in neutral and acidic media. Here, an innovative strategy to leverage the interfacial electric field (IEF) is introduced to boost the NO3RR performance. By in situ constructing tannic acid-metal ion (TA-M2+) crosslinked structure on the electrode surface, the TA-M2+-CuO NW/Cu foam sample exhibits an exceptional Faraday efficiency of 99.4% at -0.2 V versus reversible hydrogen electrode (RHE) and 83.9% at 0.0 V versus RHE under neutral and acidic conditions, respectively. The computational studies unveil that the TA-Cu2+ complex on the CuO (111) plane induces the increasing concentration of nitrate at the interface, accelerating NO3RR kinetics over HER via the IEF effect. This interfacial modulation strategy also contributes the enhanced ammonia production performance when it is employed on commercial electrode materials and flow reactors, exhibiting great potential in practical application. Overall, combined results illustrated multiple merits of the IEF effect, paving the way for future commercialization of NO3RR in the ammonia production industry.

Self-assembled carrier-free formulations based on medicinal and food active ingredients

The popularity of medicinal plants, which have a unique system and are mostly used in compound form for the prevention and treatment of a wide range of diseases, is growing worldwide. In recent years, with advances in chemical separation and structural analysis techniques, many of the major bioactive molecules of medicinal plants have been identified. However, the active ingredients in medicinal plants often possess chemical characteristics, including poor water solubility, stability and bioavailability, which limit their therapeutic applications. To address this problem, self-assembly of small molecules from medicinal food sources provides a new strategy. Driven by various types of acting forces, medicinal small molecules with modifiable groups, multiple sites of action, hydrophobic side chains, and rigid backbones with self-assembly properties are able to form various supramolecular network hydrogels, nanoparticles, micelles, and other self-assemblies. This review first summarizes the forms of self-assemblies such as supramolecular network hydrogels, nanoparticles, and micelles at the level of the action site, and discusses the recent studies on the active ingredients in medicinal plants that can be used for self-assembly, in addition to summarizing the advantages of self-assemblies for a variety of disease applications, including wound healing, antitumor, anticancer, and diabetes mellitus. Finally, the problems of self-assemblers and the possible directions for future development are presented. We firmly believe that self-assemblers have the potential to develop effective compounds from drug-food homologous plants, providing valuable information for drug research and new strategies and perspectives for the modernization of Chinese medicine.

Preparation and Characterisation of High-Density Polyethylene/Tannic Acid Composites

This research paper highlights the preparation and characterisation of high-density polyethylene (HDPE)/tannic acid (TA) composites, designed to confer antioxidant properties to HDPE, valorising a biobased filler. Indeed, tannic acid is a natural polyphenol, demonstrating, among others, strong antioxidation properties. Using a melt-mixing process, HDPE/TA composites containing various amounts of TA, ranging between 1 and 20 wt%, were prepared, and analyses on their structural, thermal, mechanical, as well as antioxidant properties were conducted. Infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction showed that TA was successfully incorporated into the HDPE matrix. Thermogravimetric analysis evidenced that the onset of thermal degradation decreased, but overall satisfactory stability was observed. The composites exhibited exceptional antioxidant properties, especially the ones with the highest TA content, although it was observed that a high amount of TA had adverse effects on the mechanical performance of the composites.

Janus and Amphiphilic MoS2 2D Sheets for Surface-Directed Orientational Assemblies toward Ex Vivo Dual Substrate Release

The two-dimensional (2-D) Janus and amphiphilic molybdenum disulfide (MoS2) nanosheet with opposite optical activities on each side (amphichiral) is synthesized by modifying sandwich-like bulk MoS2 with tannic acid and cholesterol through biphasic emulsion method. This new type of amphichiral Janus MoS2 nanosheet consists of a hydrophilic and positive optical activity tannic acid side as well as a hydrophobic and negative optical activity cholesterol side thereby characterized by circular dichroism. Surface-directed orientational differentiation assemblies are performed for the as-synthesized 2D material and are characterized by contact angle, infrared spectroscopy, X-ray photoelectron, and circular dichroism spectroscopies. The amphiphilic nature of the materials is demonstrated by the pre-organization of the nanosheets on either hydrophobic or hydrophilic surfaces, providing unprecedented properties of circular dichroism signal enhancement and wettability. Selective detachment of the surface organic groups (cholesterol and tannic acid fragments) is realized by matrix-assisted laser desorption/ionisation - time-of-flight (MALDI-TOF) mass spectrometry, and the dual substrate release in tissue is detected by ex vivo mass spectrometry imaging.

Integrated self-assembly and cross-linking technology engineered photodynamic antimicrobial film for efficient preservation of perishable foods

A new antibacterial film was constructed to combat the severe spoilage of fruits and vegetables caused by microorganisms. Specifically, photoresponsive cinnamaldehyde-tannic‑iron acetate nanospheres (CTF NPs) were prepared using ultrasonic-triggered irreversible equilibrium self-assembly and ionic cross-linking co-driven processes and were integrated into the matrix of κ-carrageenan (KC) (CTF-KC films) as functional fillers. The CTF0.4-KC film (KC film doped with 0.4 mg/mL CTF NPs) showed a 99.99% bactericidal rate against both E. coli and S. aureus, extended the storage period of cherry tomatoes from 20 to 32 days. The introduction of CTF enhanced the barrier, thermal stability, and mechanical strength properties, albeit with a slight compromise on transparency. Furthermore, the biosafety of the CTF0.4-KC film was confirmed through hemolysis and cytotoxicity tests. Together, the aforementioned results demonstrated the outstanding antibacterial and fresh-keeping properties of CTF0.4-KC. These desirable properties highlight the potential use of CTF0.4-KC films in food preservation applications.

Improving Antimicrobial Properties of Biopolymer-Based Films in Food Packaging: Key Factors and Their Impact

Biodegradable films derived from polysaccharides are increasingly considered eco-friendly alternatives to synthetic packaging in the food industry. The study's purpose was to improve the antimicrobial properties of biopolymer-based films made from starch, chitosan, alginate, and their blends (starch/chitosan and starch/alginate) and to evaluate the effects of modifiers, i.e., plant extracts, plasticizers, cross-linking agents, and nanofillers. Films were prepared via the Solution Casting Method and modified with various plasticizers, calcium chloride, oxidized sucrose, and nanofiber cellulose (NC). Chestnut, nettle, grape, and graviola extracts were tested for antimicrobial activity against Staphylococcus epidermidis, Escherichia coli, and Candida albicans. The film's mechanical and hydrophilic properties were studied as well. The chestnut extract showed the strongest antimicrobial properties, leading to its incorporation in all the films. The chitosan films displayed better antibacterial activity against Gram-positive than Gram-negative bacteria but were ineffective against C. albicans. NC significantly improved the mechanical and antimicrobial properties of the chitosan films. The alginate films, modified with various plasticizers cross-linked with calcium chloride, demonstrated the highest antimicrobial efficacy against E. coli. The starch films, cross-linked with oxidized sucrose, exhibited slightly lower antimicrobial resistance due to a more compact structure. Films such as ALG6 and ALG5, including plasticizers EPGOS and PGOS, respectively, indicated optimal hydrophilicity and mechanical properties and achieved the best antimicrobial performance against all the investigated microorganisms. All these findings highlight the potential of these biodegradable films for food packaging, offering enhanced antimicrobial activity that prolongs shelf life and reduces spoilage, making them promising candidates for sustainable food preservation.

Enhancing Strawberry Freshness: Multifunction Sustainable Films Utilizing Two Types of Modified Carbon Nanotubes for Photothermal Food Packaging

Currently, antimicrobial films with stable and efficient antibacterial activities are receiving considerable attention in the food packaging industry. Herein, a chemically/physically linked konjac glucomannan-sodium alginate (KGM-SA)@carbon nanotubes (CNTs)/Fe3+ composite film with outstanding resistance to ultraviolet radiation, oxidation, and bacteria, as well as excellent photothermal effects and mechanical properties, was successfully prepared using a solvent flow method. Tannic acid-modified carboxyl-functionalized CNTs (TCCNTs), l-cysteine-modified carboxyl-functionalized CNTs (LCCNTs), and Fe3+ were incorporated into the prepared film. The film structure of KGM-SA@CNTs/Fe3+ was characterized using various methods, confirming the formation of a dual-cross-linked network through metal-coordination bonds and hydrogen bonding. This unique structure endowed the film with excellent water vapor permeability (3.58 g mm/m2 day kPa), water resistance (water contact angle = 93.66°), and thermal stability. Further, the film exhibited outstanding photothermal conversion efficiency and stability under near-infrared irradiation (300 mW/cm2) as well as excellent bactericidal properties against Staphylococcus aureus and Escherichia coli, achieving a bacterial inhibition rate of >99%. In a strawberry preservation experiment, the KGM-SA@CNTs/Fe3+ composite film exhibited remarkable preservation effects, extending the shelf life of strawberries by 4-6 d. Thus, this photothermal antibacterial film offers a new approach for the application of CNTs in food packaging.

Nanofiltration Membranes Containing a Metal-Polyphenol Network Layer: Using Casting Solution pH as a Tool to Tailor the Separation Performance

Thin-film composite (TFC) membranes containing metal-polyphenol network (MPN) selective layers were fabricated using a supramolecular self-assembly between tannic acid (TA) and ferric ion (Fe3+). The TA-Fe3+ thin film was coated on a porous polyacrylonitrile support using aqueous solutions of TA and FeCl3 via a layer-by-layer deposition technique. The pH of the TA solution was used as a tool to alter the membrane characteristics. The surface porosity and water contact angle of the fabricated membranes gradually decreased as the pH of TA casting solutions was increased from 3 to 8.5 for both single-layered and double-layered TA-Fe3+ TFC membranes. This allowed us to tune the water permeance and the retentions of water-soluble neutral and anionic molecules by the MPN membranes by varying the pH of the casting solution. It has been shown that the water permeance decreased from 184 to 156 L·m-2·h-1·bar-1 for single TA-Fe3+ layer coated membranes when the pH was increased from 3 to 8.5, while it declined from 51 to 17 for the double TA-Fe3+ layer. Anionic solutes in aqueous solutions were highly retained compared to neutral components as the TFC membranes had a negative surface charge. Retentions of 95 and 90% were achieved for naphthol green B and orange II dyes by a double-layered M4 membrane fabricated at pH 8.5, while only 13% retention was found for the neutral riboflavin. The neutral dye riboflavin permeated 30.8 times higher than the anionic dye naphthol green B during a mixed dye filtration test through the TFC membrane prepared by using a TA solution of pH 8.5. To the best of our knowledge, this is the highest selectivity of a neutral/anionic dye pair so far reported for a TFC membrane having an MPN selective layer. Moreover, fouling tests have demonstrated that the MPN separation layers exhibit robust stability and adequate antifouling performance with a flux recovery ratio as high as 82%.

Hericium erinaceus β-glucan/tannic acid hydrogels based on physical cross-linking and hydrogen bonding strategies for accelerating wound healing

The majority of natural fungal β-glucans exhibit diverse biological functionalities, such as immunomodulation and anti-inflammatory effects, attributed to their distinctive helix or highly branched conformation This study utilized β-glucan with helix conformation and high-viscosity extracted from Hericium erinaceus, employing freeze-thaw and solvent exchange strategies to induce multiple hydrogen bonding between molecules, thereby initiating the self-assembly process of β-glucan from random coil to stable helix conformation without chemical modifications. Subsequently, the natural bioactive compound tannic acid was introduced through physical entanglement, imparting exceptional antioxidant properties to the hydrogel. The HEBG/TA hydrogel exhibited injectable properties, appropriate mechanical characteristics, degradability, temperature-responsive tannic acid release, antioxidant activity, and hemostatic potential. In vivo experiments using skin full-thickness defect and deep second-degree burn wound models demonstrated significant therapeutic efficacy, including neovascularization, and tissue regeneration. Moreover, the HEBG/TA hydrogel demonstrated its ability to regulate cytokines by effectively inhibiting the production of inflammatory mediators (TNF-α, IL-6), while simultaneously enhancing the expression of cell proliferation factor KI-67 and markers associated with angiogenesis such as CD31 and α-SMA. This study highlights the potential of combining natural β-glucan with bioactive molecules for skin repair.

Tannic acid-reinforced soy protein/oxidized tragacanth gum-based multifunctional hemostatic film for regulation of wound healing

With recent advances in the field of tissue engineering, composite films with biocompatibility, antimicrobial properties, and wound healing properties have gained potential applications in the field of wound dressings. In this research work, composite films of soy protein (S)/oxidized tragacanth gum (G) were successfully made using the solution casting process. The metal-organic framework containing curcumin (MOF) with concentrations of 5 and 10 wt% and tannic acid (TA) with concentrations of 6 and 12 wt% were entered into the polymer film. Surface morphology with scanning electron microscope (FE-SEM), thermal stability, mechanical properties, chemical structure, antioxidant, water absorption, cell viability, antibacterial activity, and biodegradability of the prepared films were investigated in laboratory conditions. In addition, the toxicity of the films in the cell environment was investigated, and the results showed that cell growth and proliferation improved in the presence of the prepared films, especially films SG/MOF10/TA6 and SG/MOF10/TA12 due to the presence of TA and MOF containing curcumin. Also, the antibacterial activity of the films showed that the presence of tannic acid and curcumin in the structure of the films increases their ability against pathogens. According to the obtained results, the newly produced nanocomposite film (SG/MOF10/TA12) has a high potential to be used for wound dressing due to its favorable characteristics and was considered the optimal film.

Tannin-encapsulated electrospun nanofibrous membrane of cellulose nanowhiskers-reinforced polysulfone for colorimetric detection of iron(III)

A nanocomposite of tannic acid and cellulose nanowhiskers (CNW)-reinforced polysulfone (PSF) was used to develop a metallochromic nanofibrous membrane sensor for iron(III) in aqueous media. Tannic acid was used as an active detecting probe, whereas the CNW@PSF composite was employed as a hosting material. Cellulose nanowhiskers (7-12 nm) were obtained from microcrystalline cellulose (MCC). According to the coloration parameters, a bathochromic shift from colorless (415 nm) to purple (561 nm) occurs when ferric cations bind to the phenolic hydroxyls of the tannic acid probe. The concentration of ferric was found to be directly correlated to the extent of the color change, demonstrating a detection limit of 0.1-250 ppm. This could be attributed to the creation of a coordinative complex between ferric ions and phenolic tannic acid. The generated nanofibers were inspected by energy-dispersive X-ray (EDX) and scanning electron microscopy (SEM). The electrospun nanofibrous membrane showed an average diameter between 75 and 150 nm. The tannic acid-containing nanofibers are remarkably reusable and simple. The tannic acid-encapsulated polysulfone nanofibrous membrane was used to detect various metal ions, demonstrating a high selectivity for Fe3+. The ideal pH range for the identification of Fe3+ was determined to be in the range of 4.25-6.75.

Advances in Mussel Adhesion Proteins and Mussel-Inspired Material Electrospun Nanofibers for Their Application in Wound Repair

Mussel refers to a marine organism with strong adhesive properties, and it secretes mussel adhesion protein (MAP). The most vital feature of MAP is the abundance of the 3,4-dihydroxyphenylalanine (DOPA) group and lysine, which have antimicrobial, anti-inflammatory, antioxidant, and cell adhesion-promoting properties and can accelerate wound healing. Polydopamine (PDA) is currently the most widely used mussel-inspired material characterized by good adhesion, biocompatibility, and biodegradability. It can mediate various interactions to form functional coatings on cell-material surfaces. Nanofibers based on MAP and mussel-inspired materials have been exerting a vital role in wound repair, while there is no comprehensive review presenting them. This Review introduces the structure of MAPs and their adhesion mechanisms and mussel-inspired materials. Second, it introduces the functionalized modification of MAPs and their inspired materials in electrospun nanofibers and application in wound repair. Finally, the future development direction and coping strategies of MAP and mussel-inspired materials are discussed. Moreover, this Review can offer novel strategies for the application of nanofibers in wound repair and bring about new breakthroughs and innovations in tissue engineering and regenerative medicine.

Spray-assisted layer-by-layer deposition of quaternized chitosan/tannic acid for the construction of multifunctional bio-based nonwoven dressings

Gauze wound dressings have received considerable attention due to their cost-effectiveness, excellent mechanical properties, and widespread applications. However, their inability to actively combat microorganisms and effectively scavenge free radicals results in suboptimal wound management. In this study, a novel nonwoven-based gauze dressing coated with quaternized chitosan/tannic acid (QCS/TA), based on electrostatic interaction and hydrogen bonding, was successfully prepared using a spray-assisted layer-by-layer assembly method. The bio-based nonwoven dressing, assembled with multiple interlacing bilayers, demonstrated outstanding antimicrobial properties, eliminating 99.99 % of Staphylococcus aureus (S. aureus) and 85 % of Escherichia coli (E. coli). Compared to the pristine nonwoven dressing, the QCS/TA-coated nonwoven dressing scavenged >85 % of the surrounding radicals within 2 h. Additionally, the nonwoven dressing exhibits excellent coagulation properties. Notably, the facile spraying procedure preserved most of the softness and breathability of the nonwoven substrate. After the deposition of seven bilayers, the bending stiffness and drape coefficient increased by only 37.63 % and 3.85 %, respectively, while the air permeability and moisture permeability reached 1712 mm/s and 3683.58 g/m2/d, respectively. This bio-based nonwoven dressing, derived from safe and non-toxic ingredients, holds promise as the next generation of multifunctional gauze dressings.

Interfacial Assembly of Free-Standing Polymer-Phenolic Films for Antibacterial and Antiultraviolet Applications

We report a facile interfacial assembly strategy for the preparation of flexible polyphenol-based films for antibacterial and antiultraviolet applications. The free-standing films can be instantaneously formed via spraying tannic acid (TA) at the surface of carboxymethyl chitosan (CMCS) solutions. Compared with the traditional casting-evaporation procedure on solid substrates, the liquid interfacial assembly method for the construction of free-standing films is rapid and facile, which prevents the interface separation procedure from the substrates. The thickness and mechanical properties of the films are well controlled by changing the incubation time. The low-field nuclear magnetic resonance was used to analyze the water distributions inside the films and to distinguish the cross-linked structure of CMCS-TA films with different thicknesses, revealing the dynamics of the film formation process. Importantly, the films exhibit outstanding antibacterial and antiultraviolet properties, which are promising in the applications of wound dressings. This study provides a new avenue for the assembly of flexible free-standing films with multifunctionality via a facile and low-cost fabrication process.

Modified Chitosan-Based Coating/Packaging Composites with Enhanced Antibacterial, Antioxidant, and UV-Resistant Properties for Fresh Food Preservation

Chitosan-based biomass packaging materials are a promising material for food preservation, but their limited solubility, antioxidant capacity, UV resistance, and mechanical properties severely restrict their application. In this study, we developed a novel chitosan-based coating/packaging composite (QCTO) using quaternary ammonium salt and tannic acid (TA)-modified chitosan (QCS-TA) and oxidized chitosan (OCS). The introduction of quaternary ammonium salt and TA effectively improves the water solubility and antibacterial, antioxidant, and UV-resistant properties of chitosan. The Schiff-base bond formed between OCS and QCS-TA, along with the TA-mediated multiple interactions, conferred the prepared composite film with good mechanical properties (69.9 MPa tensile strength) and gas barrier performance to water (14.3 g·h-1·m-2) and oxygen (3.5 g·mm·m-2·h-1). Meanwhile, the prepared QCTO composites demonstrate excellent biocompatibility and safety and are applied as coatings for strawberries and bananas as well as packaging films for mushrooms. These preservation experiments demonstrated that the prepared composites are able to effectively reduce weight loss, prevent microbial growth, maintain color, and significantly prolong the shelf life of fresh products (bananas, strawberries, and mushrooms extended shelf life by 6, 5, and 6 days, respectively). Therefore, the developed QCTO coating/packaging film shows great potential for applications in the field of food preservation and packaging.

Enhancement of hydrogen bonds between proteins and polyphenols through magnetic field treatment: Structure, interfacial properties, and emulsifying properties

In food systems, proteins and polyphenols typically coexist in a non-covalent manner. However, the inherent rigid structure of proteins may hinder the binding sites of polyphenols, thereby limiting the strength of their interaction. In the study, magnetic field (MF) treatment was used to enhance non-covalent interactions between coconut globulin (CG) and tannic acid (TA) to improve protein flexibility, enhancing their functional properties without causing oxidation of polyphenols. Based on protein structure results, the interaction between CG and TA caused protein structure to unfold, exposing hydrophobic groups. Treatment with a MF, particularly at 3 mT, further promoted protein unfolding, as evidenced by a decrease in α-helix structure and an increase in coil random. These structural transformations led to the exposure of the internal binding site bound to TA and strengthening the CG-TA interaction (polyphenol binding degree increased from 62.3 to 68.2%). The characterization of molecular forces indicated that MF treatment strengthened hydrogen bonding-dominated non-covalent interactions between CG and TA, leading to improved molecular flexibility of the protein. Specifically, at a MF treatment at 3 mT, CG-TA colloidal particles with small size and high surface hydrophobicity exhibited optimal interfacial activity and wettability (as evidenced by a three-phase contact angle of 89.0°). Consequently, CG-TA-stabilized high internal phase Pickering emulsions (HIPPEs) with uniform droplets and dense gel networks at 3 mT. Furthermore, the utilization of HIPPEs in 3D printing resulted in consistent geometric shapes, uniform surface textures, and distinct printed layers, demonstrating superior printing stability. As a result, MF treatment at 3 mT was identified as the most favorable. This research provides novel insights into how proteins and polyphenols interact, thereby enabling natural proteins to be utilized in a variety of food applications.

Ultrathin layer TAFC on BiVO4 with ligand-to-metal charge transfer enhances built-in electric field for boosting photoelectrochemical water oxidation

To reveal the mechanism of charge transfer between interfaces of BiVO4-based heterogeneous materials in photoelectrochemical water splitting system, the cocatalyst was grown in situ using tannic acid (TA) as a ligand and Fe and Co ions as metal centers (TAFC), and then uniformly and ultra-thinly coated on BiVO4 to form photoanodes. The results show that the BiVO4/TAFC achieves a superior photocurrent density (4.97 mA cm-2 at 1.23 VRHE). The charge separation and charge injection efficiencies were also significantly higher, 82.0 % and 78.9 %, respectively. From XPS, UPS, KPFM, and density functional theory calculations, Ligand-to-metal charge transfer (LMCT) acts as an electron transport highway in TAFC ultrathin layer to promote the concentration of electrons towards metal center, leading to an increase in the work function, which enhances the built-in electric field and further improves the charge transport. This study demonstrated that the LMCT pathway on TA-metal complexes enhances the built-in electric field in BiVO4/TAFC to promote charge transport and thus enhance water oxidation, providing a new understanding of the performance improvement mechanism for the surface-modified composite photoanodes.

Freezing-Tolerant Supramolecular Adhesives from Tannic Acid-Based Low-Transition-Temperature Mixtures

Natural polyphenols like tannic acid (TA) have recently emerged as multifunctional building blocks for designing advanced materials. Herein, we show the benefits of having TA in a dynamic liquid state using low-transition-temperature mixtures (LTTMs) for developing freezing-tolerant glues. TA was combined with betaine or choline chloride to create LTTMs, which direct the self-assembly of guanosine into supramolecular viscoelastic materials with high adhesion. Molecular dynamics simulations showed that the structural properties of the material are linked to strong hydrogen bonding in TA-betaine and TA-choline chloride mixtures. Notably, long-term and repeatable adhesion was achieved even at -196 °C due to the binding ability of TA's catechol and gallol units and the mixtures' glass transition temperature. Additionally, the adhesives demonstrated injectability and low toxicity against fibroblasts in vitro. These traits reveal the potential of these systems as bioadhesives for tissue repair, opening new avenues for creating multifunctional soft materials with bioactive properties.

Tannic acid crosslinked chitosan/gelatin/SiO2 biopolymer film with superhydrophobic, antioxidant and UV resistance properties for prematuring fruit packaging

The environmental pollution caused by plastic films urgently requires the development of non-toxic, biodegradable, and renewable biopolymer films. However, the poor waterproof and UV resistance properties of biopolymer films have limited their application in fruit packaging. In this work, a novel tannic acid cross-linked chitosan/gelatin film with hydrophobic silica coating (CGTS) was prepared. Relying on the adhesion of tannic acid and gelatin to silica, the coating endows CGTS film with excellent superhydrophobic properties. Especially, the contact angle reaches a maximum value 152.6°. Meanwhile, tannic acid enhanced the mechanical strength (about 36.1 %) through the forming of hydrogen bonding and the network structure. The prepared CGTS films showed almost zero transmittance to ultraviolet light and exhibited excellent radical scavenging ability (∼76.5 %, DPPH). Hence, CGTS film is suitable as a novel multifunctional packaging material for the agriculture to protect premature fruits, or the food industry used in environments exposed to ultraviolet radiation and rainwater.

Design, characterizations, and antimicrobial activity of sustainable home furnishing-based waste fabric treated using biobased nanocomposite

Clothing and textile industries are major contributors to environmental pollution including textile manufacturing through garment production, spinning, weaving, and dyeing. In this context, the sustainability textile industry is a big challenge and contributes to serving a large segment of society. Also, textile wastes could be used as a raw material for added-value products. Herein, in this study, recycling of residues fabric was treated with antimicrobial nanocomposite to reach the best use of exhausts and obtain multifunction products of aesthetic via the technical design of the waste raw materials. Besides, solving the unemployment problem by opening fields for small industry projects capable of producing high-value textile artifacts, especially when treated against microbes, can be applied to home furnishings. The waste fabric was treated via green synthesis nanocomposite based on chitosan and in situ prepared ZnONPs and cross-linked with tannic acid. The prepared nanocomposite was characterized using physicochemical analysis including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD). Additionally, the nanocomposite and treated fabric topographical behavior were studied using scanning electron microscopy (SEM) attachment with energy dispersive X-ray analysis (EDX), and images were processed to evaluate the roughness structure. Additionally, high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS) were performed to ensure the size and stability of the nanocomposite. The obtained results affirmed the green synthesis of nanocomposite with a size around 130 nm, as well as the doped ZnONPs average size of 26 nm and treated waste fabric, performed a promising attraction between nanocomposite and fabric fibers. Moreover, the antimicrobial study observed excellent activity of nanocomposite against bacteria and unicellular fungi as well.

One-Step Phase Separation and Mineralization Fabrication of Membranes for Oily Wastewater Treatment

Oily wastewater threatens the environment and the human health. Membrane technology offers a simple and efficient alternative to separating oil and water. However, complex membrane modifications are usually employed to optimize the separation performance. In this research, we develop an extremely simple one-step method to in situ calcium carbonate (CaCO3) nanoparticles onto a porous polyketone (PK) membrane via a nonsolvent induced phase separation (NIPS)-mineralization strategy. We utilized the unique chemical property of PK, which allows it to dissolve in a resorcinol aqueous solution. PK was mixed with tannic acid (TA) and calcium chloride (CaCl2) in a resorcinol aqueous solution to fabricate a casting solution. The activated membrane was cast and immersed into a sodium carbonate (Na2CO3) aqueous solution for taking the one-step NIPS-mineralization process. This proposed NIPS-mineralization mechanism comes to two conclusions: (i) the resulting membrane with comprehensive oleophobic properties and enhanced permeation flux for applications of oil/water separation with ultralow fouling and (ii) simplified the procedure to optimize the membrane performance using regular NIPS steps. The current work explores a one-step NIPS-mineralization technique that offers a novel approach to preparing membranes with highly efficient oil/water separation performance.

A coordinative modular assembly-constructed self-reinforced nano-therapeutic agent for effective antitumor-immune activation

Immunosuppressive microenvironment and poor immunogenicity are two stumbling blocks in anti-tumor immune activation. Tumor associated macrophages (TAMs) play crucial roles in immunosuppressive microenvironment, while immunogenic cell death (ICD) is a typical strategy to boost immunogenicity. Herein, we developed a coordinative modular assembly-based self-reinforced nanoparticle, (CaO2/TA)-(Fe3+/BSA) which integrated CaO2, Fe3+-tannic acid coordinated networks and albumin under the instruction of molecular dynamics simulation. (CaO2/TA)-(Fe3+/BSA) could significantly enhance Fenton reaction through Fe3+ self-reduction and H2O2 self-sufficiency, and simultaneously increased intracellular accumulation of Ca2+. The self-augmented Fenton reaction with sufficient reactive oxygen species effectively repolarized TAMs and elicited ICD with Ca2+ overload. Besides, (CaO2/TA)-(Fe3+/BSA) was confirmed to self-reinforce deep tumor drug delivery by "treatment-delivery" positive feedback based on gp60-mediated transcytosis and M2-like macrophages repolarization-mediated perfusion promotion. Resultantly, (CaO2/TA)-(Fe3+/BSA) effectively alleviated immunosuppression, provoked local and systemic immune response and potentiated anti-PD-1 antibody therapy. Our strategy highlights a facile and controllable approach to construct penetrated effective antitumor nano-immunotherapeutic agent.

Effect of tannic acid binding on the thermal degradation behavior and product toxicity of boscalid

The effect of tannic acid (TA) binding on the thermal degradation of boscalid was studied in this work. The results revealed that TA binding has a significant impact on boscalid degradation. The degradation rate constant of bound boscalid was reduced, and its corresponding half-life was significantly prolonged compared to the free state. Four identical degradation products were detected in both states through UHPLC-Q-TOF-MS, indicating that degradation products were not affected by TA binding. Based on DFT and MS analysis, the degradation pathways of boscalid included hydroxyl substitution of chlorine atoms and cleavage of CN and CC bonds. The toxicity of B2 and B3 exceeded that of boscalid. In summary, the binding of TA and boscalid significantly affected the thermal degradation rate of boscalid while preserving the types of degradation products. This study contributed to a fundamental understanding of the degradation process of bound pesticide residues in complex food matrices.

An adhesion-switchable hydrogel dressing for painless dressing removal without secondary damage

Hydrogels with strong adhesion to wet tissues are considered promising for wound dressings. However, the clinical application of adhesive hydrogel dressing remains a challenge due to the issues of secondary damage during dressing changes. Herein, we fabricated an adhesion-switchable hydrogel formed with poly(acrylamide)-co-poly(N-isopropyl acrylamide), quaternary ammonium chitosan and tannic acid. This hydrogel forms instant and robust adhesion to the skin at body temperature. However, as the temperature rises above the lower critical solution temperature (LCST), the hydrogel loses its adhesion towards the wound area due to the temperature-dependent volume phase transition of the copolymer, occurring around 45 °C. Consequently, the designed hydrogel can be easily detached from adhered tissues upon demand, providing a facile and effective method for painless dressing changes without secondary damage. This hydrogel holds great promise for long-term application in wound dressings.