Bioinspired Nanocomposites Research Articles

Tunable Waterborne Aspartic Acid-Based Covalent Adaptable Networks with Internal Catalysis and Incorporation in Bioinspired Nanocomposites

Tunable Waterborne Aspartic Acid-Based Covalent Adaptable Networks with Internal Catalysis and Incorporation in Bioinspired Nanocomposites

Construction of bio-inspired multifunctional triple-layered nanocomposite enhances the cell adhesion and treatment of wound repair

Construction of bio-inspired multifunctional triple-layered nanocomposite enhances the cell adhesion and treatment of wound repair

Catharanthus roseus-mediated CuAl2O4 nanocomposites for evaluation of killing kinetics

The present article portrayed on the killing kinetic of human pathogenic bacteria using bioinspired mesoporous CuAl2O4 nanocomposites (NCs). The NCs was fabricated using leaf extract of medicinal plant Catharanthus roseus (CR) as a green reducer and stabilizer. As bio-fabricated material was calcined at 800 °C and characterized by several analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-DRS), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Raman, Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) to authenticate its structure, phase, chemical bonding, chemical state, size and morphology behaviors. XRD and TEM revealed a reduced crystallite and nanoscale sizes of biosynthesized NCs. Moreover, XRD study exposed a cubic-structure of material, while transmission electron microscopy rendered an average particles size in range 10–15 nm. However, BET profile advocates a mesoporous nature of the particles. An effective biological molecular docking modulation assessed by substituting natural inhibitor by bioinspired NCs, while the protein PDB ID 4Z8D FabH as a receptor site for the present investigation. After assessment of molecular docking examination, the antibacterial activity of bioinspired NCs were performed against Staphylococcus aureus, Bacillus subtillis, Klebsiella pneumoniae and Escherichia coli using agar-well method. The broth culture method was employed on different pathogenic strains by kinetic growth assays and colony forming unit.

Bioinspired Dielectric Nanocomposites with High Charge-Discharge Efficiency Enabled by Superspreading-Induced Alignment of Nanosheets.

High-performance dielectric nanocomposites are promising candidates for thin-film dielectric capacitors for high-power pulse devices. However, the existing nanocomposites suffer from low charge-discharge efficiency (η), which results in severe generation and accumulation of Joule heat and subsequently the failure of the devices. In this work, we report nacre-inspired dielectric nanocomposites with outstanding η, which are enabled by superspreading shear flow-induced highly aligned two-dimensional (2D) nanofillers. Taking boron nitride nanosheets (BNNS) as an example, the highly aligned BNNS in the poly(vinylidene fluoride) (PVDF)-based nanocomposites contributes to a highly efficient Coulomb blockade effect for the injected charge carriers. Therefore, the bioinspired nanocomposites with highly aligned BNNS show significantly reduced dielectric loss (tan δ) (63.3%) and improved η (144.8%), compared to the ones with partially aligned nanosheets fabricated by solution casting. Furthermore, the optimized loading content of BNNS is as low as 3.6 wt %. The resulting nanocomposites exhibit reduced tan δ (0.018) and enhanced Eb (687 kV/mm), η (71%), and Ue (16.74 J/cm3). Our work demonstrates that the realization of high alignment of 2D nanofillers enabled by the superspreading shear flow is a promising way for the development of high-performance dielectric nanocomposites.

Bottom-Up Film-to-Bulk Assembly Toward Bioinspired Bulk Structural Nanocomposites.

Biological materials, although composed of meager minerals and biopolymers, often exhibit amazing mechanical properties far beyond their components due to hierarchically ordered structures. Understanding their structure-properties relationships and replicating them into artificial materials would boost the development of bulk structural nanocomposites. Layered microstructure widely exists in biological materials, serving as the fundamental structure in nanosheet-based nacres and nanofiber-based Bouligand tissues, and implying superior mechanical properties. High-efficient and scalable fabrication of bioinspired bulk structural nanocomposites with precise layered microstructure is therefore important yet remains difficult. Here, one straightforward bottom-up film-to-bulk assembly strategy is focused for fabricating bioinspired layered bulk structural nanocomposites. The bottom-up assembly strategy inherently offers a methodology for precise construction of bioinspired layered microstructure in bulk form, availability for fabrication of bioinspired bulk structural nanocomposites with large sizes and complex shapes, possibility for design of multiscale interfaces, feasibility for manipulation of diverse heterogeneities. Not limited to discussing what has been achieved by using the current bottom-up film-to-bulk assembly strategy, it is also envisioned how to promote such an assembly strategy to better benefit the development of bioinspired bulk structural nanocomposites. Compared to other assembly strategies, the highlighted strategy provides great opportunities for creating bioinspired bulk structural nanocomposites on demand.

Light-controlled morphological development of self-organizing bioinspired nanocomposites.

Nature's intricate biominerals inspire fundamental questions on self-organization and guide innovations towards functional materials. While advances in synthetic self-organization have enabled many levels of control, generating complex shapes remains difficult. Specifically, controlling morphologies during formation at the single micro/nanostructure level is the key challenge. Here, we steer the self-organization of barium carbonate nanocrystals and amorphous silica into complex nanocomposite morphologies by photogeneration of carbon dioxide (CO2) under ultraviolet (UV) light. Using modulations in the UV light intensity, we select the growth mode of the self-organization process inwards or outwards to form helical and coral-like morphologies respectively. The spatiotemporal control over CO2 photogeneration allows formation of different morphologies on pre-assigned locations, switching between different growth modes-to form for instance a coral on top of a helix or vice versa, and subtle sculpting and patterning of the nanocomposites during formation. These findings advance the understanding of these versatile self-organization processes and offer new prospects for tailored designs of functional materials using photochemically driven self-organization.

Predicting the Mechanical Behavior of a Bioinspired Nanocomposite through Machine Learning

Predicting the Mechanical Behavior of a Bioinspired Nanocomposite through Machine Learning

Bio-inspired graphene nanocomposite enabled electrochemical immunosensor for detection and quantification of NS1 protein of dengue virus

Dengue is a serious illness that affects a large portion of the global population. Infection with the dengue virus may have been silent or symptomatic, making identification crucial for tracking the virus's propagation and protecting society from its catastrophic consequences. The non-structural dengue protein NS1 has been used as a biomarker in the diagnosis of dengue because it circulates widely in the blood during the acute phase of the infection and is associated with viremia. In this study, we have reported the development of an electrochemical immunosensor using nanobio-inspired platform composed of ternary nanocomposite of reduced graphene oxide (rGO), polydopamine (pDA) and gold nanoparticles (AuNPs) immobilized with Anti-NS1 antibodies for the detection of NS1 protein. The nanocomposite formation and antibody immobilization are confirmed using various microscopic, spectroscopic and electrochemical techniques. The differential pulse voltammetry (DPV) has been used to investigate the detailed electrochemical properties and immunosensing response of the developed immunosensor device. The designed immunosensor showed linear detection response for NS1 protein from 1 ng ml−1 to 100 µg ml−1 with a sensitivity of 1.78 ng ml−1 mA−1 and good shelf life. This developed immunosensor with exceptionally low detection limit revealed its potential for early diagnosis of dengue virus infection.

Supramolecular cross-linking affords chitin nanofibril nanocomposites with high strength and water resistance

Polysaccharide nanofibrils of chitins or celluloses are emerging biobased building blocks for sustainable, high-performance bioinspired nanocomposites fusing high stiffness, strength, and other functionalities. Owing to their hygroscopicity, a crucial challenge towards real-life applications of these nanocomposites is to maintain their mechanical performances in the humid or even fully swollen conditions. Here, we report water resistant nanocomposites composed of sustainable chitin nanofibrils (ChNFs) and polyvinyl alcohol (PVA) that are physically cross-linked by tannic acid (TA) to enhance and stabilize wet mechanical properties. We demonstrate that the formation of polymer-coated core/shell nanofibrils at the intermediate stage is crucial for the well-defined nanopaper structures after casting. By infiltrating TA, the formation of hydrogen bonding in the PVA matrix and at the ChNF/PVA interface renders the nanocomposites with extremely high strength and stiffness, even under high humidity and swelling conditions. With the increase in the amount of conjugated TA, the Young's modulus and tensile strength of the swollen nanocomposites reach up to 3.0 GPa and 70 MPa, respectively, which are superior to the existing water-borne nanofibils/polymer nanocomposites. Moreover, the nanocomposite films show excellent gas barrier properties at high relative humidity (90%), as well as UV shielding, antibacterial properties and biodegradability, complementing the multifunctional property profile and allowing a transfer into applications as advanced packaging materials.

A micromechanical model for bioinspired nanocomposites with interphase

The stagger-aligned structures including ‘‘brick-and-mortar’’ are well-known as a generic feature in biological tough and strong nanocomposites, leading to bioinspired high-performance composites. Experimental observations have shown that the region between the stiff reinforcements and the soft matrices is not an interface of zero thickness but a nanoscale interphase. The interphases are believed to play an important role in the overall mechanical achievements; however, related theoretical models are still yet to be developed for decoding the interphase-related mechanisms. Based on the shear-lag theory, this work establishes a theoretical model for the staggered nanocomposites explicitly considering the interphase. In particular, a compact formula of the nanocomposites’ effective modulus (Ec) is derived, clearly showing the relations to a load-sustain dominant term (ER) and a term (ES) reflecting the load-transfer through shear deformation, as well as other microstructural and material parameters. With comparison to results by the finite element analysis and other existing relevant models, our model exhibits superior accuracy and simplicity, as well as general applicability. Furthermore, our model reveals an interesting working mechanism of the interphase: Ec is sensitive to the interphase properties for the shear transfer parameter (βII) being around 1.5–7.5, as the interphase undertakes both stress-transfer and stress-sustaining roles. The model and findings shed light on the role of the interphase in enhancing load-bearing biological composites and provide new insights in optimizing bioinspired nanocomposites through modulating the interphase properties.

A surpassingly stiff yet lossy multiscale nanocomposite inspired by bio-architecture

Common microstructural features inspired by bones, including the moduli-mismatching interface and the intramolecular dangling chains, are employed in designing and fabricating our bio-inspired nanocomposite in order to defeat the conflict of stiffness versus damping. The epoxy vitrimer is itself chosen to construct the intramolecular dangling chains, and then mixed with multi-walled carbon nanotubes (MWCNTs) to form the moduli-mismatching interface. Experimental and theoretical research is performed to elucidate the role of the common microstructural features on the damping of our bio-inspired nanocomposite. Dangling chains improve damping, although they are negative for moduli. The high modulus of MWCNTs not only enlarges the modulus of composites but also causes a stress jump phenomenon at the interfacial zone, which induces the irreversible production process of inelastic strain at the interface to dissipate mechanical energy. The loss modulus of MWCNTs-reinforced epoxy nanocomposites is found to reach as much as 738 MPa, which exceeds the limit of 600 MPa for traditional materials (including bones), although the common microstructural features are inspired by bones. The synergistic enhancement mechanism caused by the intramolecular dangling chains and the moduli-mismatching interface is responsible for the surpassingly stiff yet lossy performances.

Enhanced Anticancer Property of Polyphenol-Assisted Biogenic AuNPs/RGO Nanocomposites in Triple-Negative Breast Cancer Cells

The bio-inspired nanocomposites developed from reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) might be of great significance due to their exceptional physico-chemical properties. In the present work, the AuNPs/RGO nanocomposites were prepared by a green-synthesis approach using grape seed proanthocyanidin (GSP), which acts as a natural reducing and stabilizing agent. The simultaneous biosynthesis of RGO nanosheets from graphene oxide (GO) and AuNPs from chloroauric acid ions by GSP leads to the development of AuNPs/RGO nanocomposites, which were further confirmed by various analytical techniques. The analyses of the observed outcomes confirm the removal of oxygen containing moieties during the transformation process of GO to RGO. Further, AuNPs were decorated orderly on both sides of the RGO nanosheet surface with an average particle size of ~ 35 nm. The MTT-based cytotoxicity assay revealed the enhanced anticancer activity of the prepared AuNPs/RGO nanocomposites (IC50 = 15.6 μg/mL) against triple-negative breast cancer cells when compared to either AuNPs or RGO treatment alone. Moreover, enhanced ROS levels and subsequent alteration in mitochondrial membrane potential (Δψm) with nuclear fragmentation and apoptotic features were observed in AuNPs/RGO nanocomposites treated cells. This could be due to the synergistic effect of AuNPs/RGO in the triple-negative breast cancer cells.

Hierarchically structured bioinspired nanocomposites.

Next-generation structural materials are expected to be lightweight, high-strength and tough composites with embedded functionalities to sense, adapt, self-repair, morph and restore. This Review highlights recent developments and concepts in bioinspired nanocomposites, emphasizing tailoring of the architecture, interphases and confinement to achieve dynamic and synergetic responses. We highlight cornerstone examples from natural materials with unique mechanical property combinations based on relatively simple building blocks produced in aqueous environments under ambient conditions. A particular focus is on structural hierarchies across multiple length scales to achieve multifunctionality and robustness. We further discuss recent advances, trends and emerging opportunities for combining biological and synthetic components, state-of-the-art characterization and modelling approaches to assess the physical principles underlying nature-inspired design and mechanical responses at multiple length scales. These multidisciplinary approaches promote the synergetic enhancement of individual materials properties and an improved predictive and prescriptive design of the next era of structural materials at multilength scales for a wide range of applications.

Functional bioinspired nanocomposites for anticancer activity with generation of reactive oxygen species

Cancer is a debilitating and deadly disease caused by the uncontrolled growth of aberrant cell populations. This disease cannot always be controlled with traditional therapies and medicines. Different medicines are being used for this purpose, however these medicines have their side effects and are harmful to healthy cells. A better way to cure cancer disease is by limiting the agglomeration of cancer cells, minimizing their growth and their population by destroying these harmful cells. This could be achieved by controlling the function of mitochondria and DNA in cancer cells with the use of biocompatible materials with tuneable physical properties. Accordingly, research is ongoing as to the use of nanomaterials and nanotechnology in medicine. Zinc oxide semiconductor nanoparticles have displayed good anticancer behaviour. They have unique properties such as biocompatibility, good stability, and are environmentally friendly. Owing to these characteristics, they are focused on biological applications such as drug delivery and cancer therapy. In the present research work, zinc oxide, titanium dioxide nanoparticles and titanium oxide-zinc oxide nanocomposites were successfully trailed for anti-cancer activity. Pure zinc oxide nanoparticles (ZnO NPs), titanium dioxide nanoparticles (TiO2 NPs) and their nanocomposites (TiO2+ZnO NPs) were prepared by the co-precipitation technique. The structural properties were investigated by X-ray diffraction, which confirmed the Wurtzite structure of pure ZnO NPs. The morphology of the NPs was checked by scanning electron microscopy. For incident light having a higher energy band gap of nanomaterials, the electrons are excited to the conduction band and these electrons generate reactive oxygen species (ROS). The efficacy of these nanomaterials was checked by exposing the NPs to the human liver cancer cell HepG2. The MTT assay describes anticancer activity via cell viability. The cell viability of composites was observed to be greater than pure ZnO NPs. Their results showed that the structure of ZnO NPs remains the same with composites of TiO2 NPs, but the band gap of the composite was intermediate for individual samples. It also showed that the anticancer activity of composites was also less than pure ZnO NPs which is due to the reduction of ROS generation. This is observed that nanocomposites of ZnO and TiO2 could be effective in the development of a treatment of human liver cancer cells.

Triggering cell death in cancers using self-illuminating nanocomposites.

Bioinspired photocatalysis has resulted in efficient solutions for many areas of science and technology spanning from solar cells to medicine. Here we show a new bioinspired semiconductor nanocomposite (nanoTiO2-DOPA-luciferase, TiDoL) capable of converting light energy within cancerous tissues into chemical species that are highly disruptive to cell metabolism and lead to cell death. This localized activity of semiconductor nanocomposites is triggered by cancer-generated activators. Adenosine triphosphate (ATP) is produced in excess in cancer tissues only and activates nearby immobilized TiDoL composites, thereby eliminating its off-target toxicity. The interaction of TiDoL with cancerous cells was probed in situ and in real-time to establish a detailed mechanism of nanoparticle activation, triggering of the apoptotic signaling cascade, and finally, cancer cell death. Activation of TiDoL with non-cancerous cells did not result in cell toxicity. Exploring the activation of antibody-targeted semiconductor conjugates using ATP is a step toward a universal approach to single-cell-targeted medical therapies with more precision, efficacy, and potentially fewer side effects.

Scalable Nano Building Blocks of Waterborne Polyurethane and Nanocellulose for Tough and Strong Bioinspired Nanocomposites by a Self-Healing and Shape-Retaining Strategy.

Nature has given us significant inspiration to reproduce bioinspired materials with high strength and toughness. The fabrication of well-defined three-dimensional (3D) hierarchically structured nanocomposite materials from nano- to the macroscale using simple, green, and scalable methods is still a big challenge. Here, we report a successful attempt at the fabrication of multidimensional bioinspired nanocomposites (fiber, films, plates, hollow tubes, chair models, etc.) with high strength and toughness through self-healing and shape-retaining methods using waterborne polyurethane (WPU) and nanocellulose. In our method, the prepared TEMPO oxide cellulose nanofiber (TOCNF)-WPU hybrid films show excellent moisture-induced self-healing and shape-retaining abilities, which can be used to fabricate all sorts of 3D bioinspired nanocomposites with internal aligned and hierarchical architectures just using water as media. The tensile and flexural strength of the self-assembled plate can reach 186.8 and 193.2 MPa, respectively, and it also has a high toughness of 11.6 MJ m-3. Because of this bottom-up self-assembly strategy, every multidimensional structure we processed has high strength and toughness. This achievement would provide a promising future to realize a large-scale and reliable production of various sorts of bioinspired multidimensional materials with high strength and toughness in a sustainable manner.

An ultrastrong bioinspired soy protein isolate-based nanocomposite with graphene oxide intercalation

Soy protein isolate (SPI), a ubiquitous biopolymer , has attracted great attentions from scholars owing to its abundance, low cost and sustainability. However, the poor mechanical properties and low water-resistance have limited its applications. Therefore, there is a need to construct high-performance SPI-based materials. Inspired by the “brick-and-mortar” structures and interfacial interactions of nacre , a bioinspired nanocomposite was developed by intercalating graphene oxide (GO) nanosheets into the SPI-glycerin (Gly) matrix with a vacuum evaporation self-assembly technology. The obtained SPI-Gly-GO nanocomposite has shown enhanced tensile strength (18.60 ± 1.45 MPa) and modulus (275.68 ± 39.69 MPa), due to the hierarchical layered structures, and increased hydrogen bonds and covalent amido bonds. After chemical reduction, the SPI-Gly-rGO film possesses high tensile strength of 50.03 ± 2.67 MPa and high modulus of 1.7 ± 0.07 GPa, respectively, which are about 11.8 and 49.4 folds higher than that of the SPI-Gly film. Moreover, the resulting film maintains original morphologies after soaking in water for a long time, exhibiting excellent water-resistance, which is attributed to the interfacial interactions between rGO and SPI-Gly matrix. The fascinating integration characteristics enable the SPI-based materials to be used in food packages, tissue engineering, and gene delivery. The synthesis strategy provides new insights to design and fabricate high-performance SPI-based nanocomposite. A bioinspired nanocomposite, with integration of high mechanical properties and excellent water resistence, is fabricated by the synergy of hierarchical layered architectures and interfacial interactions. • A bioinspired nanocomposite based on SPI chains, Gly plasticizers andGO nanosheets is fabricated with an evaporation-induced assembly process. • The bioinspired nanocomposite is papared with the synergy of hierarchical layered architectures and interfacial interactions. • The resulting nanocomposite shows the integration of high mechanical properties and impressive water-resistance.

Efficient Softening and Toughening Strategies of Cellulose Nanofibril Nanocomposites Using Comb Polyurethane.

Cellulose nanofibrils (CNFs) have attracted attention as building blocks for sustainable materials owing to their high performance and the advantages of their abundant natural resources. Bioinspired CNF/polymer nanocomposites, consisting of a soft polymer phase and a high fraction (>50 wt %) of CNF reinforcement, have been focused on excellent mechanical properties, including Young's modulus, mechanical strength, and toughness, mimicking the energy dissipation system in nature. However, efficient softening and toughening with a small amount of the soft phase is still a challenge because a large amount of the polymer phase (nearly 50%) is still required to provide ductility and toughness. Here, we describe a topological strategy in the polymer phase for efficient toughening of bioinspired CNF nanocomposites with a water-soluble comb polyurethane (PU). The comb PU provided higher elongation at break and more efficient flexibility for the nanocomposite than the linear PU, even at a small content. Moreover, CNF nanocomposites with 30 wt % of PU content and tetrabutylammonium as bulky counterions showed enhanced toughness (180% higher) and strain at break (250% higher) when compared to pure CNF due to the promotion of slippage between nanofibrils. Scanning electron microscopy (SEM) images of the fracture surface for CNF/comb PU nanocomposites displayed the pull-out of mesoscale layers and nanofibrils, supporting that the comb topology promotes the slippage between fibrils. Furthermore, the rheological study revealed that the comb PU has an entanglement plateau modulus lower than linear PU by 1 order of magnitude, related to the loosened entanglements. Our study establishes an efficient softening and toughening strategy while using small amounts of polymer phase addition, promoting interfibrillar slippage with the loosely entangled comb PU phase.

Comparative Analysis of Bacterial Cellulose Membranes Synthesized by Chosen Komagataeibacter Strains and Their Application Potential.

This article presents a comparative analysis of bacterial cellulose membranes synthesized by several strains of the Komagataeibacter genus in terms of their specific physical, physico-chemical, and mechanical properties. Herein, the aim was to choose the most suitable microorganisms producing cellulosic materials with the greatest potential for the fabrication of bio-inspired nanocomposites. The selection was based on three main steps, starting from the evaluation of BNC biosynthetic efficiency with and without the addition of ethanol, followed by the assessment of mechanical breaking strength, and the physical parameters (compactness, structural integrity, appearance, and thickness) of the obtained biological materials. Ultimately, based on the performed screening procedure, three efficiently growing strains (K. hansenii H3 (6Et), K. rhaeticus K4 (8Et), and Komagataeibacter sp. isolated from balsamic vinegar (12Et)) were chosen for further modifications, enabling additional cellulose functionalization. Here, supplementation of the growth medium with five representative polymeric compounds (citrus/apple pectin, wheat starch, polyvinyl alcohol, polyethylene glycol) led to significant changes in BNC properties, especially dye loading abilities, mechanical strength, and water adsorption/retention capacities. The resulting nanocomposites can be potentially useful in various fields of medicine and industry, and in the future, they may become a practical and cost-effective competitor against commercial biomaterials currently available on the market.

Interfacial energy dissipation in bio-inspired graphene nanocomposites

Bio-inspired nanocomposites have been fabricated by self-assembly using graphene oxide (GO) based fillers, and their interfacial energy dissipation during cyclic deformation has been studied. The GO flakes were washed with a base solution to remove some functional groups and this base-washed GO (BwGO) obtained was also employed as a comparison to study the effect of functional groups on the interface. Raman spectroscopy was used to monitor the deformation of the fillers and to determine their stress-strain curve in the nanocomposites. The area of the hysteresis loop between the loading and unloading curves was used to calculate the interfacial energy dissipation during cyclic deformation. The presence of functional groups on GO reduced the interfacial energy dissipation in the elastic regime. The energy dissipation starts to increase with strain, and eventually when the applied strain is beyond the elastic regime, the functional groups ‘toughen’ the interface by requiring higher energy to break and also roughening the interface, similar to the behaviour of the biological composites. This work has shed light on the fabrication of bio-inspired nanocomposites and the evaluation and application of the graphene-based fillers where energy dissipation is needed, for example, in composites toughening and the damping of elastomers.