Anti-Candidal Activity and In Vitro Cytotoxicity Assessment of Graphene Nanoplatelets Decorated with Zinc Oxide Nanorods

Recent advances in the synthesis, characterization and biomedical applications of zinc oxide nanoparticles

Zinc oxide nanoparticles (ZnONPs) have become the widely used metal oxide nanoparticles and drawn the interest of global researchers due to their biocompatibility, low toxicity, sustainability and cost-effective properties. Due to their unique optical and chemical properties, it emerges as a potential candidate in the fields of optical, electrical, food packaging and biomedical applications. Biological methods using green or natural routes are more environmentally friendly, simple and less use of hazardous techniques than chemical and/or physical methods in the long run. In addition, ZnONPs are less harmful and biodegradable while having the ability to greatly boost pharmacophore bioactivity. They play an important role in cell apoptosis because they enhance the generation of reactive oxygen species (ROS) and release zinc ions (Zn2+), causing cell death. Furthermore, these ZnONPs work well in conjunction with components that aid in wound healing and biosensing to track minute amounts of biomarkers connected to a variety of illnesses. Overall, the present review discusses the synthesis and most recent developments of ZnONPs from green sources including leaves, stems, bark, roots, fruits, flowers, bacteria, fungi, algae and protein, as well as put lights on their biomedical applications such as antimicrobial, antioxidant, antidiabetic, anticancer, anti-inflammatory, antiviral, wound healing, and drug delivery, and modes of action associated. Finally, the future perspectives of biosynthesized ZnONPs in research and biomedical applications are discussed.

Nanoantibiotic effect of carbon-based nanocomposites: epicentric on graphene, carbon nanotubes and fullerene composites: a review

Carbon in many different forms especially, Graphene, Carbon nanotubes (CNTs), and Fullerene is emerging as an important material in the areas of the biomedical field for various applications. This review comprehensively describes the nano antibiotic effect of carbon-based nanocomposites: epicenter on graphene, carbon nanotubes, and fullerene Composites. It summarises the studies conducted to evaluate their antimicrobial applications as they can disrupt the cell membrane of bacteria resulting in cell death. The initial section gives a glimpse of both "Gram"-positive and negative bacteria, which have been affected by Graphene, CNTs, and Fullerene-based nanocomposites. These bacteria include Staphylococcus Aureus, Bacillus Thuringiensis, Enterococcus faecalis, Enterococcus faecium, Bacillus subtilis, Escherichia coli, Klebseilla pneumoniae, Pseudomonas aeroginosa, Pseudomonas syringae , Shigella flexneri,Candida Albicans, Mucor. Another section is dedicated to the insight of Graphene, and its types such as Graphene Oxide (GO), Reduced graphene oxide (rGO), Graphene Nanoplatelets (GNPs), Graphene Nanoribbons (GNRs), and Graphene Quantum Dots (GQDs). Insight into CNT, including both the types SWCNT and MWCNT, studied, followed by understanding fullerene is also reported. Another section is dedicated to the antibacterial mechanism of Graphene, CNT, and Fullerene-based nanocomposites. Further, an additional section is dedicated to a comprehensive review of the antibacterial characteristics of Graphene, CNT, and nanocomposites based on fullerene. Future perspectives and recommendations have also been highlighted in the last section.

Antimicrobial Activity of Graphene-Based Nanocomposites: Synthesis, Characterization, and Their Applications for Human Welfare

Graphene (GN)-related nanomaterials such as graphene oxide, reduced graphene oxide, quantum dots, etc., and their composites have attracted significant interest owing to their efficient antimicrobial properties and thus newer GN-based composites are being readily developed, characterized, and explored for clinical applications by scientists worldwide. The GN offers excellent surface properties, i.e., a large surface area, pH sensitivity, and significant biocompatibility with the biological system. In recent years, GN has found applications in tissue engineering owing to its impressive stiffness, mechanical strength, electrical conductivity, and the ability to innovate in two-dimensional (2D) and three-dimensional (3D) design. It also offers a photothermic effect that potentiates the targeted killing of cells via physicochemical interactions. It is generally synthesized by physical and chemical methods and is characterized by modern and sophisticated analytical techniques such as NMR, Raman spectroscopy, electron microscopy, etc. A lot of reports show the successful conjugation of GN with existing repurposed drugs, which improves their therapeutic efficacy against many microbial infections and also its potential application in drug delivery. Thus, in this review, the antimicrobial potentialities of GN-based nanomaterials, their synthesis, and their toxicities in biological systems are discussed.

miR-124-3p Delivered Using Exosomes Attenuates the Keratinocyte Response to IL-17A Stimulation in Psoriasis

Methods

NHEKs, HaCaT cells, and HEK 293T cells were treated with IL-17A. CCK-8 assays were performed to detect cell activity, and immunofluorescence staining and Western blotting were performed to detect the protein expression of STAT3. After isolation of exosomes via ultracentrifugation, the contents of miR-124-3p and oxidative stress markers such as superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in keratinocytes were measured. Subsequently, transcriptomic analysis was performed using RNA-seq. Data were analysed by using the “edgeR” package within R. After verifying the abnormally expressed genes stimulated by IL-17A, a dual luciferase reporter assay was used to determine the interaction between miR-124-3p and STAT3. Finally, BALB/c mice were used to establish a psoriasis model for analysis. The effect of elevated miR-124-3p on the psoriasis mouse model was determined by exosomal delivery of miR-124-3p.

Results

IL-17 intervention enhanced the cell activity of keratinocytes (P < 0.05). miR-124-3p was identified by RNA-seq as one of the differentially expressed miRNAs stimulated by IL-17A. miR-124-3p overexpression induced decreased STAT3 and MDA levels, increased SOD and GSH-Px levels in keratinocytes, and alleviated emergency responses of sclerosis damage (P < 0.05). The dual luciferase reporter assay results confirmed that STAT3 was regulated by miR-124-3p in a targeted manner (P < 0.05). Finally, miR-124-3p delivered by exosomes effectively alleviated the pathological manifestations and oxidative stress responses of psoriatic mice.

Conclusions

miR-124-3p regulates keratinocyte activity via STAT3 in response to IL-17A stimulation. The ectopic expression of miR-124-3p in psoriatic skin reduces IL-17A-induced inflammation and inhibits the STAT3 pathway, thus alleviating the symptoms of psoriasis. The findings of this study suggest that exosomes can be used to therapeutically deliver miR-124-3p to keratinocytes and psoriatic lesions, which may provide novel insight for psoriasis treatment.

Carbon nanostructures: a comprehensive review of potential applications and toxic effects

There is no doubt that nanotechnology has revolutionized our life since the 1970s when it was first introduced. Nanomaterials have helped us to improve the current products and services we use. Among the different types of nanomaterials, the application of carbon-based nanomaterials in every aspect of our lives has rapidly grown over recent decades. This review discusses recent advances of those applications in distinct categories, including medical, industrial, and environmental applications. The first main section introduces nanomaterials, especially carbon-based nanomaterials. In the first section, we discussed medical applications, including medical biosensors, drug and gene delivery, cell and tissue labeling and imaging, tissue engineering, and the fight against bacterial and fungal infections. The next section discusses industrial applications, including agriculture, plastic, electronic, energy, and food industries. In addition, the environmental applications, including detection of air and water pollutions and removal of environmental pollutants, were vastly reviewed in the last section. In the conclusion section, we discussed challenges and future perspectives.

Beta vulgaris Assisted Fabrication of Novel Ag-Cu Bimetallic Nanoparticles for Growth Inhibition and Virulence in Candida albicans

Beta vulgaris extract contains water-soluble red pigment betanin and is used as a food colorant. In this study, the biogenic Ag-Cu bimetallic nanoparticles were synthesized and characterized by different spectroscopic and microscopic techniques, including UV-Visible, FTIR, TEM. SEM-EDX, XRD, and TGA. Further, Ag-Cu bimetallic nanoparticles capped with Beta vulgaris biomolecules were evaluated for their antifungal activity against Candida albicans via targeting its major virulence factors, including adherence, yeast to hyphae transition, extracellular enzyme secretion, biofilm formation, and the expression of genes related to these pathogenic traits by using standard methods. C. albicans is an opportunistic human fungal pathogen that causes significant morbidity and mortality, mainly in immunocompromised patients. The current antifungal therapy is limited with various shortcomings such as host toxicity and developing multidrug resistance. Therefore, the development of novel antifungal agents is urgently required. Furthermore, NPs were screened for cell viability and cytotoxicity effect. Antifungal susceptibility testing showed potent antifungal activity of the Ag-Cu bimetallic NPs with a significant inhibitory effect on adherence, yeast to hyphae transition, extracellular enzymes secretion, and formation of biofilms in C. albicans at sub-inhibitory and inhibitory concentrations. The RT-qPCR results at an MIC value of the NPs exhibited a varying degree of downregulation in expression levels of virulence genes. Results also revealed the dose-dependent effect of NPs on cellular viability (up to 100%) using MUSE cell analyzer. Moreover, the low cytotoxicity effect of bimetallic NPs has been observed using haemolytic assay. The overall results indicated that the newly synthesized Ag-Cu bimetallic NPs capped with Beta vulgaris are proven to possess a potent anticandidal activity, by affecting the vital pathogenic factors of C. albicans.

Biocompatibility and Antibiofilm Properties of Calcium Silicate-Based Cements: An In Vitro Evaluation and Report of Two Clinical Cases

Simple Summary

Calcium silicate-based cements are successfully applied in the different fields of endodontics and vital pulp therapy. To better assess the properties of these bioactive materials, the present in vitro and in vivo study aimed to compare the biocompatibility and antibiofilm properties of ProRoot MTA and Biodentine. Human osteogenic sarcoma (Saos-2) cells were cultured in the presence of both materials and evaluated. Moreover, the bioactive cements were in vivo applied to perform vital pulp therapy on immature permanent teeth affected by reversible pulpitis. Saos-2 cells’ viability was slightly greater in the presence of ProRootMTA than Biodentine and cells would grow in a better way on ProRootMTA disks than on Biodentine ones. Moreover, ProRootMTA showed a powerful antibiofilm effect towards Streptococcus mutans. The in vitro results were clinically supported by a 100% success rate after 2 years of follow-up.

Abstract

Calcium silicate-based cements have reached excellent levels of performance in endodontics, providing predictable and successful results. To better assess the properties of these bioactive materials, the present study aimed to compare the biocompatibility and antibiofilm properties of ProRoot MTA and Biodentine. Human osteogenic sarcoma (Saos-2) cells were cultured on ProRoot MTA and Biodentine samples or in the presence of both cement extracts. Cell viability assay, measurement of reactive oxygen species (ROS), immunofluorescence analysis, as well as morphological evaluations were conducted. Moreover, Streptococcus mutans was used to assess the biofilm forming ability on ProRoot MTA and Biodentine disks. Finally, both cements were applied in vivo to treat immature permanent teeth affected by reversible pulpitis. Results: Cell viability assay demonstrated that Saos-2 cells had a dose- and time-dependent cytotoxicity to both analyzed cements, although cells exposed to ProRoot MTA showed a better cell vitality than those exposed to Biodentine (p < 0.001). Both cements demonstrated ROS production while this was greater in the case of Biodentine than ProRoot MTA (p < 0.001). Immunofluorescence images of the cytoskeleton and focal adhesions showed no differences in Saos-2 cells grown in the presence of ProRoot MTA eluate; whereas in the Biodentine groups, cells showed a morphology and focal adhesions more similar to that of the control sample, as the eluate concentration decreased. Morphological analysis revealed that Saos-2 cells were more flattened and exhibited better spreading when attached to ProRoot MTA disks than to Biodentine ones. The antibiofilm properties showed a time-dependent powerful inhibition of S. mutans superficial colonization and an antibiofilm effect of both cements. Clinically, complete root formation of the treated elements was achieved using the two studied cements, showing stable results over time. ProRoot MTA and Biodentine was demonstrated to be biocompatible and to possess antibiofilm properties. Their clinical application in vital pulp therapy provided successful outcomes after 2 years of follow-up.

Al-Suhaimi E, Hussain M, Yousuf Bari M, Mehmood Ali S, Al-Jameel SS, Slimani Y, Khan FA, Baykal A. Ultrasonic Synthesis and Biomedical Application of Mn0.5Zn0.5ErxYxFe2-2xO4 Nanoparticles

In the present study, biocompatible manganese nanoparticles have been linked with zinc and iron molecules to prepare different derivatives of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs (x = 0.02, 0.04, 0.06, 0.08, 0.10), using an ultrasonication approach. The structure, surface morphology, and chemical compositions of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs were elucidated by X-ray diffractometer (XRD), High-resolution transmission electron microscopy (HR-TEM), scanning electron microscope (SEM), and Energy Dispersive X-Ray Analysis (EDX) techniques. The bioactivity of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs on normal (HEK-293) and (HCT-116) colon cancer cell line was evaluated. The Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs treatment post 48 h resulted in a significant reduction in cells (via MTT assay, having an IC₅₀ value between 0.88 µg/mL and 2.40 µg/mL). The specificity of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs were studied by treating them on normal cells line (HEK-293). The results showed that Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs did not incur any effect on HEK-293, which suggests that Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs selectively targeted the colon cancerous cells. Using Candida albicans, antifungal activity was also studied by evaluating minimum inhibitory/fungicidal concentration (MIC/MFC) and the effect of nanomaterial on the germ tube formation, which exhibited that NPs significantly inhibited the growth and germ tube formation. The obtained results hold the potential to design nanoparticles that lead to efficient bioactivity.

Novel Structures and Applications of Graphene-Based Semiconductor Photocatalysts: Faceted Particles, Photonic Crystals, Antimicrobial and Magnetic Properties

Graphene, graphene oxide, reduced graphene oxide and their composites with various compounds/materials have high potential for substantial impact as cheap photocatalysts, which is essential to meet the demands of global activity, offering the advantage of utilizing “green” solar energy. Accordingly, graphene-based materials might help to reduce reliance on fossil fuel supplies and facile remediation routes to achieve clean environment and pure water. This review presents recent developments of graphene-based semiconductor photocatalysts, including novel composites with faceted particles, photonic crystals, and nanotubes/nanowires, where the enhancement of activity mechanism is associated with a synergistic effect resulting from the presence of graphene structure. Moreover, antimicrobial potential (highly needed these days), and facile recovery/reuse of photocatalysts by magnetic field have been addresses as very important issue for future commercialization. It is believed that graphene materials should be available soon in the market, especially because of constantly decreasing prices of graphene, vis response, excellent charge transfer ability, and thus high and broad photocatalytic activity against both organic pollutants and microorganisms.

Phytogenic Fabrication of Ag-Fe Bimetallic Nanoparticles for Cell Cycle Arrest and Apoptosis Signaling Pathways in Candida auris by Generating Oxidative Stress

Novel green synthetic nanomedicines have been recognized as alternative therapies with the potential to be antifungal agents. Apoptosis induction, cell cycle arrest and activation of the antioxidant defense system in fungal cells have also gained attention as emerging drug targets. In this study, a facile and biodegradable synthetic route was developed to prepare Ag-Fe bimetallic nanoparticles using aqueous extract of Beta vulgaris L. Surface plasmon resonance of Beta vulgaris-assisted AgNPs nanoparticles was not observed in the UV-visible region of Ag-Fe bimetallic NPs, which confirms the formation of Ag-Fe nanoparticles. Beta vulgaris-assisted Ag-Fe NPs were characterized by FTIR spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and TGA-DTG analysis for their structural and morphological properties. The as-prepared Ag-Fe NPs were well dispersed and spherical with the average particle size of 15 nm. The antifungal activity of these Ag-Fe NPs against clinical isolates of Candida auris was determined by broth microdilution and cell viability assays. For insights into mechanisms, induction of apoptosis and triggering cell cycle arrest were studied following standard protocols. Furthermore, analysis of antioxidant defense enzymes was determined spectrophotometrically. Antifungal susceptibility results revealed high antifungal activity with MIC values ranging from 0.19 to 0.39 µg/mL. Further studies showed that Ag-Fe NPs were able to induce apoptosis, cell cycle arrest in G2/M phase and disturbances in primary and secondary antioxidant enzymes. This study presents the potential of Ag-Fe NPs to inhibit and potentially eradicate C. auris by inducing apoptosis, cell cycle arrest and increased levels of oxidative stress.

Facile Bio-Fabrication of Ag-Cu-Co Trimetallic Nanoparticles and Its Fungicidal Activity against Candida auris

Candida auris is an emergent multidrug-resistant pathogen that can lead to severe bloodstream infections associated with high mortality rates, especially in hospitalized individuals suffering from serious medical problems. As Candida auris is often multidrug-resistant, there is a persistent demand for new antimycotic drugs with novel antifungal action mechanisms. Here, we reported the facile, one-pot, one-step biosynthesis of biologically active Ag-Cu-Co trimetallic nanoparticles using the aqueous extract of Salvia officinalis rich in polyphenols and flavonoids. These medicinally important phytochemicals act as a reducing agent and stabilize/capping in the nanoparticles' fabrication process. Fourier Transform-Infrared, Scanning electron microscopy, Transmission Electron Microscopy, Energy dispersive X-Ray, X-ray powder diffraction and Thermogravimetric analysis (TGA) measurements were used to classify the as-synthesized nanoparticles. Moreover, we evaluated the antifungal mechanism of as-synthesized nanoparticles against different clinical isolates of C. auris. The minimum inhibitory concentrations and minimum fungicidal concentrations ranged from 0.39-0.78 μg/mL and 0.78-1.56 μg/mL. Cell count and viability assay further validated the fungicidal potential of Ag-Cu-Co trimetallic nanoparticles. The comprehensive analysis showed that these trimetallic nanoparticles could induce apoptosis and G2/M phase cell cycle arrest in C. auris. Furthermore, Ag-Cu-Co trimetallic nanoparticles exhibit enhanced antimicrobial properties compared to their monometallic counterparts attributed to the synergistic effect of Ag, Cu and Co present in the as-synthesized nanoparticles. Therefore, the present study suggests that the Ag-Cu-Co trimetallic nanoparticles hold the capacity to be a lead for antifungal drug development against C. auris infections.

Workers' Exposure Assessment during the Production of Graphene Nanoplatelets in R&D Laboratory

Widespread production and use of engineered nanomaterials in industrial and research settings raise concerns about their health impact in the workplace. In the last years, graphene-based nanomaterials have gained particular interest in many application fields. Among them, graphene nanoplatelets (GNPs) showed superior electrical, optical and thermal properties, low-cost and availability. Few and conflicting results have been reported about toxicity and potential effects on workers’ health, during the production and handling of these nanostructures. Due to this lack of knowledge, systematic approaches are needed to assess risks and quantify workers’ exposure to GNPs. This work applies a multi-metric approach to assess workers’ exposure during the production of GNPs, based on the Organization for Economic Cooperation and Development (OECD) methodology by integrating real-time measurements and personal sampling. In particular, we analyzed the particle number concentration, the average diameter and the lung deposited surface area of airborne nanoparticles during the production process conducted by thermal exfoliation in two different ways, compared to the background. These results have been integrated by electron microscopic and spectroscopic analysis on the filters sampled by personal impactors. The study identifies the process phases potentially at risk for workers and reports quantitative information about the parameters that may influence the exposure in order to propose recommendations for a safer design of GNPs production process.

ZnO Nanomaterials: Current Advancements in Antibacterial Mechanisms and Applications

The prevalence of various diseases caused by bacteria has been increasing, and some traditional antibiotics have been reported to have varying degrees of resistance. ZnO nanomaterials (ZnO-NMs), due to their excellent broad-spectrum antibacterial properties, lasting antibacterial effects, and excellent biocompatibility, have quickly become the research focus of new antibacterial agents. While the narrow light response range of ZnO-NMs has limited the antibacterial performance to some extent and modifying it by various means to improve its response under visible light, such as doping metal/non-metal atoms, depositing noble metals and coupling carbon materials, which is a new research hotspot. Herein, the current mainstream claims about the antibacterial mechanisms and applications of ZnO-NMs are reviewed.

Effects of different graphene-based nanomaterials as elicitors on growth and ganoderic acid production by Ganoderma lucidum

Graphene-based nanomaterials (GBNs) have attracted considerable interest nowadays due to their wide range of applications. However, very little attention has been paid to the application of nanomaterials as potential elicitors for production of valuable metabolites. Herein, aiming to earn insight into effects of nanomaterials on secondary metabolite biosynthesis by medicinal fungi, we evaluated the influence of GBNs on growth and production of ganoderic acid (GA) by Ganoderma lucidum in submerged culture. Graphene oxide (GO), reduced graphene oxide (rGO), and rGO/Fe₃ O₄ nanocomposite were synthesized successfully and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis. The prepared nanomaterials were added to the culture of G. lucidum at final concentrations of 50, 100, and 150 mg/L on Day 5. The results showed that the elicitation of G. lucidum with GO and rGO decreased the cell dry weight and GA production slightly, especially in higher concentrations. However, rGO/Fe₃ O₄ nanocomposite not negatively affected cell growth and improved GA production. G. lucidum growth rate responded to elicitation experiments differently and depended on the type of nanomaterials and their concentrations, but almost all GBNs caused an increase in GA content (mg/100 mg dry weight). Also, field emission scanning electron microscopy morphological study showed that under elicitation, mycelia were more condensed and tightly stacked together. The findings from this study may suggest that GBNs in low concentrations could be applied as elicitors to secondary metabolites production from higher fungus, but further environmental, physiological, and biological studies required.

Toxicological response of the model fungus Saccharomyces cerevisiae to different concentrations of commercial graphene nanoplatelets

Graphene nanomaterials have attracted a great interest during the last years for different applications, but their possible impact on different biological systems remains unclear. Here, an assessment to understand the toxicity of commercial polycarboxylate functionalized graphene nanoplatelets (GN) on the unicellular fungal model Saccharomyces cerevisiae was performed. While cell proliferation was not negatively affected even in the presence of 800 mg L-1 of the nanomaterial for 24 hours, oxidative stress was induced at a lower concentration (160 mg L-1), after short exposure periods (2 and 4 hours). No DNA damage was observed under a comet assay analysis under the studied conditions. In addition, to pinpoint the molecular mechanisms behind the early oxidative damage induced by GN and to identify possible toxicity pathways, the transcriptome of S. cerevisiae exposed to 160 and 800 mg L-1 of GN was studied. Both GN concentrations induced expression changes in a common group of genes (337), many of them related to the fungal response to reduce the nanoparticles toxicity and to maintain cell homeostasis. Also, a high number of genes were only differentially expressed in the GN800 condition (3254), indicating that high GN concentrations can induce severe changes in the physiological state of the yeast.