Search

Excessive biofluid and infection around wounds hinder wound healing. However, conventionally antibacterial wound dressings cannot simultaneously achieve effective biofluid control and intelligent infection treatment, tending to overhydrate wounds and develop drug-resistant bacteria due to the limitations of antibacterial components and material structures. The design of a nanozyme composite cryogel with interconnected macroporous structures, excellent designability, and lower chance of drug-resistance is greatly needed. Herein, Fe-MIL-88NH

Natural intervertebral disks (IVDs) exhibit distinctive anisotropic mechanical support and dissipation performances due to their well-developed special microstructures. As the intact IVD structure degrades, the absence of function will lead to severe backache. However, the complete simulation for the characteristic structure and function of native IVD is unattainable using current methods. In this work, by overall construction of the two-phase structure of native IVD (extraction of the naturally aligned cellulose framework and in situ polymerization of the nanocomposite hydrogel), a complete wood framework IVD (WF-IVD) is manufactured containing elastic nanocomposite hydrogel-based nucleus pulposus (NP) and anisotropic wood cellulose hydrogel-based annulus fibrosus (AF). In addition to the imitation and construction of the natural structure, WF-IVD also achieves favorable mechanical matching and good biocompatibility and possesses unique mechanical buckling buffer characteristics owing to the aligned fiber bundles. This study offers a promising strategy for the mimicking and construction of complex native tissues.

Pump it up Carbon nanotube yarns can be used as electrochemical actuators because infiltration with ions causes a contraction in length and an expansion in diameter. Either positive or negative ions can cause this effect. Chu et al. constructed an all-solid-state muscle that eliminated the need for an electrolyte bath, which may expand the potential for its use in applications. By infiltrating the yarns with charged polymers, the fibers start partially swollen, so the length can increase through the loss of ions. It is thus possible to increase the overall stroke of the muscle. Further, these composite materials show a surprising increase in stroke with scan rate. Science , this issue p. 494

The ingenious design of multi-functional materials to simultaneously achieve the accurate detection of targets and effective treatment of target-related diseases is of great significance for both practical and clinical applications. Accordingly, based on their advantages of facile synthesis and function designability, functional nanomaterials have become promising candidates for integrating multi-functionality into one platform, especially carbon dot (CD)-based materials. Herein, deferoxamine (DFO)-inspired CDs with integrated “sense and treatment” potential were elaborately designed and fabricated via a one-pot hydrothermal synthesis by employing L-aspartic acid (Asp) and 2,5-diaminobenzenesulfonic acid (DABSA) as the reactants. A series of characterization results distinctly confirmed that the synthesized CDs possessed a unique chemical composition, uniform spherical morphology (diameter of around 5 nm) and good dispersibility in aqueous solution, exhibiting excellent fluorescence stability under different conditions. Owing to the complexation interaction between Fe3+ and the functional groups of CDs, the selective and sensitive detection of Fe3+ could be successfully realized through fluorescent and colorimetric dual-mode detection based on the statistic quenching in the initial stage, and subsequently the FRET process. Furthermore, these CDs could be utilized for cellular imaging and effective Fe3+ detection due to their outstanding biocompatibility and cytoplasmatic distribution. More significantly, these DFO-inspired CDs could remarkably promote the proliferation of various mammalian cells. Particularly, the results in this work obviously indicated that this type of CDs could weaken the damage of Fe3+ towards the physiological behaviors of cells, helping the cells to regain their capability of differentiation after ferric toxicosis. Therefore, this work presents an original approach for the design and fabrication of multi-functional materials according to the “one stone, three birds” strategy, which may be an optional solution to develop various multi-functional platforms for disease diagnosis and corresponding clinical treatment.

In recent years, infection-associated implant failures caused by bacteria intrusion and biofilm formation have become a severe threat to human health. To effectively solve these problems, the functional modification of the implant interface is considered to be promising strategy for inhibiting bacterial infection after implantation. However, the modification processes still face some limitations, including complicated procedures, unitary function and high cost. In this work, mussel-bioinspired hyperbranched polymeric coatings (TXPDG) are elaborately designed and synthesized via the Michael addition reaction of poly(ethylene glycol) diacrylate (PEGDA) and dopamine (DOPA), utilizing trimethylolpropane triacrylate (TMPTA) and gentamicin (GEN) as branching and end-capping agents, respectively. By means of adjusting the molar ratios of the reactants, a series of TXPDG coatings with controllable branching degrees (BD) and GEN content were successfully obtained and used for the interface modification of diverse substrates via a facile immersion process, which can be attributed to the universal adhesion of catechol pedants in the molecular structure. The firmly formed T20PDG coating on the substrate surface exhibits excellent antibacterial performance towards both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus because of the GEN terminal groups. In addition, BSA protein adsorption assessment confirms that these TXPDG polymeric coatings also show prominent antifouling properties, rendering the heterogenous resistance of the implant surface to prevent serious stimulus response. More importantly, TXPDG polymeric coatings present remarkable biocompatibility, with no negative influence on the spreading and proliferation of the MC3T3-E1 cells. Overall, this work not only describes a strategy for the design and synthesis of multi-functional hyperbranched polymers, but also reveals the potential applications of functional polymeric coatings on the interface modification of implants to prevent infection-associated implantation failure.

Fantastic structures in nature have inspired much incredible research. Wood, a typical model of anisotropy and hierarchy, has been widely investigated for its mechanical properties and water extraction abilities, although applications in biological areas remain challenging. Delignified wood composite with in situ deposited hydroxyapatite (HAp) and infiltrated polycaprolactone (PCL) is hereby fabricated in an attempt to mimic natural bone. The inherent structure and properties of wood are carefully preserved during the fabrication, showing anisotropic mechanical properties in the radial direction (420 MPa) and longitudinal direction (20 MPa). In addition, it also performs directional liquid transport, effectively inducing the migration and alignment of cells to simulate the uniform seeding behavior of various cells in natural bone. Moreover, the synergistic effect of blended HAp and PCL largely promotes cell proliferation and osteogenic differentiation, providing a promising candidate for bone regeneration materials.

The ingenious design of multi-functional materials to simultaneously achieve the accurate detection of targets and effective treatment of target-related diseases is of great significance for both practical and clinical applications. Accordingly, based on their advantages of facile synthesis and function designability, functional nanomaterials have become promising candidates for integrating multi-functionality into one platform, especially carbon dot (CD)-based materials. Herein, deferoxamine (DFO)-inspired CDs with integrated "sense and treatment" potential were elaborately designed and fabricated via a one-pot hydrothermal synthesis by employing l-aspartic acid (Asp) and 2,5-diaminobenzenesulfonic acid (DABSA) as the reactants. A series of characterization results distinctly confirmed that the synthesized CDs possessed a unique chemical composition, uniform spherical morphology (diameter of around 5 nm) and good dispersibility in aqueous solution, exhibiting excellent fluorescence stability under different conditions. Owing to the complexation interaction between Fe3+ and the functional groups of CDs, the selective and sensitive detection of Fe3+ could be successfully realized through fluorescent and colorimetric dual-mode detection based on the statistic quenching in the initial stage, and subsequently the FRET process. Furthermore, these CDs could be utilized for cellular imaging and effective Fe3+ detection due to their outstanding biocompatibility and cytoplasmatic distribution. More significantly, these DFO-inspired CDs could remarkably promote the proliferation of various mammalian cells. Particularly, the results in this work obviously indicated that this type of CDs could weaken the damage of Fe3+ towards the physiological behaviors of cells, helping the cells to regain their capability of differentiation after ferric toxicosis. Therefore, this work presents an original approach for the design and fabrication of multi-functional materials according to the "one stone, three birds" strategy, which may be an optional solution to develop various multi-functional platforms for disease diagnosis and corresponding clinical treatment.

Although carbon dots (CDs) have been synthesized and applied in a variety of biological fields, such as disease diagnosis and gene/drug delivery, the exploration of facile bioinspired synthesis and applications of CDs is still of great significance. Particularly, recent increasing research has clearly confirmed that nanomaterials can affect a series of physiological behaviors and functions of mesenchymal stem cells (MSCs) (e.g., differentiation and pluripotency). Therefore, it is very important to develop multifunctional nanomaterials to simultaneously realize the cellular labelling and regulation of MSC behaviors in practical applications. Herein, sulfonated glycosaminoglycan-bioinspired CDs as bi-functional nanomaterials were ingeniously designed for cellular imaging and promoting the differentiation of rat bone MSCs (rBMSCs) in different culture media, which simultaneously met the two fundamental requirements in the field of MSC-based treatments (e.g., precisely directing the differentiation of MSCs and effective cellular labeling). These bifunctional CDs were successfully prepared via one-pot hydrothermal synthesis by using d-glucosamine hydrochloride (GA·HCl) and sodium p-styrenesulfonate (NaSS) as the reactants. The synthesized CDs with a uniform particle size (around 4 nm) dispersed well in aqueous solutions and exhibited remarkable fluorescence stability under different conditions. Additionally, cell viability and proliferation results demonstrated that the CDs possessed good biocompatibility, having negligible effects on the self-renewal potential of rBMSCs. The as-prepared CDs presented a cytoplasmatic distribution after being ingested by rBMSCs; thus, they are particularly suitable for cellular imaging. More importantly, the addition of CDs to osteogenic and chondrogenic induction media (OIM and CIM), respectively, was capable of effectively promoting the osteogenic and chondrogenic differentiation of rBMSCs due to the generation of reactive oxygen species (ROS) while having no influence on their pluripotency. In brief, this study not only implements a cellular labeling method based on CDs that were synthesized by a biomimicking strategy, but also paves a new way to regulate the differentiation of MSCs by designing multifunctional nanomaterials; this will enable the extensive development of facile synthesis methods and new applications of CDs and will also provide some research foundations for MSC-based fields.

Herein, a series of foldable buckypaper/polyacrylonitrile (BP/PAN) composite films were developed in a facile strategy. This strategy was based on electrospun and vacuum pressurized filtration methods. The composite film had better mechanical properties than pristine BP via interface reinforcing, but not deprived of excellent conductivity. The maximum tensile strength and elongation at break of BP/PAN films were 1.45 and 11.65 times than pristine BP, respectively. Moreover, BP/PAN film had higher electromagnetic interference (EMI) shielding effectiveness (63.7–65 dB) in the Ku band (12–18 GHz) than pristine BP (34.3–42.9 dB), due to interfaces forming between PAN fibers and CNTs. The BP/PAN composite as a promising EMI shielding material could be utilized in military and civil applications, such as flexible antenna, EMI shielding clothes and soft portable electronic products.

As a typical representative of crucial glycosaminoglycans (GAGs), chondroitin sulfate (CS) with sulfonated polysaccharide in structures extensively exists in the extracellular matrix (ECM) and exhibits peculiar bioactivity on the regulation of cells behaviors and fates (e.g. proliferation and differentiation) in organisms. Nevertheless, some intrinsic disadvantages of natural CS mainly ascribe to the intricate structure and inhomogeneous composition (especially the uncontrollable sulfonate degrees), resulting in overt restrictions on its physiological functions and applications. Although recent bionic synthesis of artificial GAGs analogues at the molecular level have already provides an efficient strategy to reconstruct GAG for regulating the cellular behaviors and fates, it still remains great challenges to rationally design and synthesize GAGs analogues with special composition and structure for precisely mimicking ECM. Simultaneously, the relevant regulation process of GAG analogues on cell fate needs to be further studied as well. Herein, chondroitin sulfate-analogue (CS-analogue) hydrogels with diverse contents of saccharide and sulfonate units in the networks were fabricated through photo-polymerization and then characterized by Fourier transform infrared (FT-IR) spectroscopy, zeta potential and scanning electron microscope (SEM). Additionally, CS-analogue hydrogels with proper mechanical properties exhibited favorable swelling, degradation performance and prominent cytocompatibility. According to cell cultivation results, CS-analogue hydrogel with a certain proportion of saccharide and sulfonate units presented preferable promotion on the adhesion, spreading, proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs), shedding light on the significance of saccharide and sulfonate units in regulating cell behaviors. Furthermore, BMSCs cultivated with CS-analogue hydrogels under different culture conditions were also systematically investigated, revealing that with the help of cultivation environment CS-analogue hydrogels owned the remarkable capacity of directing either chondrogenic or osteogenic differentiation of BMSCs. Therefore, it is envisioned that versatile CS-analogue hydrogels would have promising application prospects in the biomedical and clinical fields.

Nanozyme belonging to artificial enzyme is a term describing nanomaterial with enzyme-like characteristics. Great research advances have been acquired in the field of nanozymes due to their striking merits. Inspired by natural enzymes that disrupt the structural integrity of cells or interfere with metabolism, nanozymes which can effectively avoid generation of bacterial resistance may become potential alternatives for antibiotics in the context of the continuous emergence and rapid spread of drug-resistant bacteria and the slow development of new antibiotics. Naturally, nanozymes inevitably have some inherent defects, which need to be compensated by forming composite materials with other components to play a synergistic effect. What's more, nanozyme-based composite materials retain the advantages of nanozymes and integrate multiple functions into a single system to achieve an intelligent and multi-functional therapeutic model. This is a new strategy for combating bacteria/biofilms in the future. In this review, firstly we cover the general mechanisms and design principles of nanozyme-based composite materials for fighting against bacteria/biofilms and the typical types of nanozymes for resisting bacteria/biofilms. Meanwhile the applications and the advantages of nanozyme-based composite materials for anti-bacteria and anti-biofilms are emphasized. Finally, the challenges and prospects of nanozyme-based composite materials for combating bacteria/biofilms are discussed for future research in this field.

Considering that detection on cations or ions still meets some challenges in achieving the effectivity and selectivity just by employing one platform, the ingenious fabrication of nanomaterials exhibits an increasing research interests for the preponderance in improving or integrating the performance of single platform. Herein, a fluorescent hybrid nanomaterials based on an organic dye 4-methylumbelliferone (4-MU) as modifier and D-arginine as carbon cores has been developed via a facile one-step hydrothermal synthesis, forming carbon dots (CDs)/4-MU hybrid nanomaterials (CDs-4-MU). This kind of nanomaterials can improve the sensitive and selective detection of single CDs towards Fe3+ ions in different matrices. The detection mechanism of CDs-4-MU towards Fe3+ can be attributed to an electron transfer process between CDs-4-MU and Fe3+, leading to the fluorescence quenching. The limit of detection (LOD) and corresponding linear range in tris-HCl buffer solution are 0.68 μM and 2.29–200 μM, respectively. Furthermore, this nanomaterial can also achieve a detection of Fe3+ ions in real samples such as tap water, culture medium and fetal bovine serum. In particular, CDs-4-MU exhibits a good biocompatibility and can be uptaken by MC3T3 cells, thus can be applied for Fe3+ ions detection in cellular level and cellular imaging. Therefore, this work provides a versatile strategy for the synthesis of CDs-based hybrid nanomaterials and opens a new pathway for improving the ion detection in real samples, which is of significance in practical applications.

Articular cartilage, due to its avascular nature and the low cell density, is hard to regenerate once damaged, thus requiring surgical intervention. Natural cartilage exhibits a complex anisotropic feature with nonlinear and viscoelastic mechanical properties owning to complicated architecture making it attractive to mimic the structure. Here, we demonstrate a three-zone composite hydrogel with superficial, middle and deep zones incorporating into cellulose fabric, cellulose nanofiber and wood cellulose fiber respectively to prepare a stack layout composite hydrogel inspired by cartilage architecture with zone-dependent mechanical properties. The results indicate that the three-zone cellulose reinforced polyethylene glycol-based composite hydrogel demonstrates hydrogel creates native-like articular cartilage with zone-dependent, nonlinear and viscoelastic mechanical properties. The compressive moduli of the superficial, middle and deep zones are 298 kPa, 182 kPa and 9.8 MPa respectively, and the middle zone possess obvious nonlinear features. Furthermore, the highly aligned wood frame channels endow deep zone with nutrition and cell transport behaviors which are beneficial to the process of cartilage regeneration. Therefore, the bio-inspired three-zone composite hydrogel has a promising potential application for cartilage repair.

The high temperature infrared stealth glassfiber reinforced polymer composite based on silver particles modified carbon nanotube paper (SMCNP) material is fabricated successfully by a facile method, which possesses thin, lightweight, broad wavelength band and low infrared emissivity features. The conductivity increases 673% after being modified by small amount silver particles retaining the original mechanical property. Infrared emissivity decreases more than 38.9–55.7% from 0.85 to 0.65 in 3–5 μm and 0.45 to 0.2 in 8–14 μm, respectively. The specific radiant energy decreases by 43.2% in full wavelength after modified and the radiant power maximally reduce 72.5%. Above all, compare with the as-prepared CNP, the SMCNP broaden the absorption wavelength of the infrared spectra, especially in the range of 3–5 μm indicating the silver particles have significant contribution to increase the property. Considering the engineering application, this modified material was integrated with engineering matrix material, using glassfiber prepreg as an example, and still showed excellent energy saving results. Therefore, the SMCNP is a progressive candidate for infrared stealth application.

A meso/macropore carbon nanotube paper (CNP) and a self-heating fiber reinforced polymer composite of CNP/glassfiber/epoxy (CGE) based on the meso/macropore CNP were fabricated in this article. The pore diameters mainly distribute from 30 to 90 nm characterized using nitrogen adsorption isotherms at 77 K. The electric conductivities of the CNP and CGE composite are 77.8 and 64.9 S cm−1. Electric heating performance of CGE was investigated at different heat flux densities, wind speed and ambient temperature. A uniform temperature distributed was observed on the surface of CGE detected by an infrared temperature camera. The electric heating performance was verified by deicing a certain amount of ice at different heat flux densities under two kinds of ambient conditions: −22 °C without wind and −22 °C with 14 m/s of the wind speed. The deicing time under the two conditions were less than 220 and 450 s, respectively. The feasibility of the deicing performance was demonstrated through a series of experiments and the results indicate this material is a promising candidate as an electric heating material for deicing.

Carbon nanotube paper (CNP) based multi-functional composite material is an attractive candidate for deicing, flame retardancy, thermal insulation and lighting strike protection due to the excellent conductivity, light weight and thin dimensions. In this article, multi-functional carbon nanotube paper was fabricated successfully by using commercial carbon nanotube. As a deicing composite material, carbon nanotube was used directly without pretreatment in fabricating carbon nanotube paper. The conductivities of the carbon nanotube paper and deicing composite were 77.8S/cm and 64.9S/ respectively. Electrical heating and deicing performance were test by infrared camera with deicing time less than 220s and 450s to melt a certain amount of ice under different ambient condition. CNT was grafted by zirconium (IV) butoxide solution and dimethyl dichlorosilicane to form co-oligomers on the tube surface while oligomers decompose under a certain temperature to develop an inorganic layer of silicon zirconium oxide. The oxidizing temperature of carbon nanotube increases more than 20°C and the weight loss rate decreases 20% than the untreated carbon nanotube. Lightning protection material required high electro conductivity, due to the utmost high current in a short time. Therefore, silver nanoparticles were deposited on the surface of carbon nanotube with the diameter around 100nm. The conductivity increased sharply from 84s/cm to1756s/cm with the mount of 5.9wt% Ag of the modified carbon nanotube paper because the silver nanoparticles deposited on the surface. In addition, the silver modified also can be used as thermal insulation material decreasing the infrared radiation.

Carbon nanopapers (CNPs) are promising candidate materials for device areas and engineering. In this chapter, the fabrication strategies including chemical vapor deposition and solution-based deposition are summarized in the first part. In the application section, various potential applications are briefly illustrated, such as transistors, transparent electrodes, flexible displays, flame retardancy, deicing, and lightning strike protection, which are mainly due to CNPs' electrical, optical, and mechanical properties.

In this paper, a novel self-heating composite material utilizing carbon nanotubes (CNTs) paper is designed and fabricated successfully. The carbon nanotube paper was prepared by multiple steps of CNTs dispersion and suspension filtration as shown in Fig1. a and characterized by scanning electron microscopy thermo gravimetric analysis nitrogen adsorption isotherms at 77K and so on. The surface of the as-prepared CNTs paper is smooth and very flexible. The conductivity of the CNTs paper could be regulated from 30 S/cm to 200 S/cm. The fabricating process of the self-heating is shown in Fig.1 b and the electric heating performance under different ambient temperature, power changing from 4.3W to 44.8W and wind speed ranging from 8m/s to 14m/s was discussed. In addition, the feasibility of the application in the deicing of the composite was simulated by the software of Fluent. The thermal behavior was discussed combining the experimental and simulated values, especially the temperature field distribution under different wind speed. The maximum heating rate can reach 2℃/s under different condition. The equilibrium temperature and energy consumption of the composite at different power compared with the commercial kanthal electric heating film were also investigated. The energy consumption of the self-heating material is less than the kanthal electric heating film to reach the same equilibrium temperature which may be caused by the difference of heat capacity. The experimental and simulated results indicate the electric heating performance of CNTs paper-based composite is superior to the commercial kanthal electric heating film and has feasibility in the field of deicing.

Carbon Nanotube (CNT), for its excellent mechanical, electrical properties and nano size, large special surface physical property, become the most promising material. But carbon nanotube can still fabricated in micro dimension, and can’t be made into macro size, so to the carbon nanotube filled composite can’t explore the properties of the CNT. Carbon nano-paper is made of pure CNT, with micro pore, and it turn micro sized CNT into macro shaped membrane. Based on the piezo-resistivity and electrical conductivity of the carbon nano-paper, we used the carbon nano-paper as functional layers fabricate functional composite, and studies its strain sensing, composite material deicing and shape memory polymer (SMP) material electric actuation performance. The results shown that the resin can pregnant the nano paper, and there was good bond for nano paper and composite. The functional composite can monitoring the strain with high sensitivity comparing to foil strain gauge. The functional composite can be heated via the carbon nano paper with low power supply and high heating rate. The composite has good deicing and heat actuation performance to composite material. For the good strain sensing, electric conductivity and self-heating character of the carbon nano-paper composite, it can be used for self sensing, anti lightning strike and deicing of composite materials in aircrafts and wind turbine blades.