Tunable Structured 2D Nanobiocatalysts: Synthesis, Catalytic Properties and New Horizons in Biomedical Applications.

2D materials have offered essential contributions to boosting biocatalytic efficiency in diverse biomedical applications due to the intrinsic enzyme-mimetic activity and massive specific surface area for loading metal catalytic centers. Since the difficulty of high-quality synthesis, the varied structure, and the tough choice of efficient surface loading sites with catalytic properties, the artificial building of 2D nanobiocatalysts still faces great challenges. Here, in this review, a timely and comprehensive summarization of the latest progress and future trends in the design and biotherapeutic applications of 2D nanobiocatalysts is provided, which is essential for their development. First, an overview of the synthesis-structure-fundamentals and structure-property relationships of 2D nanobiocatalysts, both metal-free and metal-based is provided. After that, the effective design of the active sites of nanobiocatalysts is discussed. Then, the progress of their applied research in recent years, including biomedical analysis, biomedical therapeutics, pharmacokinetics, and toxicology is systematically highlighted. Finally, future research directions of 2D nanobiocatalysts are prospected. Overall, this review to provide cutting-edge and multidisciplinary guidance for accelerating future developments and biomedical applications of 2D nanobiocatalysts is expected.

Smart Graphene Textiles for Biopotential Monitoring: Laser-Tailored Electrochemical Property Enhancement.

While most of the research in graphene-based materials seeks high electroactive surface area and ion intercalation, here, we show an alternative electrochemical behavior that leverages graphene's potential in biosensing. We report a novel approach to fabricate graphene/polymer nanocomposites with near-record conductivity levels of 45 Ω sq-1 and enhanced biocompatibility. This is realized by laser processing of graphene oxide in a sandwich structure with a thin (100 µm) polyethylene terephthalate film on a textile substrate. Such hybrid materials exhibit high conductivity, low polarization, and stability. In addition, the nanocomposites are highly biocompatible, as evidenced by their low cytotoxicity and good skin adhesion. These results demonstrate the potential of graphene/polymer nanocomposites for smart clothing applications.

Alveoli-Inspired Carbon Cathodes with Interconnected Porous Structure and Asymmetric Coordinated Vanadium Sites for Superior Li-S Batteries.

Accelerating sulfur conversion catalysis to alleviate the shuttle effect has become a novel paradigm for effective Li-S batteries. Although nitrogen-coordinated metal single-atom (M-N4) catalysts have been investigated, further optimizing its utilization rate and catalytic activities is urgently needed for practical applications. Inspired by the natural alveoli tissue with interconnected structure and well-distributed enzyme catalytic sites on the wall for the simultaneously fast diffusion and in-situ catalytic conversion of substrates, here, we proposed the controllable synthesis of bioinspired carbon cathode with interconnected porous structure and asymmetric coordinated V-S1N3 sites for efficient and stable Li-S batteries. The enzyme-mimetic V-S1N3 shows asymmetric electronic distribution and high tunability, therefore enhancing in-situ polysulfide conversion activities. Experimental and theoretical results reveal that the high charge asymmetry degree and large atom radius of S in V-S1N3 result in sloping adsorption for polysulfide, thereby exhibiting low thermodynamic energy barriers and long-range stability (0.076% decay over 600 cycles).

Metal-organic framework-based adsorbents for blood purification: progress, challenges, and prospects.

Blood purification, such as hemodialysis (HD), plasma exchange (PE), and hemoperfusion (HP), is widely applied in patients with organ failure (such as kidney and liver failure). Among them, HP mainly relies on porous adsorbents to efficiently adsorb accumulated metabolic wastes and toxins, thus improving purification efficiency. Metal-organic frameworks (MOFs), with a high porosity, large surface area, high loading capacity, and tailorable topology, are emerging as some of the most promising materials for HP. Compared with non-metal framework counterparts, the self-built metal centers of MOFs feature the intrinsic advantages of coordination with toxin molecules. However, research on MOFs in blood purification is insufficient, particularly in contrast to materials applied in other biomedical applications. Thus, to broaden this area, this review first discusses the essential characteristics, potential mechanisms, and structure-function relationship between MOFs and toxin adsorption based on porosity, topology, ligand functionalization, metal centers, and toxin types. Moreover, the stability, utilization safety, and hemocompatibility of MOFs are illustrated for adsorbent selection. The current development and progress in MOF composites for HD, HP, and extracorporeal membrane oxygenation (ECMO) are also summarized to highlight their practicability. Finally, we propose future opportunities and challenges from materials design and manufacture to the computational prediction of MOFs in blood purification. It is anticipated that our review will expand the interest of researchers for more impact in this area.

Immobilization of carbonic anhydrase on modified PES membranes for artificial lungs.

The introduction of carbonic anhydrase (CA) onto an extracorporeal membrane oxygenation (ECMO) membrane can improve the permeability of carbon dioxide (CO2). However, existing CA-grafting methods have limitations, and the hemocompatibility of current substrate membranes of commercial ECMO is not satisfactory. In this study, a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxy succinimide (NHS) activation method is adopted to graft CA with CO2-catalyzed conversion activity onto a polyethersulfone (PES) membrane, which is prepared by a phase inversion technique after in situ crosslinking polymerization of 1-vinyl-2-pyrrolidone (VP) and acrylic acid (AA) in PES solution. The characterization results reveal that CA has been grafted onto the modified PES membrane successfully and exhibits catalytic activity. The kinetic parameters of esterase activity verify that the grafted amount of active CA increases with an increase in the concentration of the CA incubation solution. The CA-grafted membrane (CA-M) can accelerate the conversion of bicarbonate to CO2 in water and blood, which demonstrates the special catalytic activity towards bicarbonate of CA. Finally, blood compatibility tests prove that the CA-M does not lead to hemolysis, shows suppressed protein adsorption and increased coagulation time, and is suitable for application in ECMO. This work demonstrates a green and efficient method for preparing bioactive materials and has practical guiding significance for subsequent pulmonary membrane research and ECMO applications.

Delocalization Engineering of Heme-Mimetic Artificial Enzymes for Augmented Reactive Oxygen Catalysis.

Developing artificial enzymes based on organic molecules or polymers for reactive oxygen species (ROS)-related catalysis has broad applicability. Herein, inspired by porphyrin-based heme mimics, we report the synthesis of polyphthalocyanine-based conjugated polymers (Fe-PPc-AE) as a new porphyrin-evolving structure to serve as efficient and versatile artificial enzymes for augmented reactive oxygen catalysis. Owing to the structural advantages, such as enhanced π-conjugation networks and π-electron delocalization, promoted electron transfer, and unique Fe-N coordination centers, Fe-PPc-AE showed more efficient ROS-production activity in terms of Vmax and turnover numbers as compared with porphyrin-based conjugated polymers (Fe-PPor-AE), which also surpassed reported state-of-the-art artificial enzymes in their activity. More interestingly, by changing the reaction medium and substrates, Fe-PPc-AE also revealed significantly improved activity and environmental adaptivity in many other ROS-related biocatalytic processes, validating the potential of Fe-PPc-AE to replace conventional (poly)porphyrin-based heme mimics for ROS-related catalysis, biosensors, or biotherapeutics. It is suggested that this study will offer essential guidance for designing artificial enzymes based on organic molecules or polymers.

Polyoxometalate-Structured Materials: Molecular Fundamentals and Electrocatalytic Roles in Energy Conversion.

Polyoxometalates (POMs), a kind of molecular metal oxide cluster with unique physical-chemical properties, have made essential contributions to creating efficient and robust electrocatalysts in renewable energy systems. Due to the fundamental advantages of POMs, such as the diversity of molecular structures and large numbers of redox active sites, numerous efforts have been devoted to extending their application areas. Up to now, various strategies of assembling POM molecules into superstructures, supporting POMs on heterogeneous substrates, and POMs-derived metal compounds have been developed for synthesizing electrocatalysts. From a multidisciplinary perspective, the latest advances in creating POM-structured materials with a unique focus on their molecular fundamentals, electrocatalytic roles, and the recent breakthroughs of POMs and POM-derived electrocatalysts, are systematically summarized. Notably, this paper focuses on exposing the current states, essences, and mechanisms of how POM-structured materials influence their electrocatalytic activities and discloses the critical requirements for future developments. The future challenges, objectives, comparisons, and perspectives for creating POM-structured materials are also systematically discussed. It is anticipated that this review will offer a substantial impact on stimulating interdisciplinary efforts for the prosperities and widespread utilizations of POM-structured materials in electrocatalysis.

Conjugated Network Supporting Highly Surface-Exposed Ru Site-Based Artificial Antioxidase for Efficiently Modulating Microenvironment and Alleviating Solar Dermatitis.

Solar dermatitis, a form of acute radiation burn that affects the skin, results from overexposure to ultraviolet B (UVB) radiation in strong sunlight. Cell damage caused by the accumulation of reactive oxygen species (ROS) produced by UVB radiation plays an important role in UVB-induced inflammation in the skin. Here, for efficiently scavenging excess ROS, modulating the microenvironment, and alleviating solar dermatitis, a π-conjugated network polyphthalocyanine supporting a highly surface-exposed Ru active site-based artificial antioxidase (HSE-PPcRu) is designed and fabricated with excellent ROS-scavenging, antioxidant, and anti-inflammatory capabilities. In photodamaged human keratinocyte cells, HSE-PPcRu could modulate mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B signaling pathways, prevent DNA damage, suppress apoptosis, inhibit pro-inflammatory cytokine secretion, and alleviate cell damage. In vivo animal experiments reveal the higher antioxidant and anti-inflammatory efficacies of HSE-PPcRu by reversing the activation of p38 and c-Jun N-terminal kinase, inhibiting expression of cyclooxygenase-2, interleukin-6, interleukin-8, and tumor necrosis factor-α. This work not only provides an idea for alleviating solar dermatitis via catalytically scavenging ROS and modulating the microenvironment but also offers a strategy to design an intelligent conjugated network-based artificial antioxidase with a highly surface-exposed active site.

Spiky Artificial Peroxidases with V-O-Fe Pair Sites for Combating Antibiotic-Resistant Pathogens.

With the sharp rise of antibiotic-resistant pathogens worldwide, it is of enormous importance to create new strategies for combating pathogenic bacteria. Here, we create an iron oxide-based spiky artificial peroxidase (POD) with V-O-Fe pair sites (V-Fe2 O3 ) for combating methicillin-resistant Staphylococcus aureus (MRSA). The experimental studies and theoretical calculations demonstrate that the V-Fe2 O3 can achieve the localized "capture and killing" bifunction from the spiky morphology and massive reactive oxygen species (ROS) production. The V-Fe2 O3 can reach nearly 100 % bacterial inhibition over a long period by efficiently oxidizing the lipid membrane. Our wound disinfection results identify that the V-Fe2 O3 can not only efficiently eliminate MRSA and their biofilm but also accelerate wound recovery without causing noticeable inflammation and toxicity. This work offers essential insights into the critical roles of V-O-Fe pair sites and localized "capture and killing" in biocatalytic disinfection and provides a promising pathway for the de novo design of efficient artificial peroxidases.

Pt-Clusters-Equipped Antioxidase-Like Biocatalysts as Efficient ROS Scavengers for Treating Periodontitis.

Developing high-efficiency artificial biocatalysts for scavenging reactive oxygen species (ROS) is critical for treating inflammation diseases and promoting tissue regeneration. By mimicking the active sites in catalase, here, a Pt-clusters-equipped antioxidase-like biocatalysts (Pt─CN) with superior catalytic abilities for stem cell protection and periodontitis treatment are reported. Owing to the excellent effects of multiple Pt clusters, Pt─CN yields exceptional catalytic ROS-scavenging activities for multiple types of ROS. In vitro studies show that Pt─CN can effectively protect stem cell survival, adhesion, and differentiation in a high ROS levels microenvironment. Additionally, Pt─CN can reduce the M1/M2 ratio of macrophages when stimulated by lipopolysaccharide. In vivo treatment of mouse periodontitis further confirms the protection against bone loss and reduction in the inflammatory response. This study provides a basis for the application of biocatalysts with Pt catalytic center in macrophage polarization, stem cell protection, and periodontitis treatment, thus offering a new strategy for the design of high-performance artificial biocatalysts.

Synthesis of Chiral Triazine Frameworks for Enantiodiscrimination.

Manipulation of the structure of covalent organic frameworks at the molecular level is an efficient strategy to shift their biological, physicochemical, optical, and electrical properties in the desired windows. In this work, we report on a new method to construct chiral triazine frameworks using metal-driven polymerization for enantiodiscrimination. The nucleophilic substitution reaction between melamine and cyanuric chloride was performed in the presence of PdCl2, ZnCl2, and CuCl2 as chirality-directing agents. Palladium, with the ability of planar complex formation, was able to assemble monomers in two-dimensions and drive the reaction in two directions, leading to a two-dimensional triazine network with several micrometers lateral size. Nonplanar arrangements of monomers in the presence of ZnCl2 and CuCl2, however, resulted in calix and bouquet structures, respectively. While 2D and bouquet structures showed strong negative and positive bands in the CD spectra, respectively, their calix counterparts displayed long-range weak negative bands. In spite of the ability of both calix and bouquet networks to load l-histidine 35 and 50% more than d-histidine from pure enantiomers, respectively, only calix counterparts were able to take up this enantiomer (78%) from the racemic mixture. The two-dimensional polytriazine network did not show any specific interactions with pure enantiomers or their racemic mixtures.

Engineering Zinc-Organic Frameworks-Based Artificial Carbonic Anhydrase with Ultrafast Biomimetic Centers for Efficient Hydration Reactions.

Constructing effective and robust biocatalysts with carbonic anhydrase (CA)-mimetic activities offers an alternative and promising pathway for diverse CO2 -related catalytic applications. However, there is very limited success has been achieved in controllably synthesizing CA-mimetic biocatalysts. Here, inspired by the 3D coordination environments of CAs, this study reports on the design of an ultrafast ZnN3 -OH2 center via tuning the 3D coordination structures and mesoporous defects in a zinc-dipyrazolate framework to serve as new, efficient, and robust CA-mimetic biocatalysts (CABs) to catalyze the hydration reactions. Owing to the structural advantages and high similarity with the active center of natural CAs, the double-walled CAB with mesoporous defects displays superior CA-like reaction kinetics in p-NPA hydrolysis (V0  = 445.16 nM s-1 , Vmax  = 3.83 µM s-1 , turnover number: 5.97 × 10-3  s-1 ), which surpasses the by-far-reported metal-organic frameworks-based biocatalysts. This work offers essential guidance in tuning 3D coordination environments in artificial enzymes and proposes a new strategy to create high-performance CA-mimetic biocatalysts for broad applications, such as CO2 hydration/capture, CO2 sensing, and abundant hydrolytic reactions.

Promoting Stem Cell Mechanosensing and Osteogenesis by Hybrid Soft Fibers.

Bone regenerative biomaterials are essential in treating bone defects as they serve as extracellular matrix (ECM) mimics, creating a favorable environment for cell attachment, proliferation, and differentiation. However, the currently used bone regenerative biomaterials mostly exhibit high stiffness, which may lead to difficulties in degradation and thus increase the risk of foreign body ingestion. In this study, we prepared soft fibrous scaffolds modified with Zn-MOF-74 nanoparticles via electrostatic spinning. The soft fibers (only 1 kPa) permit remodeling under cellular adhesive force, optimizing the mechanical cues in the microenvironment to support cell adhesion and mechanosensing. In addition, the incorporation of Zn-MOF-74 nanoparticles enables the stable and sustained release of zinc ions, promoting stem cell mechanotransduction and osteogenic differentiation. Therefore, the hybrid soft fibers facilitate the regeneration of new bone in the rat femoral defect model, which provides a promising approach for regenerative medicine.

Reactive oxygen nanobiocatalysts: activity-mechanism disclosures, catalytic center evolutions, and changing states.

Benefiting from low costs, structural diversities, tunable catalytic activities, feasible modifications, and high stability compared to the natural enzymes, reactive oxygen nanobiocatalysts (RONBCs) have become dominant materials in catalyzing and mediating reactive oxygen species (ROS) for diverse biomedical and biological applications. Decoding the catalytic mechanism and structure-reactivity relationship of RONBCs is critical to guide their future developments. Here, this timely review comprehensively summarizes the recent breakthroughs and future trends in creating and decoding RONBCs. First, the fundamental classification, activity, detection method, and reaction mechanism for biocatalytic ROS generation and elimination have been systematically disclosed. Then, the merits, modulation strategies, structure evolutions, and state-of-art characterisation techniques for designing RONBCs have been briefly outlined. Thereafter, we thoroughly discuss different RONBCs based on the reported major material species, including metal compounds, carbon nanostructures, and organic networks. In particular, we offer particular insights into the coordination microenvironments, bond interactions, reaction pathways, and performance comparisons to disclose the structure-reactivity relationships and mechanisms. In the end, the future challenge and perspectives for RONBCs are also carefully summarised. We envision that this review will provide a comprehensive understanding and guidance for designing ROS-catalytic materials and stimulate the wide utilisation of RONBCs in diverse biomedical and biological applications.

Highly Reversible Zn Metal Anode with Low Voltage Hysteresis Enabled by Tannic Acid Chemistry.

The zinc dendrites and side reactions formed on the zinc anode have greatly hindered the development of aqueous zinc-ion batteries (ZIBs). Herein, we introduce tannic acid (TA) as an additive in the ZnSO4 (ZSO) electrolyte to enhance the reversible Zn plating/stripping behavior. TA molecules are found to adsorb onto the zinc surface, forming a passivation layer and replacing some of the H2O molecules in the Zn2+ solvation sheath to form the [Zn(H2O)6-xTAx]2+ complex; this process effectively prevents side reactions. Moreover, the lower desolvation energy barrier of the [Zn(H2O)6-xTAx]2+ structure facilitates uniform Zn metal deposition and enables a stable plating/stripping lifespan of 2500 h with low voltage hysteresis (53 mV at 0.5 mA cm-2) as compared to the ZSO electrolyte (167 h and 104 mV). Additionally, the incorporation of the MnO2 cathode in the TA + ZSO electrolyte shows improved cycling capacity retention, from 64% (ZSO) to 85% (TA + ZSO), after 250 cycles at 1 A g-1, demonstrating the effectiveness of the TA additive in enhancing the performance of ZIBs.

Correction: Reactive oxygen nanobiocatalysts: activity-mechanism disclosures, catalytic center evolutions, and changing states.

Correction for 'Reactive oxygen nanobiocatalysts: activity-mechanism disclosures, catalytic center evolutions, and changing states' by Sujiao Cao et al., Chem. Soc. Rev., 2023, https://doi.org/10.1039/d3cs00087g.

Comparison of Fungal Genera Isolated from Cucumber Plants and Rhizosphere Soil by Using Various Cultural Media.

Plant endophytic fungi and rhizosphere soil fungi are often reported as biocontrol agents against plant pathogens or with plant growth promotion potential. Four treatments were performed in field and greenhouse experiments where cucumber plants were inoculated with Trichoderma harzianum and Fusarium oxysporum in 2022. The roots, stems and leaves of cucumber plants and their rhizosphere soil were collected twice individually from the field and greenhouse for isolation of cucumber endophytic and rhizosphere soil fungi. All fungal strains were identified through sequence similarity of the ITS1-5.8s-ITS2 rDNA region. The potato dextrose agar (PDA) media yielded the highest number of genera isolated from cucumber plants, rhizosphere soil and both compared to other media. There were no significant differences among the four media for the isolation of all cucumber endophytic fungi. However, in the roots, the number of endophytic fungi isolated by MRBA was significantly higher than that isolated on malt extract agar (MEA), while in the stems, the number of fungi isolated with PDA was significantly higher than that isolated with Martin's rose bengal agar medium (MRBA). PDA had significantly higher isolation efficiency for the rhizosphere soil fungi than MRBA. The 28 fungal genera had high isolation efficiency, and the endophytic Trichoderma strains were significantly more isolated by MEA than those of MRBA. It is suggested that PDA can be used as a basic medium, and different cultural media can be considered for specific fungal genera.

An Extracellular Vesicle-Cloaked Multifaceted Biocatalyst for Ultrasound-Augmented Tendon Matrix Reconstruction and Immune Microenvironment Regulation.

The healing of tendon injury is often hindered by peritendinous adhesion and poor regeneration caused by the accumulation of reactive oxygen species (ROS), development of inflammatory responses, and the deposition of type-III collagen. Herein, an extracellular vesicles (EVs)-cloaked enzymatic nanohybrid (ENEV) was constructed to serve as a multifaceted biocatalyst for ultrasound (US)-augmented tendon matrix reconstruction and immune microenvironment regulation. The ENEV-based biocatalyst exhibits integrated merits for treating tendon injury, including the efficient catalase-mimetic scavenging of ROS in the injured tissue, sustainable release of Zn2+ ions, cellular uptake augmented by US, and immunoregulation induced by EVs. Our study suggests that ENEVs can promote tenocyte proliferation and type-I collagen synthesis at an early stage by protecting tenocytes from ROS attack. The ENEVs also prompted efficient immune regulation, as the polarization of macrophages (Mφ) was reversed from M1φ to M2φ. In a rat Achilles tendon defect model, the ENEVs combined with US treatment significantly promoted functional recovery and matrix reconstruction, restored tendon morphology, suppressed intratendinous scarring, and inhibited peritendinous adhesion. Overall, this study offers an efficient nanomedicine for US-augmented tendon regeneration with improved healing outcomes and provides an alternative strategy to design multifaceted artificial biocatalysts for synergetic tissue regenerative therapies.

Nanomaterials-Enabled Physicochemical Antibacterial Therapeutics: Toward the Antibiotic-Free Disinfections.

Bacterial infection continues to be an increasing global health problem with the most widely accepted treatment paradigms restricted to antibiotics. However, the overuse and misuse of antibiotics have triggered multidrug resistance of bacteria, frustrating therapeutic outcomes, and leading to higher mortality rates. Even worse, the tendency of bacteria to form biofilms on living and nonliving surfaces further increases the difficulty in confronting bacteria because the extracellular matrix can act as a robust barrier to prevent the penetration of antibiotics and resist environmental damage. As a result, the inability to eliminate bacteria and biofilms often leads to persistent infection, implant failure, and device damage. Therefore, it is of paramount importance to develop alternative antimicrobial agents while avoiding the generation of bacterial resistance to prevent the large-scale growth of bacterial resistance. In recent years, nano-antibacterial materials have played a vital role in the antibacterial field because of their excellent physical and chemical properties. This review focuses on new physicochemical antibacterial strategies and versatile antibacterial nanomaterials, especially the mechanism and types of 2D antibacterial nanomaterials. In addition, this advanced review provides guidance on the development direction of antibiotic-free disinfections in the antibacterial field in the future.

Ultralow Ru Single Atoms Confined in Cerium Oxide Nanoglues for Highly-Sensitive and Robust H2 O2 -Related Biocatalytic Diagnosis.

Exploring highly efficient, portable, and robust biocatalysts is a great challenge in colorimetric biosensors. To overcome the challenging states in creating single-atom biocatalysts, such as insufficient activity and stability, here, this work has engineered a unique CeO2 support as nanoglue to tightly anchor the Ru single-atom sites (CeO2 -Ru) with strong electronic coupling for achieving highly sensitive and robust H2 O2 -related biocatalytic diagnosis. The morphology and chemical/electronic structure analysis demonstrates that the Ru atoms are well-dispersed on CeO2 surface to form high-density active sites. Benefiting from the unique structure, the prepared CeO2 -Ru exhibits outstanding peroxidase (POD) like catalytic activity and selectivity to H2 O2 . Steady-state kinetic study results show that the CeO2 -Ru presents the highest Vmax and turnover number than the state-of-the-art POD-like biocatalysts. Consequently, the CeO2 -Ru discloses a high efficiency, good selectivity, and robust stability in the colorimetric detection of L-cysteine, glucose, and uric acid. Notably, the limit of detection (LOD) can reach 0.176 × 10-3 m for the L-cysteine, 0.095 × 10-3 m for the glucose, and 0.088 × 10-3 m for the uric acid via cascade reaction. This work suggests that the proposed unique CeO2 nanoglue will offer a new path to create single-atom noble metal biocatalysts and take a step closer to future biotherapeutic and biocatalytic applications.