Metal Ion-Directed Functional Metal-Phenolic Materials

A protective growth factor delivery strategy based on polyphenol-protein self-assembly to promote inflammatory bone regeneration

The efficacy of growth factor delivery-based therapies for bone tissue regeneration is frequently undermined by oxidative stress, especially under inflammatory conditions, which results in structure damage and function inactivation of growth factors. Herein, a straightforward and universal protective delivery strategy is proposed by employing the multiple physical interactions between epigallocatechin-3-gallate (EGCG) and growth factors (e.g., neuregulin-1/NRG-1) to efficiently form self-assembled particles (NE APs). NE APs provide sustained release of NRG-1 while protecting it from oxidative damage, preserving its biological functions of cell recruitment, migration, and angiogenesis. Additionally, NE APs leverage EGCG's ability to scavenge reactive oxygen species and maintain mitochondrial homeostasis, while synergistically enhancing TNF/NF-κB/JAK-STAT signaling pathways to support immune responses and osteogenic differentiation. In vivo experiments demonstrated that NE APs create a favorable microenvironment for bone regeneration through stem cell recruitment, angiogenesis, and immune modulation, effectively promoting the repair of inflammatory bone defects. This versatile protective delivery strategy, based on polyphenol and growth factor self-assembly, offers the potential to advance the application of growth factors in regenerative medicine.

New biological strategies for preventing and controlling food contaminants in the supply chain: Smart use of common plant-derived substances

Traditional means of contaminant management that rely on chemical additives and high-temperature processing have raised concerns about long-term safety and environmental issues in the modern food supply chain. Therefore, sustainable, safe, and innovative strategies are urgently needed. Plant-derived substances are known for their biological activity and antifouling potential as natural alternatives for contamination control. This review examines the sources of various contaminants, the categories of plant-derived substances, the action mechanisms, and their feasibility in the food supply chain. The smart use of plant-derived substances to improve microbial, chemical, and metal contamination in the food blockchain is not only a profound fusion of nature and technology, but also a mutual combination of ecological preservation and food safety. However, the realization of its commercialization is subject to multiple sanctions, but as the thorny issues are gradually resolved, the consolidation and market for the new strategies will thrive.

A carrier-free ultrasound-responsive polyphenol nanonetworks with enhanced sonodynamic-immunotherapy for synergistic therapy of breast cancer

Sonodynamic therapy (SDT) is an efficient non-invasive strategy for treating breast cancer. However, the therapeutic efficacy of SDT is greatly limited by various defense mechanisms in the tumor microenvironment, particularly the overexpression of B-cell lymphoma-2 (Bcl-2). In this study, based on drug self-delivery systems, a carrier-free ultrasound-responsive polyphenol nanonetwork (GTC) was developed to enhance SDT by inhibiting Bcl-2. A one-pot method, involving the interaction of the polyphenolic Bcl-2 inhibitor gossypol (GOS), transferrin, and the sonosensitizer chlorin e6 (Ce6), was used to synthesize the GTC. The GTC was efficiently internalized by MDA-MB-231 and 4T1 cells through specific binding to transferrin receptors, and no external carriers were needed. After cellular internalization, GOS increased the lethality of Ce6-mediated SDT by reducing the expression of the Bcl-2 protein, which caused multiple toxic effects. RNA-seq analysis confirmed the transcriptomic alterations in oxidative stress and apoptotic pathways induced by the GTC nanosystem. In vivo studies revealed that GOS-assisted SDT not only eliminated tumors through sonodynamic effects and triggered immunogenic cell death but also enhanced sono-immunotherapy, thus effectively suppressing distant tumors and metastasis. This study might provide insights into carrier-free nanomedicines for SDT-based synergistic tumor therapy.

Biophysiochemically favorable, antithrombotic and pro-endothelial coordination compound nanocoating of copper (II) with protocatechuic acid & nattokinase on flow-diverting stents

Neurovascular flow-diverting stents (FDSs) are revolutionizing the paradigm for treatment of intracranial aneurysms, but they still face great challenges like post- implantation acute thrombosis and delayed reendothelialization. Surface modification is of crucial relevance in addressing such key issues. In this study, we fabricated an ultrathin nanocoating out of copper (II) together with protocatechuic acid (PCA) and nattokinase (NK) bioactive molecules on NiTi FDSs via a coordination chemistry approach, with favorable biophysiochemical interactions, to fulfill this goal. This coating was identified as covalently-anchored and compactly covering the FDSs substrate, with unique nano-structured morphology as well as superhydrophilicity. The in vitro coagulation and whole blood assays demonstrated that the modified FDS's surfaces showed improved antithrombogenicity, with reduced platelet and fibrinogen adhesion, as well as their aggregation and activation, and consequently prolonged clotting time leading to decreased thrombosis occurrence. Human umbilical vein endothelial cell cultures confirmed the modified capability of FDSs to promote endothelial cell proliferation and migration. The ex vivo experiments verified that modified FDSs had clearly in-stent patency without thrombi formation, as compared to the bare FDSs bearing thromboembolic blockage. It was postulated that these enhanced biocompatibilities can be attributable to the copper-catalyzed nitric oxide (NO) released as a functional mediator, the nature of the PCA and NK molecules, as well as the synergic biophysiochemical surface/interface interactions. Our strategy may not only open a new avenue for surface-functionalizing neurovascular FDSs for medical purpose but also help better-understand interfacial phenomena on the advanced biomaterials.

Elongated Magnetic Nanorobots with Multi-Enzymatic Cascades for Active In Vivo Tumor Targeting and Enhanced Chemodynamic Therapy

Targeted delivery of therapeutic agents to malignant tissues is crucial for enhancing clinical outcomes and reducing side effects. Magnetic nanorobots (MNRs) present a promising strategy for controlled delivery, leveraging external magnetic fields to achieve precise in vivo targeting. This work develops elongated MNRs comprising linearly arranged magnetic nanoparticles linked by metal-polyphenol complexes (MPCs) for magnetic-field-directed active tumor targeting and synergistic tumor therapy. The MNRs are created by assembling 30 nm Fe3O4 nanoparticles, tannic acid, and ferrous ions (Fe2+) under a uniform magnetic field, resulting in elongated chain-like structures fixed by MPCs, which also promotes peroxidase-like activity. These structures show a greater magnetic response than individual nanoparticles, offering flexibility in magnetic manipulation. The MPCs coating allows tailored surface modifications with glucose oxidase, copper ions (Cu2+), and human serum albumin (HSA), producing colloidally stable MNRs with a built-in multienzymatic cascade (MNRs@GOx/Cu/HSA) that consumes glucose, generates •OH, and depletes the antioxidant glutathione (GSH). Collectively, surface-engineered multifunctional MNRs demonstrate improved in vivo tumor targeting driven by external magnetic fields, leading to efficient localized chemodynamic therapy. The tailored structural and functional properties of the developed MNRs render them suitable for targeted cargo delivery, minimally invasive surgery, and localized treatments in disease sites.

Facile Fabrication of Injectable Multifunctional Hydrogels Based on Gallium-Polyphenol Networks with Superior Antibacterial Activity for Promoting Infected Wound Healing

Multifunctional hydrogels hold significant promise for promoting the healing of infected wounds but often fall short in inhibiting antibiotic-resistant pathogens, and their clinical translation is limited by complex preparation processes and high costs. In this study, a multifunctional hydrogel is developed by combining metal-phenolic networks (MPNs) formed by tannic acid (TA) and gallium ions (Ga3⁺) with chitosan (CS) through a simple one-step method. The resulting CS-TA-Ga3⁺ (CTG) hydrogel is cost-effective and exhibits desirable properties, including injectability, self-healing, pH responsiveness, hemostasis, antioxidant, anti-inflammatory, and antibacterial activities. Importantly, the CTG hydrogels are effective against antibiotic-resistant pathogens due to the unique antibacterial mechanism of Ga3⁺. In vivo studies demonstrate that the CTG hydrogel promotes follicle formation and collagen deposition, accelerating the healing of infected wounds by inhibiting blood loss, suppressing bacterial growth, and modulating the inflammatory microenvironment. These findings highlight the CTG hydrogel's potential as an advanced and translational dressing for enhancing the healing of infected wounds.

Immunomodulatory and bone regenerative properties of copper/procyanidins-modified titanium surfaces

The inflammatory response triggered by the interaction between implants and macrophages is essential for bone regeneration around these implants. This study presents the application of dopamine hydrochloride to develop a copper and procyanidins coating on titanium surfaces to investigate its effects on bacterial inhibition, macrophage polarization, and osteogenic differentiation. The results demonstrated that this copper/procyanidins coating significantly suppressed the growth of Escherichia coli and Staphylococcus aureus. Notably, the initial release of Cu2+ ions promoted macrophage polarization toward a pro-inflammatory phenotype while stimulating the secretion of anti-inflammatory factors. Subsequently, the reduced Cu2+ release combined with procyanidins facilitated the transition from M1 to M2 macrophages-an essential process for bacterial phagocytosis and bone regeneration. Furthermore, this coating enhanced the secretion of osteogenic factors by bone marrow mesenchymal stem cells, enhancing their osteogenic differentiation and integration with bone tissue. These findings highlight the potential of copper/procyanidins coating in developing implant surfaces with immune-modulating and sustained antibacterial properties.

Perceiving and Countering Marine Biofouling: Structure, Forces, and Processes at Surfaces in Sea Water Across the Length Scales

In marine industries, severe economic losses are caused by accumulating organisms on surfaces in biofouling processes. Establishing a universal and nontoxic protocol to eliminate biofouling has been a notoriously difficult task due to the complexity of the marine organisms' interactions with surfaces and the chemical, mechanical, and morphological diversity of the surfaces involved. The tremendous variety of environmental parameters in marine environments further complicates this field. For efficient surface engineering to combat fouling, secretion, chemical structure, and properties of biobased adhesives and adhesion mechanisms must be understood. Advanced characterization techniques, like Atomic Force Microscopy (AFM), now allow one to study the three parameters determining surface adhesion and, eventually, fouling, i.e., morphology, chemistry, and surface mechanical modulus. By AFM, characterization can now be performed across length scales from nanometers to hundreds of micrometers. This review provides an up-to-date account of the most promising AFM-based approaches for imaging and characterizing natural adhesives provided by marine organisms. We summarize the current understanding of the molecular basis and the related relevant processes of marine fouling. We focus on applications of AFM "beyond imaging", i.e., to study interactions between adhesives and the surfaces involved. Additionally, we discuss the performance enhancement of polymer antifouling coatings using information derived from AFM. Knowledge and control of marine adhesion can be applied to prevent marine fouling, as well as to design bioadhesives to enhance potential medical applications. We present some milestone results and conclude with an outlook discussing novel possibilities for designing antifouling coatings and medical bioadhesives.

Multiplex immunochromatographic assay based on triple-color aggregation-induced emission fluorescent microspheres with good biocompatibility for the simultaneous detection of veterinary drugs in aquatic products

BACKGROUND

The simultaneous presence of multiple veterinary drug residues in a single sample poses a significant challenge for food safety analysis. Compared with traditional single-target detection, multiplex detection can not only provide richer sample information to raise the detection efficiency and reduce the possibility of false positives and omissions, but also decrease sample volume, shorten detection time, and lower costs. The luminance of aggregation-induced emission fluorescent microspheres (AIEFMs) can be enhanced by loading more fluorophores. The AIEFMs exhibit more advantages such as bright colors, excellent monodispersity, and high photostability, making them widely applicable in food safety.

RESULTS

We successfully developed a multiplex immunochromatographic assay (ICA) using triple-color AIEFMs as signal labels for the simultaneous detection of three veterinary drugs: chloramphenicol (CAP), diethylstilbestrol (DES), and diazepam (DZP). AIEFMs with good biocompatibility were synthesized via a simple and quick one-pot method based on the self-aggregation of AIEgens and the coating of metal-polyphenol network formed through the coordination of proanthocyanidin and Fe3+ in a tetrahydrofuran/water mixed solution. The as-prepared AIEFMs were rapidly conjugated with antibodies to synthesize AIEFM probes without any coupling reagent, and the multiplex AIEFMs-ICA was established for the detection of CAP, DES, and DZP. Under optimal conditions, the detection limits for CAP, DES, and DZP were 1.67, 410, and 5 pg/mL, respectively. The average recoveries of these veterinary drugs in fish and shrimp samples ranged from 85.40 % to 113.15 %, demonstrating the reliability and stability of the multiplex AIEFMs-ICA.

SIGNIFICANCE

The multiplex AIEFMs-ICA exhibited excellent signal output capacity, high specificity, and remarkable sensitivity. In brief, the developed multiplex AIEFMs-ICA shows great potential in the on-site detection of veterinary drugs and other targets.

Sustainable Pb(II) Removal and Recovery from Wastewater Using a Bioinspired Metal-Phenolic Hybrid Membrane with Efficient Regeneration

High-performance adsorbents often require efficient selectivity in wastewater, recoverability, and ease of multiple regeneration cycles, but achieving this remains a significant challenge. We report a new strategy for the efficient removal of lead (Pb(II)) from contaminated water streams using an innovative tannic acid (TA)-Fe(III)-based metal-phenolic network (MPN) hybrid membrane (MPN-PAM). This novel membrane exploits the tunable pH-sensitive coordination structure of the MPN to achieve selective removal and recovery of Pb(II) while enabling efficient membrane regeneration by filtration. This membrane demonstrates superior selectivity for Pb(II) with a removal efficiency of up to 98 % and an adsorption capacity of approximately 117.58 mg/g, even in the presence of high salinity, as well as coexisting heavy metals. The membrane maintains high Pb(II) removal efficiency over 20 consecutive cycles and 95 % efficiency over 10 regeneration cycles. Under continuous operation, it treats approximately 85 L per m2 of membrane, reducing Pb(II) concentrations to trace levels (~40 μg/L), meeting electroplating wastewater standard (GB21900-2008). Additionally, even low concentrations of Pb(II) (<5 mg/L) are efficiently purified to below WHO drinking water standard (10 μg/L). The operational cost for treating Pb(II)-contaminated wastewater is about $0.13 per ton, highlighting the cost-effectiveness and potential for large-scale application in wastewater treatment.

Metal-polyphenol Multistage Competitive Coordination System for Colorimetric Monitoring Meat Freshness

A low-cost, high-precision, and secure real-time system for monitoring food freshness can significantly improve spoilage issues, yet traditional colorimetric sensor arrays often suffer from chemical dyes' high toxicity and limited color changes. Here, a metal-polyphenol network colorimetric sensor array (MPN-CSA) is built for detecting total volatile base nitrogen (TVB-N) markers of meat freshness. The multi-level competitive coordination process between the metal-polyphenol system and amine substances endows the system with color changes far beyond those of traditional dyes (reaching a detection limit of 300 ppb). By integrating convolutional neural network (CNN) technology, an online platform is developed for monitoring meat freshness, achieving an overall detection accuracy rate of 99.83%. This environmentally friendly, economically viable MPN-CSA that monitors the freshness of meat in complex storage environments can be incorporated into food packaging boxes, enabling consumers and suppliers to assess the freshness of meat in real-time, thus helping to reduce food waste and prevent foodborne illnesses.

Carbon-supported Fe single atom nanozymes with long-lasting ROS generation and high NIR photothermal performance for synergistic cancer therapy

Synergistic therapy combining photothermal therapy (PTT) and chemodynamic therapy (CDT) has proven to be a highly effective strategy for cancer treatment. However, PTT heavily relies on the accumulation of therapeutic agents at the tumor site. The peroxidase (POD) activity of common catalysts can be rapidly exhausted during the accumulation process, prior to laser intervention, thereby diminishing the synergistic enhancement effect of the combined therapy. Therefore, a carbon-based nanozyme featuring single Fe atoms (Fe SAzyme) for long-term reactive oxygen species (ROS) generation is developed to address this challenge. While maintaining robust POD performance, Fe SAzyme exhibits a high photothermal conversion efficiency of 64.78 % at 808 nm. Short-term hyperthermia resulted in rapid tumor ablation, while sustained ROS generation induced persistent oxidative stress on cancer cells. Both in vitro and in vivo biological tests confirmed significant tumor growth inhibition, demonstrating the potential of Fe SAzyme as a potent agent for cancer treatment.

Solvation enabled highly efficient gradient assembly creates robust metal-phenolic coatings

Metal-phenolic networks (MPNs) are supramolecular materials that have received interest in various fields, including biomedicine, separations, environmental remediation, and catalysis. Despite recent advances, the construction of thick and robust MPN coatings that withstand harsh conditions (e.g., acidic, alkaline) remains challenging. In addition, the interfacial assembly of MPNs in mixed solvents (e.g., water and nonaqueous solvents) has not been investigated. Herein, a solvent-regulated (water/ethylene glycol) gradient assembly strategy that can regulate the coordination kinetics of MPNs to realize thick (up to 1.5 μm) and robust MPN coatings on various substrates is presented. Through mediating interactions between polyphenols, a balance is achieved between the aggregation, precipitation, and continuous assembly of well-dispersed precursors. The gradient assembly of polyphenols and metal ions results in lateral and longitudinal cross-linking leading to the formation of robust MPN coatings. The potential application of the coatings in oil/water separation is demonstrated by their excellent performance (oil intrusion pressure of 2.0 kPa and water flux of 2.59 × 105 L m-2h-1), long-term stability, tolerance to various harsh conditions, and thick oil fouling. This study provides further insight into the assembly mechanism of MPNs.

Tannic acid-based bio-MOFs with antibacterial and antioxidant properties acquiring non-hemolytic and non-cytotoxic characteristics

Tannic acid (TA) based bio-metal phenolic networks (bio-MPNs) were prepared by using Cu(II), Zn(II), Bi(III), Ce(III), La(III), and Ti(IV) metal ions. TA-based bio-MPNs exhibited wedge-shaped pores between 16.4 and 25.8 nm pore size ranges. The higher gravimetric yield% was achieved for TA-Bi(III), and TA-Ti(IV) bio-MPNs with more than 90 %, and higher surface area was observed for TA-La(IIII) bio-MPNs as 56.2 m2/g with 17.3 nm average pore sizes. All TA-based MPNs are non-hemolytic with less than 5 % hemolysis ratio, whereas TA-based Bio-MPNs do not affect blood clotting with > 90 % blood clotting indexes except for TA-Cu(II) Bio-MPNs at 0.1 mg/mL concentration. Moreover, TA-Bi(III) and TA-Ce(III) Bio-MPNs were found to be safer materials showing no significant toxicity on L929 fibroblast cells at 100 μg/mL concentration, along with TA-based Bio-MPNs prepared with Cu(II), Zn(II), La(III), and Ti(IV) metal ions that could be safely used in in vivo applications at 1 μg/mL concentration. It has been proven by 2 different antioxidant tests that the prepared TA-based Bio-MPNs show antioxidant properties even if their TA-derived antioxidant properties decrease. Furthermore, all types of TA-based Bio-MPNs show great antimicrobial activity depending on the metal ion or microorganism types and the highest antibacterial/antifungal effect was determined for TA-Cu(II), and TA-Zn(II) Bio-MPNs with the lowest MBC/MFC values against Pseudomonas aeruginosa ATCC 10145, Bacillus subtilis ATCC 6633, and Candida albicans ATCC 10231.

Machine Learning-Assisted Prediction of Photothermal Metal-Phenolic Networks

Photothermal therapy (PTT) demonstrates significant potential in cancer treatment, wound healing, and antibacterial therapy, with its efficacy largely depending on the performance of photothermal agents (PTAs). Metal-phenolic network (MPN) materials are ideal PTA candidates due to their low cost, good biocompatibility and excellent ligand-to-metal charge transfer properties. However, not all MPNs exhibit significant photothermal properties, and the vast chemical space of MPNs (over 700,000 potential combinations) complicates the screening of high-photothermal materials. To address this challenge, this study introduces machine learning (ML) methods for predicting the photothermal performance of MPNs. A database of photothermal properties of 80 modular MPNs was constructed, and the ML process was optimized through feature engineering and model training. The selected extreme gradient boosting model (XGBoost) successfully identified 1,654 high photothermal MPNs from a virtual database of 44,438. Subsequent experimental validation revealed a remarkable success rate of 70 % in predicting high photothermal MPNs. Additionally, several previously unreported high photothermal MPNs were discovered, demonstrating advantages in photothermal antibacterial applications. This study offers an innovative ML-driven approach for the efficient screening of MPN materials, providing a solid foundation for PTA design in PTT and other biomedical applications.

Antimicrobial Phenolic Materials: From Assembly to Function

Infectious diseases pose considerable challenges to public health, particularly with the rise of multidrug-resistant pathogens that globally cause high mortality rates. These pathogens can persist on surfaces and spread in public and healthcare settings. Advances have been made in developing antimicrobial materials to reduce the transmission of pathogens, including materials composed of naturally sourced polyphenols and their derivatives, which exhibit antimicrobial potency, broad-spectrum activity, and a lower likelihood of promoting resistance. This review provides an overview of recent advances in the fabrication of antimicrobial phenolic biomaterials, where natural phenolic compounds act as active antimicrobial agents or encapsulate other antimicrobial agents (e.g., metal ions, antimicrobial peptides, natural biopolymers). Various forms of phenolic biomaterials synthesized through these two strategies, including antimicrobial particles, capsules, hydrogels, and coatings, are summarized, with a focus on their application in wound healing, bone repair and regeneration, oral health, and antimicrobial coatings for medical devices. The potential of these advanced phenolic biomaterials provides a promising therapeutic approach for combating antimicrobial-resistant infections and reducing microbial transmission.

A Semi-Interpenetrating Network Hydrogel with Excellent Photothermal Antibacterial and ROS Scavenging Activities for MRSA-Infected Wounds

The prolonged infection of bacteria at the wound site may lead to serious physical problems. Herein, a multifunctional macroporous hydrogel with superior photothermal antibacterial and ROS scavenging activity (denoted as M-XG gel) was designed for the treatment of MRSA-infected wounds. The M-XG gels are composed of embedding Prussian blue nanoparticles (PBNPs) as photothermal converters and chelating ferric ions with xanthan gum (XG) and dopamine (DA) to form a semipermeable network. The introduction of DA occupies the cross-link sites of ferric ions, further increasing the pore size (200-500 μm open macropores) and endowing the hydrogel with ideal adhesion. The increase of cross-link sites in PBNPs formed a promising equilibrium M-XG gel with identical macroporous structures and toughened mechanical performance. The metal ligands between ferric ions and catechols, as well as the unique photothermal response of PBNPs, endow the hydrogels with a fast and stable near-infrared (NIR) photothermal conversion efficiency (48%). In the MRSA-infected SD rat trauma model, wounds treated with the M-XG gel group had completely closed after 14 days, effectively controlling wound bacterial infection and accelerating angiogenesis and collagen deposition, synergistically promoting infected wound healing. Therefore, the photothermal hydrogel with a semi-interpenetrating network demonstrates its great potential for infected wound tissue engineering.

Metal-Phenolic Network Hydrogel Vaccine Platform for Enhanced Humoral Immunity against Lethal Rabies Virus

Rabies, caused by rabies virus (RABV), is a zoonotic disease with a high mortality rate that has attracted global attention with the goal of eradication by 2030. However, rabies can only be prevented by appropriate and multiple vaccinations, which impede widespread vaccination in developing countries due to its high expenditure. Designing single-dose vaccines is a pressing challenge in the prevention of rabies and other infectious diseases. Herein, a metal-phenolic network (MPN)-based hydrogel vaccine (designated as CGMR) was developed to stimulate potent humoral immunity against RABV infection by a single immunization, resulting in 4.3-fold and 1.8-fold enhancements of virus-neutralizing antibody compared with that induced by inactivated RABV and alum adjuvant. The CGMR, cross-linked by phenol-modified chitosan with manganese ion, could prolong residence time by confining the antigen to the network of hydrogel, acting as a "hydrogel antigen depot". It also stimulated the activation of the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon gene (STING) pathway, facilitating dendritic cell maturation and antigen presentation. The vaccine formulation recruited immunocytes and activated the germinal center, enhancing and sustaining humoral immune responses against the virulent RABV challenge. Collectively, this injectable manganese-based hydrogel vaccine provides a universal and ideal avenue for rabies and other infectious diseases.

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.

Tailored Fibrils Approach via Ag(I).Peptidomimetic-Based Interface Design: Efficient Encapsulation of Diverse Active Pharmaceutical Ingredients in Wastewater Remediation during Effluent Treatment Plant (ETP) Processing

Pharmaceutical pollution in wastewater poses significant environmental and public health concerns worldwide. Chloramphenicol (CP), an antibiotic widely used in medical and veterinary applications, is among the active pharmaceutical ingredients (APIs) frequently detected in aquatic environments. This study explored the encapsulation of chloramphenicol API in contaminated wastewater using rationally designed fibrations based on the silver metal ion-directed self-assembly of fibrillator-type self-assembling ligand (ANS-3). We further investigated the removal of various commonly prescribed drugs, including antibiotics such as β-lactam (amoxicillin), fluoroquinolone (ciprofloxacin), aminoglycoside (neomycin), and tetracycline; antiparasitic agents with antiprotozoal properties (praziquantel and metronidazole); nonsteroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone and ketoprofen; the vasodilator isoxsuprine; amphiphilic antidepressants (amitriptyline); and the antiviral drug amantadine. The findings validated the crucial influence of polar multifunctionality and structural complexity in enhancing interactions with Ag.ANS-3 matrix, emphasizing its potential for efficient drug sequestration. First, picolinic acid (PA) and phenylalanine (F) were evaluated for their ability to form fibrillar structures, and their morphological characterization revealed well-defined fibrillar networks with varying degrees of porosity and interconnectivity. Then, the strategic inclusion of leucine in synthesizing ANS-3 facilitated the formation of robust fibrillar networks, employing its hydrophobic interactions to drive the self-assembly process. Finally, the encapsulation of APIs was evaluated using Ag(I) metal ion-driven ANS-3 based self-assembled nanofibrous material. This research contributes to the development of innovative physicochemical wastewater treatment strategies for environmental remediation and validates the importance of rational design in encapsulation-based wastewater remediation technologies.

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.

Coacervate-Derived Assembly of Poly(ethylene glycol) Nanoparticles for Combinational Tumor Therapy

Coacervates have garnered significant attention as potential drug carriers. However, the instability resulting from their intrinsic membrane-free nature restricts the application of coacervates in drug delivery. Herein, the engineering of poly(ethylene glycol) nanoparticles (PEG NPs) is reported using coacervates composed of PEG and polyphenols as the templates, where PEG is subsequently cross-linked based on different chemistries (e.g., thiol-disulfide exchange, click chemistry, and Schiff base reaction). The reported assembly strategy avoids the template removal process and the resultant PEG NPs exhibit excellent stability in the physiological environment compared to coacervates. The presence of polyphenols in PEG NPs enables the loading of various cargos including metal ions (i.e., Ru, Gd, Mn, Fe) and drug molecules (i.e., doxorubicin), which demonstrates their promise in magnetic resonance imaging and combinational tumor therapy. This work provides a promising strategy to promote the development of coacervate-derived NPs as a drug delivery system for biomedical applications.

Enhancing the Implant Osteointegration via Supramolecular Co-Assembly Coating with Early Immunomodulation and Cell Colonization

Osteointegration, the effective coupling between an implant and bone tissue, is a highly intricate biological process. The initial stages of bone-related immunomodulation and cellular colonization play crucial roles, but have received limited attention. Herein, a novel supramolecular co-assembled coating of strontium (Sr)-doped metal polyphenol networks (MPN) modified with c(RGDfc) is developed and well-characterized, for eliciting an early immunomodulation and cellular colonization. The results showed that the (Sr-MPN)@RGD coating significantly regulated the polarization of macrophages to the M2 phenotype by controllable release of Sr, and promote the initial adhesion of bone marrow mesenchymal stem cells (BMSCs) by RGD presented on MPN. Notably, the (Sr-MPN)@RGD attenuated osteoclast differentiation and oxidative stress as well as enhanced osteoblast differentiation and angiogenesis due to macrophage polarization toward M2 phenotype, which in turn has a profound effect on neighboring cells through paracrine signaling. In vivo results showed that the (Sr-MPN)@RGD coating manifested superior osseointegration and bone maturation to the bare Ti-rod or Ti-rod coated with MPN and Sr-MPN. This work contributed to the design of multifunctional implant coatings that address the complex biological process of osteointegration from the perspective of orchestrating stem cell recruitment with immunomodulatory strategies.

Concurrent effects and dynamic wetting abilities of nanometals anchored redox-active Janus nanoarchitectures on cotton fabric for sustainable catalysis and disinfection

Designing an ideal catalyst with antifouling performance and enhanced conversion efficiency can prevent microbial or dye contamination and protect the active phase of the catalysts at the triple-phase interface during disinfection processes. Herein, we developed an Lous-leaf-inspired nanometal anchored redox-active Janus nanoarchitecture with dynamic wetting abilities and synergistic catalytic/antibacterial performances. Specifically, the redox-active hydrophilic polydopamine (PDA) was used to mediate the localized self-assembly and nucleation of Ag on a cotton fabric without using other reductants. This catalyst coating features a superficial Janus nanoarchitecture and context-dependent hydrophobic surface, resulting in a charge- and/or air bubble-involved spontaneous wetting phenomenon for contamination droplet during catalytic reactions. Their synergistically enhanced catalytic degradation of industrial dyes and free radical scavenging abilities were validated. The PDA@Ag modified fabric exhibited excellent washing resistance, achieving >99 % antibacterial performance against E. coli after being washed 20 times. The proof-of-concept for an optimal catalyst and protective coating has been demonstrated with multiple anti-fouling strategies such as a self-cleaning/anti-adhesion surface, enhanced photothermal effect and antibacterial properties. Eventually, this rationally designed Janus nanoarchitecture interface was supposed to address the trade-off issues commonly encountered at the droplet-based triple-phase interfacial reaction with a dynamic changed active phase and excellent catalytic/antibacterial performances.

Facile synthesis of hydrangea-like copper-tannic acid networks for separation and purification of His-rich proteins with exceptional performance

Highly selective separation and purification of histidine-rich (His-rich) proteins from complex biological samples is crucial for disease diagnosis, but it still remains a challenge. In this work, hydrangea-like Cu-tannic acid (TA) networks were fabricated via one-step assembly of Cu2+ and natural polyphenol for separation and purification of bovine hemoglobin (BHb) from complex biosamples. The preparation procedure was simple, fast and cost-effective. Interestingly, hydrangea-like morphology was obtained by the cross-linked assembly of Cu-TA nanosheets and resulted in a hierarchically porous structure. Benefiting from the large surface area and highly abundant Cu2+, hydrangea-like Cu-TA networks exhibited exceptional adsorption performance towards BHb including ultra-high adsorption capacity (25 116.6 mg g-1) and excellent selectivity. Moreover, hydrangea-like Cu-TA networks possessed good reusability for five adsorption-desorption cycles without the need for regeneration in fresh reaction solution. In addition, hydrangea-like Cu-TA networks were successfully adopted for highly selective separation and purification of BHb from a complex biosample (bovine whole blood). In a word, this work demonstrated that hydrangea-like Cu-TA networks could act as a cost-effective and sustainable adsorbent with exceptional performance, which showed great potential in separation and purification of His-rich proteins for the omics analysis and disease diagnosis.

Multifunctional metal-phenolic nanoparticles with antibacterial and anti-inflammatory effects for osteomyelitis management

Osteomyelitis is a serious inflammatory disease mostly caused by bacterial infections. It is necessary to simultaneously eradicate bacterial cells and inhibit inflammation in treating osteomyelitis. Herein, we design an innovative zinc ion (Zn2+)-based nano delivery system for the management of osteomyelitis. Taking advantage of the coordination self-assembly of Zn2+, quercetin (QU), and ε-poly-L-lysine (EPL), Zn2+-containing nanoparticles (denoted as ZQE NPs) are prepared. ZQE NPs are spherical nanoparticles with amorphous structures. They are stable in the physiological neutral environment but can be dissociated in an acidic microenvironment of infection sites. Since Zn2+ is encapsulated into ZQE NPs by coordination interaction, the deactivation of Zn2+ by proteins can be effectively avoided. Therefore, ZQE NPs can maintain excellent bactericidal activity in a protein-rich environment, while dissociative Zn2+ doesn't exhibit obvious bactericidal ability. Meanwhile, ZQE NPs are highly effective at scavenging intracellular reactive oxygen species (ROS) and inhibiting pro-inflammatory cytokines, due to the strong anti-inflammatory effects of QU and Zn2+. The in vivo therapeutic efficacy of ZQE NPs is assessed using a rat model of methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis. Results demonstrate that ZQE NPs effectively eradicate bacterial cells and reduce inflammation in vivo, thereby promoting osteogenesis and recovery of osteomyelitis.

Thiol-Enhanced Interfacial and Internal Deposition of Metal-Polyphenol Networks for Permanent Hair Dyeing

Metal polyphenolic networks (MPNs) are becoming more and more attractive for nontoxic hair dyeing, but their coloring effect is not satisfactory because of the limited interfacial deposition and the absence of internal deposition. Moreover, there is a lack of understanding of the driving factors of the interfacial deposition of MPNs on hair. Herein, we develop a simple yet efficient strategy that transforms disulfide bonds of the hair into thiol groups by thioglycolic acid (TGA) to highly enhance the coloring effect of MPNs at a low temperature. The highly reactive thiol groups react with Fe2+ to form Fe-S bonds, greatly facilitating the interfacial and internal deposition of MPNs and thus resulting in rapid coloration and high darkness. Moreover, the TGA-assisted MPNs-dyed (TGA/MPN) hair shows high resistance to washing with a shampoo. Further, it is found that the connection of thiol groups to the MPNs endows the TGA/MPN hair with similar mechanical and structural properties to the natural white hair and even enables simultaneous hair dyeing and perming. This study offers a novel universal strategy for hair dyeing and permeation with MPNs.

Ordered Assembly of Natural Phenolic Building Blocks for Supramolecular Crystalline Materials

Biomacromolecules such as DNA, proteins, and lipids in nature are constructed by 'bottom-up' assembly with diverse functions and structural ordered characteristics. Supramolecular assemblies have been employed to mimic the natural complexity by manipulating the subtle variations of functional groups. Nevertheless, the intricate design of the driving forces or sophisticated synthesis of molecular skeletons poses challenges in fabricating highly ordered assemblies. Natural phenolic molecules with anisotropic functional groups exhibit potential as versatile building blocks for a wide range of supramolecular crystalline materials with tailored assembly and controlled functionalities. The inherent and anisotropic phenolic groups engage in ordered assembly with various materials via directional covalent bonds (e. g., condensation and coordination) as well as multiple molecular interactions (e. g., hydrogen bonding and π-π interactions), leading to the formation of supramolecular crystalline materials with diverse functionalities. This Concept presents the assembly mechanisms of crystalline phenolic materials and their applications, showcasing the effective utilization of ordered assembly by natural phenolic building blocks.

Investigating the Role of Surface Confinement and Reaction Dynamics in the Production of Polyphenol-Based Nanoparticles

The use of polyphenol-based particles as functional materials has demonstrated great promise for applications ranging from targeted therapeutics to environmental remediation due to their biocompatibility, potent reactivity, and modular chemistry. Despite these rich benefits, polyphenols remain difficult to formulate with due to their susceptibility to spontaneous aggregation in aqueous environments. In this study, we explore conditions that leverage this aggregation as a feature to seed the production of monodispersed (polydispersity index of <0.1) nanoparticles with controlled diameters <200 nm. To accomplish this goal, we evaluated the assembly dynamics of a heterogeneous population of green tea extracts in water and investigated the interplay between temperature, time, and surface confinement in both fixed vessels and emulsion droplets on particle size and uniformity. In both cases, homogeneous nanoparticles are created, highlighting a feasible pathway to control and scale the production of polyphenolic nanostructures for future materials applications.

Biomimetic nanoparticles co-deliver hirudin and lumbrukinase to ameliorate thrombus and inflammation for atherosclerosis therapy

Atherosclerosis (AS) is a progressive inflammatory disease, and thrombosis most likely leads to cardiovascular morbidity and mortality globally. Thrombolytic drugs alone cannot completely prevent thrombotic events, and treatments targeting thrombosis also need to regulate the inflammatory process. Based on the dynamic pathological development of AS, biomimetic thrombus-targeted nanoparticles HMTL@PM were prepared. Hirudin and lumbrukinase, effective substances of traditional Chinese medicine, were self-assembled under the action of tannic acid and Mn2+. HMTL@PM dissociated in the weakly acidic microenvironment of atherosclerosis and exhibited excellent therapeutic effects, including alleviating inflammation, dissolving thrombus, anticoagulation, and promoting cholesterol efflux. HMTL@PM effectively regulated the progression of AS and provided a new perspective for the development of drug delivery systems for AS therapy, which holds important research significance for reducing the mortality of cardiovascular and cerebrovascular diseases.

Synergistic modification of ovalbumin by pH-driven and metal-phenolic networks: Development of dysphagia friendly high internal phase Pickering emulsions

Dysphagia is a common functional disorder that limits the variety of available foods. This study explored the coordination assembly of tannic acid (TA) with Fe3+ to form a metal-phenolic network (MPN) and developed ovalbumin (OVA)/MPN via a pH-driven method as a novel emulsifier to stabilize high internal phase Pickering emulsions (HIPPEs). Results indicated that, following pH-driven treatment, the OVA/MPN composite particles exhibited smaller sizes, enhanced electrostatic repulsion, and improved stability. UV-visible spectroscopy confirmed the successful assembly of MPN with OVA, while pH-driven processes facilitated MPN formation. Multi-spectral technology showed that MPN altered the intermolecular interactions and structural properties of OVA. The cooperatively modified OVA demonstrated superior interfacial wettability and emulsifying properties. Rheological studies revealed that all HIPPEs exhibited gel-like behavior and shear-thinning characteristics. HIPPEs stabilized by OVA, modified synergistically through pH-driven and MPN introduction, showed a dense network structure with higher viscosity, modulus, yield stress, and elasticity. IDDSI testing showed that HIPPEs with TA below 8 mg/mL had low-risk swallowing characteristics, while those with 12 mg/mL exhibited reduced rheological performance and failed the Level 4 dysphagia test. These findings provide crucial insights for the future development of HIPPEs suitable for individuals with dysphagia.

Metal-phenolic network biointerface-mediated cell regulation for bone tissue regeneration

Bone tissue regeneration presents a significant challenge in clinical treatment due to inadequate coordination between implant materials and reparative cells at the biomaterial-bone interfaces. This gap underscores the necessity of enhancing interaction modulation between cells and biomaterials, which is a crucial focus in bone tissue engineering. Metal-polyphenolic networks (MPN) are novel inorganic-organic hybrid complexes that are formed through coordination interactions between phenolic ligands and metal ions. These networks provide a multifunctional platform for biomedical applications, with the potential for tailored design and modifications. Despite advances in understanding MPN and their role in bone tissue regeneration, a comprehensive overview of the related mechanisms is lacking. Here, we address this gap by focusing on MPN biointerface-mediated cellular regulatory mechanisms during bone regeneration. We begin by reviewing the natural healing processes of bone defects, followed by a detailed examination of MPN, including their constituents and distinctive characteristics. We then explore the regulatory influence of MPN biointerfaces on key cellular activities during bone regeneration. Additionally, we illustrate their primary applications in addressing inflammatory bone loss, regenerating critical-size bone defects, and enhancing implant-bone integration. In conclusion, this review elucidates how MPN-based interfaces facilitate effective bone tissue regeneration, advancing our understanding of material interface-mediated cellular control and the broader field of tissue engineering.

Harnessing ROS Amplification and GSH Depletion Using a Carrier-Free Nanodrug to Enhance Ferroptosis-Based Cancer Therapy

Ferroptosis, a non-apoptotic form of cell death characterized by the production of reactive oxygen species (ROS) and massive accumulation of lipid peroxidation (LPO), shows significant promise in cancer therapy. However, the overexpression of glutathione (GSH) at the tumor site and insufficient ROS often result in unsatisfactory therapeutic efficacy. A multistage, GSH-consuming, and ROS-providing carrier-free nanodrug capable of efficiently loading copper ions (Cu2+), sorafenib (SRF), and chlorogenic acid (CGA) (Cu2+-CGA-SRF, CCS-NDs) is developed to mediate enhanced ferroptosis therapy. Through a reductive intracellular environment, Cu2+ in the CCS-NDs reacted with intracellular GSH, alleviating the antioxidant capacity of tumor tissues and triggering the release of drugs. Meanwhile, the released SRF inhibited system xc-, thereby blocking cystine uptake and reducing GSH synthesis in tumor cells. By depleting stored GSH and inhibiting its synthesis, CCS-NDs achieved efficient GSH depletion and increased accumulation of toxic LPO. More importantly, the high concentration of CGA in the CCS-NDs induced ROS generation, further promoting ferroptosis. Both in vitro and in vivo results demonstrated that CCS-NDs effectively triggered ferroptosis in tumor cells by inactivating glutathione peroxidase 4 and inducing LPO. Overall, the carrier-free nanodrug CCS-NDs offer a promising strategy for regulating GSH and LPO levels in ferroptosis-based cancer therapy.

Supramolecular self-assembly of high-loaded horseradish peroxidase and biorecognized antibody into Au/polydopamine nanocomposites for sensitive immunoassay of E. coli O157:H7 in milk

It is an urgent need of rapid and sensitive method for detection of Escherichia coli O157:H7 (E. coli O157:H7), a class of hazardous foodborne pathogens in food safety. The traditional enzyme-linked immunosorbent assay (ELISA), a dominant rapid detection technic, takes disadvantages of low test sensitivity due to the insufficient enzyme loading capacity. In this study, we successfully synthesized the self-assembled Au/polydopamine (PDA)/HRP nanocomposites with the high enzyme loading on the outer surface and in the inner space. The high catalytic activity of Au/PDA/HRP was maintained by virtue of its hyperbranched flexible structure. For E. coli O157:H7 detection in milk samples, the proposed immunoassay achieved a visual cut-off value of 103 cfu mL-1 and a low limit of detection (LOD) of 2.8 × 102 cfu mL-1, 33 and 46 times more sensitive than the traditional ELISA, respectively. The tremendous advantages of high sensitivity, excellent specificity and adequate recovery make it promising for sensitively monitoring various kinds of pathogenic bacteria in food safety.

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.

Material-independent film formation and autonomous degradation of Cu2+-tetrahydroxy-1,4-benzoquinone metal-organic complexes

Metal-organic complexes (MOCs) have extensively been studied as prominent components in interface engineering. Once the designated missions of MOC films are achieved, or while they are still operational, it is preferred that the films undergo degradation on demand in certain circumstances. Current research on MOC-film degradation predominantly relies on chemical treatment, which can alter the states and conditions of specific systems. This work utilizes tetrahydroxy-1,4-benzoquinone (THBQ), a redox-active organic ligand, for material-independent MOC film formation with Cu2+ ions, achieving automatic, self-adaptive degradation of Cu2+-THBQ MOC films upon exposure to air. The results provide a versatile platform for facilitating the spatiotemporal control of (bio)chemical actions in MOC-encapsulated systems, as well as advancing drug delivery systems and air-responsive sensors where variations in O2 levels are critical.

CaGA nanozymes with multienzyme activity realize multifunctional repair of acute wounds by alleviating oxidative stress and inhibiting cell apoptosis

Acute wounds result from damage to the skin barrier, exposing underlying tissues and increasing susceptibility to bacterial and other pathogen infections. Improper wound care increases the risk of exposure and infection, often leading to chronic nonhealing wounds, which cause significant patient suffering. Early wound repair can effectively prevent the development of chronic nonhealing wounds. In this study, Ca-Gallic Acid (CaGA) nanozymes with multienzyme catalytic activity were constructed for treating acute wounds by coordinating Ca ions with gallic acid. CaGA nanozymes exhibit high superoxide dismutase/catalase (SOD/CAT) catalytic activity and good antioxidant performance in vitro. In vitro experiments demonstrated that CaGA nanozymes can effectively promote cell migration, efficiently scavenge ROS, maintain mitochondrial homeostasis, reduce inflammation, and decrease cell apoptosis. In vivo, CaGA nanozymes promoted granulation tissue formation, accelerated collagen fiber deposition, and reconstructed skin appendages, thereby accelerating acute wound healing. CaGA nanozymes have potential clinical application value in wound healing treatment.

Facile Synthesis of Fe-Based Metal-Quinone Networks for Mutually Enhanced Mild Photothermal Therapy and Ferroptosis

Mild photothermal therapy (MPTT) has emerged as a promising therapeutic modality for attenuating thermal damage to the normal tissues surrounding tumors, while the heat-induced upregulation of heat shock proteins (HSPs) greatly compromises the curative efficacy of MPTT by increasing cellular thermo-tolerance. Ferroptosis has been identified to suppress the overexpression of HSPs by the accumulation of lipid peroxides and reactive oxygen species (ROS), but is greatly restricted by overexpressed glutathione (GSH) in tumor microenvironment and undesirable ROS generation efficiency. Herein, a synergistic strategy based on the mutual enhancement of MPTT and ferroptosis is proposed for cleaving HSPs to recover tumor cell sensitivity. A facile method for fabricating a series of Fe-based metal-quinone networks (MQNs) by coordinated assembly is proposed and the representative FTP MQNs possess high photothermal conversion efficiency (69.3 %). Upon 808 nm laser irradiation, FTP MQNs not only trigger effective MPTT to induce apoptosis but more significantly, potentiate Fenton reaction and marked GSH consumption to boost ferroptosis, and the reinforced ferroptosis effect in turn can alleviate the thermal resistance by declining the HSP70 defense and reducing ATP levels. This study provides a valuable rationale for constructing a large library of MQNs for achieving mutual enhancement of MPTT and ferroptosis.

Building of CuO2@Cu-TA@DSF/DHA Nanoparticle Targets MAPK Pathway to Achieve Synergetic Chemotherapy and Chemodynamic for Pancreatic Cancer Cells

Background/Objectives: With the increase of reactive oxygen species (ROS) production, cancer cells can avoid cell death and damage by up-regulating antioxidant programs. Therefore, it will be more effective to induce cell death by using targeted strategies to further improve ROS levels and drugs that inhibit antioxidant programs. Methods: Considering that dihydroartemisinin (DHA) can cause oxidative damage to protein, DNA, or lipids by producing excessive ROS, while, disulfiram (DSF) can inhibit glutathione (GSH) levels and achieve the therapeutic effect by inhibiting antioxidant system and amplifying oxidative stress, they were co-loaded onto the copper peroxide nanoparticles (CuO2) coated with copper tannic acid (Cu-TA), to build a drug delivery system of CuO2@Cu-TA@DSF/DHA nanoparticles (CCTDD NPs). In response to the tumor microenvironment, DHA interacts with copper ion (Cu2+) to produce ROS, and a double (diethylthiocarbamate)-copper (II) (CuET) is generated by the complexation of DSF and Cu2+, which consumes GSH and inhibits antioxidant system. Meanwhile, utilizing the Fenton-like effect induced by the multi-copper mode can achieve ROS storm, activate the MAPK pathway, and achieve chemotherapy (CT) and chemodynamic (CDT). Results: Taking pancreatic cancer cell lines PANC-1 and BxPC-3 as the research objects, cell line experiments in vitro proved that CCTDD NPs exhibit efficient cytotoxicity on cancer cells. Conclusions: The CCTDD NPs show great potential in resisting pancreatic cancer cells and provides a simple strategy for designing powerful metal matrix composites.

Supramolecular assembly of Polydopamine@Fe nanoparticles with near-infrared light-accelerated cascade catalysis applied for synergistic photothermal-enhanced chemodynamic therapy

Chemodynamic therapy (CDT) via Fenton-like reaction is greatly attractive owing to its capability to generate highly cytotoxic •OH radicals from tumoral hydrogen peroxide (H2O2). However, the antitumor efficacy of CDT is often challenged by the relatively low radical generation efficiency and the high levels of antioxidative glutathione (GSH) in tumor microenvironment. Herein, an innovative photothermal Fenton-like catalyst, Fe-chelated polydopamine (PDA@Fe) nanoparticle, with excellent GSH-depleting capability is constructed via one-step molecular assembly strategy for dual-modal imaging-guided synergetic photothermal-enhanced chemodynamic therapy. Fe(III) ions in PDA@Fe nanoparticles can consume the GSH overexpressed in tumor microenvironment to avoid the potential •OH consumption, while the as-produced Fe(II) ions subsequently convert tumoral H2O2 into cytotoxic •OH radicals through the Fenton reaction. Notably, PDA@Fe nanoparticles demonstrate excellent near-infrared light absorption that results in superior photothermal conversion ability, which further boosts above-mentioned cascade catalysis to yield more •OH radicals for enhanced CDT. Taken together with T1-weighted magnetic resonance imaging (MRI) contrast enhancement (r1 = 8.13 mM-1 s-1) and strong photoacoustic (PA) imaging signal of PDA@Fe nanoparticles, this design finally realizes the synergistic photothermal-chemodynamic therapy. Overall, this work offers a new promising paradigm to effectively accommodate both imaging and therapy functions in one well-defined framework for personalized precision disease treatment.

Assembly and biological functions of metal-biomolecule network nanoparticles formed by metal-phosphonate coordination

Metal-organic networks have attracted widespread interest owing to their hybrid physicochemical properties. Natural biomolecules represent attractive building blocks for these materials because of their inherent biological function and high biocompatibility; however, assembling them into coordination network materials, especially nanoparticles (NPs), is challenging. Herein, we exploit the coordination between metal ions and phosphonate groups, which are present in many biomolecules, to form metal-biomolecule network (MBN) NPs in aqueous solution at room temperature. Various phosphonate-containing biomolecules, including plant phytate, DNA, and proteins, were used to assemble MBN NPs with tunable physicochemical properties (e.g., size). In addition to excellent biocompatibility and high cargo-loading efficiency (>95%), these two-component MBN NPs have various biological functionalities, including endosomal escape, immune regulation, and molecular recognition, thus offering advantages over nonbiomolecular-based coordination materials. This work expands our understanding of metal-organic chemistry with the emerging class of metal-biomolecule systems and provides a pathway for incorporating biofunctionalities into advanced coordination materials for diverse fields.

Efficient green synthesis of biocompatible MPN fluorescent microspheres via hydrophobic-force-driven strategy for enhanced immunochromatographic assays

The unique fluorescence properties of aggregation-induced emission (AIE) fluorescent microspheres (FMs) make them ideal signal markers. Traditional synthesis methods are complex, labor-intensive, and hazardous, leading to AIEFMs that lack biocompatibility and require further modification for immunoprobe preparation. This study introduces a novel hydrophobic force-driven method for rapid synthesis of highly biocompatible FMs (H-FMs), demonstrating their benefits in immunochromatographic assay (ICA) applications. The metal-polyphenol network (MPN) shell around the AIEgen core structure of H-FMs is quickly and safely formed by depositing MPN onto AIEgen nano-aggregates, achieving high dye utilization, affordability, and design flexibility, while producing H-FMs with fluorescence across 300-800 nm. The excellent biocompatibility of H-FMs eliminates the need for additional modifications, allowing antibodies to be coupled swiftly (within 10 min) with a high coupling efficiency of 93.4 %. The resulting immunoprobes exhibit strong target recognition and 90.6 % fluorescence retention over 30 days. These features support their application in double antibody sandwich and competitive ICA formats, with detection limits of 9.62 × 10² CFU/mL for E. coli O157:H7 and 0.0081 ng/mL for AFM1. This study provides new insights into designing fluorescent probes for safety monitoring of hazardous materials in the environment.

Recent advances of copper-based metal phenolic networks in biomedical applications

Metal-phenolic Networks (MPNs) are a novel class of nanomaterial developed gradually in recent years which are self-assembled by metal ions and polyphenolic ligands. Due to their environmental protection, good adhesion, and biocompatibility with green phenolic ligands, MPNs can be used as a new type of nanomaterial. They show excellent properties such as anti-inflammatory, antioxidant, antibacterial, and anticancer, and have been widely studied in the biomedical field. As one of the most common subclasses of the MPNs family, copper-based MPNs have been widely studied for drug delivery, Photodynamic Therapy (PDT), Chemo dynamic Therapy (CDT), antibacterial and anti-inflammatory, bone tissue regeneration, skin regeneration wound repair, and metal ion imaging. In this paper, the preparation strategies of different types of copper-based MPNs are reviewed. Then, the application status of copper-based MPNs in the biomedical field under different polyphenol ligands is introduced in detail. Finally, the existing problems and challenges of copper-based MPNs are discussed, as well as their future application prospects in the biomedical field.

Tailoring Core-Shell Metal Coordination for Smart Seed Coatings in Sustainable Agriculture

The international agriculture and food security sector is grappling with challenges like low crop yields, soil health deficiencies, and inefficient agrochemical use. The application of smart nanotechnology in agriculture, particularly surface functionalization, holds promise but has limited implementation. Engineered nanomaterials used as seed treatments, known as nanopriming, offer a simple technology to improve crop yield and stress tolerance. In this study, a multicomponent platform called Phelm (Phenolic network with a lipid core and metal coordinated shell) is proposed for encapsulating a commercial plant growth regulator, indole-3 acetic acid (IAA). Phelm comprises a hydrophobic solid lipid core, loaded with IAA, and an outer metal coordinated phenolic shell of tannic acid (TA) and Fe3+. The platform aims to treat seeds with encapsulated IAA, which can be controllably released, as well as protect the germination process at high salt concentrations. Phelm showed a remarkable increase in growth parameters of wheat seeds up to 58.6%, despite being irrigated with high concentrations of saltwater (100 mM). These findings suggest that nanopriming of seeds can effectively increase their efficacy even under abiotic stress conditions, which can drastically improve crop yields. Moreover, we envisage that the Phelm core/shell assembly can encapsulate a wide range of agrochemicals and biostimulants to promote sustainable and smart agricultural practices.

Trojan Horse Strategy for Wireless Electrical Stimulation-Induced Zn2+ Release to Regulate Neural Stem Cell Differentiation for Spinal Cord Injury Repair

Due to the uncertain differentiation of neural stem cells (NSCs), replenishing lost neurons by endogenous neural differentiation to repair spinal cord injury (SCI) remains challenging. The electrical stimulation-induced drug release is a promising approach for the localized and controlled release of drugs to regulate the differentiation of NSCs into neurons. Here, we developed Zn-PDA@BT nanoparticles acted as Trojan Horse to enter cells through endocytosis for Zn2+-controlled release therapy by the potentials generated by the piezoelectric effect. Due to the presence of polydopamine (PDA), under ultrasound stimulation, the electrical signal derived from the piezoelectric effect of barium titanate nanoparticles can be attracted to the surface of Trojan Horse nanoparticles to facilitate the controlled release of Zn2+. And Zn2+ bonded with PDA can increase the intracellular Zn2+ concentration within mouse-derived NSCs (mNSCs) to regulate the differentiation of mNSCs, which could enhance excitatory neuronal differentiation and inhibit astrocyte differentiation of mNSCs by activating the TGF-β and p53 pathways. More importantly, this Trojan Horse therapy allowed mNSCs to differentiate into mature neurons in 5 days, while the natural differentiation process took 10 days. Moreover, the transplantation of mNSC-ingested Zn-PDA@BT nanoparticles effectively replenished lost neurons at the damaged site and promoted function recovery after SCI in vivo, demonstrating the great potential of electrical stimulation-induced Zn2+ release for SCI repair.

Metal Polyphenol Nanoparticle-Based Chemo/Ferroptosis Synergistic Therapy for the Treatment of Oral Squamous Cell Carcinoma

Despite the use of surgical resection and chemotherapy in the clinical treatment of oral squamous cell carcinoma (OSCC), the 5-year survival rates of advanced patients are low. Therefore, more efficient strategies are urgently needed. Herein, a chemo/ferroptosis synergistic therapeutic system-DMEFe nanoparticles (NPs) is established for the treatment of OSCC. To create this system, the chemotherapeutic agent doxorubicin (DOX) was loaded into mesoporous silica nanoparticles and further coated with a pH-sensitive metal polyphenol (iron ion and epigallocatechin gallate). These nanoparticles displayed excellent pH-sensitive drug-control release properties, and the release ratio of DOX at pH 5.5 was twice as high than that at pH 7.4. Additionally, DMEF NPs were effectively taken up by the OSCC cell line SSC-25, which greatly impeded the proliferation of these cells. Notably, these nanoparticles increased the intracellular level of reactive oxygen species and effectively exhibited cytotoxity effects. The mechanistic results proved that DMEFe NPs regulated the expression of ferroptosis-related genes to induce ferroptosis of SSC-25 cells. Eventually, this chemo/ferroptosis therapeutic system exhibited remarkable antitumor effects and provided a novel strategy for the treatment of OSCC.

Green Synthesis of Zinc Oxide Nanoparticles Using Puerarin: Characterization, Antimicrobial Potential, Angiogenesis, and In Ovo Safety Profile Assessment

BACKGROUND

Zinc oxide nanobiocomposites were successfully synthesized using a green synthesis approach. The process involves the utilization of the isoflavone puerarin, resulting in the formation of PUE-ZnO NPs.

METHODS

Physico-chemical and biological characterization techniques including X-ray dif-fraction (XRD), UV-vis spectroscopy, Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and in ovo methods were employed to study the main characteristics of this novel hybrid material.

RESULTS

The PUE-ZnO NPs were confirmed to have been successfully synthesized with a UV absorption peak at 340 nm, the XRD analysis demonstrating their high purity and crystallinity. The energy band-gap value of 3.30 eV suggests possible photocatalytic properties. Both SEM and AFM images revealed the nanoparticle`s quasi-spherical shape, roughness, and size. Good tolerability and anti-irritative effects were recorded in ovo on the chorioallantoic membrane (CAM).

CONCLUSIONS

According to these results, the synthesis of green PUE-ZnO NPs may be a promising future approach for biomedical and personal care applications.

Metal-phenolic network composites: from fundamentals to applications

Composites with tailored compositions and functions have attracted widespread scientific and industrial interest. Metal-phenolic networks (MPNs), which are composed of phenolic ligands and metal ions, are amorphous adhesive coordination polymers that have been combined with various functional components to create composites with potential in chemistry, biology, and materials science. This review aims to provide a comprehensive summary of both fundamental knowledge and advancements in the field of MPN composites. The advantages of amorphous MPNs, over crystalline metal-organic frameworks, for fabricating composites are highlighted, including their mild synthesis, diverse interactions, and numerous intrinsic functionalities. The formation mechanisms and state-of-the-art synthesis strategies of MPN composites are summarized to guide their rational design. Subsequently, a detailed overview of the chemical interactions and structure-property relationships of composites based on different functional components (e.g., small molecules, polymers, biomacromolecules) is provided. Finally, perspectives are offered on the current challenges and future directions of MPN composites. This tutorial review is expected to serve as a fundamental guide for researchers in the field of metal-organic materials and to provide insights and avenues to enhance the performance of existing functional materials in applications across diverse fields.

mRNA delivery enabled by metal-organic nanoparticles

mRNA therapeutics are set to revolutionize disease prevention and treatment, inspiring the development of platforms for safe and effective mRNA delivery. However, current mRNA delivery platforms face some challenges, including limited organ tropism for nonvaccine applications and inflammation induced by cationic nanoparticle components. Herein, we address these challenges through a versatile, noncationic nanoparticle platform whereby mRNA is assembled into a poly(ethylene glycol)-polyphenol network stabilized by metal ions. Screening a range of components and relative compositional ratios affords a library of stable, noncationic, and highly biocompatible metal-organic nanoparticles with robust mRNA transfection in vitro and in mice. Intravenous administration of the lead mRNA-containing metal-organic nanoparticles enables predominant protein expression and gene editing in the brain, liver, and kidney, while organ tropism is tuned by varying nanoparticle composition. This study opens an avenue for realizing metal-organic nanoparticle-enabled mRNA delivery, offering a modular approach to assembling mRNA therapeutics for health applications.