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Biomimetic porous materials have contributed to the enhancement of solar-driven evaporation rate in interfacial desalination and clean water production. However, due to the presence of numerous microbes in water environment, biofouling should occur inside porous materials to clog the channels for water transfer, resulting in obvious inhibition of the solar-driven evaporation efficacy in long-term use. To prevent and control biofouling in porous materials for solar-driven evaporation, a facile and environment-friendly design is required in real application. Oak wood possesses vertically aligned channels for transpiration and polyphenol compounds with antimicrobial activity. In this work, inspired by the oak wood, we developed an anti-biofouling shape-memory chitosan scaffold with unidirectional channels and tannic acid coating (oak-inspired scaffold). The shape-memory property facilitated rapid decoration with oak-inspired photothermal and anti-biofouling coating inside the scaffold, respectively, which also promotes the material durability by avoiding the external force-induced permanent structure failure. More importantly, the oak-inspired tannic acid coating not only prevented bacterial adhesion and colonization, but also inhibited fungal interference. They were subjected to a microbe-rich environment, and after 3 days, the evaporation rates of the untreated chitosan scaffolds were obviously decreased to 1.24, 1.16 and 1.19 kg m

The abuse of antibiotics resulted in the emergence of antibiotics-resistant bacteria, which has raised a great social concern together with the impetus to develop effective antibacterial materials. Herein, the synthesis of biocompatible enzyme-responsive Ag nanoparticle assemblies (ANAs) and their application in the high-efficiency targeted antimicrobial treatment of methicillin-resistant Staphylococcus aureus (MRSA) have been demonstrated. The ANAs could collapse and undergo stable/collapsed transition on approaching MRSA because of the serine protease-like B enzyme proteins (SplB)-triggered decomposition of the branched copolymers which have been employed as the macrotemplate in the synthesis of responsive ANAs. This transition contributed greatly to the high targeting affinity and efficiency of ANAs to MRSA. The minimum inhibitory concentration and minimum bactericidal concentration against MRSA were 2.0 and 32.0 μg mL-1, respectively. Skin wound healing experiments confirmed that the responsive ANAs could serve as an effective wound dressing to accelerate the healing of MRSA infection.

An in situ forming hydrogel has emerged as a promising wound dressing recently. As physically cross-linked hydrogels are normally unstable, most in situ forming hydrogels are chemically cross-linke...

The ever-growing global crisis of multidrug-resistant bacteria has triggered a tumult of activity in the design and development of antibacterial formulations. Here, atomically thin antimony selenide nanosheets (Sb2Se3 NSs), a minimal-toxic and low-cost semiconductor material, were explored as a high-performance two-dimensional (2D) antibacterial nanoagent via a liquid exfoliation strategy integrating cryo-pretreatment and polyvinyl pyrrolidone (PVP)-assisted exfoliation. When cultured with bacteria, the obtained PVP-capped Sb2Se3 NSs exhibited intrinsic long-term antibacterial capability, probably due to the reactive oxygen species generation and sharp edge-induced membrane cutting during physical contact between bacteria and nanosheets. Upon near-infrared laser irradiation, Sb2Se3 NSs achieved short-time hyperthermia sterilization because of strong optical absorption and high photothermal conversion efficiency. By virtue of the synergistic effects of these two broad-spectrum antibacterial mechanisms, Sb2Se3 NSs exhibited high-efficiency inhibition of conventional Gram-negative Escherichia coli, Gram-positive methicillin-resistant Staphylococcus aureus, and wild bacteria from a natural water pool. Particularly, these three categories of bacteria were completely eradicated after being treated with Sb2Se3 NSs (300 μM) plus laser irradiation for only 5 min. In vivo wound healing experiment further demonstrated the high-performance antibacterial effect. In addition, Sb2Se3 NSs depicted excellent biocompatibility due to the biocompatible element constitute and bioinert PVP modification. This work enlightened that atomically thin Sb2Se3 NSs hold great promise as a broad-spectrum 2D antibacterial nanoagent for various pathogenic bacterial infections.

To meet the demand for clean water, solar-driven water evaporation has recently drawn growing attention due to the high efficiency and environment-friendly procedure. For the transportation of water, these evaporation devices mostly possess porous structures. However, for long-term use in the natural environment, it is highly required to prevent biofouling induced channel plugging due to the universal existence of microbes in the natural water. Herein, we fabricated a double-layered GO–chitosan/ZnO scaffold (GCZ scaffold) as the solar steam device. The upper GO aerogel layer serves as a solar thermal converter, while the lower chitosan/ZnO composite layer serves as a unidirectional water pump. This GCZ scaffold exhibits a high water evaporation rate and good solar energy conversion efficiency under 10 sun and one sun irradiations, respectively. Moreover, the embedding of ZnO nanoparticles in the lower chitosan layer effectively controls the formation of biofilms in the unidirectional channels, resulting in an anti-biofouling solar-driven water evaporator. Compared to the ZnO-free scaffold suffering from the biofouling induced channel plugging, this anti-biofouling GCZ scaffold maintains a high solar-driven water evaporation rate and efficiency (89.4% for E. coli and 89.7% for S. aureus) even after cultivating in the bacterial suspensions for 3 days. This anti-biofouling solar-driven water evaporator evidently improves the lifetime of the material in natural water, conducive to further commercial applications.

A synthesis procedure based on single-capillary electrospinning and hard-template method was provided to synthesize hierarchical α-Fe2O3/SnO2 nanofibers. The samples exhibit unique microstructure where α-Fe2O3 nanoparticles were evenly decorated on three-dimensional SnO2 fibrous scaffold. During preparation, the α-Fe2O3 nanoparticles and SnO2 nanofibers were formed synchronously. Within the composite nanomaterials, the Fe/Sn content ratio can be adjusted by changing the diameter of SnO2 nanofibers backbone. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and nitrogen adsorption-desorption analysis were used to characterize the structure of the synthesized products. By loading α-Fe2O3 nanoparticles, the grain growth of SnO2 was effectively restrained during heat treatment in air. The optimum Fe/Sn content ratio of α-Fe2O3/SnO2 heterostructures with the highest sensitivity was obtained through ethanol sensing measurements. Compared to pure α-Fe2O3 and SnO2 nanofibers, the binary composite nanofibers exhibits not only enhanced ethanol sensing response, but also higher dependence of response to the change of ethanol concentration. The remarkable improvement of sensing performance can be attributed to the synergetic effect of the component phases. The influences of heterojunctions on the gas sensing properties of α-Fe2O3/SnO2 nanofibers were discussed.

High-performance composites containing various kinds of nanofibers as reinforcing building blocks have recently received considerable attention, owing to their superior mechanical properties. One of the effective strategies to reinforce these composites involves strengthening interfacial interactions via covalent bonds. However, in contrast to nanosheets, covalent bonds have been rarely used in nanofiber-reinforced composites. Herein, we report the macroscale fabrication of a series of Ag nanowire (NW)-thiolated chitosan (TCS) composite films via spray induced self-assembly. The obtained films were significantly strengthened by Ag–S covalent bonds formed between the Ag NWs and the thiol groups of TCS. The tensile strength of the optimized Ag NW-TCS film was up to 3.9 and 1.5 times higher compared with that of pure TCS and Ag NW-chitosan (CS) films, respectively.

The abuse of antibiotics resulted in the emergence of antibiotics-resistant bacteria, which has raised a great social concern together with the impetus to develop effective antibacterial materials. Herein, the synthesis of biocompatible enzyme-responsive Ag nanoparticle assemblies (ANAs) and their application in the high-efficiency targeted antimicrobial treatment of methicillin-resistant

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Bioinspired unidirectional porous materials have emerged as a unique class of scaffolds for the fabrication of macroscopic nanomaterial assemblies. However, these scaffolds usually serve simply as mechanical carriers to support various building blocks. Here, we report that the unidirectional silk fibroin scaffold can not only act as a carrier, but also serve as a controllable multiscale reactor to achieve the in situ synthesis of a Ag3 PO4 nanowire network anchored to ordered channels. Both the silk fibroin matrix and the interface play important roles in the nucleation and growth of the Ag3 PO4 nanowires. This unidirectional composite scaffold can be used for efficient water disinfection. Furthermore, the facile chemical transformation of Ag3 PO4 in the composite scaffold into Ag2 S provided an analogous unidirectional composite silk scaffold that displays both efficient solar water evaporation effect and antibacterial activity. It is expected that this method can be extended to fabricate a series of silk-based unidirectional composite scaffolds with varying functionalities.

Due to the well-recognized biocompatibility, silk fibroin hydrogels have been developed for biomedical applications including bone regeneration, drug delivery and cancer therapy. For the treatment of cancer, silk-based photothermal agents exhibit the high photothermal conversion efficiency, but the limited light penetration depth of photothermal therapy restricts the treatment of some tumors in deep positions, such as liver tumor and glioma. To provide an alternative strategy, here we developed an injectable magnetic hydrogel based on silk fibroin and iron oxide nanocubes (IONCs). The as-prepared ferrimagnetic silk fibroin hydrogel could be easily injected through a syringe into tumor, especially rabbit hepatocellular carcinoma in deeper positions using ultrasound-guided interventional treatment. Compared with photothermal agents, the embedded IONCs endowed the ferrimagnetic silk fibroin hydrogel with remote hyperthermia performance under an alternating magnetic field, resulting in the effective magnetic hyperthermia of deep tumors including subcutaneously implanted tumor model in Balb/c mouse after the coverage of a fresh pork tissue and orthotopic transplantation liver tumor in rabbit. Furthermore, due to the confinement of IONCs in silk fibroin hydrogel, the undesired thermal damage toward normal tissue could be avoided compared with directly administrating monodispersed magnetic nanoparticles.

Neurodegenerative disorders such as Huntington's disease (HD) are fundamentally caused by accumulation of misfolded aggregate-prone proteins. Previous investigations have shown that these toxic protein aggregates could be degraded through autophagy induced by small molecules as well as by nanomaterials. However, whether engineered nanomaterials have the capacity to degrade these protein aggregates via the ubiquitin-proteasome system (UPS), the other major pathway for intracellular protein turnover, was unknown. Herein, we have synthesized biocompatible MnFe

The pursuit of food safety and environmental protection has encouraged the development of new antifungal agents to replace traditional fungicides. Here we present an integrated green nanotechnology using inorganic materials, Ag3PO4 micro/nano-crystals, which could enhance the efficiency of fungicide sodium o-phenyl phenolate (SOPP) but without its residue remaining. The experiments demonstrate that the micro/nano Ag3PO4 was effective in inhibiting fungal hyphae growth against Phytophthora capsici and Botrytis cinerea. After being combined with Ag3PO4 micro/nanocrystals, the antifungal activities of fungicides SOPP and cyproconazole were enhanced. More importantly, it was found that over 90% of the SOPP was decomposed by the Ag3PO4 at a dose of 1.6 g L−1 under simulated sunlight irradiation within 2 h, exhibiting a much better photocatalytic activity than ZnO nanoparticles (NPs). These achievements demonstrate that this green nanotechnology could reduce fungicide usage without compromising on pathogen control and provide a residue-free effect under natural environmental conditions. Furthermore, it was found that the antifungal activity of Ag3PO4 was not due to the production of ROS but strongly related to interaction with fungal cells and the release of Ag+ ions. The mechanism for the synergistic enhanced antifungal effect was speculated from three possible aspects: (a) Ag3PO4 micro/nano-crystals and Ag+ ions promoting the penetration of OPP ions into the cell interior; (b) formation of a Ag3PO4–SOPP composite; and (c) multiple modes of antifungal action of the Ag3PO4–SOPP system.

Neurodegenerative disorders such as Huntington's disease (HD) are fundamentally caused by accumulation of misfolded aggregate-prone proteins. Previous investigations have shown that these toxic protein aggregates could be degraded through autophagy induced by small molecules as well as by nanomaterials. However, whether engineered nanomaterials have the capacity to degrade these protein aggregates via the ubiquitin-proteasome system (UPS), the other major pathway for intracellular protein turnover, was unknown. Herein, we have synthesized biocompatible MnFe2O4 nanoparticles (NPs) and demonstrated their unique effect in accelerating the clearance of mutant huntingtin (Htt) protein exhibiting 74 glutamine repeats [Htt(Q74)]. UPS, rather than autophagy, was responsible for the efficient Htt(Q74) degradation facilitated by MnFe2O4 NPs. Meanwhile, we demonstrated that MnFe2O4 NPs enhanced K48-linked ubiquitination of GFP-Htt(Q74). Moreover, ubiqinlin-1, but not p62/SQSTM1, served as the ubiquitin receptor that mediated the enhanced degradation of Htt(Q74) by MnFe2O4 NPs. Our findings may have implications for developing novel nanomedicine for the therapy of HD and other polyglutamine expansion diseases.

The influence of Escherichia coliform secretion (E. coli-secretion) and melamine on the crystallization of calcium oxalate has been investigated in order to determine its role in morphological control and the effects on the kinetics of the calcium oxalate crystals. The crystals obtained were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and thermal gravimetric analyzer. At the same time, conductivity meter and zeta potentiometer have been used to study the kinetic process of the crystal formation. The results show that, in the absence of E. coli-secretion, calcium oxalate monohydrate (COM) was obtained, which is the most stable crystal form of calcium oxalate and the major component of urinary stones, while in the presence of the secretion, the obtained crystals were calcium oxalate dehydrate (COD) instead of COM. Simulation experiments under artificial urine circumstance further demonstrated the drastic effect of E. coli-secretion on the...

In this paper, the selectively enhanced antibacterial effects of ZnO nanorods with several kinds of conventional medical antibiotics are investigated. Compares to gentamicin, clarithromycin and ofloxacin, ZnO nanorods could obviously achieve synergistic antibacterial effects with ceftriaxone against Escherichia coli (E. coli). Meanwhile, ultraviolet (UV) activation is adopted to induce higher antibacterial activity of ceftriaxone-ZnO nanorods than that of pure ceftriaxone or ZnO nanorods. The results of colony-forming capability test, infrared ray (IR) spectrum, and detection of reactive oxygen species (ROS) indicated that ceftriaxone may the facilitate the entry of ZnO nanorods into bacterial cell, and this effect would play an important role in mechanisms of such antibacterial behavior under the conditions of this study.

Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering.

Here we reported a residue-free green nanotechnology which synergistically enhance the pesticides efficiency and successively eliminate its residue. We built up a composite antifungal system by a simple pre-treating and assembling procedure for investigating synergy. Investigations showed 0.25 g/L ZnO nanoparticles (NPs) with 0.01 g/L thiram could inhibit the fungal growth in a synergistic mode. More importantly, the 0.25 g/L ZnO NPs completely degraded 0.01 g/L thiram under simulated sunlight irradiation within 6 hours. It was demonstrated that the formation of ZnO-thiram antifungal system, electrostatic adsorption of ZnO NPs to fungi cells and the cellular internalization of ZnO-thiram composites played important roles in synergy. Oxidative stress test indicated ZnO-induced oxidative damage was enhanced by thiram that finally result in synergistic antifungal effect. By reducing the pesticides usage, this nanotechnology could control the plant disease economically, more significantly, the following photocatalytic degradation of pesticide greatly benefit the human social by avoiding negative influence of pesticide residue on public health and environment.

In this paper, the selectively enhanced antibacterial effects of ZnO nanorods with several kinds of conventional medical antibiotics are investigated. Compares to gentamicin, clarithromycin and ofloxacin, ZnO nanorods could obviously achieve synergistic antibacterial effects with ceftriaxone against Escherichia coli (E. coli). Meanwhile, ultraviolet (UV) activation is adopted to induce higher antibacterial activity of ceftriaxone-ZnO nanorods than that of pure ceftriaxone or ZnO nanorods. The results of colony-forming capability test, infrared ray (IR) spectrum, and detection of reactive oxygen species (ROS) indicated that ceftriaxone may the facilitate the entry of ZnO nanorods into bacterial cell, and this effect would play an important role in mechanisms of such antibacterial behavior under the conditions of this study.