The formation of bacterial biofilm is a major challenge in clinical applications. The main aim of this study is to describe the synthesis, characterization and biocidal potential of zinc oxide ...nanoparticles (NPs) against bacterial strain Pseudomonas aeruginosa. These nanoparticles were synthesized via soft chemical solution process in a very short time and their structural properties have been investigated in detail by using X-ray diffraction and transmission electron microscopy measurements. In this work, the potential of synthesized ZnO-NPs (∼ 10-15 nm) has been assessed in-vitro inhibition of bacteria and the formation of their biofilms was observed using the tissue culture plate assays. The crystal violet staining on biofilm formation and its optical density revealed the effect on biofilm inhibition. The NPs at a concentration of 100 µg/mL significantly inhibited the growth of bacteria and biofilm formation. The biofilm inhibition by ZnO-NPs was also confirmed via bio-transmission electron microscopy (Bio-TEM). The Bio-TEM analysis of ZnO-NPs treated bacteria confirmed the deformation and damage of cells. The bacterial growth in presence of NPs concluded the bactericidal ability of NPs in a concentration dependent manner. It has been speculated that the antibacterial activity of NPs as a surface coating material, could be a feasible approach for controlling the pathogens. Additionally, the obtained bacterial solution data is also in agreement with the results from statistical analytical methods.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies ...of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ammonia (NH3) is a vital compound in diversified fields, including agriculture, automotive, chemical, food processing, hydrogen production and storage, and biomedical applications. Its extensive ...industrial use and emission have emerged hazardous to the ecosystem and have raised global public health concerns for monitoring NH3 emissions and implementing proper safety strategies. These facts created emergent demand for translational and sustainable approaches to design efficient, affordable, and high-performance compact NH3 sensors. Commercially available NH3 sensors possess three major bottlenecks: poor selectivity, low concentration detection, and room-temperature operation. State-of-the-art NH3 sensors are scaling up using advanced nano-systems possessing rapid, selective, efficient, and enhanced detection to overcome these challenges. MXene–polymer nanocomposites (MXP-NCs) are emerging as advanced nanomaterials of choice for NH3 sensing owing to their affordability, excellent conductivity, mechanical flexibility, scalable production, rich surface functionalities, and tunable morphology. The MXP-NCs have demonstrated high performance to develop next-generation intelligent NH3 sensors in agricultural, industrial, and biomedical applications. However, their excellent NH3-sensing features are not articulated in the form of a review. This comprehensive review summarizes state-of-the-art MXP-NCs fabrication techniques, optimization of desired properties, enhanced sensing characteristics, and applications to detect airborne NH3. Furthermore, an overview of challenges, possible solutions, and prospects associated with MXP-NCs is discussed.
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•2D borophene flatland is emerging suitable for high-performance application.•Developing functionalized borophene is suitable for efficient biosensing prototypes.•These systems can be ...translated for POC application.•IoMT and smartphone supported such systems are required for personalized healthcare.
2D-materials-based biosensing, supported by artificial intelligence (AI) and internet-of-medical things (IoMT), has emerged as a new technological platform for intelligent diagnostics at point-of-care (POC). To achieve a desired biosensing, high performance engineering in smart functionalized opto-electric 2D materials is crucial. Recently, borophene has emerged as one of such advanced platforms due to its high electroactive surface, anisotropic behaviour, high electron transport, controlled optical properties, feasibility of deposition in thin films, and possibility to generate surface functionalities. Although ease of fabrication still stands challenging, borophene could be deposited on flexible substrate, functionalized using chemistries to immobilize bio-actives, and control over electro-optical properties to develop a highly sensitive biosensing systems operated by smartphone to achieve early stage POC diagnosis. This letter is an attempt to project borophene for smart bio-sensing.
Advanced wound scaffolds that integrate active substances to treat chronic wounds have gained significant recent attention. While wound scaffolds and advanced functionalities have previously been ...incorporated into one medical device, the wirelessly triggered release of active substances has remained the focus of many research endeavors. To combine multiple functions including light‐triggered activation, antiseptic, angiogenic, and moisturizing properties, a 3D printed hydrogel patch encapsulating vascular endothelial growth factor (VEGF) decorated with photoactive and antibacterial tetrapodal zinc oxide (t‐ZnO) microparticles is developed. To achieve the smart release of VEGF, t‐ZnO is modified by chemical treatment and activated through ultraviolet/visible light exposure. This process would also make the surface rough and improve protein adhesion. The elastic modulus and degradation behavior of the composite hydrogels, which must match the wound healing process, are adjusted by changing t‐ZnO concentrations. The t‐ZnO‐laden composite hydrogels can be printed with any desired micropattern to potentially create a modular elution of various growth factors. The VEGF‐decorated t‐ZnO‐laden hydrogel patches show low cytotoxicity and improved angiogenic properties while maintaining antibacterial functions in vitro. In vivo tests show promising results for the printed wound patches, with less immunogenicity and enhanced wound healing.
To treat chronic wounds, a smart wound scaffold based on growth factors decorated tetrapodal zinc oxide (t‑ZnO)‐laden 3D printed hydrogel patches, which possess light‐triggered activation, anti‐bacterial, angiogenic, and tissue regeneration properties is reported. Through in vivo tests, the multi‐functional wound scaffolds show less immunogenicity and enhance wound healing, which make them interesting candidates for future smart wound dressing platforms.
Flexible, electrically conducting, high temperature stable ceramics with very high porosities are fabricated from interpenetrated metal oxide nano‐microstructures in a versatile manner in a novel ...flame transport synthesis approach. The Young's modulus of these networks can be tuned from wool type to rubber like based on the density, type and interconnections of the building blocks. Semiconducting behavior allows multifunctional applications like the electrical readout of the mechanical history.
The fabrication of nanoscale CuO/Cu2O heterostructure with mixed phases in CuxOy nano-crystals grown by chemical deposition was done by rapid thermal annealing RTA. Ethanol vapour sensing studies ...evidenced that nanoscale CuO/Cu2O nano-crystals became an efficient material candidates for sensing after RTA in 60s. Faster response and recovery times for ethanol vapour sensors based on 0.95wt% Zn-doped CuO/Cu2O are reported. Mechanisms of ethanol vapour sensing have been proposed in details for CuO/Cu2O heterojunction.
•Formation of the nanoscale CuO/Cu2O heterostructure with mixed phases in CuxOy nano-crystals was done by RTA in 60s.•Ethanol vapour sensing studies evidenced that nanoscale CuO/Cu2O nano-crystals are efficient p-type material candidates for sensing.•Effects of rapid thermal annealing process on sensing gas response of CuxOy nano-crystals have been investigated.•Faster response and recovery times for ethanol vapour sensors based on 0.9wt% Zn-doped CuO/Cu2O are reported.•Mechanisms of ethanol vapour sensing have been proposed in details for CuO/Cu2O heterojunction.
Copper oxide nanostructures are fascinating nanomaterials due to their remarkable electrical, optical, thermal, and sensing properties given that their tunability and the stabilization of specific phases are uniquely possible at the nanoscale dimensions.
The present study reports on nano-crystalline copper oxide thin films via a simple synthesis from chemical solutions (SCS) followed by two types of thermal annealing, namely rapid thermal annealing (RTA) and conventional thermal annealing (TA). We report on the enhanced ethanol sensing performances of the device structures based on synthesized copper oxide nanocrystals with one and two distinctly different phases, namely Cu2O, CuO, as well as mixed phases CuO/Cu2O.
A gradient in phase change of nano-crystals was observed for annealed samples starting from CuO on the top to Cu2O in their central region. RTA effects on the gas response of the CuxOy nano-crystals have been identified as unprecedented selectivity and sensitivity to ethanol vapours at different temperatures. An increase in resistance value of about one order in magnitude was detected for samples treated by conventional-TA at 400°C for 30min at optimal operating temperature of 300°C and RTA at 525°C for 60s at lower optimal operating temperature of 275°C. It has been observed that the response and recovery times for pure copper oxide-based sensors can be significantly improved by Zn-doping, e.g. from ∼4.1s and ∼10.5s to about 3.3s and 7.2s, respectively.
The obtained results were discussed in details and it provide an exciting alternative for fast, sensitive, and selective detection of trace gases, which could be of several benefits in the technologies dealing with public securities and environmental monitoring applications.
Although vaccination represents the most promising way to stop or contain the coronavirus disease 2019 (COVID-19) pandemic and safety and effectiveness of available vaccines were proven, a small ...number of individuals who received anti-SARS-CoV-2 vaccines developed a prothrombotic syndrome. Vaccine-induced immune thrombotic thrombocytopenia (VITT) can be triggered by the adenoviral vector-based vaccine, whereas lipid nanoparticle-mRNA-based vaccines can induce rare cases of deep vein thrombosis (DVT). Although the main pathogenic mechanisms behind this rare phenomenon have not yet been identified, both host and vaccine factors might be involved, with pathology at least in part being related to the vaccine-triggered autoimmune reaction. In this review, we are considering some aspects related to pathogenesis, major risk factors, as well as peculiarities of diagnosis and treatment of this rare condition.
•In rare cases, SARS-CoV-2 vaccines can cause severe thrombotic events.•Mechanisms of vaccine-induced immune thrombotic thrombocytopenia (VITT) are unknown.•VITT is similar to autoimmune heparin-induced thrombocytopenia (HIT).•Both vaccine components and host conditions can contribute to VITT.
► Zinc oxide tetrapods as anti-HSV-2 agents. ► Zinc oxide tetrapods as virus trapping agents. ► Antiviral neutralizing effects of zinc oxide tetrapods. ► Therapeutic effects of viral entry blocking. ...► Zinc oxide tetrapods block viral spread.
The attachment of Herpes simplex virus type-2 (HSV-2) to a target cell requires ionic interactions between negatively charged cell surface co-receptor heparan sulfate (HS) and positively charged residues on viral envelop glycoproteins, gB and gC. Effective blocking of this first step of HSV-2 pathogenesis demonstrates significant prophylactic effects against the viral disease; any in vitro therapeutic effects of blocking this interaction, however, are not clear. Here, we provide new evidence that zinc oxide tetrapod micro-nanostructures synthesized by flame transport approach significantly block HSV-2 entry into target cells and, in addition, demonstrate the potential to stop the spread of the virus among already infected cells. The zinc oxide tetrapods (ZnOTs) also exhibit the ability to neutralize HSV-2 virions. Natural target cells such as human vaginal epithelial and HeLa cells showed highly reduced infectivity when infected with HSV-2 virions that were pre-incubated with the ZnOTs. The mechanism behind the ability of ZnOTs to prevent, neutralize or reduce HSV-2 infection relies on their ability to bind the HSV-2 virions. We used fluorescently labeled ZnOTs and GFP-expressing HSV-2 virions to demonstrate the binding of the ZnOTs with HSV-2. We also show that the binding and hence, the antiviral effects of ZnOTs can be enhanced by illuminating the ZnOTs with UV light. Our results provide new insights into the anti-HSV-2 effects of ZnOT and rationalize their development as a HSV-2 trapping agent for the prevention and/or treatment of infection. The observed results also demonstrate that blocking HSV-2 attachment can have prophylactic as well as therapeutic applications.
Direct growth of quasi-one-dimensional nano- and microstructures in desired places of complex shaped substrates using simple growth methods is highly demanded aspect for various applications. In this ...work, we have demonstrated direct integration of ZnO nano- and microneedles into Si trenches by a novel flame transport synthesis approach in a single fabrication step. Growth of partially and fully covered or filled trenches in Si substrate with ZnO nano- and microneedles has been investigated and is discussed here. Detailed microstructural studies revealed the evolution of the ZnO nano- and microneedles as well as their firm adhesion to the wall in the Si trenches. Micro-photoluminescence measurements at different locations along the length of needles confirmed the good crystalline quality and also the presence of whispering gallery mode resonances on the top of needles due to their hexagonal shape. Faceted ZnO nano- and microstructures are also very important candidates with regard to photocatalytic activity. First, photocatalytic measurements from the grown ZnO nano- and microneedles have shown strong degradation of methylene blue, which demonstrate that these structures can be of significant interest for photocatalysis and self-cleaning chromatography columns.
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