Perovskite hydroxide-based laccase mimics with controllable activity for environmental remediation and biosensing.

Constructing relatively inexpensive nanomaterials to simulate the catalytic performance of laccase is of great significance in recent years. Although research on improving laccase-like activity by regulating ligands of copper (amino acids or small organic molecules, etc.) have achieved remarkable success. There are few reports on improving laccase-like activity by adjusting the composition of metal Cu. Here, we used perovskite hydroxide AB(OH)6 as a model to evaluate the relationship between Cu based alloys and their laccase-like activity. We found that when the Cu/Mn alloy ratio of the perovskite hydroxide A point is greater than 1, the laccase-like activity of the binary alloy perovskite hydroxide is higher than that of the corresponding single Cu. Based on the measurements of XPS and ICP-MS, we deduced that the improvements of laccase-like activity mainly attribute to the ratio of Cu+/Cu2+and the content of Cu. Moreover, two types of substrates (toxic pollutants and catechol neurotransmitters) were used to successfully demonstrated such nanozymes' excellent environmental protecting function and biosensing property. This work will provide a novel approach for the construction and application of laccase-like nanozymes in the future.

Fe3O4 nanoparticles entrapped in the inner surfaces of N-doped carbon microtubes with enhanced biomimetic activity.

Tubular structured composites have attracted great interest in catalysis research owing to their void-confinement effects. In this work, we synthesized a pair of hollow N-doped carbon microtubes (NCMTs) with Fe3O4 nanoparticles (NPs) encapsulated inside NCMTs (Fe3O4@NCMTs) and supported outside NCMTs (NCMTs@Fe3O4) while keeping other structural features the same. The impact of structural effects on the catalytic activities was investigated by comparing a pair of hollow-structured nanocomposites. It was found that the Fe3O4@NCMTs possessed a higher peroxidase-like activity when compared with NCMTs@Fe3O4, demonstrating structural superiority of Fe3O4@NCMTs. Based on the excellent peroxidase-like catalytic activity and stability of Fe3O4@NCMTs, an ultra-sensitive colorimetric method was developed for the detection of H2O2 and GSH with detection limits of 0.15 µM and 0.49 µM, respectively, which has potential application value in biological sciences and biotechnology.

Nanozymes with biomimetically designed properties for cancer treatment.

Nanozymes, as a type of nanomaterials with enzymatic catalytic activity, have demonstrated tremendous potential in cancer treatment owing to their unique biomedical properties. However, the heterogeneity of tumors and the complex tumor microenvironment pose significant challenges to the in vivo catalytic efficacy of traditional nanozymes. Drawing inspiration from natural enzymes, scientists are now using biomimetic design to build nanozymes from the ground up. This approach aims to replicate the key characteristics of natural enzymes, including active structures, catalytic processes, and the ability to adapt to the tumor environment. This achieves selective optimization of nanozyme catalytic performance and therapeutic effects. This review takes a deep dive into the use of these biomimetically designed nanozymes in cancer treatment. It explores a range of biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry. A significant focus is on tweaking the nanozyme structures to boost their catalytic performance, integrating them into complex enzyme networks similar to those in biological systems, and adjusting functions like altering tumor metabolism, reshaping the tumor environment, and enhancing drug delivery. The review also covers the applications of specially designed nanozymes in pan-cancer treatment, from catalytic therapy to improved traditional methods like chemotherapy, radiotherapy, and sonodynamic therapy, specifically analyzing the anti-tumor mechanisms of different therapeutic combination systems. Through rational design, these biomimetically designed nanozymes not only deepen the understanding of the regulatory mechanisms of nanozyme structure and performance but also adapt profoundly to tumor physiology, optimizing therapeutic effects and paving new pathways for innovative cancer treatment.

Biomimetic peroxidase MOF-Fe promotes bone defect repair by inhibiting TfR2 and activating the BMP2 pathway.

BACKGROUND: Large bone defects pose a clinical treatment challenge; inhibiting transferrin receptor 2 (TfR2), which is involved in iron metabolism, can promote osteogenesis. Iron-based metal-organic frameworks (MOF-Fe) particles not only inhibit TfR2 but also serve as biomimetic catalysts to remove hydrogen peroxide in reactive oxygen species (ROS); excess ROS can disrupt the normal functions of osteoblasts, thereby hindering bone regeneration. This study explored the potential effects of MOF-Fe in increasing osteogenic activity and clearing ROS. METHODS: In vitro experiments were performed to investigate the osteogenic effects of MOF-Fe particles and assess their impact on cellular ROS levels. To further validate the role of MOF-Fe in promoting bone defect repair, we injected MOF-Fe suspensions into the femoral defects of SD rats and implanted MOF-Fe-containing hydrogel scaffolds in rabbit cranial defect models and observed their effects on bone healing. RESULTS: In vitro, the presence of MOF-Fe significantly increased the expression levels of osteogenesis-related genes and proteins compared to those in the control group. Additionally, compared to those in the untreated control group, the cells treated with MOF-Fe exhibited a significantly increased ability to remove hydrogen peroxide from ROS and generate oxygen and water within the physiological pH range. In vivo experiments further confirmed the positive effect of MOF-Fe in promoting bone defect repair. CONCLUSION: This study supports the application of MOF-Fe as an agent for bone regeneration, particularly for mitigating ROS and activating the bone morphogenetic protein (BMP) pathway, demonstrating its potential value.

Highly oriented hydrogels for tissue regeneration: design strategies, cellular mechanisms, and biomedical applications.

Many human tissues exhibit a highly oriented architecture that confers them with distinct mechanical properties, enabling adaptation to diverse and challenging environments. Hydrogels, with their water-rich "soft and wet" structure, have emerged as promising biomimetic materials in tissue engineering for repairing and replacing damaged tissues and organs. Highly oriented hydrogels can especially emulate the structural orientation found in human tissue, exhibiting unique physiological functions and properties absent in traditional homogeneous isotropic hydrogels. The design and preparation of highly oriented hydrogels involve strategies like including hydrogels with highly oriented nanofillers, polymer-chain networks, void channels, and microfabricated structures. Understanding the specific mechanism of action of how these highly oriented hydrogels affect cell behavior and their biological applications for repairing highly oriented tissues such as the cornea, skin, skeletal muscle, tendon, ligament, cartilage, bone, blood vessels, heart, etc., requires further exploration and generalization. Therefore, this review aims to fill that gap by focusing on the design strategy of highly oriented hydrogels and their application in the field of tissue engineering. Furthermore, we provide a detailed discussion on the application of highly oriented hydrogels in various tissues and organs and the mechanisms through which highly oriented structures influence cell behavior.

Artificial structural proteins: Synthesis, assembly and material applications.

Structural proteins have evolved over billions of years and offer outstanding mechanical properties, such as resilience, toughness and stiffness. Advances in modular protein engineering, polypeptide modification, and synthetic biology have led to the development of novel biomimetic structural proteins to perform in biomedical and military fields. However, the development of customized structural proteins and assemblies with superior performance remains a major challenge, due to the inherent limitations of biosynthesis, difficulty in mimicking the complexed macroscale assembly, etc. This review summarizes the approaches for the design and production of biomimetic structural proteins, and their chemical modifications for multiscale assembly. Furthermore, we discuss the function tailoring and current applications of biomimetic structural protein assemblies. A perspective of future research is to reveal how the mechanical properties are encoded in the sequences and conformations. This review, therefore, provides an important reference for the development of structural proteins-mimetics from replication of nature to even outperforming nature.

Gas Evolution as a Tool to Study Reaction Kinetics Under Biomimetic Conditions.

The field of bioorthogonal chemistry is rapidly growing, presenting successful applications of organic and transition metal-catalysed reactions in cells and living systems (in vivo). The development of such reactions typically proceeds through many iterative steps focused on biocompatibility and fast reaction kinetics to ensure product formation. However, obtaining kinetic data, even under simulated biological (biomimetic) conditions, remains a challenge due to substantial concentrations of salts and biomolecules hampering the use of typically employed solution-phase analytical techniques. In this study, we explored the suitability of gas evolution as a probe to study kinetics under biomimetic conditions. As proof of concept, we show that the progress of two transition metal-catalysed bioorthogonal chemical reactions can be accurately monitored, regardless of the complexity of the medium. As such, we introduce a protocol to gain more insight into the performance of a catalytic system under biomimetic conditions to further progress iterative catalyst development for in vivo applications.

Injectable extracellular matrix-mimetic hydrogel based on electrospun Janus fibers.

To date, the reported injectable hydrogels have failed to mimic the fibrous architecture of the extracellular matrix (ECM), limiting their biological effects on cell growth and phenotype. Additionally, they lack the micro-sized pores present within the ECM, which is unfavorable for the facile transport of nutrients and waste. Herein, an injectable ECM-mimetic hydrogel (IEMH) was fabricated by shortening and dispersing Janus fibers capable of self-curling at body temperature into pH 7.4 phosphate buffer solution. The IEMH could be massively prepared through a side-by-side electrospinning process combined with ultraviolet irradiation. The IEMHs with only 5 wt% fibers could undergo sol-gel transition at body temperature to become solid gels with desirable stability, sturdiness, and elasticity and self-healing ability. In addition, they possessed notable pseudoplasticity, which is beneficial to injection at room temperature. The results obtained from characterization analysis via scanning electron microscopy, total internal reflection fluorescence microscopy, nuclear magnetic resonance spectroscopy, and Fourier-transform infrared spectroscopy indicate that their sol-gel transition under physiological conditions stems from the synergistic action of the tight entanglements between thermally-induced self-curling fibers and the hydrophobic interaction between the fibers. An MTT assay using C2C12 myoblast cells was performed to examine the in vitro cytotoxicity of IEMHs for biomedical applications, and the cell viability was found to be more than 95%.

Single-atom nanozymes with peroxidase-like activity: A review.

Single-atom nanozymes (SANs) are nanomaterials-based nanozymes with atomically dispersed enzyme-like active sites. SANs offer improved as well as tunable catalytic activity. The creation of extremely effective SANs and their potential uses have piqued researchers' curiosity due to their advantages of cheap cost, variable catalytic activity, high stability, and large-scale production. Furthermore, SANs with uniformly distributed active centers and definite coordination structures offer a distinctive opportunity to investigate the structure-activity correlation and control the geometric and electrical features of metal centers. SANs have been extensively explored in photo-, thermal-, and electro-catalysis. However, SANs suffer from the following disadvantages, such as efficiency, non-mimicking of the 3-D complexity of natural enzymes, limited and narrow range of artificial SANs, and biosafety aspects. Among a quite limited range of artificial SANs, the peroxidase action of SANs has attracted significant research attention in the last five years with the aim of producing reactive oxygen species for use in cancer therapy, and water treatment among many other applications. In this review, we explore the recent progress of different SANs as peroxidase mimics, the role of the metal center in enzymatic activity, possible prospects, and underlying limitations in real-time applications.

Advances in the application of metal oxide nanozymes in tumor detection and treatment.

Natural enzymes play an important role to support the regular life activities of the human body. However, the application conditions of natural enzymes are harsh and there are limitations in their use. As artificial enzymes, nanozymes possess the substrate specificity of natural enzymes. Due to the advantages of low cost, good stability and strong catalytic properties, nanozymes hold a wide range of applications in the fields of sensing, chemical, food and medicine. Some of the more common ones are noble metal nanozymes, metal oxide nanozymes and carbon-based nanozymes. Among them, metal oxide nanozymes have attracted much attention because of their decent fixity, exceedingly good physicochemical properties and other advantages. Today, malignant tumors pose a great danger to the human body and are a serious threat to human health. However, traditional treatments have more side effects, and finding new treatment modalities is particularly important for tumor treatment. For example, enzyme therapy can be used to catalyze reactions in the body to achieve tumor treatment. Nanozymes can exert enzymatic activity and effectively treat malignant tumors through catalysis and synergy, and have made certain progress. This paper reviews the detection and application of metal oxide nanozymes in tumor detection and treatment in recent years and provides an outlook on their future application and development.

pH-Stimulated Response Gating for Mimic Cytochrome C Transport on Biomimetic Asymmetric Nanochannels.

Proteins are vital components in cells, biological tissues, and organs, playing a pivotal role in growth and developmental processes in living organisms. Cytochrome C (Cyt C) is a class of heme proteins found in almost all life and is involved in cellular energy metabolic processes such as respiration, mainly as electron carriers or terminal reductases. It binds cardiolipin in the inner mitochondrial membrane, leading to apoptosis. It is a challenge to design a simple and effective artificial system to mimic the complex Cyt C biological transport process. In this paper, an asymmetric biomimetic pH-driven protein gate is described by introducing arginine (Arg) at one end of an hourglass-shaped nanochannel. The nanochannel shows a sensitive protonation-driven protein gate that can be "off" at pH = 7 and "on" at pH = 2. Further studies show that differences in the binding of Arg and Cyt C at different levels of protonation lead to different switching behaviors within the nanochannels, which in turn lead to different surface charges within the nanochannels. It can be used for detecting Cyt C and as an excellent and robust gate for developing integrated circuits and nanoelectronic logic devices.

A Mesostructure Multivariant-Assembly Reinforced Ultratough Biomimicking Superglue.

The imitation of mussels and oysters to create high-performance adhesives is a cutting-edge field. The introduction of inorganic fillers is shown to significantly alter the adhesive's properties, yet the potential of mesoporous materials as fillers in adhesives is overlooked. In this study, the first report on the utilization of mesoporous materials in a biomimetic adhesive system is presented. Incorporating mesoporous silica nanoparticles (MSN) profoundly enhances the adhesion of pyrogallol (PG)-polyethylene imine (PEI) adhesive. As the MSN concentration increases, the adhesion strength to glass substrates undergoes an impressive fivefold improvement, reaching an outstanding 2.5 mPa. The adhesive forms an exceptionally strong bond, to the extent that the glass substrate fractures before joint failure. The comprehensive tests involving various polyphenols, polymers, and fillers reveal an intriguing phenomenon-the molecular structure of polyphenols significantly influences adhesive strength. Steric hindrance emerges as a crucial factor, regulating the balance between π-cation and charge interactions, which significantly impacts the multicomponent assembly of polyphenol-PEI-MSN and, consequently, adhesive strength. This groundbreaking research opens new avenues for the development of novel biomimetic materials.

BioinspiredLLM: Conversational Large Language Model for the Mechanics of Biological and Bio-Inspired Materials.

The study of biological materials and bio-inspired materials science is well established; however, surprisingly little knowledge is systematically translated to engineering solutions. To accelerate discovery and guide insights, an open-source autoregressive transformer large language model (LLM), BioinspiredLLM, is reported. The model is finetuned with a corpus of over a thousand peer-reviewed articles in the field of structural biological and bio-inspired materials and can be prompted to recall information, assist with research tasks, and function as an engine for creativity. The model has proven that it is able to accurately recall information about biological materials and is further strengthened with enhanced reasoning ability, as well as with Retrieval-Augmented Generation (RAG) to incorporate new data during generation that can also help to traceback sources, update the knowledge base, and connect knowledge domains. BioinspiredLLM also has shown to develop sound hypotheses regarding biological materials design and remarkably so for materials that have never been explicitly studied before. Lastly, the model shows impressive promise in collaborating with other generative artificial intelligence models in a workflow that can reshape the traditional materials design process. This collaborative generative artificial intelligence method can stimulate and enhance bio-inspired materials design workflows. Biological materials are at a critical intersection of multiple scientific fields and models like BioinspiredLLM help to connect knowledge domains.

Bioinspired Amino Acid Based Materials in Bionanotechnology: From Minimalistic Building Blocks and Assembly Mechanism to Applications.

Inspired by natural hierarchical self-assembly of proteins and peptides, amino acids, as the basic building units, have been shown to self-assemble to form highly ordered structures through supramolecular interactions. The fabrication of functional biomaterials comprised of extremely simple biomolecules has gained increasing interest due to the advantages of biocompatibility, easy functionalization, and structural modularity. In particular, amino acid based assemblies have shown attractive physical characteristics for various bionanotechnology applications. Herein, we propose a review paper to summarize the design strategies as well as research advances of amino acid based supramolecular assemblies as smart functional materials. We first briefly introduce bioinspired reductionist design strategies and assembly mechanism for amino acid based molecular assembly materials through noncovalent interactions in condensed states, including self-assembly, metal ion mediated coordination assembly, and coassembly. In the following part, we provide an overview of the properties and functions of amino acid based materials toward applications in nanotechnology and biomedicine. Finally, we give an overview of the remaining challenges and future perspectives on the fabrication of amino acid based supramolecular biomaterials with desired properties. We believe that this review will promote the prosperous development of innovative bioinspired functional materials formed by minimalistic building blocks.

Disruption of diatom attachment on marine bioinspired antifouling materials based on Brill (Scophthalmus rhombus).

Bioinspired surfaces, due to their nano and micro topographical features, offer a promising approach for the development of novel antifouling solutions. The study of surface topography has gained popularity in recent years, demonstrating significant potential in mimicking natural structures that could be manufactured for application in the marine environment. This research focuses on investigating the antifouling (AF) performance of bio-inspired micro-textures inspired by Brill fish scales, Scophthalmus rhombus, under static laboratory conditions, using two common fouling diatom species, Amphora coffeaeformis and Nitzschia ovalis. In this study, we evaluate six engineered surfaces, inspired by Brill fish scales, fabricated through a 2-photon polymerization (2PP) process, for their potential as antifouling solutions. The investigation explores the settlement behaviour of microfouling organisms, comparing these mechanisms with theoretical models to guide the future design of antifouling materials. A key emphasis is placed on the impact of surface topography on the disruption of cellular response. Our results suggest that cells smaller than 10 µm, exceeding the peak-to-peak distances between surface features, comfortably position themselves between adjacent features. On the other hand, as peak-to-peak distances decrease, cells shift from settling within uniform gaps to resting on top of surface features. Surfaces with sharpened edges demonstrate a more substantial reduction in diatom attachments compared to those with rounded edges. Furthermore, all micro-textured surfaces exhibit a significant decrease in colony formation compared to control samples. In conclusion, this study shows the potential to manipulate cellular responses through topographical features, providing valuable insights for the design of effective antifouling materials. The results contribute to the growing body of knowledge in biomimetic antifouling strategies using a novel marine organism for inspiration to design practical structures that can be replicated.

Biomimetic crimped/aligned microstructure to optimize the mechanics of fibrous hybrid materials for compliant vascular grafts.

The precise mechanical properties of many tissues are highly dependent on both the composition and arrangement of the nanofibrous extracellular matrix. It is well established that collagen nanofibers exhibit a crimped microstructure in several tissues such as blood vessel, tendon, and heart valve. This collagen fiber arrangement results in the classic non-linear 'J-shaped' stress strain curve characteristic of these tissues. Synthetic biomimetic fibrous materials with a crimped microstructure similar to natural collagen demonstrate similar mechanical properties to natural tissues. The following work describes a nanofabrication method based on electrospinning used to fabricate two component hybrid electrospun fibrous materials that mimic the microstructure and mechanical properties of vascular tissue. The properties of these samples can be precisely and predictably optimized by modifying fabrication parameters. Tubular grafts with biomimetic microstructure were constructed to demonstrate the potential of this fabrication method in vascular graft replacement applications. It was possible to closely match both the overall geometry and the compliance of specific blood vessels by optimizing graft microstructure.

Mussel-Inspired Cation-π Interactions: Wet Adhesion and Biomimetic Materials.

Cation-π interaction is one of the most important noncovalent interactions identified in biosystems, which has been proven to play an essential role in the strong adhesion of marine mussels. In addition to the well-known catecholic amino acid, l-3,4-dihydroxyphenylalanine, mussel foot proteins are rich in various aromatic moieties (e.g., tyrosine, phenylalanine, and tryptophan) and cationic residues (e.g., lysine, arginine, and histidine), which favor a series of short-range cation-π interactions with adjustable strengths, serving as a prototype for the development of high-performance underwater adhesives. This work highlights our recent advances in understanding and utilizing cation-π interactions in underwater adhesives, focusing on three aspects: (1) the investigation of the cation-π interaction mechanisms in mussel foot proteins via force-measuring techniques; (2) the modulation of cation-π interactions in mussel mimetic polymers with the variation of cations, anions, and aromatic groups; (3) the design of wet adhesives based on these revealed principles, leading to functional materials in the form of films, coacervates, and hydrogels with biomedical and engineering applications. This review provides valuable insights into the development and optimization of smart materials based on cation-π interactions.

Carbon-coated copper nanocrystals with enhanced peroxidase-like activity for sensitive colorimetric determination of 2,4-dinitrophenylhydrazine.

Carbon-coated copper nanocrystals (CuNCs) with peroxidase-like activity were hydrothermally prepared by using copper acetate, citric acid (CA) and histidine (His) as the precursors. Various shaped CuNCs, including urchin-like, slab-like and spherical appearance were facilely prepared by addition of different amount of NaNO2 in the precursor solutions. When 3,3',5,5'-tetramethylbenzidine (TMB) was used as the substrate, the CuNCs with urchin-like appearance have greatest peroxidase-like activity and their Michaelis-Menten constant (Km) and the maximum rate constant (νmax) are respectively 8.8 and 1.2 times higher than that obtained from horseradish peroxidase (HRP). The production of reactive oxygen species (ROS) was confirmed by radical quenching and electron spin resonance (ESR) tests. Subsequent studies have found that the CuNCs catalyzed color reaction of TMB can be selectively quenched by the environmental pollutant 2,4-dinitrophenylhydrazine (2,4-DNPH). Thus a new colorimetric method for the determination of 2,4-DNPH with a linear range of 0.60-20 µM was developed and a limit of detection (LOD) as low as 0.166 µM was achieved. The results obtained not only reveal the tunability of the peroxidase-like activity of Cu-based nanomaterials, but also provide a new method for the sensitive determination of environmental contaminate.

Vision-controlled jetting for composite systems and robots.

Recreating complex structures and functions of natural organisms in a synthetic form is a long-standing goal for humanity1. The aim is to create actuated systems with high spatial resolutions and complex material arrangements that range from elastic to rigid. Traditional manufacturing processes struggle to fabricate such complex systems2. It remains an open challenge to fabricate functional systems automatically and quickly with a wide range of elastic properties, resolutions, and integrated actuation and sensing channels2,3. We propose an inkjet deposition process called vision-controlled jetting that can create complex systems and robots. Hereby, a scanning system captures the three-dimensional print geometry and enables a digital feedback loop, which eliminates the need for mechanical planarizers. This contactless process allows us to use continuously curing chemistries and, therefore, print a broader range of material families and elastic moduli. The advances in material properties are characterized by standardized tests comparing our printed materials to the state-of-the-art. We directly fabricated a wide range of complex high-resolution composite systems and robots: tendon-driven hands, pneumatically actuated walking manipulators, pumps that mimic a heart and metamaterial structures. Our approach provides an automated, scalable, high-throughput process to manufacture high-resolution, functional multimaterial systems.

Biomimetic mineralization by confined diffusion with viscous hyaluronan network: Assembly of hierarchical flower-like supraparticles.

Biomolecules-mediated biomimetic mineralization has been extensively investigated and applied to fabricate nano-assemblies with unique hierarchical architectures and salient properties. The confined-source ion diffusion plays a key role in the biomineralization process, but little investigative efforts have focused on it. Here, we developed a simple method to mimic the in vivo condition by a confined diffusion method, and hydroxyapatite nanoflower assemblies (HNAs) with exquisite hierarchical architectures were obtained. The HNAs were assembled from needle-like hybrid nanocrystals of hydroxyapatite and hyaluronan. The results revealed that the strong interactions between ions and hyaluronan led to the nucleation of hydroxyapatite and the following aggregation. The combination of the external diffusion field and the internal multiple interactions induced the self-assembling processes. Additionally, HNAs with colloid stability and excellent biocompatibility were proved to be a promising cargo carrier for intranuclear delivery. This work presents a novel biomimetic mineralization strategy based on confined diffusion system for fabricating delicate hydroxyapatite, which offers a new perspective for the development of biomimetic strategies.