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Abstract  A new method of dispersing the aggregated strontium hexaferrite (SrFe12O19) magnetic nanoparticles in organic solvents such as propylene glycol monomethyl ether acetate (PGMEA), propylene glycol (PG), and glycerol, by an ultrasonic bath is reported herein. The particles size of SrFe12O19 after treatment with the PGMEA is in the range 70–100 nm. The structure of dispersed SrFe12O19 was characterized using transmission electron microscopy (TEM), high resolution scanning electron microscopy (HR SEM) and thermo gravimetric analysis (TGA). This dispersed material was used for the preparation of a topical magnetic cosmetic product as follows: The dispersion of SrFe12O19 in PG was mixed with “Dermud-Ahava Body Cream”, an ‘oil in water’ emulsion of a Dead Sea mineral cosmetic, “AHAVA”, and the magnetic properties of the created composite were determined. The ferrimagnetic behavior of the composite has been demonstrated as being very similar to the behavior of strontium hexaferrite itself. [ABSTRACT FROM AUTHOR]

Rechargeable Mg-ion Batteries (RMB) containing a Mg metal anode offer the promise of higher specific volumetric capacity, energy density, safety, and economic viability than lithium-ion battery technology, but their realization is challenging. The limited availability of suitable inorganic cathodes compatible with electrolytes relevant to Mg metal anode restricts the development of RMBs. Despite the promising capability of some oxides to reversibly intercalate Mg +2 ions at high potential, its lack of stability in chloride-containing ethereal electrolytes, relevant to Mg metal anode hinders the realization of a full practical RMB. Here the successful in situ encapsulation of monodispersed spherical V 2 O 5 (≈200 nm) is demonstrated by a thin layer of VS 2 (≈12 nm) through a facile surface reduction route. The VS 2 layer protects the surface of V 2 O 5 particles in RMB electrolyte solution (MgCl 2 + MgTFSI in DME). Both V 2 O 5 and V 2 O 5 @VS 2 particles demonstrate high initial discharge capacity. However, only the V 2 O 5 @VS 2 material demonstrates superior rate performance, Coulombic efficiency (100%), and stability (138 mA h g -1 discharge capacity after 100 cycles), signifying the ability of the thin VS 2 layer to protect the V 2 O 5 cathode and facilitate the Mg +2 ion intercalation/deintercalation into V 2 O 5 ., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

Catheter-associated urinary tract infections (CAUTI) are among the most common bacterial infections associated with prolonged hospitalization and increased healthcare expenditures. Despite recent advances in the prevention and treatment of these infections, there are still many challenges remaining, among them the creation of a durable catheter coating, which prevents bacterial biofilm formation. The current work reports on a method of protecting medical tubing endowed with antibiofilm properties. Silicone catheters coated sonochemically with ZnO nanoparticles (NPs) demonstrated excellent antibiofilm effects. Toward approval by the European Medicines Agency, it was realized that the ZnO coating would not withstand the regulatory requirements of avoiding dissolution for 14 days in artificial urine examination. Namely, after exposure to urine for 14 days, the coating amount was reduced by 90%. Additional coatings with either carbon or silica maintained antibiofilm activity against Staphylococcus aureus while resisting dissolution in artificial urine for 14 days (C- or SiO 2 -protected catheters exhibited only 29% reduction). HR-SEM images of the protected catheters indicate the presence of the ZnO coating as well as the protective layer. Antibiofilm activity of all catheters was evaluated both before and after exposure to artificial urine. It was shown that before artificial urine exposure, all coated catheters showed high antibiofilm properties compared to the uncoated control. Exposure of ZnO-coated catheters, without the protective layer, to artificial urine had a significant effect exhibited by the decrease in antibiofilm activity by almost 2 orders of magnitude, compared to unexposed catheters. Toxicity studies performed using a reconstructed human epidermis demonstrated the safety of the improved coating. Exposure of the epidermis to ZnO catheter extracts in artificial urine affects tissue viability compared with control samples, which was not observed in the case of ZnO NPs coating with SiO 2 or C. We suggest that silica and carbon coatings confer some protection against zinc ions release, improving ZnO coating safety.

Packaging bags made of polyethylene (PE) were sonochemically coated with edible antibacterial nanoparticles of chitosan (CS). In this work, the nanoparticles (NPs) were deposited on the surface of PE packaging bags by applying sonication waves on an acetic solution of chitosan. The characterization of CS NPs and PE bags was conducted by physicochemical techniques. The results showed that the coated bags had longer freshness than the uncoated ones. Furthermore, the characterization of cucumber, mushroom, and garlic placed into coated and uncoated PE bags was conducted by monitoring various parameters such as mass loss, total soluble solids, pH, and visual inspection. The study revealed that the PE bags coated with CS NPs showed a noticeable result in extending the shelf life of fresh produce. Finally, the antibacterial activity of PE bags was evaluated against various bacterial species. Hence, the PE bags coated with CS NPs could be a promising candidate for elongating the shelf life of packaged fresh produce., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 Published by Elsevier Ltd.)

In the last few decades, point-of-care (POC) sensors have become increasingly important in the detection of various targets for the early diagnostics and treatment of diseases. Diverse nanomaterials are used as building blocks for the development of smart biosensors and magnetite nanoparticles (MNPs) are among them. The intrinsic properties of MNPs, such as their large surface area, chemical stability, ease of functionalization, high saturation magnetization, and more, mean they have great potential for use in biosensors. Moreover, the unique characteristics of MNPs, such as their response to external magnetic fields, allow them to be easily manipulated (concentrated and redispersed) in fluidic media. As they are functionalized with biomolecules, MNPs bear high sensitivity and selectivity towards the detection of target biomolecules, which means they are advantageous in biosensor development and lead to a more sensitive, rapid, and accurate identification and quantification of target analytes. Due to the abovementioned properties of functionalized MNPs and their unique magnetic characteristics, they could be employed in the creation of new POC devices, molecular logic gates, and new biomolecular-based biocomputing interfaces, which would build on new ideas and principles. The current review outlines the synthesis, surface coverage, and functionalization of MNPs, as well as recent advancements in magnetite-based biosensors for POC diagnostics and some perspectives in molecular logic, and it also contains some of our own results regarding the topic, which include synthetic MNPs, their application for sample preparation, and the design of fluorescent-based molecular logic gates.

Carbon dots (CDs) were simply prepared from charcoal by hydrothermal processing at 180 °C for 15 h without any chemicals. The as-prepared CDs with an average diameter of 5 ± 6 nm exhibited a predominant absorption peak at 290 nm, corresponding to the n to π* transition of the oxygen functional groups (C═O) and the free amine functional groups (-NH 2 ). The resulting CDs were then incorporated into cotton and polyester by facile ultrasonication for 1 h. The obtained CD-coated fabrics were first evaluated for their UV-blocking capability and then for their antibacterial properties against two model pathogens: Gram-negative E. coli and Gram-positive S. aureus . Both cotton and polyester showed no UV protection at 280 or 380 nm; conversely, cotton or polyester decorated with CDs exhibited a UV blocking ratio of 82-98%. The CD-coated fabrics showed 100% antibacterial activities against E. coli and S. aureus, whereas the pristine fabrics showed no effect. The CDs/fabrics could adsorb Hg 2+ and Fe 3+ , resulting in a drastic fluorescence quenching. As such, this distinct feature was exploited for the removal and detection of these two ions with the limits of detection of 55and 72 μM, respectively.

Metal-semiconductor interfaces are ubiquitous in modern electronics. These quantum-confined interfaces allow for the formation of atomically thin polarizable metals and feature rich optical and optoelectronic phenomena, including plasmon-induced hot-electron transfer from metal to semiconductors. Here, we report on the metal-semiconductor interface formed during the intercalation of zero-valent atomic layers of tin (Sn) between layers of MoS 2 , a van der Waals layered material. We demonstrate that Sn interaction leads to the emergence of gap states within the MoS 2 band gap and to corresponding plasmonic features between 1 and 2 eV (0.6-1.2 μm). The observed stimulation of the photoconductivity, as well as the extension of the spectral response from the visible regime toward the mid-infrared suggests that hot-carrier generation and internal photoemission take place.

The demand for improved indoor air quality, especially during the pandemic of Covid-19, has led to renewed interest in antiviral and antibacterial air-conditioning systems. Here, air filters of vehicles made of nonwoven polyester filter media were sonochemically coated with CuO nanoparticles by a roll-to-roll coating method. The product, aimed at providing commuters with high air quality, showed good stability and mechanical properties and potent activity against Escherichia coli and Staphylococcus aureus bacteria, H1N1 influenza, and two SARS-CoV-2 variants. The filtering properties of a coated filter were tested, and they were similar to those of the uncoated filter. Leaching tests as a function of airflow were conducted, and the main outcome was that the coating was stable and particles were not detached from the coated media. Extension to other air-conditioning systems was straightforward.

Tailoring the precise construction of non-precious metals and carbon-based heterogeneous catalysts for electrochemical oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) is crucial for energy conversion applications. Herein, this work reports the composite of Ni doped Fe 2 O 3 (Ni-Fe 2 O 3 ) with mildly oxidized multi-walled CNT (O-CNT) as an outstanding Mott-Schottky catalyst for OER and MOR. O-CNT acts as a co-catalyst which effectively regulates the charge transfer in Ni-Fe 2 O 3 and thus enhances the electrocatalytic performance. Ni-Fe 2 O 3 /O-CNT exhibits a low onset potential of 260 mV and overpotential 310 mV @ 10 mA cm -2 for oxygen evolution. Being a Mott-Schottky catalyst, it achieves the higher flat band potential of -1.15 V with the carrier density of 0.173×10 24  cm -3 . Further, in presence of 1 M CH 3 OH, it delivers the MOR current density of 10 mA cm -2 at 1.46 V vs. RHE. The excellent electrocatalytic OER and MOR activity of Ni-Fe 2 O 3 /O-CNT could be attributed to the synergistic interaction between Ni-doped Fe 2 O 3 and O-CNT., (© 2022 The Authors. ChemPlusChem published by Wiley-VCH GmbH.)

Supercapacitors are considered potential energy storage devices and have drawn significant attention due to their superior intrinsic advantages. Herein, we report the synthesis of ReS 2 embedded in MoS 2 nanosheets (RMS-31) by a hydrothermal technique. The prepared RMS-31 electrode material demonstrated superior pseudocapacitive behavior in 1 M KOH electrolyte solution, which is confirmed by the heterostructure of RMS-31 nanosheet architectures. RMS-31 has a specific capacitance of 244 F g -1 at a current density of 1 A g -1 and a greater areal capacitance of 540 mF cm -2 at a current density of 5 mA cm -2 . The symmetric supercapacitor device with the RMS-31 electrode delivers an energy density of 28 W h cm -2 with a power density of 1 W cm -2 and reveals long-term stability at a constant current density of 5 mA cm -2 for 10,000 cycles while accomplishing a retention of 66.5%. The high performance of this symmetric device is attributed to the synergistic effect of ReS 2 and MoS 2 and the presence of the metallic 1T-MoS 2 phase in the RMS-31 electrode. To the best of our knowledge, this is the first report of increasing the interlayer spacing of 2H-MoS 2 by incorporating ReS 2 for symmetric supercapacitor applications.

Magnetite nanoparticles with different surface coverages are of great interest for many applications due to their intrinsic magnetic properties, nanometer size, and definite surface morphology. Magnetite nanoparticles are widely used for different medical-biological applications while their usage in optics is not as widespread. In recent years, nanomagnetite suspensions, so-called magnetic ferrofluids, are applied in optics due to their magneto-optical properties. This review gives an overview of nanomagnetite synthesis and its properties. In addition, the preparation and application of magnetic nanofluids in optics, nanophotonics, and magnetic imaging are described.

This study aims to investigate the effects of a novel ZnCuO nanoparticle coating for dental implants-versus those of conventional titanium surfaces-on bacteria and host cells. A multispecies biofilm composed of Streptococcus sanguinis , Actinomyces naeslundii , Porphyromonas gingivalis , and Fusobacterium nucleatum was grown for 14 days on various titanium discs: machined, sandblasted, sandblasted and acid-etched (SLA), ZnCuO-coated, and hydroxyapatite discs. Bacterial species were quantified with qPCR, and their viability was examined via confocal microscopy. Osteoblast-like and macrophage-like cells grown on the various discs for 48 h were examined for proliferation using an XTT assay, and for activity using ALP and TNF-α assays. The CSLM revealed more dead bacteria in biofilms grown on titanium than on hydroxyapatite, and less on sandblasted than on machined and ZnCuO-coated surfaces, with the latter showing a significant decrease in all four biofilm species. The osteoblast-like cells showed increased proliferation on all of the titanium surfaces, with higher activity on the ZnCuO-coated and sandblasted discs. The macrophage-like cells showed higher proliferation on the hydroxyapatite and sandblasted discs, and lower activity on the SLA and ZnCuO-coated discs. The ZnCuO-coated titanium has anti-biofilm characteristics with desired effects on host cells, thus representing a promising candidate in the complex battle against peri-implantitis.

Transition-metal dichalcogenides (TMDCs) are unique layered materials with exotic properties. So, examining their structures holds tremendous importance. 2H-MoSe 2 (analogous to MoS 2 ; Gr. 6 TMDC) is a crucial optoelectronic material studied extensively using Raman spectroscopy. In this regard, low-frequency Raman (LFR) spectroscopy can probe this material's structure as it reveals distinct vibration modes. Here, we focus on understanding the microstructural evolution of different 2H-MoSe 2 morphologies and their layers using LFR scattering. We grew phase-pure 2H-MoSe 2 (with variable microstructures) directly on a Mo foil using a two-furnace ambient-pressure chemical vapor deposition (CVD) system by carefully controlling the process parameters. We analyzed the layers of exfoliated flakes after ultrasonication and drop-cast 2H-MoSe 2 of different layer thicknesses by choosing different concentrations of 2H-MoSe 2 solutions. Further detailed analyses of the respective LFR regions confirm the presence of newly identified Raman signals for the 2H-MoSe 2 nanosheets drop-cast on Raman-grade CaF 2 . Our results show that CaF 2 is an appropriate Raman-enhancing substrate compared to Si/SiO 2 as it presents new LFR modes of 2H-MoSe 2 . Therefore, CaF 2 substrates are a promising medium to characterize in detail other TMDCs using LFR spectroscopy., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Catheter-associated urinary tract infections (CAUTIs), caused by biofilms, are the most frequent health-care associated infections. Novel antibiofilm coatings are needed to increase the urinary catheters' life-span, decrease the prevalence of CAUTIs and reduce the development of antimicrobial resistance. Herein, antibacterial zinc oxide nanoparticles (ZnO NPs) were decorated with a biofilm matrix-degrading enzyme amylase (AM) and simultaneously deposited onto silicone urinary catheters in a one-step sonochemical process. The obtained nano-enabled coatings inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus by 80% and 60%, respectively, for up to 7 days in vitro in a model of catheterized bladder with recirculation of artificial urine due to the complementary mode of antibacterial and antibiofilm action provided by the NPs and the enzyme. Over this period, the coatings did not induce toxicity to mammalian cell lines. In vivo, the nano-engineered ZnO@AM coated catheters demonstrated lower incidence of bacteriuria and prevent the early onset of CAUTIs in a rabbit model, compared to the animals treated with pristine silicone devices. The nano-functionalization of catheters with hybrid ZnO@AM coatings appears as a promising strategy for prevention and control of CAUTIs in the clinic., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

To mitigate the associated challenges of instability and capacity improvement in Na 3 V 2 (PO 4 ) 2 F 3  (NVPF), rationally designed uniformly distributed hollow spherical NVPF and coating the surface of NVPF with ultrathin (≈2 nm) amorphous TiO 2  by atomic layer deposition is demonstrated. The coating facilitates higher mobility of the ion through the cathode electrolyte interphase (CEI) and enables higher capacity during cycling. The TiO 2 @NVPF exhibit discharge capacity of >120 mAhg -1 , even at 1C rates, and show lower irreversible capacity in the first cycle. Further, nearly 100% capacity retention after rate performance in high current densities and 99.9% coulombic efficiency after prolonged cycling in high current density is reported. The improved performance in TiO 2 @NVPF is ascribed to the passivation behavior of TiO 2  coating which protects the surface of NVPF from volume expansion, significantly less formation of carbonates, and decomposition of electrolyte, which is also validated through post cycling analysis. The study shows the importance of ultrathin surface protection artificial CEI for advanced sodium-ion battery cathodes. The protection layer is diminishing parasitic reaction, which eventually enhances the Na ion participation in reaction and stabilizes the cathode structure., (© 2021 Wiley-VCH GmbH.)

Production of multilayered microstructures composed of conducting and insulating materials is of great interest as they can be utilized as microelectronic components. Current proposed fabrication methods of these microstructures include top-down and bottom-up methods, each having their own set of drawbacks. Laser-based methods were shown to pattern various materials with micron/sub-micron resolution; however, multilayered structures demonstrating conducting/insulating/conducting properties were not yet realized. Here, we demonstrate laser printing of multilayered microstructures consisting of conducting platinum and insulating silicon oxide layers by a combination of thermally driven reactions with microbubble-assisted printing. PtCl 2 dissolved in N -methyl-2-pyrrolidone (NMP) was used as a precursor to form conducting Pt layers, while tetraethyl orthosilicate dissolved in NMP formed insulating silicon oxide layers identified by Raman spectroscopy. We demonstrate control over the height of the insulating layer between ∼50 and 250 nm by varying the laser power and number of iterations. The resistivity of the silicon oxide layer at 0.5 V was 1.5 × 10 11 Ωm. Other materials that we studied were found to be porous and prone to cracking, rendering them irrelevant as insulators. Finally, we show how microfluidics can enhance multilayered laser microprinting by quickly switching between precursors. The concepts presented here could provide new opportunities for simple fabrication of multilayered microelectronic devices.

Simultaneous water and ethanol-based synthesis and coating of copper and zinc oxide (CuO/ZnO) nanoparticles (NPs) on bandages was carried out by ultrasound irradiation. High resolution-transmission electron microscopy demonstrated the effects of the solvent on the particle size and shape of metal oxide NPs. An antibacterial activity study of metal-oxide-coated bandages was carried out against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). CuO NP-coated bandages made from both water and ethanol demonstrated complete killing of S. aureus and E. coli bacteria within 30 min., whereas ZnO NP-coated bandages demonstrated five-log reductions in viability for both kinds of bacteria after 60 min of interaction. Further, the antibacterial mechanism of CuO/ZnO NP-coated bandages is proposed here based on electron spin resonance studies. Nanotoxicology investigations were conducted via in vivo examinations of the effect of the metal-oxide bandages on frog embryos (teratogenesis assay- Xenopus ). The results show that water-based coatings resulted in lesser impacts on embryo development than the ethanol-based ones. These bandages should therefore be considered safer than the ethanol-based ones. The comparison between the toxicity of the metal oxide NPs prepared in water and ethanol is of great importance, because water will replace ethanol for bulk scale synthesis of metal oxide NPs in commercial companies to avoid further ignition problems. The novelty and importance of this manuscript is avoiding the ethanol in the typical water:ethanol mixture as the solvent for the preparation of metal oxide NPs. Ethanol is ignitable, and commercial companies are trying the evade its use. This is especially important these days, as the face mask produced by sonochemistry (SONOMASK) is being sold all over the world by SONOVIA, and it is coated with ZnO.

The emergence of bacteria resistant to antibiotics and the resulting infections are increasingly becoming a public health issue. Multidrug-resistant (MDR) bacteria are responsible for infections leading to increased morbidity and mortality in hospitals, prolonged time of hospitalization, and additional burden to financial costs. Therefore, there is an urgent need for novel antibacterial agents that will both treat MDR infections and outsmart the bacterial evolutionary mechanisms, preventing further resistance development. In this study, a green synthesis employing nontoxic lignin as both reducing and capping agents was adopted to formulate stable and biocompatible silver-lignin nanoparticles (NPs) exhibiting antibacterial activity. The resulting silver-lignin NPs were approximately 20 nm in diameter and did not agglomerate after one year of storage at 4 °C. They were able to inhibit the growth of a panel of MDR clinical isolates, including Staphylococcus aureus , Staphylococcus epidermidis , Pseudomonas aeruginosa , Klebsiella pneumoniae , and Acinetobacter baumannii , at concentrations that did not affect the viability of a monocyte-derived THP-1 human cell line. Furthermore, the exposure of silver-lignin NPs to the THP-1 cells led to a significant increase in the secretion of the anti-inflammatory cytokine IL-10, demonstrating the potential of these particles to act as an antimicrobial and anti-inflammatory agent simultaneously. P. aeruginosa genes linked with efflux, heavy metal resistance, capsular biosynthesis, and quorum sensing were investigated for changes in gene expression upon sublethal exposure to the silver-lignin NPs. Genes encoding for membrane proteins with an efflux function were upregulated. However, all other genes were membrane proteins that did not efflux metals and were downregulated.

Among the most reliable techniques for exfoliation of two-dimensional (2D) layered materials, sonication-assisted liquid-phase exfoliation (LPE) is considered as a cost-effective and straightforward method for preparing graphene and its 2D inorganic counterparts at reasonable sizes and acceptable levels of defects. Although there were rapid advances in this field, the effect and outcome of the sonication frequency are poorly understood and often ignored, resulting in a low exfoliation efficiency. Here, we demonstrate that simple mild bath sonication at a higher frequency and low power positively contributes to the thickness, size, and quality of the final exfoliated products. We show that monolayer graphene flakes can be directly exfoliated from graphite using ethanol as a solvent by increasing the frequency of the bath sonication from 37 to 80 kHz. The statistical analysis shows that ∼77% of the measured graphene flakes have a thickness below three layers with an average lateral size of 13 μm. We demonstrate that this approach works for digenite (Cu 9 S 5 ) and silver sulfide (Ag 2 S), thus indicating that this exfoliation technique can be applied to other inorganic 2D materials to obtain high-quality few-layered flakes. This simple and effective method facilitates the formation of monolayer/few layers of graphene and transition metal chalcogenides for a wide range of applications.

The use of CuO nanoparticles (NPs) has increased greatly and their potential effects on human health need to be investigated. Differentiated Caco-2 cells were treated from the apical (Ap) and the basolateral (Bl) compartment with different concentrations (0, 10, 50 and 100 μg/mL) of commercial or sonochemically synthesized (sono) CuO NPs. Sono NPs were prepared in ethanol (CuOe) or in water (CuOw), obtaining CuO NPs differing in size and shape. The effects on the Caco-2 cell barrier were assessed via transepithelial electrical resistance (TEER) evaluation just before and after 1, 2 and 24 hours of exposure and through the analysis of cytokine release and biomarkers of oxidative damage to proteins after 24 hours. Sono CuOe and CuOw NPs induced a TEER decrease with a dose-dependent pattern after Bl exposure. Conversely, TEER values were not affected by the Ap exposure to commercial CuO NPs and, concerning the Bl exposure, only the lowest concentration tested (10 μg/mL) caused a TEER decrease after 24 hours of exposure. An increased release of interleukin-8 was induced by sono CuO NPs after the Ap exposure to 100 μg/mL and by sono and commercial CuO after the Bl exposure to all the concentrations. No effects of commercial and sono CuO NPs on interleukin-6 (with the only exception of 100 μg/mL Bl commercial CuO) and tumor necrosis factor-α release were observed. Ap treatment with commercial and CuOw NPs was able to induce significant alterations on specific biomarkers of protein oxidative damage (protein sulfhydryl group oxidation and protein carbonylation)., (© 2020 John Wiley & Sons, Ltd.)

We report a facile and robust room-temperature NO 2 sensor fabricated using bi- and multi-layered 2H variant of tungsten di-selenide (2H-WSe 2 ) nanosheets, exhibiting high sensing characteristics. A simple liquid-assisted exfoliation of 2H-WSe 2 , prepared using ambient pressure chemical vapor deposition, allows smooth integration of these nanosheets on transducers. Three sensor batches are fabricated by modulating the total number of layers (L) obtained from the total number of droplets from a homogeneous 2H-WSe 2 dispersion, such as ∼2L, ∼5-6L, and ∼13-17L, respectively. The gas-sensing attributes of 2H-WSe 2 nanosheets are investigated thoroughly. Room temperature (RT) experiments show that these devices are specifically tailored for NO 2 detection. 2L WSe 2 nanosheets deliver the best rapid response compared to ∼5-6L or ∼13-17L. The response of 2L WSe 2 at RT is 250, 328, and 361% to 2, 4, and 6 ppm NO 2 , respectively. The sensor showed nearly the same response toward low NO 2 concentration even after 9 months of testing, confirming its remarkable long-term stability. A selectivity study, performed at three working temperatures (RT, 100, and 150 °C), shows high selectivity at 150 and 100 °C. Full selectivity toward NO 2 at RT confirms that 2H-WSe 2 nanosheet-based sensors are ideal candidates for NO 2 gas detection.

In the context of nosocomial infections, there is an urgent need to develop efficient nanomaterials (NMs) with antibacterial properties for the prevention of infection diseases. Metal oxide nanoparticles (MeO-NPs) are promising candidates for the development of new antibacterial textiles. However, the direct exposure to MeO-NPs and MeO-coated NMs through skin contact could constitute a severe hazard for human health. In this work, the toxicity of copper and zinc oxide (CuO, ZnO) NPs antimicrobial-coated textiles was assessed on an in vitro reconstructed 3D model of epidermis. Thus, MeO-NPs and extracts from MeO-coated NMs were tested on EpiDerm™ skin model according to OECD TG 431 (Corrosion Test) and 439 (Irritation Test), respectively. Skin surface fluids composition is a crucial aspect to be considered in the development of NMs that have to encounter this tissue. So, for the irritation test, coated textiles were extracted in artificial sweat solutions at pH 4.7 and 6.5. Skin tissue viability, pro-inflammatory interleukin-8 secretion and morphological alteration of intermediate and actin filaments of keratinocytes were evaluated after 18 h exposure to extracts from CuO- and ZnO-coated textiles. Analysis of extracts at the two pH conditions indicated that released ions and not NPs are involved in promoting adverse effects on epidermis. Since Cu 2+ and Zn 2+ ions are known to penetrate epidermis, Balb/3 T3 cells were used as model of dermis. Fibroblasts viability was investigated after the exposure to trans-epidermis permeated ions, collected from EpiDerm™ basal supernatants, and to extracts, as representative of a direct interaction of ions with dermis cells by wounded skin. From our data we can conclude that: 1) skin surface fluids composition is a key parameter for the stability of NPs-coated textiles; 2) MeO ions released from coated textiles can deeply affect the epidermal tissue and the underlying dermal cells upon trans-epidermal permeation; 3) skin barrier integrity is a fundamental prerequisite that should be taken into account during the assessment of NMs safety by direct contact exposure., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Details of apatite formation and development in bone below the nanometer scale remain enigmatic. Regulation of mineralization was shown to be governed by the activity of non-collagenous proteins with many bone diseases stemming from improper activity of these proteins. Apatite crystal growth inhibition or enhancement is thought to involve direct interaction of these proteins with exposed faces of apatite crystals. However, experimental evidence of the molecular binding events that occur and that allow these proteins to exert their functions are lacking. Moreover, recent high-resolution measurements of apatite crystallites in bone have shown that individual crystallites are covered by a persistent layer of amorphous calcium phosphate. It is therefore unclear whether non-collagenous proteins can interact with the faces of the mineral crystallites directly and what are the consequences of the presence of a disordered mineral layer to their functionality. In this work, the regulatory effect of recombinant osteopontin on biomimetic apatite is shown to produce platelet-shaped apatite crystallites with disordered layers coating them. The protein is also shown to regulate the content and properties of the disordered mineral phase (and sublayers within it). Through solid-state NMR atomic carbon-phosphorous distance measurements, the protein is shown to be located in the disordered phases, reaching out to interact with the surfaces of the crystals only through very few sidechains. These observations suggest that non-phosphorylated osteopontin acts as regulator of the coating mineral layers and exerts its effect on apatite crystal growth processes mostly from afar with a limited number of contact points with the crystal.

We report a facile two-furnace APCVD synthesis of 2H-WSe 2 . A systematic study of the process parameters is performed to show the formation of the phase-pure material. Extensive characterization of the bulk and exfoliated material confirm that 2H-WSe 2 is layered (i.e., 2D). X-ray diffraction (XRD) confirms the phase, while high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM) clarify the morphology of the material. Focused ion beam scanning electron microscopy (FIB-SEM) estimates the depth of the 2H-WSe 2 formed on W foil to be around 5-8 μm, and Raman/UV-vis measurements prove the quality of the exfoliated 2H-WSe 2 . Studies on the redox processes of lithium-ion batteries (LiBs) show an increase in capacity up to 500 cycles. On prolonged cycling, the discharge capacity up to the 50th cycle at 250 mA/g of the material shows a stable value of 550 mAh/g. These observations indicate that exfoliated 2H-WSe 2 has promising applications as an LiB electrode material., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

There is a huge demand for materials capable of simple detection or separation after conjugation with specific biologic substances when applied as a diagnostic tools. Taking into account the photoluminescence properties of C-dots and the highly magnetic properties of Fe(0), a new hybrid composite of these components was synthesized via ultrasound irradiation. The material was fully characterized by various physicochemical techniques. The main goal of the current study was to obtain a highly magnetic and intense fluorescent hybrid material. The goal was achieved. In addition, magnetic particles tended to agglomerate. The new hybrid can be suspended in ethanol, which is an additional feature of the current research. The dispersion of the hybrid nanoparticles in ethanol was achieved by utilizing the interaction of iron particles with C-dots which were decorated with functional groups on their surface. The newly formed hybrid material has potential applications in diagnostic by conjugating with specific antibodies or with any other biologic compounds. Such application may be useful in detection of various diseases such as: cancer, tuberculosis, etc.

The increase in antibiotic resistance reported worldwide poses an immediate threat to human health and highlights the need to find novel approaches to inhibit bacterial growth. In this study, we present a series of gold nanoparticles (Au NPs) capped by different N-heterocyclic molecules (N_Au NPs) which can serve as broad-spectrum antibacterial agents. Neither the Au NPs nor N-heterocyclic molecules were toxic to mammalian cells. These N_Au NPs can attach to the surface of bacteria and destroy the bacterial cell wall to induce cell death. Sonochemistry was used to coat Au NPs on the surface of fabrics, which showed superb antimicrobial activity against multi-drug resistant (MDR) bacteria as well as excellent efficacy in inhibiting bacterial biofilms produced by MDR bacteria. Our study provides a novel strategy for preventing the formation of MDR bacterial biofilms in a straightforward, low-cost, and efficient way, which holds promise for broad clinical applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this article, we report a facile approach for the synthesis of an inexpensive catalyst of bimetallic Hg/Pd alloys comprising nanoparticles with various structures using a unique ultrasonic reaction that is conducted without the use of any reducing agent. The nanoparticles of Hg/Pd alloys (HgPd and Hg 2 Pd 5 ) were achieved for the first time by sonicating an aqueous solution of Palladium (II) nitrate with metallic liquid mercury, as evidenced by XRD. EDS further confirmed the presence of Pd and Hg elements in the alloy. The surface morphology and structure of the nanoparticles have been systematically investigated by HRSEM, HRTEM and SAED pattern. In order to explore the catalytic activity of the as-synthesized nanoalloys, the catalytic reduction of 4-nitrophenol and a few other nitrophenol derivatives were investigated. Excellent catalytic activity was obtained for Hg/Pd (1:1) alloy, and the rate constant for the reduction of 4-NP with Hg/Pd at room temperature was found to be 58.4 × 10 -3  s -1 , which is possibly the highest ever reported. The catalyst exhibited superior stability and reusability when compared with those reported in the literature for other catalysts based on noble metals., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Micro-patterning of a metal organic framework (MOF) from a solution of precursors is achieved by local laser heating. Nano-sized MOFs are formed, followed by rapid assembly due to convective flows around a heat-induced micro-bubble. This laser-induced bottom-up technique is the first to suggest simultaneous synthesis and micro-patterning of MOFs, alleviating the need for pre-preparation and stabilization.

One of the many challenges in the study of chiral nanosurfaces and nanofilms is the design of accurate and controlled nanoscale films with enantioselective activity. Controlled design of chiral nanofilms creates the opportunity to develop chiral materials with nanostructured architecture. Molecular layer deposition (MLD) is an advanced surface-engineering strategy for the preparation of hybrid inorganic-organic thin films, with a desired embedded property; in our study this is chirality. Previous attempts to grow enantioselective thin films were mostly focused on self-assembled monolayers or template-assisted synthesis, followed by removal of the chiral template. Here, we report a method to prepare chiral hybrid inorganic-organic nanoscale thin films with controlled thickness and impressive enantioselective properties. We present the use of an MLD reactor for sequenced vapor deposition to produce enantioselective thin films, by embedding the chirality of chiral building blocks into thin films. The prepared thin films demonstrate enantioselectivity of ∼20% and enantiomeric excess of up to 50%. We show that our controlled synthesis of chiral thin films generates opportunities for enantioselective coatings over various templates and 3D membranes.

Antimicrobial textiles can contribute to the fighting against antibiotic resistance pathogenic microorganisms. Polypyrrole is a conjugated polymer that exerts a biocidal action thanks to positive charges on its backbone chain produced during it synthesis. In this work, dispersions of stable polypyrrole nanoparticles were produced by chemical oxidative polymerization at room temperature in water. An ultrasound-assisted coating process was then used to effectively treat a polyester fabric with the nanoparticles to obtain an optimal antibacterial coating which efficiently eradicates the bacteria. The results showed that the treated fabric with about 4 g/m 2 of polypyrrole had log bacteria reductions of 6.0 against Staphylococcus aureus and 7.5 against Escherichia coli. The combination of a polypyrrole synthesis in the form of water nanoparticles dispersions and a continuous coating of fabrics supported by ultrasound overcomes some issues of upscaling of the traditional in-situ chemical deposition used until now for the production of polypyrrole-coated textiles., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Most antibacterial agents demand their action in the form of a liquid for compatibility and ease of use in biosystems, which are mainly composed of biological fluids. Controlling the colloidal stability of metal oxide nanocolloids, in parallel with minimizing the effect of using a large amount of surfactant on their biocidal activity and cytotoxicity, remains a challenge. Here, we address the stability of nanocolloids of ZnO and CuO in the presence of polymer surfactants and the influence of the surface capping on their antibacterial activity and cytotoxicity. The metal oxide nanoparticles (NPs) were synthesized sonochemically in a single step and tested against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus to validate their biocidal efficacy. Cytotoxicity studies were performed on human alveolar epithelial cells. Polyethylene glycol- and polyvinyl alcohol-capped NPs are observed to show the minimum cytotoxicity whereas polyethylene imine-capped and pristine metal oxide NPs are toxic to the mammalian cells. The cytotoxic and antibacterial properties of the stable nanocolloids displayed an inverse relation, highlighting the role and significance of the polymer capping. The nontoxic biocidal nanocolloids showed an effective antibacterial efficacy of 99.9% in 2 h., Competing Interests: The authors declare no competing financial interest.

Purpose: This work examined the antibacterial and physical effects of a novel Zn-CuO nanocoating applied on a silicone hydrogel contact lens., Methods: Zn-CuO coating of PureVision balafilcon-A soft contact lenses (Bausch&Lomb, Rochester, NY) was performed by sonochemical deposition using a high-intensity ultrasonic horn. Non-coated PureVision lenses served as a control in all experiments. Adhesion assays for P. aerueginosa and S. epidermidis to the coated lenses were performed to identify the minimal coating concentration which still possessed antibacterial activity. Lens water content, oxygen transfer light transfer, leaching, and electron microscopy studies were performed using this concentration., Results: Coated lenses showed 3-5 log reductions in adhesion of both species. The lowest tested coating concentration of 0.02 wt% led to a log reduction of 3.25 ± 1.25 of P. aeruginosa CFU/lens (P = 0.007) and a log reduction of 4.37 ± 0.75 of S. epidermidis (p = 0.0007). Using this coating concentration, water content (36%, 33.6%), oxygen transfer (87.22 ± 10.96, 92.18 ± 2.38, × 10 -11 (cm 2 /s)(mlO 2 )/(ml × mmHg)), p = 0.12), and light transfer properties did not differ significantly between the coated and the control contact lenses. In the range of 380-780 nm wavelength, the coated lenses transmitted 96.47 ± 1.52% while the control lenses transmitted 97.36 ± 1.35%. The corresponding values for the range of 300-380 nm wavelength were 79.343 ± 8.754 and 80.169 ± 1.35. Leaching studies for 0.5 mM coated lenses have demonstrated the excellent stability of the coating with the release of only 0.005% of the coating after 1 week of exposure to the test solution., Conclusion: Sonochemical-assisted nanocoating of contact lenses showed significant and consistent antibacterial activity while preserving the basic properties of a silicone hydrogel contact lens.

Multifunctional substrates with superhydrophobic and biocidal properties are gaining interest for a wide range of applications; however, the production of such surfaces remains challenging. Here, the sonochemical method is utilized to impart superhydrophobicity and antimicrobial properties to a polyethylene (PE) sheet. This is achieved by sonochemically depositing nanoparticles (NPs) of a hydrophobic fluoro-polymer (FP) on the PE sheets. The polymer is a flexible, transparent fluoroplastic composed of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride in the form of a powder. The NPs of polymers are generated and deposited on the surface of the PE using ultrasound irradiation. Optimizing the process results in a homogeneous distribution of 110-200 nm of NPs on the PE surface. The coated surface displays a water-contact angle of 160°, indicating excellent superhydrophobicity. This superhydrophobic surface shows high stability under outdoor conditions for two months, which is essential for various applications. In addition, metal-oxide nanoparticles (CuO or ZnO NPs) were integrated into the polymer coating to achieve antibacterial properties and increase the surface roughness. The metal oxides were also deposited sonochemically. The antibacterial activity of the FP@ZnO and FP@CuO PE composites was tested against the bacterium Staphylococcus aureus, and the results show that the FP@CuO PE can effectively eradicate the bacteria. This study highlights the feasibility of using the sonochemical method to deposit two separate functions, opening up new possibilities for producing "smart" novel surfaces., (Copyright © 2018 Elsevier B.V. All rights reserved.)

An important preventive measure for providing a bacteria-free environment for the patients is the introduction of highly efficient and durable antibacterial textiles in hospitals. This work describes a single step sono-enzymatic process for coating of cotton medical textiles with antibacterial ZnO nanoparticles (NPs) and gallic acid (GA) to produce biocompatible fabrics with durable antibacterial properties. Cellulose substrates, however, need pre-activation to achieve sufficient stability of the NPs on their surface. Herein, this drawback is overcome by the simultaneous sonochemical deposition of ZnO NPs and the synthesis of a bio-based adhesive generated by the enzymatic cross-linking of GA in which the NPs were embedded. GA possesses the multiple functions of an antibacterial agent, a building block of the cross-linked phenolic network, and as a compound providing the safe contact of the coated materials with human skin. The ZnO NPs-GA coated fabrics maintained above 60% antibacterial efficacy even after 60 washing cycles at 75 °C hospital laundry regime., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this review, we report the functionalization of textiles composed of nanoscale reactive materials in the treatment of wounds and skin diseases such as acne. In view of the growing demand for high-quality textiles, much research is focused on the creation of antimicrobial finishings for fabrics, in order to protect customers from pathogenic or odorgenerating microorganisms. We present coatings from inorganic, organic and biochemical nanoparticles (NPs) on surfaces that impart the ability to kill bacteria, avoid biofilm formation and speed up the recovery of wounds. In all three cases, sonochemistry is used for immobilizing the nanoparticles on the surfaces. The Introduction broadly covers the progress of nanotechnology in the fields of wound and skin care. The first section of this review outlines the mechanism of the ultrasound-assisted deposition of nanoparticles on textiles. The coating can be performed by an in-situ process in which the nanoparticles are formed and subsequently thrown onto the surface of the fabrics at a very high speed. This approach was used in depositing metal-oxide NPs such as ZnO, CuO and Zn-CuO or the organic NPs of tannic acid, chitosan, etc. on textiles. In addition, the sonochemical process can be used as a "throwing stone" technique, namely, previously synthesized or commercially purchased NPs can be placed in the sonication bath and sonicated in the presence of the fabric. The collapse of the acoustic bubble in the solution causes the throwing of the immersed commercial NPs onto the textiles. This section will also outline why sonochemical deposition on textiles is considered the best coating technique. The second section will discuss new applications of the sonochemically- coated textiles in killing bacteria, avoiding biofilm formation and more. Two points should be noted: 1) the review will primarily report results obtained at Bar-Ilan University and 2) since for all textiles tested in our experiments (cotton, polyester, nylon, nonwoven) similar results were obtained, the type of textile used in a specific experiment will not be mentioned - textiles will be discussed in general. It is also worth emphasizing that this review concentrates only on the sonochemical coating of textiles, ignoring other deposition techniques., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Nano metal oxides have been proposed as alternatives to silver (Ag) nanoparticles (NPs) for antibacterial coatings. Here, cotton and polyester-cotton fabrics were sonochemically coated with zinc oxide (ZnO) and copper oxide (CuO) NPs. By varying the reaction solvent (water or ethanol), NPs with different sizes and shapes were synthesized. The cytotoxic and pro-inflammatory effects of studied NPs were investigated in vitro in human alveolar epithelial A549 and macrophage-like THP1 cells. To understand the potential respiratory impact of the NPs, the coated textiles were subjected to the abrasion tests, and the released airborne particles were measured. A very small amount of the studied metal oxides NPs was released from abrasion of the textiles coated by the ethanol-based sonochemical process. The release from the water-based coating was comparably higher. Lung and immune cells viability decreased after 24 h of exposure only at the highest studied NPs concentration (100 μg/mL). Different from the ZnO NPs, both formulations of CuO NPs induced IL-8 release in the lung epithelial cells already at subtoxic concentrations (1-10 μg/mL) but not in immune cells. All of the studied NPs did not induce IL-6 release by the lung and immune cells. Calculations revealed that the exposures of the NPs to human lung due to the abrasion of the textiles were lower or comparable to the minimum doses in the cell viability tests (0.1 μg/mL), at which acute cytotoxicity was not observed. The results alleviate the concerns regarding the potential risk of these metal oxide NPs in their applications for the textile coating and provide insight for the safe-by-design approach.

Chronic wound fluids have elevated concentration of human neutrophil elastase (HNE) which can be used as inflammation/infection marker. Our goal is to develop functional materials for fast diagnosis of wound inflammation/infection by using HNE as a specific marker. For that, fluorogenic peptides with a HNE-specific cleavage sequence were incorporated into traditional textile dressings, to allow real-time detection of the wound status. Two different fluorogenic approaches were studied in terms of intensity of the signal generated upon HNE addition: a fluorophore 7-amino-4-trifluormethylcoumarin (AFC) conjugated to a HNE-specific peptide and two fluorophore/quencher pairs (FAM/Dabcyl and EDANS/Dabcyl) coupled to a similar peptide as a Förster resonance energy transfer (FRET) strategy. Also, two immobilization methods were tested: sonochemistry immobilization onto a cotton bandage and glutaraldehyde (GTA)-assisted chemical crosslinking onto a polyamide dressing. The immobilized fluorogenic AFC peptide showed an intense fluorescence emission in the presence of HNE. HNE also induced an enhanced fluorescent signal with the EDANS/Dabcyl FRET peptide which showed to be a more sensitive and effective strategy than the AFC peptide. However, its chemical immobilization onto the polyamide dressing greatly decreased its detection, mainly due to the more difficult access of the enzyme to the cleavage sequence of the immobilized peptide. After optimization of the in situ immobilization, it will be possible to use these fluorescence-functionalized dressings for an effective and specific monitoring of chronic wounds by simply using a portable ultraviolet (UV) light source. We envision that the development of this point-of-care medical device for wound control will have a great impact on patient's life quality and reduction of costs on health care system.

Zinc-doped copper oxide nanocomposites (nZn-CuO NPs) are novel nanparticles synthesized by our group. In the present study, the antitumor effects and the underlying molecular mechanisms of the nZn-CuO NPs were investigated. The cytotoxicity of nZn-CuO NPs against several types of cancer cell lines was studied using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS)/phenazinemethosulfate (PMS) assay. Results showed that nZn-CuO NPs exerted obvious antiproliferation effects on cancer cells and relatively weak antiproliferation effects on normal cells. The antitumor mechanisms of nZn-CuO NPs were further investigated using human liver cancer HepG2 cells and human pancreatic cancer Panc28 cells. Hoechst 33342 staining and FITC-Annexin V/PI staining showed that nZn-CuO NPs could induce cell apoptosis in a dose dependent manner. Cell-cycle analysis using flow cytometry revealed that nZn-CuO NPs were able to arrest the cell cycle in the G2/M phase. Also, nZn-CuO NPs were found to induce reactive oxygen species (ROS) generation. Further studies confirmed that nZn-CuO NPs could increase p-IKKα/β and nucleus p-NF-κB p65 expressions and decrease IKKα, IKKβ, IκBα, and nucleus NF-κB p65 expressions in both cell lines. Overall, our data demonstrated that nZn-CuO NPs could selectively inhibit the growth of cancer cells via ROS-mediated NF-κB activation. The current study provides primary evidence that nZn-CuO NPs possess the potential to be developed as a novel anticancer agent.

One of the limitations in the applications and commercialization of metal oxides in diverse fields is their inferior colloidal stability. The ability of metal oxide nanoparticles (MONPs) to remain in the suspended form for long duration is influenced by the particle size and the capping efficiency of the surfactant employed. Among the metal oxides, ZnO is exploited as an effective biocidal agent. For practical applications, the incorporation of ZnO into liquids using a stabilizer is of importance, and therefore synthesizing nanoparticles with high dispersity in solution still remains a challenge. The present work is aimed at synthesizing ZnO nanoparticles (NPs) in colloidal form with great stability, minimal particle size and high antibacterial activity. Herein, we report a single step synthesis of ZnO colloids in aqueous medium by using a biocompatible polymer PVA (poly(vinyl alcohol)) as a stabilizing agent. Both ZnO (without PVA) and ZnO-PVA NPs are prepared using ultrasonic irradiation and their differing particle sizes, stabilities and antibacterial activities are correlated. ESR measurements reveal that ZnO NPs of reduced particle size (∼5 nm) produced increased levels of reactive-oxygen species (ROS). The biocidal effect of the colloidal solution was examined on two bacterial species: Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The results revealed an enhancement in the antibacterial activity for the ZnO-PVA nanofluid.

The antimicrobial finishing is a must for production of medical textiles, aiming at reducing the bioburden in clinical wards and consequently decreasing the risk of hospital-acquired infections. This work reports for the first time on a simultaneous sonochemical/enzymatic process for durable antibacterial coating of cotton with zinc oxide nanoparticles (ZnO NPs). The novel technology goes beyond the "stepwise" concept we proposed recently for enzymatic pre-activation of the fabrics and subsequent sonochemical nano-coating, and is designed to produce "ready-to-use" antibacterial medical textiles in a single step. A multilayer coating of uniformly dispersed NPs was obtained in the process. The enzymatic treatment provides better adhesion of the ZnO NPs and, as a consequence, enhanced coating stability during exploitation. The NPs-coated cotton fabrics inhibited the growth of the medically relevant Staphylococcus aureus and Escherichia coli respectively by 67% and 100%. The antibacterial efficiency of these textile materials resisted the intensive laundry regimes used in hospitals, though only 33% of the initially deposited NPs remained firmly fixed onto the fabrics after multiple washings., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The sonochemical technique has already been proven as one of the best coating methods for stable functionalization of substrates over a wide range of applications. Here, we report for the first time on the simultaneous sonochemical dyeing and coating of textiles with antibacterial metal oxide (MO) nanoparticles. In this one-step process the antibacterial nanoparticles are synthesized in situ and deposited together with dye nanoparticles on the fabric surface. It was shown that the antibacterial behavior of the metal oxides was not influenced by the presence of the dyes. Higher K/S values were achieved by sonochemical deposition of the dyes in comparison to a dip-coating (exhaustion) process. The stability of the antibacterial properties and the dye fastness was studied for 72 h in saline solution aiming at medical applications.

There is an urgent need for antimicrobial functionalization of urinary catheters to prevent microbial colonization and biofilm formation on them. Here, the antimicrobial hydrogen peroxide (H 2 O 2 ) producing enzyme cellobiose dehydrogenase (CDH) was for the first time grafted onto polydimethylsiloxanes (PDMS) using an ultrasound assisted coating method. This resulted in the development of an effective in situ continous H 2 O 2 producing system able to continuously prevent microbial colonization and biofilm formation on catheters. This enzyme has an added advantage that it uses various oligosaccharides including expolysaccharides (an important part of the bioflim produced by the microbes while colonizing biomaterials) as electron donors to produce H 2 O 2 . Successful immobilization of active CDH nanoparticles on PDMS was confirmed by ESEM and AFM analysis as well as quantification of H 2 O 2 . Depending on the initial enzyme concentration, CDH-nanoparticles of varying sizes from 65 ± 17 nm to 93 ± 17 nm were created by the ultrasonic waves and subsequently deposited on the PDMS surface. PDMS sheets treated for 3 min produced 18 μM of H 2 O 2 within 2 hours which was sufficient to significantly reduce the amount of viable S. aureus cells as well as the total amount of biomass deposited on the surface. The ultrasound assisted coating of antimicrobial enzymes therefore provides an easy approach to immobilize enzymes and create a surface with antimicrobial properties.

The increased resistances to conventional antibiotics determine a strong need for new antibacterials, and specific syntheses at the nanoscale promise to be helpful in this field. A novel Zinc-doped Copper oxide nanocomposite (nZn-CuO) has been recently sonochemically synthesized and successfully tested also against multi-drug resistant bacteria. After synthesis and characterization of the physicochemical properties, the new nZn-CuO is here evaluated by the Frog Embyo Teratogenesis Assay-Xenopus test for its toxicological potential and this compared with that of nCuO and nZnO synthesized under the same conditions. No lethal effects are observed, while malformations and growth retardation slightly increase after nZn-CuO exposure. Nevertheless, these effects are smaller than those of nZnO. NP uptake by embryo tissues increase significantly with increasing NP concentrations, while no significant accumulation and adverse effects are seen after exposure to soluble Cu(2+) and Zn(2+) at the concentrations dissolved from the NPs. Key oxidative response genes are upregulated by nZn-CuO, as well as by nCuO and nZnO, suggesting the common mechanism of action. Considering the enhanced biocidal activity shown by the nanocomposite, together with the results presented in this study, we can affirm that the doping of the metal oxide nanoparticles should be considered a useful tool to engineer a safer nano-antibacterial., (© The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

The ability to scale-up the sonochemical coating of medical textiles with antibacterial nanoparticles is demonstrated in the current paper. A roll-to-roll pilot installation to coat textiles was built taking into consideration the requirements of the sonochemical process. A long-run experiment was conducted in which 2500 m of fabric were coated with antibacterial ZnO nanoparticles (NPs). The metal oxide NPs were deposited from an ethanol:water solution. In this continuous process a uniform concentration of coated NPs over the length/width of the fabric was achieved. The antibacterial efficiency of the sonochemically-coated textiles was validated in a hospital environment by a reduction in the occurrence of nosocomial infections. NP-coated bed sheets, patient gowns, pillow cover, and bed covers were used by 21 patients. For comparison 16 patients used regular textiles. The clinical data indicated the reduced occurrence of hospital-acquired infections when using the metal oxide NP-coated textiles. In order to reduce the cost of the coating process and considering safety issues during manufacturing, the solvent (ethanol:water) (9:1 v:v) used for the long-run experiment, was replaced by water. Although lesser amounts of ZnO NPs were deposited on the fabric in the water-based process the antibacterial activity of the textiles was preserved due to the smaller size of the particles., (Copyright © 2015 Elsevier B.V. All rights reserved.)