Engineering functional mesoporous materials from plant polyphenol based coordination polymers

Recent advances in tannic acid-based gels: Design, properties, and applications

With the flourishing of mussel-inspired chemistry, the fast-growing development for environmentally friendly materials, and the need for inexpensive and biocompatible analogues to PDA in gel design, TA has led to its gradual emergence as a research focus due to its remarkable biocompatible, renewable, sustainable and particular physicochemical properties. As a natural building block, TA can be used as a substrate or crosslinker, ensuring versatile functional polymeric networks for various applications. In this review, the design of TA-based gels is summarized in detail (i.e., different interactions such as: metal coordination, electrostatic, hydrophobic, host-guest, cation-π and π-π stacking interactions, hydrogen bonding and various reactions including: phenol-amine Michael and Schiff base, phenol-thiol Michael addition, phenol-epoxy ring opening reaction, etc.). Subsequently, TA-based gels with a variety of functionalities, including mechanical, adhesion, conductive, self-healing, UV-shielding, anti-swelling, anti-freezing, shape memory, antioxidant, antibacterial, anti-inflammatory and responsive properties are introduced in detail. Then, a summary of recent developments in the use of TA-based gels is provided, including bioelectronics, biomedicine, energy, packaging, water treatment and other fields. Finally, the difficulties that TA-based gels are currently facing are outlined, and an original yet realistic viewpoint is provided in an effort to spur future development.

Rapid and Sensitive Detection of 2-Ethylhexanol Vapor Utilizing Mesoporous Neodymium-Doped Indium Oxide for Real-Time Monitoring of Overheated Electrical Cables

Rapid and sensitive detection of 2-ethylhexanol vapor, a critical indicator of overheating in electrical cables, is essential for the early warning of potential electrical fires. However, traditional chemiresistive gas sensors are inadequate for real-time detection of 2-ethylhexanol owing to its chemical stability. Herein, a chemiresistive gas sensor based on mesoporous Nd-doped In2O3 is designed for rapid detection of ppb-level 2-ethylhexanol vapor. The sensor exhibits a high response (22.8@1 ppm), excellent sensitivity (4.7 ppm-1), a short response time (29 s), and a low detection limit (760 ppb). After Nd doping, the response of the mesoporous Nd-doped In2O3 sensor is approximately 20 folds higher than that of the In2O3 sensor. Furthermore, a wireless sensing device has been developed to enable real-time monitoring of cable overheating. The outstanding sensing performance can be attributed to neodymium doping within the mesoporous framework, which enhances the accessibility of active sites on the interface of sensing materials, increases the concentration of surface-adsorbed oxygen at the gas-solid interface, and improves the adsorption capacity for 2-ethylhexanol. This work showcases an efficient semiconductor metal oxide gas sensor capable of rapidly and sensitively detecting parts per billion levels of 2-ethylhexanol induced by the overheating of electrical cables, demonstrating significant potential for early warning of electrical fires.

Urushiol-dextran SPIONs magnetic recyclable nanoparticles immobilizing vancomycin (V@DU@Fe) for antibacterial application

In this study, magnetic nanocarriers (DU@Fe, Davg = 281.6 nm, zeta potential -28.0 mV) were fabricated using dextran, urushiol as the shell and superparamagnetic iron oxide nanoparticles (SPIONs) as the core. Subsequently, the specific ligand Lys-D-Ala-D-Ala of vancomycin (Van) was grafted onto the surface of DU@Fe, which generated nanoparticles (Lys-D-Ala-D-Ala@DU@Fe) with an average particle size of 385.5 nm and a zeta potential of -16.8 mV via specific and robust interaction. Ultimately, the immobilization capacity of Van reached up to 294.1 mg·g-1 for efficient antibacterial properties. Moreover, the assembly process adhered to the pseudo-second-order kinetics model (R2 = 0.998-0.999) and the Langmuir adsorption isotherm model (R2 = 0.999, 30 °C). Notably, V@DU@Fe effectively adhered to the cell envelopes of both Gram-negative and Gram-positive bacteria, achieving rapid bactericidal effects within 1 h. Furthermore, it maintained over 85.0 % of its initial antibacterial efficiency against S. aureus and S. epidermidis even after six recycles. Therefore, this study provides strategies and methods for the development of urushiol-dextran intelligent SPIONs nanomedicines.

Preparation of Hierarchical Porous Monoliths With High Surface Areas by a Solvent Knitting Strategy

Hierarchical porous hypercrosslinked monoliths (PolyHIPE-HCP) with ultrahigh specific surface areas are prepared via a solvent knitting strategy. Compared to previous work, the solvent knitting strategy is carried out in a relatively low air-controlled atmosphere with gradient heating starting from low temperature while using DCM (Dichloromethane) as both a solvent and a cross-linker, allowing for a slow and controlled cross-linking process, thereby achieving a BET surface area ranging from 514 to 728 m2 g-1. Scanning electron microscopy (SEM) shows that the knitting process does not affect the presence of macroporous structure in the PolyHIPE. With the introduction of mesopores and micropores, these hierarchical porous monoliths exhibit significant potential for applications in gas adsorption and water treatment. Hence, a universal, simple and low-cost method to synthesize polymeric monoliths with hierarchically porous structure and higher surface area is proposed, which has fascinating prospects in industrialization.

GSH responsive AuNRs@TFF nanotheranostic for NIR-II photoacoustic imaging-guided CDT/PTT synergistic cancer therapy

Gold nanorods (AuNRs) are important photothermal therapeutic agents; however, a single therapy does not achieve satisfactory outcomes, and the synthesis process often leads to the adsorption of cetyltrimethylammonium bromide on the surface of AuNRs, which reduces its biocompatibility. Natural polyphenols are abundant in natural plants and have good biocompatibility. The metal-polyphenol network is formed by the coordination of metal ions and polyphenols, which has good drug loading, surface adhesion, and biocompatibility. In this study, the metal-polyphenol network structure formed by a transition metal (iron) and natural polyphenol tannic acid was used to modify the surface of gold nanorods (AuNRs@TF). Additionally, the surfaces of AuNRs were modified using the targeted functional molecule mercapto folic acid (AuNRs@TFF). The constructed composite nanomaterials AuNRs@TFF has good biocompatibility and tumor targeting ability. Tannic acid‑iron degrades in the tumor microenvironment and releases iron ions that catalyze the Fenton reaction, thereby facilitating chemodynamic therapy. The good photo-thermal ability of AuNRs generate good photoacoustic signals to facilitate photoacoustic imaging mediation and enhances photothermal and chemodynamic therapy performance. This study expands on the application of AuNRs in the field of nanomedicine. The simple and effective design of AuNRs@TFF provides a strategy for the development of synergistic therapeutic agents for photothermal therapy and chemodynamic therapy.

Controllable self-assembly of double polyphenol-metal-network: A universal gravel-like lignin catalysts for water purification

Lignin has attracted wide attention in sustainable environment remediation, especially the polyphenol-metal-network (PMN) based on lignin that shows unique applicability. In this work, by self-assembly of double PMN formed by lignin, plant tannins (TA) and Fe ions, a universal gravel-like lignin catalysts were reported for cost-efficient water purification. A controllable self-assembly technique dependent in pH was developed, achieving the controllable synthesis of materials with highly uniformity. Driven by strong multiple intermolecular interactions and PMN mediated TA-Fe Fenton system, this bio-based material exhibited efficient interfacial capture (65.70 mg·g-1) and in-situ degradation performance (95.40 %), and removed ubiquitous dye contaminants through static and flowing operation. Benefiting from this, effective flowing purify platform that continuously purify large-scale dye-containing wastewater through flowthrough strategy was profiled, confirming the potential in real industrial system. The theoretical calculations including molecular dynamics simulation contributed to providing insightful comprehension for co-assembly of system and their intermolecular interaction with dye molecules. Additionally, this material also showed magnetic response ability, stable reusability performance, and extended preparation advantages. This work provided a facile strategy to develop advanced lignin-based double PMN derived materials to support water purification by utilizing solid-waste to repair liquid-waste.

Advances in the preparation and application of cellulose-based antimicrobial materials: A review

The rise of polymer materials in modern life has drawn attention to renewable, easily biodegradable, environmentally-friendly bio-based polymers. Notably, significant research has been dedicated to creating green antimicrobial functional materials for the biomedical field using natural polymer materials. Cellulose is a rich natural biomass organic polymer material. Given its favorable attributes like film-forming capability, biodegradability, and biocompatibility, it is extensively employed to tackle a wide range of challenges confronting humanity today. However, its inherent drawbacks, such as insolubility in water and most organic solvents, hygroscopic nature, difficulty in melting, and limited antimicrobial properties, continue to pose challenges for realizing the high-value applications of cellulose. Achieving multifunctionality and more efficient application of cellulose still poses major challenges. In this regard, the current development status of cellulose materials was reviewed, covering the classification, preparation methods, and application status of cellulose-based antimicrobial materials. The application value of cellulose-based antimicrobial materials in biomedicine, textiles, food packaging, cosmetics and wastewater treatment was summarised. Finally, insights were provided into the developing prospects of cellulose-based antimicrobial materials were provided.

Aromatic Biobased Polymeric Materials Using Plant Polyphenols as Sustainable Alternative Raw Materials: A Review

In the foreseeable future, the development of petroleum-based polymeric materials may be limited, owing to the gradual consumption of disposable resources and the increasing emphasis on environmental protection policies. Therefore, it is necessary to focus on introducing environmentally friendly renewable biobased materials as a substitute for petroleum-based feed stocks in the preparation of different types of industrially important polymers. Plant polyphenols, a kind of natural aromatic biomolecule, exist widely in some plant species. Benefiting from their special macromolecular structure, high reactivity, and broad abundance, plant polyphenols are potent candidates to replace the dwindling aromatic monomers derived from petroleum-based resources in synthesizing high-quality polymeric materials. In this review, the most related and innovative methods for elaborating novel polymeric materials from plant polyphenols are addressed. After a brief historical overview, the classification, structural characteristics, and reactivity of plant polyphenols are summarized in detail. In addition, some interesting and innovative works concerning the chemical modifications and polymerization techniques of plant polyphenols are also discussed. Importantly, the main chemical pathways to create plant polyphenol-based organic/organic-inorganic polymeric materials as well as their properties and possible applications are systematically described. We believe that this review could offer helpful references for designing multifunctional polyphenolic materials.

Mesoporous zinc-polyphenol nanozyme for attenuating renal ischemia-reperfusion injury

Aim: To target the reactive oxygen species (ROS) accumulation and renal tubular epithelial cell (rTEC) death in renal ischemia-reperfusion injury (IRI), we constructed a nanoparticle that offers ROS scavenging and rTEC-death inhibition: mesoporous zinc-tannic acid nanozyme (ZnTA).Materials & methods: After successfully constructing ZnTA, we proceeded to examine its effect on ROS accumulation, cellular ferroptosis and apoptosis, as well as injury severity.Results: Malondialdehyde, Fe2+ amounts and 4-HNE staining demonstrated that ZnTA effectively attenuated rTEC ferroptosis. TUNEL staining confirmed that Zn2+ carried by ZnTA could effectively inhibit caspase 3 and caspase 9, mitigating apoptosis. Finally, it reduced renal IRI through the synergistic effect of ROS scavenging and cell-death inhibition.Conclusion: This study is expected to provide a paradigm for a combined therapeutic strategy for renal IRI.

Synergistic sensitization effects of single-atom gold and cerium dopants on mesoporous SnO2 nanospheres for enhanced volatile sulfur compound sensing

The real-time monitoring of volatile sulfur compounds is indispensable; however, it continues to pose a significant challenge due to issues such as limited performance towards parts-per-billion (ppb)-level gas. Herein, a concept of synergistic sensitization effects involving single-atom gold (Au) and cerium (Ce) dopants is proposed to boost the sensing performance of allyl mercaptan, a common volatile sulfur compound. As a proof-of-concept, a chemiresistive gas sensor based on mesoporous SnO2 nanospheres with single-atom Au decoration and Ce dopant (denoted Au/Ce-SnO2) is successfully synthesized. The synthesis of Au/Ce-SnO2 is achieved through the utilization of a self-template strategy, employing metal-phenolic hybrids as a precursor. The obtained materials exhibit high specific surface area (89.4 m2 g-1), and small particle size (∼86 nm). The gas sensor reveals unprecedented sensitivity (0.097 ppb-1) and ultra-low detection limit (0.74 ppb), surpassing all state-of-the-art allyl mercaptan gas sensors. Furthermore, a wireless gas sensor is constructed for highly selective and real-time monitoring of allyl mercaptan. The decoration of single-atom Au facilitates the adsorption and dissociation of oxygen and target gases. Simultaneously, the Ce dopant enhances the oxidation of allyl mercaptan. The sensing performance is boosted by the mesoporous framework of SnO2, as well as the synergistic sensitization effects resulting from single-atom Au decoration and Ce doping, thereby facilitating its potential application in environmental and health-related domains.

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.

Wireless Gas Sensor Based on the Mesoporous ZnO-SnO2 Heterostructure Enables Ultrasensitive and Rapid Detection of 3-Methylbutyraldehyde

Achieving ultrasensitive and rapid detection of 3-methylbutyraldehyde is crucial for monitoring chemical intermediate leakage in pharmaceutical and chemical industries as well as diagnosing ventilator-associated pneumonia by monitoring exhaled gas. However, developing a sensitive and rapid method for detecting 3-methylbutyraldehyde poses challenges. Herein, a wireless chemiresistive gas sensor based on a mesoporous ZnO-SnO2 heterostructure is fabricated to enable the ultrasensitive and rapid detection of 3-methylbutyraldehyde for the first time. The mesoporous ZnO-SnO2 heterostructure exhibits a uniform spherical shape (∼79 nm in diameter), a high specific surface area (54.8 m2 g-1), a small crystal size (∼4 nm), and a large pore size (6.7 nm). The gas sensor demonstrates high response (18.98@20 ppm), short response/recovery times (13/13 s), and a low detection limit (0.48 ppm) toward 3-methylbutyraldehyde. Furthermore, a real-time monitoring system is developed utilizing microelectromechanical systems gas sensors. The modification of amorphous ZnO on the mesoporous SnO2 pore wall can effectively increase the chemisorbed oxygen content and the thickness of the electron depletion layer at the gas-solid interface, which facilitates the interface redox reaction and enhances the sensing performance. This work presents an initial example of semiconductor metal oxide gas sensors for efficient detection of 3-methylbutyraldehyde that holds great potential for ensuring safety during chemical production and disease diagnosis.

Polyphenolic Nanoparticle Platforms (PARCELs) for In Vitro and In Vivo mRNA Delivery

Despite their successful implementation in the COVID-19 vaccines, lipid nanoparticles (LNPs) still face a central limitation in the delivery of mRNA payloads: endosomal trapping. Improving upon this inefficiency could afford improved drug delivery systems, paving the way toward safer and more effective mRNA-based medicines. Here, we present polyphenolic nanoparticle platforms (PARCELs) as effective mRNA delivery systems. In brief, our investigation begins with a computationally guided structural analysis of 1825 discrete polyphenolic structural data points across 73 diverse small molecule polyphenols and 25 molecular parameters. We then generate structurally diverse PARCELs, evaluating their in vitro mechanism and activity, ultimately highlighting the superior endosomal escape properties of PARCELs relative to analogous LNPs. Finally, we examine the in vivo biodistribution, protein expression, and therapeutic efficacy of PARCELs in mice. In undertaking this approach, the goal of this study is to establish PARCELs as viable delivery platforms for safe and effective mRNA delivery.

"Three-in-One" Multifunctional Hollow Nanocages with Colorimetric Photothermal Catalytic Activity for Enhancing Sensitivity in Biosensing

Immunochromatographic assays (ICAs) have been widely used in the field detection of mycotoxin contaminants. Nevertheless, the lack of multisignal readout capability and the ability of signaling tags to maintain their biological activity while efficiently loading antibodies remain a great challenge in satisfying diverse testing demands. Herein, we proposed a novel three-in-one multifunctional hollow vanadium nanomicrosphere (high brightness-catalytic-photothermal properties)-mediated triple-readout ICA (VHMS-ICA) for sensitive detection of T-2. As the key to this biosensing strategy, vanadium was used as the catalytic-photothermal characterization center, and natural polyphenols were utilized as the bridging ligands for coupling with the antibody while self-assembling with formaldehyde cross-linking into a hollow nanocage-like structure, which offers the possibility of realizing a three-signal readout strategy and improving the coupling efficiency to the antibody while preserving its biological activity. The constructed sensors showed a detection limit (LOD) of 2 pg/mL for T-2, which was about 345-fold higher than that of conventional gold nanoparticle-based ICA (0.596 ng/mL). As anticipated, the detection range of VHMS-ICA was extended about 8-fold compared with the colorimetric signal alone. Ultimately, the proposed immunosensor performed well in maize and oat samples, with satisfactory recoveries. Owing to the synergistic and complementary interactions between distinct signaling modes, the establishment of multimodal immunosensors with multifunctional tags is an efficient strategy to satisfy diversified detection demands.

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.

A stable Mn(II) coordination polymer demonstrating proton conductivity and quantitative sensing of oxytetracycline in aquaculture

The construction and investigation of dual-functional coordination polymers (CPs) with proton conduction and luminescence sensing is of great significance in clean energy and agricultural monitoring fields. In this work, an Mn-based coordination polymer (Mn-CP), namely, [Mn0.5(HL)] (H2L = HOOCC6H4C6H4CH2PO(OH)OCH3), was hydrothermally synthesized. Mn-CP has a one-dimensional (1D) chain structure, in which uncoordinated -COOH groups can serve as potential sites for fluorescence sensing. Moreover, Mn-CP shows good water and pH stabilities, offering the feasibility for proton conduction and sensing applications. Mn-CP displays comparatively high proton conductivity of 1.07 × 10-4 S cm-1 at 368 K and 95% relative humidity (RH), which is promising for proton conduction materials. Moreover, it can serve as a repeatable, highly selective, and visualized fluorescence sensor for detecting oxytetracycline (OTC). More importantly, Mn-CP reveals an amazing quantitative sensing of OTC in actual samples such as seawater, aquaculture freshwater, soil infiltration solutions, and tap water. This work proves the excellent application potential of dual-functional CPs in the field of clean energy and environmental protection, especially for the fluorescence detection of antibiotics in aquaculture systems.

Field assessment of coconut-based activated carbon systems for the treatment of herbicide contamination

Once released into the environment, herbicides can move through soil or surface water to streams and groundwater. Filters containing adsorbent media placed in fields may be an effective solution to herbicide loss in the environment. However, to date, no study has investigated the use of adsorbent materials in intervention systems at field-scale, nor has any study investigated their optimal configuration. Therefore, the aim of this paper was to examine the efficacy of low-cost, coconut-based activated carbon (CAC) intervention systems, placed in streams and tributaries, for herbicide removal. Two configurations of interventions were investigated in two agricultural catchments and one urban area in Ireland: (1) filter bags and (2) filter bags fitted into polyethylene pipes. Herbicide sampling was conducted using Chemcatcher® passive sampling devices in order to identify trends in herbicide exceedances at the sites, and to quantifiably assess, compare, and contrast the efficiency of the two intervention configurations. While the Chemcatcher® passive sampling devices are capable of analysing eighteen different acid herbicides, only six different acid herbicides (2,4-D, clopyralid, fluroxypyr, MCPA, mecoprop and triclopyr) were ever detected within the three catchment areas, which were also the only acid herbicides used therein. The CAC was capable of complete herbicide removal, when the water flow was slow (0.5-1 m3 s-1), and the interventions spanned the width and depth of the waterway. Overall, the reduction in herbicide concentrations was better for the filter pipes than for the filter bags, with a 48% reduction in detections and a 37% reduction in exceedances across all the sampling sites for the filter pipe interventions compared to a 13% reduction in the number of detections and a 24% reduction in exceedances across all sampling sites for the filter bag interventions (p < 0.05). This study demonstrates, for the first time, that CAC may be an effective in situ remediation strategy to manage herbicide exceedances close to the source, thereby reducing the impact on environmental and public health.

Synthesis of Mesoporous Lanthanum-Doped SnO2 Spheres for Sensitive and Selective Detection of the Glutaraldehyde Disinfectant

Glutaraldehyde disinfectant has been widely applied in aquaculture, farming, and medical treatment. Excessive concentrations of glutaraldehyde in the environment can lead to serious health hazards. Therefore, it is extremely important to develop high-performance glutaraldehyde sensors with low cost, high sensitivity, rapid response, fabulous selectivity, and low limit of detection. Herein, mesoporous lanthanum (La) doped SnO2 spheres with high specific surface area (52-59 m2 g-1), uniform mesopores (with a pore size concentrated at 5.7 nm), and highly crystalline frameworks are designed to fabricate highly sensitive gas sensors toward gaseous glutaraldehyde. The mesoporous lanthanum-doped SnO2 spheres exhibit excellent glutaraldehyde-sensing performance, including high response (13.5@10 ppm), rapid response time (28 s), and extremely low detection limit of 0.16 ppm. The excellent sensing performance is ascribed to the high specific surface area, high contents of chemisorbed oxygen species, and lanthanum doping. DFT calculations suggest that lanthanum doping in the SnO2 lattice can effectively improve the adsorption energy toward glutaraldehyde compared to pure SnO2 materials. Moreover, the fabricated gas sensors can effectively detect commercial glutaraldehyde disinfectants, indicating a potential application in aquaculture, farming, and medical treatment.

Highly efficient removal of Cr(VI) from wastewater using electronegative SA/EGCG@Ti/SA/PVDF sandwich membrane

The use of green, non-toxic raw materials is of great significance to the sustainable development of the environment, among which epigallocatechin gallate (EGCG) is a renewable carbon source from plants. At present, there is a lack of research on the metal-polyphenol nanomaterials their use in water decontamination. In this study, a novel SA/EGCG@Ti/SA/PVDF (SESP) sandwich membrane was prepared to effectively solve the problems of difficult recovery of nanomaterials and the leaching of metal ions. The membrane was made by scraping SA on the surface of the PVDF substrate as the bottom protective layer, depositing EGCG@Ti NPs as the functional layer, then coating SA as the surface isolation layer, and finally cross-linking with anhydrous calcium chloride. Results showed that EGCG@Ti NPs dispersed well on the surface of the SA/PVDF basement membrane. SESP sandwich membrane had good hydrothermal and acid-base stability, and it can be applied to wastewater with multiple co-existing heavy metals (e.g., Cu, Pb, Cd, and Ni). The contact angle and pure water flux of the SESP sandwich membrane with a negatively charged surface were 14.0-15.6° and 171.40 L/m2 h, respectively. The pure water flux of the regenerated membrane after BSA pollution recovered to 98.68 L/m2 h, and the interception efficiency and the interception flux of Cr(VI) were 100 % and 72.92 L/m2 h at 40 min of interception, respectively. Additionally, the removal efficiency of Cr(VI) by SESP sandwich membrane was maintained above 83 % for simulated wastewater and 100 % for actual wastewater after five adsorption-desorption cycles. Cr(VI) and Cr(III) can be removed simultaneously with the negatively charged SESP sandwich membrane. EDS and XPS analysis showed that the removal of Cr(VI) was controlled by the Donnan effect, anion exchange, chelation/complexation, and reduction mechanism. In contrast, Cr(III) was mainly influenced by electrostatic attraction and chelation/complexation mechanisms. In conclusion, the newly prepared sandwich membrane has good application potential in treating Cr(VI) wastewater.

A Modified Small Intestinal Submucosa Patch with Multifunction to Promote Scarless Repair and Reinvigoration of Urethra

To reconstruct and restore the functions of the male urethra is a challenging task for urologists. The acellular matrix graft currently used in the clinics is mono-functional and may cause a series of complications including stricture, fibrosis, and stone formation. As a result, such graft materials cannot meet the increasing demand for multifunctionality in the field of urethral tissue engineering. In this context, a multifunctional urethral patch is designed for the repair of urethral defects by mixing protocatechualdehyde (PCA) with small intestinal submucosa (SIS) under an alkalin condition to allow cross linking. As shown, the PCA/SIS patch possesses excellent biocompatibility, antioxidant activity, and anti-inflammatory property. More importantly, this patch can remarkably promote the adhesion, proliferation, and directional extension of rabbit bladder epithelial mucous cells (R-EMCs) as well as rabbit bladder smooth muscle cells (R-SMCs), and upregulate the expression of cytokeratin in the EMCs and contractile protein in the SMCs in vitro. In vivo experiments also confirm that the PCA/SIS patch can significantly enhance scarless repair of urethral defects in rabbits by facilitating smooth muscle regeneration, reducing excessive collagen deposition, and accelerating re-epithelialization and neovascularization. Taken together, the newly developed multifunctional PCA/SIS patch provides a promising candidate for urethral regeneration.

Recent Advances of Metal-Polyphenol Coordination Polymers for Biomedical Applications

Nanomedicine has provided cutting-edge technologies and innovative methods for modern biomedical research, offering unprecedented opportunities to tackle crucial biomedical issues. Nanomaterials with unique structures and properties can integrate multiple functions to achieve more precise diagnosis and treatment, making up for the shortcomings of traditional treatment methods. Among them, metal-polyphenol coordination polymers (MPCPs), composed of metal ions and phenolic ligands, are considered as ideal nanoplatforms for disease diagnosis and treatment. Recently, MPCPs have been extensively investigated in the field of biomedicine due to their facile synthesis, adjustable structures, and excellent biocompatibility, as well as pH-responsiveness. In this review, the classification of various MPCPs and their fabrication strategies are firstly summarized. Then, their significant achievements in the biomedical field such as biosensing, drug delivery, bioimaging, tumor therapy, and antibacterial applications are highlighted. Finally, the main limitations and outlooks regarding MPCPs are discussed.

An Enhanced Photosensitive Sensor Based on ITO/MWCNTs@Polymer Composite@BiVO4 for Quercetin Detection

The fact that antioxidants scavenge free radicals in the human body and naturally treat many health problems that will occur in this way has increased the consumption of antioxidant-containing foods. However, consumption of artificially prepared antioxidants could cause cancer. Therefore, antioxidants from natural sources are preferred. Quercetin is an antioxidant present in natural samples. In this article, multi-walled carbon nanotubes (MWCNTs), a polymer composite (PC) consisting of a mixture of 15% (by mass) polystyrene (PST), 15% (by mass) polyacrylonitrile (PAN) and 70% (by mass) polyindole (PIN), and semiconducting BiVO₄ were used to prepare electrodes, and then a photosensitive ITO/MWCNTs@PC@BiVO₄-based sensor was fabricated for quercetin detection. Quercetin was analyzed via the photosensitive ITO/MWCNTs@PC@BiVO₄ sensor in 0.1 M phosphate buffered saline (pH 7.4) solutions including various quercetin concentrations. The constructed quercetin sensor displayed a wide linear response between 10 and 200 μM and a limit of detection of 0.133 μM. The developed photosensitive ITO/MWCNTs@PC@BiVO4 demonstrated a high sensitivity (442 µA mM^-1 cm^-2), good reproducibility (relative standard deviation 3.6%), high selectivity and long-term stability (>49 days) towards quercetin sensing. The photoelectrochemical sensor was then applied to detection of quercetin in black tea as a real-life sample. Our study could lead to the development of novel photosensitive PC polyphenol sensors.

Catalytic hydrogenation of levulinic acid to γ-valerolactone over lignin-metal coordinated carbon nanospheres in water

The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) has attracted much attention, as GVL can be used as biofuel, green solvent, and platform chemical. Inspired by Stöber method, various lignin-metal coordinated colloidal nanospheres (LCS) from lignin and cetyltrimethylammonium bromide (CTAB) were synthesized in which the metal ions (Co²⁺) replace formaldehyde as the crosslinker. The characterization of the catalyst revealed that alkali lignin was first self-assembled with CTAB through electrostatic attraction to form a lignin polymer, the subsequent addition of metal ions (Co²⁺) promoted the aggregation of lignin polymers and generated the LCS. Increasing calcination temperature for LCS resulted in the Co²⁺ being reduced to metallic Co. The lignin-metal coordinated colloidal nanospheres calcined at 500 °C possess both CoO and metallic Co active sites, which effectively accelerated the hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) than simplex metallic Co active sites. A 99.8 % yield of GVL with 100 % LA conversion was obtained after 60 min reaction time at 200 °C and 2 MPa H₂.

Sensitive electrochemical assay of acetaminophen based on 3D-hierarchical mesoporous carbon nanosheets

Acetaminophen plays a key role in first-line Covid-19 cure as a supportive therapy of fever and pain. However, overdose of acetaminophen may give rise to severe adverse events such as acute liver failure in individual. In this work, 3D-hierarchical mesoporous carbon nanosheet (hMCNS) microspheres with superior properties were fabricated using simple and quick strategy and applied for sensitive quantification of acetaminophen in pharmaceutical formulation and rat plasmas after administration. The hMCNS microspheres are prepared via chemical etching of zinc oxide (ZnO) nanoparticles from a zinc-gallic acid precursor composite (Zn-GA) synthesized by high-temperature anaerobic pyrolysis. The obtained hMCNS could enhance analytes accessibility and accelerate proton transfer in the interface, hence increasing the electrochemical performance. Under optimized experimental conditions, the proposed electrochemical sensor achieves a detection limit of 3.5 nM for acetaminophen. The prepared electrochemical sensor has been successfully applied for quantification of acetaminophen in pharmaceutical formulations and the rat plasma samples before and after administration. Meanwhile, this sensor is compared with high-performance liquid chromatography (HPLC) as a reference technology, showing an excellent accuracy. Such an electrochemical sensor has great potential and economic benefits for applications in the fields of pharmaceutical assay and therapeutic drug monitoring (TDM).

On-Demand Removable Self-Healing and pH-Responsive Europium-Releasing Adhesive Dressing Enables Inflammatory Microenvironment Modulation and Angiogenesis for Diabetic Wound Healing

Current diabetic wound treatments remain unsatisfactory due to the lack of a comprehensive strategy that can integrate strong applicability (tissue adhesiveness, shape adaptability, fast self-healability, and facile dressing change) with the initiation and smooth connection of the cascade wound healing processes. Herein, benefiting from the multifaceted bonding ability of tannic acid to metal ions and various polymers, a family of tannin-europium coordination complex crosslinked citrate-based mussel-inspired bioadhesives (TE-CMBAs) are specially developed for diabetic wound healing. TE-CMBAs can gel instantly (< 60 s), possess favorable shape-adaptability, considerable mechanical strengths, high elasticity, considerable wet tissue adhesiveness (≈40 kPa), favorable photothermal antimicrobial activity, excellent anti-oxidant activity, biocompatibility, and angiogenetic property. The reversible hydrogen bond crosslinking and sensitive metal-phenolic coordination also confers TE-CMBAs with self-healability, pH-responsive europium ion and TA releasing properties and on-demand removability upon mixing with borax solution, enabling convenient painless dressing change and the smooth connection of inflammatory microenvironment modulation, angiogenesis promotion, and effective extracellular matrix production leveraging the acidic pH condition of diabetic wounds. This adhesive dressing provides a comprehensive regenerative strategy for diabetic wound management and can be extended to other complicated tissue healing scenarios.

Synthesis of Mesoporous Ag2O/SnO2 Nanospheres for Selective Sensing of Formaldehyde at a Low Working Temperature

Formaldehyde (HCHO) is a prevalent indoor gas pollutant that has been seriously endangering human health. Developing semiconductor metal oxide (SMO) gas sensors for selective measurement of formaldehyde at low working temperatures remains a great challenge. In this work, silver/tin-polyphenol hybrid spheres are applied as a sacrificial template for the fabrication of spherical mesoporous Ag₂O/SnO₂ sensing materials. The obtained mesoporous Ag₂O/SnO₂ spheres have a uniform particle size (∼80 nm), large pore size (5.8 nm), and high specific surface area (71.3 m² g^-1). The response is 140 toward formaldehyde (10 ppm) at a low working temperature (75 °C). The detection limit reaches a low level of 23.6 ppb. Most importantly, it has excellent selectivity toward interfering gases. When the concentration of the interfering gas (e.g., ethanol) is 5 times as high as that of formaldehyde, the response is little affected. Theoretical calculations suggest that the addition of Ag₂O can significantly enhance the adsorption energy toward formaldehyde, thus improving formaldehyde sensing performance. This work demonstrates an efficient self-template synthesis strategy for noble metal catalyst-decorated mesoporous metal oxide spheres, which could boost gas sensing performance at a lower working temperature.