Metal Ion-Directed Functional Metal-Phenolic Materials

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.

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.

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.

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.

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.

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.

Metals at the Helm: Revolutionizing Protein Assembly and Applications

Protein assembly is an essential process in biological systems, where proteins self-assemble into complex structures with diverse functions. Inspired by the exquisite control over protein assembly in nature, scientists have been exploring ways to design and assemble protein structures with precise control over their topologies and functions. One promising approach for achieving this goal is through metal coordination, which utilizes metal-binding motifs to mediate protein-protein interactions and assemble protein complexes with controlled stoichiometry and geometry. Metal coordination provides a modular and tunable approach for protein assembly and de novo structure design, where the metal ion acts as a molecular glue that holds the protein subunits together in a specific orientation. Metal-coordinated protein assemblies have shown great potential for developing functional metalloproteinase, novel biomaterials and integrated drug delivery systems. In this review, an overview of the recent advances in protein assemblies benefited from metal coordination is provided, focusing on various protein arrangements in different dimensions including protein oligomers, protein nanocage and higher-order protein architectures. Moreover, the key metal-binding motifs and strategies used to assemble protein structures with precise control over their properties are highlighted. The potential applications of metal-mediated protein assemblies in biotechnology and biomedicine are also discussed.

Neutrophil Extracellular Traps-Inspired Bismuth-Based Polypeptide Nanonets for Synergetic Treatment of Bacterial Infections

Excessive use of antibiotics and the formation of bacterial biofilms can lead to persistent infections caused by drug-resistant bacteria, rendering ineffective immune responses and even life-threatening. There is an urgent need to explore synergistic antibacterial therapies across all stages of infection. Drawing inspiration from the antibacterial properties of neutrophil extracellular traps (NETs) and integrating the bacterial biofilm dispersal mechanism involving boronic acid-catechol interaction, the multifunctional bismuth-based polypeptide nanonets (PLBA-Bi-Fe-TA) are developed. These nanonets are designed to capture bacteria through a coordination complex involving cationic polypeptides (PLBA) with boronic acid-functionalized side chains, alongside metal ions (bismuth (Bi) and iron (Fe)), and tannic acid (TA). Leveraging the nanoconfinement-enhanced high-contact network-driven multiple efficiency, PLBA-Bi-Fe-TA demonstrates the excellent ability to swiftly capture bacteria and their extracellular polysaccharides. This interaction culminates in the formation of a highly hydrophilic complex, effectively enabling the rapid inhibition and dispersion of antibiotic-resistant bacterial biofilms, while Fe-TA shows mild photothermal ability to further assist fluffy mature biofilm. In addition, Bi is beneficial to regulate the polarization of macrophages to pro-inflammatory phenotype to further kill escaping biofilm bacteria. In summary, this novel approach offers a promising bionic optimization strategy for treating bacterial-associated infections at all stages through synergetic treatment.

The Core-Shell Microneedle with Probiotic Extracellular Vesicles for Infected Wound Healing and Microbial Homeostasis Restoration

Wound healing is a dynamic process involving the timely transition of organized phases. However, infected wounds often experience prolonged inflammation due to microbial overload. Thus, addressing the viable treatment needs across different healing stages is a critical challenge in wound management. Herein, a novel core-shell microneedle (CSMN) patch is designed for the sequential delivery of tannic acid-magnesium (TA-Mg) complexes and extracellular vesicles from Lactobacillus druckerii (LDEVs). Upon application to infected sites, CSMN@TA-Mg/LDEV releases TA-Mg first to counteract pathogenic overload and reduce reactive oxygen species (ROS), aiding the transition to proliferative phase. Subsequently, the sustained release of LDEVs enhances the activities of keratinocytes and fibroblasts, promotes vascularization, and modulates the collagen deposition. Notably, dynamic track of microbial composition demonstrates that CSMN@TA-Mg/LDEV can both inhibit the aggressive pathogen and increase the microbial diversity at wound sites. Functional analysis further highlights the potential of CSMN@TA-Mg/LDEV in facilitating wound healing and skin barrier restoration. Moreover, it is confirmed that CSMN@TA-Mg/LDEV can accelerate wound closure and improve post-recovery skin quality in the murine infected wound. Conclusively, this innovative CSMN patch offers a rapid and high-quality alternative treatment for infected wounds and emphasizes the significance of microbial homeostasis.

Cell Membrane Engineered Polypeptide Nanonets Mimicking Macrophage Aggregates for Enhanced Antibacterial Treatment

Drug-resistant bacterial infections and their lipopolysaccharide-related inflammatory complications continue to pose significant challenges in traditional treatments. Inspired by the rapid initiation of resident macrophages to form aggregates for efficient antibacterial action, this study proposes a multifunctional and enhanced antibacterial strategy through the construction of novel biomimetic cell membrane polypeptide nanonets (R-DPB-TA-Ce). The design involves the fusion of end-terminal lipidated polypeptides containing side-chain cationic boronic acid groups (DNPLBA) with cell membrane intercalation engineering (R-DPB), followed by coordination with the tannic acid-cerium complex (TA-Ce) to assemble into a biomimetic nanonet through boronic acid-polyphenol-metal ion interactions. In addition to the ability of RAW 264.7 macrophages cell membrane components' (R) ability to neutralize lipopolysaccharide (LPS), R-DPB-TA-Ce demonstrated enhanced capture of bacteria and its LPS, leveraging nanoconfinement-enhanced multiple interactions based on the boronic acid-polyphenol nanonets skeleton combined with polysaccharide. Utilizing these advantages, indocyanine green (ICG) is further employed as a model drug for delivery, showcasing the exceptional treatment effect of R-DPB-TA-Ce as a new biomimetic assembled drug delivery system in antibacterial, anti-inflammatory, and wound healing promotion. Thus, this strategy of mimicking macrophage aggregates is anticipated to be further applicable to various types of cell membrane engineering for enhanced antibacterial treatment.

Polyvinyl alcohol/PEDOT:PSS with Fe3+/amylopectin enabled highly tough, anti-freezing and healable hydrogels for multifunctional wearable sensors

In recent years, hydrogel-based flexible sensors have garnered increasing attention in research. Ionic hydrogels, enriched with large amounts of ionic liquids, exhibit electrical conductivity, excellent electrochemical stability, anti-freezing, and antimicrobial properties. However, most ionic hydrogels suffer from poor mechanical properties, limiting their adaptability to more complex application scenarios. Integrating conductive polymers into hydrogels leads to desirable features such as increased specific surface area, soft and biocompatible interfaces, and high electrolyte permeability. In this study, we successfully prepared Fe3+/Ap@PVA/PEDOT double-network hydrogel. Utilizing polyvinyl alcohol (PVA) as the primary matrix, we introduced PEDOT:PSS and FeCl3 to confer conductivity to the hydrogel. The incorporation of amylopectin (Ap) further enhanced mechanical performance. The resulted hydrogel sensor exhibits outstanding mechanical properties, allowing for stretching up to 347 % and withstanding a tensile force of 505 kPa. In addition, it exhibits excellent antifreeze properties (can work at -30 °C), healability, water retention, and high sensitivity to stretching (GF = 4.72 at a 200 % strain ratio), compression (GF = 2.97 at a 12 % compressive ratio), and temperature (TCR = 2.46). These remarkable properties of the hydrogel make it possible in applications such as human motion monitoring, handwriting recognition, and temperature sensing.

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.

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.

A Metal-Phenolic Network-Enabled Nanoadjuvant to Modulate Immune Responses

The presence of hierarchical suppressive pathways in the immune system combined with poor delivery efficiencies of adjuvants and antigens to antigen-presenting cells are major challenges in developing advanced vaccines. The present study reports a nanoadjuvant constructed using aluminosilicate nanoparticles (as particle templates), incorporating cytosine-phosphate-guanosine (CpG) oligonucleotides and small-interfering RNA (siRNA) to counteract immune suppression in antigen-presenting cells. Furthermore, the application of a metal-phenolic network (MPN) coating, which can endow the nanoparticles with protective and bioadhesive properties, is assessed with regard to the stability and immune function of the resulting nanoadjuvant in vitro and in vivo. Combining the adjuvanticity of aluminum and CpG with RNA interference and MPN coating results in a nanoadjuvant that exhibits greater accumulation in lymph nodes and elicits improved maturation of dendritic cells in comparison to a formulation without siRNA or MPN, and with no observable organ toxicity. The incorporation of a model antigen, ovalbumin, within the MPN coating demonstrates the capacity of MPNs to load functional biomolecules as well as the ability of the nanoadjuvant to trigger enhanced antigen-specific responses. The present template-assisted fabrication strategy for engineering nanoadjuvants holds promise in the design of delivery systems for disease prevention, as well as therapeutics.

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.

Crystalline Metal-Organic Framework Coatings Engineered via Metal-Phenolic Network Interfaces

Crystalline metal-organic frameworks (MOFs) have garnered extensive attention owing to their highly ordered porous structure and physicochemical properties. However, their practical application often requires their integration with various substrates, which is challenging because of their weakly adhesive nature and the diversity of substrates that exhibit different properties. Herein, we report the use of amorphous metal-phenolic network coatings to facilitate the growth of crystalline MOF coatings on various particle and planar substrates. Crystalline MOFs with different metal ions and morphologies were successfully deposited on substrates (13 types) of varying sizes, shapes, and surface chemistries. Furthermore, the physicochemical properties of the coated crystalline MOFs (e.g., composition, thickness) could be tuned using different synthesis conditions. The engineered MOF-coated membranes demonstrated excellent liquid and gas separation performance, exhibiting a high H2 permeance of 63200 GPU and a H2/CH4 selectivity of 10.19, likely attributable to the thin nature of the coating (~180 nm). Considering the vast array of MOFs available (>90,000) and the diversity of substrates, this work is expected to pave the way for creating a wide range of MOF composites and coatings with potential applications in diverse fields.

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.

Carboxymethyl chitosan-dialdehyde glucan/polydopamine carrier targeted delivery Bacillus subtilis on enhancing oral utilization and intestinal colonization in mice

Most probiotics are difficult to resist the invasion of gastrointestinal physiological and pathological environments, which limits their beneficial effects. The design of a pH-responsive and adhesive double-layer carrier (Carboxymethyl chitosan polyaldehyde polysaccharide, CMCS-DHG/PDA) aims to safeguard the activity of probiotics and enhance their intestinal colonization. The results obtained from UV-vis spectroscopy and XPS analysis revealed the formation of a polydopamine nanocoating surrounding Bacillus subtilis, and the outer carrier formed a Schiff base covalent bond, providing sufficient mechanical properties for the carrier. The carrier exhibited a significantly higher degree of swelling under pH 1.2 compared to pH 7.4, indicating its pronounced pH responsiveness. The CMCS-DHG/PDA carrier not only provided protection for B. subtilis against simulated digestive fluids, but also improved its tolerance to bile and antibiotics. In addition, carrier-protected probiotics showed extraordinary mucosal adhesion, which could significantly improve oral bioavailability and intestinal colonization. Finally, the impact of carrier-protected B. subtilis on gut microbiota was explored, revealing that the carrier protected B. subtilis could significantly improve the diversity, richness, and composition of gut microbiota. Concurrently, it promoted the formation of short chain fatty acids, creating a more beneficial environment for intestinal health.

Orally biomimetic metal-phenolic nanozyme with quadruple safeguards for intestinal homeostasis to ameliorate ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is defined by persistent inflammatory processes within the gastrointestinal tract of uncertain etiology. Current therapeutic approaches are limited in their ability to address oxidative stress, inflammation, barrier function restoration, and modulation of gut microbiota in a coordinated manner to maintain intestinal homeostasis.

RESULTS

This study involves the construction of a metal-phenolic nanozyme (Cur-Fe) through a ferric ion-mediated oxidative coupling of curcumin. Cur-Fe nanozyme exhibits superoxide dismutase (SOD)-like and •OH scavenging activities, demonstrating significant anti-inflammatory and anti-oxidant properties for maintaining intracellular redox balance in vitro. Drawing inspiration from Escherichia coli Nissle 1917 (EcN), a biomimetic Cur-Fe nanozyme (CF@EM) is subsequently developed by integrating Cur-Fe into the EcN membrane (EM) to improve the in vivo targeting ability and therapeutic effectiveness of the Cur-Fe nanozyme. When orally administered, CF@EM demonstrates a strong ability to colonize the inflamed colon and restore intestinal redox balance and barrier function in DSS-induced colitis models. Importantly, CF@EM influences the gut microbiome towards a beneficial state by enhancing bacterial diversity and shifting the compositional structure toward an anti-inflammatory phenotype. Furthermore, analysis of intestinal microbial metabolites supports the notion that the therapeutic efficacy of CF@EM is closely associated with bile acid metabolism.

CONCLUSION

Inspired by gut microbes, we have successfully synthesized a biomimetic Cur-Fe nanozyme with the ability to inhibit inflammation and restore intestinal homeostasis. Collectively, without appreciable systemic toxicity, this work provides an unprecedented opportunity for targeted oral nanomedicine in the treatment of ulcerative colitis.

An Osteoimmunomodulatory Biopatch Potentiates Stem Cell Therapies for Bone Regeneration by Simultaneously Regulating IL-17/Ferroptosis Signaling Pathways

Currently, there are still great challenges in promoting bone defect healing, a common health problem affecting millions of people. Herein an osteoimmunity-regulating biopatch capable of promoting stem cell-based therapies for bone regeneration is developed. A totally biodegradable conjugate is first synthesized, which can self-assemble into bioactive nano micelles (PPT NMs). This nanotherapy effectively improves the osteogenesis of periodontal ligament stem cells (PDLSCs) under pathological conditions, by simultaneously regulating IL-17 signaling and ferroptosis pathways. Incorporation of PPT NMs into biodegradable electrospun nanofibers affords a bioactive patch, which notably improves bone formation in two rat bone defect models. A Janus bio patch is then engineered by integrating the bioactive patch with a stem cell sheet of PDLSCs. The obtained biopatch shows additionally potentiated bone regeneration capacity, by synergistically regulating osteoimmune microenvironment and facilitating stem cell differentiation. Further surface functionalization of the biopatch with tannic acid considerably increases its adhesion to the bone defect, prolongs local retention, and sustains bioactivities, thereby offering much better repair effects in rats with mandibular or cranial bone defects. Moreover, the engineered bioactive patches display good safety. Besides bone defects, this osteoimmunity-regulating biopatch strategy can be applied to promote stem cell therapies for spinal cord injury, wound healing, and skin burns.

Adsorption and separation technologies based on supramolecular macrocycles for water treatment

The escalating challenges in water treatment, exacerbated by climate change, have catalyzed the emergence of innovative solutions. Novel adsorption separation and membrane filtration methodologies, achieved through molecular structure manipulation, are gaining traction in the environmental and energy sectors. Separation technologies, integral to both the chemical industry and everyday life, encompass concentration and purification processes. Macrocycles, recognized as porous materials, have been prevalent in water treatment due to their inherent benefits: stability, adaptability, and facile modification. These structures typically exhibit high selectivity and reversibility for specific ions or molecules, enhancing their efficacy in water purification processes. The progression of purification methods utilizing macrocyclic frameworks holds promise for improved adsorption separations, membrane filtrations, resource utilization, and broader water treatment applications. This review encapsulates the latest breakthroughs in macrocyclic host-guest chemistry, with a focus on adsorptive and membrane separations. The aim is to spotlight strategies for optimizing macrocycle designs and their subsequent implementation in environmental and energy endeavors, including desalination, elemental extraction, seawater energy harnessing, and sustainable extraction. Hopefully, this review can guide the design and functionality of macrocycles, offering a significantly promising pathway for pollutant removal and resource utilization.

Metal-polyphenol self-assembled nanodots for NIR-II fluorescence imaging-guided chemodynamic/photodynamic therapy-amplified ferroptosis

The effectiveness of tumor treatment using reactive oxygen species as the primary therapeutic medium is hindered by limitations of tumor microenvironment (TME), such as intrinsic hypoxia in photodynamic therapy (PDT) and overproduction of reducing glutathione (GSH) in chemodynamic therapy (CDT). Herein, we fabricate metal-polyphenol self-assembled nanodots (Fe@BDP NDs) guided by second near-infrared (NIR-II) fluorescence imaging. The Fe@BDP NDs are designed for synergistic combination of type-I PDT and CDT-amplified ferroptosis. In a mildly acidic TME, Fe@BDP NDs demonstrate great Fenton activity, leading to the generation of highly toxic hydroxyl radicals from overproduced hydrogen peroxide in tumor cells. Furthermore, Fe@BDP NDs show favorable efficacy in type-I PDT, even in tolerating tumor hypoxia, generating active superoxide anion upon exposure to 808 nm laser irradiation. The significant efficiency in reactive oxygen species (ROS) products results in the oxidation of sensitive polyunsaturated fatty acids, accelerating lethal lipid peroxidation (LPO) bioprocess. Additionally, Fe@BDP NDs illustrate an outstanding capability for GSH depletion, causing the inactivation of glutathione peroxidase 4 and further promoting lethal LPO. The synergistic type-I photodynamic and chemodynamic cytotoxicity effectively trigger irreversible ferroptosis by disrupting the intracellular redox homeostasis. Moreover, Fe@BDP NDs demonstrate charming NIR-II fluorescence imaging capability and effectively accumulated at the tumor site, visualizing the distribution of Fe@BDP NDs and the treatment process. The chemo/photo-dynamic-amplified ferroptotic efficacy of Fe@BDP NDs was evidenced both in vitro and in vivo. This study presents a compelling approach to intensify ferroptosis via visualized CDT and PDT. STATEMENT OF SIGNIFICANCE: In this study, we detailed the fabrication of metal-polyphenol self-assembled nanodots (Fe@BDP NDs) guided by second near-infrared (NIR-II) fluorescence imaging, aiming to intensify ferroptosis via the synergistic combination of type-I PDT and CDT. In a mildly acidic TME, Fe@BDP NDs exhibited significant Fenton activity, resulting in the generation of highly toxic •OH from overproduced H2O2 in tumor cells. Fe@BDP NDs possessed a remarkable capability for GSH depletion, resulting in the inactivation of glutathione peroxidase 4 (GPX4) and further accelerating lethal LPO. This study presented a compelling approach to intensify ferroptosis via visualized CDT and PDT.

Natural Products from Herbal Medicine Self-Assemble into Advanced Bioactive Materials

Novel biomaterials are becoming more crucial in treating human diseases. However, many materials require complex artificial modifications and synthesis, leading to potential difficulties in preparation, side effects, and clinical translation. Recently, significant progress has been achieved in terms of direct self-assembly of natural products from herbal medicine (NPHM), an important source for novel medications, resulting in a wide range of bioactive supramolecular materials including gels, and nanoparticles. The NPHM-based supramolecular bioactive materials are produced from renewable resources, are simple to prepare, and have demonstrated multi-functionality including slow-release, smart-responsive release, and especially possess powerful biological effects to treat various diseases. In this review, NPHM-based supramolecular bioactive materials have been revealed as an emerging, revolutionary, and promising strategy. The development, advantages, and limitations of NPHM, as well as the advantageous position of NPHM-based materials, are first reviewed. Subsequently, a systematic and comprehensive analysis of the self-assembly strategies specific to seven major classes of NPHM is highlighted. Insights into the influence of NPHM structural features on the formation of supramolecular materials are also provided. Finally, the drivers and preparations are summarized, emphasizing the biomedical applications, future scientific challenges, and opportunities, with the hope of igniting inspiration for future research and applications.

Mussel-inspired interface deposition strategy for mesoporous metal-phenolic nanospheres with superior antioxidative, photothermal and antibacterial performance

Metal-phenolic networks (MPNs) have emerged as a versatile and multifunctional platform applied in bioimaging, disease treatment, electrocatalysis, and water purification. The synthesis of MPNs with mesoporous frameworks and ultra-small diameters (<200 nm), crucial for post-modification, cargo loading, and mass transport, remains a formidable challenge. Inspired by mussel chemistry, mesoporous metal-phenolic nanospheres (MMPNs) are facilely prepared by direct deposition of the metal-polyphenol complex on the interface of oil nano-droplets composed of block copolymers/1,3,5-trimethylbenzene followed by a spontaneous template-removal process. Due to the penetrable and stable networks, the oil nano-droplets gradually leak from the networks driven by shear stress during the stirring process. As a result, MMPNs are obtained without additional template removal procedures such as solvent extraction or high-temperature calcination. The materials have a large pore size (∼12.1 nm), uniform spherical morphology with a small particle size (∼99 nm), and a large specific surface area (49.8 m2 g-1). Due to the abundant phenolic hydroxyl groups, the MMPNs show excellent antioxidative property. The MMPNs also have excellent photothermal property, whose photothermal conversion efficiency was 40.9 %. Moreover, the phenolic hydroxyl groups can reduce Ag+ in situ to prepare Ag nanoparticles loaded MMPNs composites, which have excellent inhibition performance of drug-resistant bacteria biofilm.

Microbe-material hybrids for therapeutic applications

As natural living substances, microorganisms have emerged as useful resources in medicine for creating microbe-material hybrids ranging from nano to macro dimensions. The engineering of microbe-involved nanomedicine capitalizes on the distinctive physiological attributes of microbes, particularly their intrinsic "living" properties such as hypoxia tendency and oxygen production capabilities. Exploiting these remarkable characteristics in combination with other functional materials or molecules enables synergistic enhancements that hold tremendous promise for improved drug delivery, site-specific therapy, and enhanced monitoring of treatment outcomes, presenting substantial opportunities for amplifying the efficacy of disease treatments. This comprehensive review outlines the microorganisms and microbial derivatives used in biomedicine and their specific advantages for therapeutic application. In addition, we delineate the fundamental strategies and mechanisms employed for constructing microbe-material hybrids. The diverse biomedical applications of the constructed microbe-material hybrids, encompassing bioimaging, anti-tumor, anti-bacteria, anti-inflammation and other diseases therapy are exhaustively illustrated. We also discuss the current challenges and prospects associated with the clinical translation of microbe-material hybrid platforms. Therefore, the unique versatility and potential exhibited by microbe-material hybrids position them as promising candidates for the development of next-generation nanomedicine and biomaterials with unique theranostic properties and functionalities.

Mg-gallate metal-organic framework-based sprayable hydrogel for continuously regulating oxidative stress microenvironment and promoting neurovascular network reconstruction in diabetic wounds

Chronic diabetic wounds are the most common complication for diabetic patients. Due to high oxidative stress levels affecting the entire healing process, treating diabetic wounds remains a challenge. Here, we present a strategy for continuously regulating oxidative stress microenvironment by the catalyst-like magnesium-gallate metal-organic framework (Mg-GA MOF) and developing sprayable hydrogel dressing with sodium alginate/chitosan quaternary ammonium salts to treat diabetic wounds. Chitosan quaternary ammonium salts with antibacterial properties can prevent bacterial infection. The continuous release of gallic acid (GA) effectively eliminates reactive oxygen species (ROS), reduces oxidative stress, and accelerates the polarization of M1-type macrophages to M2-type, shortening the transition between inflammation and proliferative phase and maintaining redox balance. Besides, magnesium ions adjuvant therapy promotes vascular regeneration and neuronal formation by activating the expression of vascular-associated genes. Sprayable hydrogel dressings with antibacterial, antioxidant, and inflammatory regulation rapidly repair diabetic wounds by promoting neurovascular network reconstruction and accelerating re-epithelialization and collagen deposition. This study confirms the feasibility of catalyst-like MOF-contained sprayable hydrogel to regulate the microenvironment continuously and provides guidance for developing the next generation of non-drug diabetes dressings.

Constructing 2D Polyphenols-Based Crosslinked Networks for Ultrafast and Selective Uranium Extraction from Seawater

The role of tannins (TA), a well-known abundant and ecologically friendly chelating ligand, in metal capture has long been studied. Different kinds of TA-containing adsorbents are synthesized for uranium capture, while most adsorbents suffer from unfavorable adsorption kinetics. Herein, the design and preparation of a TA-containing 2D crosslinked network adsorbent (TANP) is reported. The ≈1.8-nanometer-thick TANP films curl up into micrometer-scale pores, which contribute to fast mass transfer and full exposure of active sites. The coordination environment of uranyl (UO2 2+) ions is explored by integrated analysis of U L3-edge XANES and EXAFS. Density functional theory calculations indicate the energetically favorable UO2 2+ binding. Consequently, TANP with excellent adsorption kinetics presents a high uranium capture capacity (14.62 mg-U g-Ads-1) and a high adsorption rate (0.97 mg g-1 day-1) together with excellent selectivity and biofouling resistance. Life cycle assessment and cost analysis demonstrate that TANP has tremendous potential for application in industrial-scale uranium extraction from seawater.

Tetraselmis species for environmental sustainability: biology, water bioremediation, and biofuel production

With increasing demand of fossil fuels and water pollution and their environmental impacts, marine green microalgae have gained special attention in both scientific and industrial  fields. This is due to their fast growth in non-arable lands with high photosynthetic activity, their metabolic plasticity, as well as their high CO2 capture capacity. Tetraselmis species, green and eukaryotic microalgae, are not only considered as a valuable source of biomolecules including pigments, lipids, and starch but also widely used in biotechnological applications. Tetraselmis cultivation for high-value biomolecules and industrial use was demonstrated to be a non-cost-effective strategy because of its low demand in nutrients, such as phosphorus and nitrogen. Recently, phycoremediation of wastewater rich in nutrients, chemicals, and heavy metals has become an efficient and economic-alternative that allows the detoxification of waters and induces mechanisms in algal cells for biomolecules rich-energy synthesis to regulate their metabolic pathways. This review aims to shed light on Tetraselmis species for their different culture conditions and metabolites bioaccumulation, as well as their human health and environmental applications. Additionally, phycoremediation of contaminants associated to biofuel production in Tetraselmis cells and their different intracellular and extracellular mechanisms have also been investigated.

Metal Ion Responsive Luminescent Bio-Templated Co-Assemblies: Label-Free Detection of Multi-Metal Ions in Aqueous Media

Recently, anionic bio-templates have emerged as promising platforms for designing dynamic and stimuli-responsive chromophoric assemblies capable of light harvesting in aqueous media thereby mimicking natural photosynthesis. Here, we present multi-metal ion-responsive luminescent co-assemblies between cationic pyrene-imidazolium amphiphile and anionic bio-templates (ATP, heparin, and DNA) in aqueous media. The anionic bio-templates enhance Förster resonance energy transfer (FRET) in the co-assemblies, with pyrene serving as an excellent donor for generating tunable multi-luminescent materials with embedded acceptor dyes. However, a significant loss in energy transfer towards acceptor dyes was observed in the presence of various metal ions, attributed to excimeric emission quenching facilitated by electron transfer between the pyrene chromophore and metal ions. Interestingly, detailed studies revealed that only ATP-based co-assemblies exhibited quenching phenomena in the presence of metal ions, contrasting with heparin and ctDNA co-assemblies. Additionally, label-free detection of multi-metal ions in aqueous environments, such as Fe2+, Fe3+, and Cu2+ ions, was successfully achieved with lower detection limits of 0.01 μM (3 ppb), 0.12 μM (30 ppb), and 0.58 μM (150 ppb) respectively. These co-assemblies hold significant promise for practical applications in environmental and biomedical sensing, enabling sensitive monitoring of metal ion concentrations.

An Encyclopedic Compendium on Chemosensing Supramolecular Metal-Organic Gels

Chemosensing, an interdisciplinary scientific domain, plays a pivotal role ranging from environmental monitoring to healthcare diagnostics and (inter)national security. Metal-organic gels (MOGs) are recognized for their stability, selectivity, and responsiveness, making them valuable for chemosensing applications. Researchers have explored the development of MOGs based on different metal ions and ligands, allowing for tailored properties and sensitivities, and have even demonstrated their applications as portable sensors such as paper-based test strips for practical use. Herein, several studies related to MOGs development and their applications in the chemosensing field via UV-visible or luminance along with electrochemical approach are presented. These papers explored MOGs as versatile materials with their use in sensing bio or environmental analytes. This review provides a foundational understanding of key concepts, methodologies, and recent advancements in this field, fostering the scientific community.

Metal-Drug Coordination Nanoparticles and Hydrogels for Enhanced Delivery

Drug delivery is a key component of nanomedicine, and conventional delivery relies on the adsorption or encapsulation of drug molecules to a nanomaterial. Many delivery vehicles contain metal ions, such as metal-organic frameworks, metal oxides, transition metal dichalcogenides, MXene, and noble metal nanoparticles. These materials have a high metal content and pose potential long-term toxicity concerns leading to difficulties for clinical approval. In this review, recent developments are summarized in the use of drug molecules as ligands for metal coordination forming various nanomaterials and soft materials. In these cases, the drug-to-metal ratio is much higher than conventional adsorption-based strategies. The drug molecules are divided into small-molecule drugs, nucleic acids, and proteins. The formed hybrid materials mainly include nanoparticles and hydrogels, upon which targeting ligands can be grafted to improve efficacy and further decrease toxicity. The application of these materials for addressing cancer, viral infection, bacterial infection inflammatory bowel disease, and bone diseases is reviewed. In the end, some future directions are discussed from fundamental research, materials science, and medicine.

Metal-Flavonoid Interactions-From Simple Complexes to Advanced Systems

For many years, metal-flavonoid complexes have been widely studied as a part of drug discovery programs, but in the last decade their importance in materials science has increased significantly. A deeper understanding of the role of metal ions and flavonoids in constructing simple complexes and more advanced hybrid networks will facilitate the assembly of materials with tailored architecture and functionality. In this Review, we highlight the most essential data on metal-flavonoid systems, presenting a promising alternative in the design of hybrid inorganic-organic materials. We focus mainly on systems containing CuII/I and FeIII/II ions, which are necessary in natural and industrial catalysis. We discuss two kinds of interactions that typically ensure the formation of metal-flavonoid systems, namely coordination and redox reactions. Our intention is to cover the fundamentals of metal-flavonoid systems to show how this knowledge has been already transferred from small molecules to complex materials.

Multifunctional Integrated Organic-Inorganic-Metal Hybrid Aerogel for Excellent Thermal Insulation and Electromagnetic Shielding Performance

Vehicles operating in space need to withstand extreme thermal and electromagnetic environments in light of the burgeoning of space science and technology. It is imperatively desired to high insulation materials with lightweight and extensive mechanical properties. Herein, a boron-silica-tantalum ternary hybrid phenolic aerogel (BSiTa-PA) with exceptional thermal stability, extensive mechanical strength, low thermal conductivity (49.6 mW m-1 K-1), and heightened ablative resistance is prepared by an expeditious method. After extremely thermal erosion, the obtained carbon aerogel demonstrates noteworthy electromagnetic interference (EMI) shielding performance with an efficiency of 31.6 dB, accompanied by notable loading property with specific modulus of 272.8 kN·m kg-1. This novel design concept has laid the foundation for the development of insulation materials in more complex extreme environments.

Quantitative and rapid detection of nanoplastics labeled by luminescent metal phenolic networks using surface-enhanced Raman scattering

The escalating prevalence of nanoplastics contamination in environmental ecosystems has emerged as a significant health hazard. Conventional analytical methods are suboptimal, hindered by their inefficiency in analyzing nanoplastics at low concentrations and their time-intensive processes. In this context, we have developed an innovative approach that employs luminescent metal-phenolic networks (L-MPNs) coupled with surface-enhanced Raman spectroscopy (SERS) to separate and label nanoplastics, enabling rapid, sensitive and quantitative detection. Our strategy utilizes L-MPNs composed of zirconium ions, tannic acid, and rhodamine B to uniformly label nanoplastics across a spectrum of sizes (50-500 nm) and types (e.g., polystyrene, polymethyl methacrylate, polylactic acid). Rhodamine B (RhB) functions as a Raman reporter within these L-MPNs-based SERS tags, providing the requisite sensitivity for trace measurement of nanoplastics. Moreover, the labeling with L-MPNs aids in the efficient separation of nanoplastics from liquid media. Utilizing a portable Raman instrument, our methodology offers cost-effective, swift, and field-deployable detection capabilities, with excellent sensitivity in nanoplastic analysis and a detection threshold as low as 0.1 μg/mL. Overall, this study proposes a highly promising strategy for the robust and sensitive analysis of a broad spectrum of particle analytes, underscored by the effective labeling performance of L-MPNs when coupled with SERS techniques.

Intramolecular Cation-π Interactions Organize Bowl-Shaped, Luminescent Molecular Containers

Molecules with nonplanar architectures are highly desirable due to their unique topological structures and functions. We report here the synthesis of two molecular containers (1 ⋅ 3Br- and 1 ⋅ 3Cl-), which utilize intramolecular cation-π interactions to enforce macrocylic arrangements and exhibit high binding affinity and luminescent properties. Remarkably, the geometry of the cation-π interaction can be flexibly tailored to achieve a precise ring arrangement, irrespective of the angle of the noncovalent bonds. Additionally, the C-H⋅⋅⋅Br- hydrogen bonds within the container are also conducive to stabilizing the bowl-shaped conformation. These bowl-shaped conformations were confirmed both in solution through NMR spectroscopy and in the solid state by X-ray studies. 1 ⋅ 3Br- shows high binding affinity and selectivity: F->Cl-, through C-H⋅⋅⋅X- (X=F, Cl) hydrogen bonds. Additionally, these containers exhibited blue fluorescence in solution and yellow room-temperature phosphorescence (RTP) in the solid state. Our findings illustrate the utility of cation-π interactions in designing functional molecules.

Direct Assembly of Bioactive Nanoparticles Constructed from Polyphenol-Nanoengineered Albumin

Albumin nanoparticles are widely used in biomedicine due to their safety, low immunogenicity, and prolonged circulation. However, incorporating therapeutic molecules into these carriers faces challenges due to limited binding sites, restricting drug conjugation efficiency. We introduce a universal nanocarrier platform (X-UNP) using polyphenol-based engineering to incorporate phenolic moieties into albumin nanoparticles. Integration of catechol or galloyl groups significantly enhances drug binding and broadens the drug conjugation possibilities. Our study presents a library of X-UNP nanoparticles with improved drug-loading efficiency, achieving up to 96% across 10 clinically used drugs, surpassing conventional methods. Notably, ibuprofen-UNP nanoparticles exhibit a 5-fold increase in half-life compared with free ibuprofen, enhancing in vivo analgesic and anti-inflammatory effectiveness. This research establishes a versatile platform for protein-based nanosized materials accommodating various therapeutic agents in biotechnological applications.

Exploring Caffeic Acid and Lignosulfonate as Key Phenolic Ligands for Metal-Phenolic Network Assembly

Films formed by metals and phenols through a coordinative interaction have been extensively studied in previous years. We report the successful formation of MPN films from the phenolic compounds caffeic acid and lignosulfonate using Fe3+ ions for complexation. The likewise examined p-coumaryl alcohol showed some MPN film formation tendency, while for coniferyl alcohol and sinapyl alcohol, no successful film buildup could be observed. These newly formed films were compared to tannic acid-Fe3+ films as a reference. Film growth and degradation were tracked by using UV-vis absorption spectroscopy. The films were degradable under different conditions such as alkaline environments or in the presence of a strong chelator. Small hollow capsules with a diameter of 3 μm and thicknesses in the nanometer range were produced. Additionally, the prepared films showed varying colors and levels of wettability. By utilizing the films' coating properties, we successfully dyed human hair in various colors.

Dual-Epigenetically Relieving the MYC-Correlated Immunosuppression via an Advanced Nano-Radiosensitizer Potentiates Cancer Immuno-Radiotherapy

Cancer cells can upregulate the MYC expression to repair the radiotherapy-triggered DNA damage, aggravating therapeutic resistance and tumor immunosuppression. Epigenetic treatment targeting the MYC-transcriptional abnormality may intensively solve this clinical problem. Herein, 5-Aza (a DNA methyltransferase inhibitor) and ITF-2357 (a histone deacetylase inhibitor) are engineered into a tungsten-based nano-radiosensitizer (PWAI), to suppress MYC rising and awaken robust radiotherapeutic antitumor immunity. Individual 5-Aza depletes MYC expression but cannot efficiently awaken radiotherapeutic immunity. This drawback can be overcome by the addition of ITF-2357, which triggers cancer cellular type I interferon (IFN-I) signaling. Coupling 5-Aza with ITF-2357 ensures that PWAI does not evoke the treated model with high MYC-related immune resistance while amplifying the radiotherapeutic tumor killing, and more importantly promotes the generation of IFN-I signal-related proteins involving IFN-α and IFN-β. Unlike the radiation treatment alone, PWAI-triggered immuno-radiotherapy remarkably enhances antitumor immune responses involving the tumor antigen presentation by dendritic cells, and improves intratumoral recruitment of cytotoxic T lymphocytes and their memory-phenotype formation in 4T1 tumor-bearing mice. Downgrading the radiotherapy-induced MYC overexpression via the dual-epigenetic reprogramming strategy may elicit a robust immuno-radiotherapy.

Controlled Self-Assembly of Natural Polyphenols Driven by Multiple Molecular Interactions

Nature has exhibited a high degree of control over the structures and functions. Supramolecules have been utilized to mimic the subtle assembly in nature. However, sophisticated synthesis of molecular skeletons or programmable design of the driving forces raises great challenges in fabricating high-level superstructures in a controlled manner. Natural polyphenols show great promises as building blocks for a diverse of assemblies with controlled structures and functionalities. The intrinsically embedded phenolic groups (i. e., catechol and galloyl groups) are readily forming multiple molecular interactions, including coordination, hydrogen bonding, and π-π interactions with various materials of inorganic particles, organic compounds, synthetic polymers, and biomacromolecules, providing the self-assembled structures or nanocoating on surfaces. Subsequent assembly occurred by further bonding of polyphenols to construct supraparticles. To gain control over the self-assembly, the key lies in the interplay among the molecular interactions with one or two being dominant. In this Perspective, we introduce the representative polyphenol-based assemblies and their derived supraparticles to exhibit the effective harness of the controlled self-assembly by polyphenols.

Bioinspired cytomembrane coating besieges tumor for blocking metabolite transportation

The metabolite transport inhibition of tumor cells holds promise to achieve anti-tumor efficacy. Herein, we presented an innovative strategy to hinder the delivery of metabolites through the in-situ besieging tumor cells with polyphenolic polymers that strongly adhere to the cytomembrane of tumor cells. Simultaneously, these polymers underwent self-crosslinking under the induction of tumor oxidative stress microenvironment to form an adhesive coating on the surface of the tumor cells. This polyphenol coating effectively obstructed glucose uptake, reducing metabolic products such as lactic acid, glutathione, and adenosine triphosphate, while also causing reactive oxygen species to accumulate in the tumor cells. The investigation of various tumor models, including 2D cells, 3D multicellular tumor spheroids, and xenograft tumors, demonstrated that the polyphenolic polymers effectively inhibited the growth of tumor cells by blocking key metabolite transport processes. Moreover, this highly adhesive coating could bind tumor cells to suppress their metastasis and invasion. This work identified polyphenolic polymers as a promising anticancer candidate with a mechanism by impeding the mass transport of tumor cells.

Immobilizing c(RGDfc) on the surface of metal-phenolic networks by thiol-click reaction for accelerating osteointegration of implant

The limited osteointegration often leads to the failure of implant, which can be improved by fixing bioactive molecules onto the surface, such as arginyl-glycyl-aspartic acid (RGD): a cell adhesion motif. Metal-Phenolic Networks (MPNs) have garnered increasing attention from different disciplines in recent years due to their simple and rapid process for depositing on various substrates or particles with different shapes. However, the lack of cellular binding sites on MPNs greatly blocks its application in tissue engineering. In this study, we present a facile and efficient approach for producing PC/Fe@c(RGDfc) composite coatings through the conjugation of c(RGDfc) peptides onto the surface of PC/Fe-MPNs utilizing thiol-click reaction. By combined various techniques (ellipsometry, X-ray photoelectron spectroscopy, Liquid Chromatography-Mass Spectrometry, water contact angle, scanning electronic microscopy, atomic force microscopy) the physicochemical properties (composition, coating mechanism and process, modulus and hydrophilicity) of PC/Fe@c(RGDfc) surface were characterized in detail. In addition, the PC/Fe@c(RGDfc) coating exhibits the remarkable ability to positively modulate cellular attachment, proliferation, migration and promoted bone-implant integration in vivo, maintaining the inherent features of MPNs: anti-inflammatory, anti-oxidative properties, as well as multiple substrate deposition. This work contributes to engineering MPNs-based coatings with bioactive molecules by a facile and efficient thiol-click reaction, as an innovative perspective for future development of surface modification of implant materials.

Self-assembled nanodrug delivery systems for anti-cancer drugs from traditional Chinese medicine

Traditional Chinese medicine (TCM) is a combination of raw herbs and herbal extracts with a plethora of documented beneficial bioactivities, which has unique advantages in anti-tumor therapy, and many of its major bioactive molecules have been identified in recent years due to advances in chemical separation and structural analysis. However, the major chemical classes of plant-derived bioactive compounds frequently possess chemical properties, including poor water solubility, stability, and bioavailability, that limit their therapeutic application. Alternatively, natural small molecules (NSMs) containing these components possess modifiable groups, multiple action sites, hydrophobic side chains, and a rigid skeleton with self-assembly properties that can be exploited to construct self-assembled nanoparticles with therapeutic effects superior to their individual constituents. For instance, the construction of a self-assembled nanodrug delivery system can effectively overcome the strong hydrophobicity and poor in vivo stability of NSMs, thereby greatly improving their bioavailability and enhancing their anti-tumor efficacy. This review summarizes the self-assembly methods, mechanisms, and applications of a variety of NSMs, including terpenoids, flavonoids, alkaloids, polyphenols, and saponins, providing a theoretical basis for the subsequent research on NSMs and the development of SANDDS.