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Bacterial Nanocellulose Obtained Using Medusomyces gisevii SA-12: in Vivo Evaluation of Allergenic and Sensitizing Properties upon Oral Administration
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Published: 05 May 2023 by MDPI in The 4th International Online Conference on Nanomaterials session Poster

An industrially scalable technology for the production of bacterial nanocellulose has been developed using a symbiotic culture of Medusomyces gisevii strain Sa-12 on a semi-synthetic glucose medium and hydrolysates of pretreated oat husks. The unique properties of the material consist in extraordinary values of the content of cellulose allomorph Iα (C) in the range of 94-100% and the degree of crystallinity (CI) in the range of 88-93%, which is due to the specifics of the use of this producing community. Possible applications of the material include food ingredients, packaging materials with improved functional characteristics, medical devices, diagnostic tools, and drug delivery agents. The potential allergenicity and sensitizing properties of bacterial nanocellulose following a daily oral intake for 35 days were studied using a model antigen - the protein of chicken egg ovalbumin in an in vivo experiment on a model of systemic anaphylaxis in Wistar rats. The results obtained demonstrated in the experimental group a tendency to decrease the mortality of animals caused by the developed reaction of systemic anaphylaxis as a result of the introduction of a resolving dose of the model antigen. Based on the study of the levels of specific circulating IgG and the results of assessing the severity of systemic anaphylaxis reactions, bacterial nanocellulose has no allergenic and sensitizing properties when consumed by the Wistar rats with a diet for 35 days.

  • Open access
  • 12 Reads
The Effect of Nickel Nanoparticles Administered Orally on the Content of Trace Elements in the Internal Organs of Rats
Published: 05 May 2023 by MDPI in The 4th International Online Conference on Nanomaterials session Poster

Assessing the risks of nanomaterials exposure to consumer health requires studying their effect on metabolic processes in the body, in particular, on mineral homeostasis, the exchange of essential and toxic chemical elements. Nickel nanoparticles (NiNp) are used as components of hydrogenation catalysts, as well as pesticides. The aim of the work was to study the homeostasis of essential and toxic trace elements under the influence of oral administration to Wistar rats for 92 days of two types of NiNp with an average diameter of 53.7 and 70.9 nm at doses of 0.1, 1.0, and 10 mg/kg bw. In the liver, kidneys, and spleen the content of Ni, as well as 28 other essential, toxic and non-established biological function elements was determined by inductively coupled plasma mass spectrometry. In rats treated with NiNp, various changes in the indicators of homeostasis of trace elements were observed, including increased bioaccumulation of lead in the liver, gonads and brain, arsenic in the spleen, aluminum in the liver and brain. The introduction of nanoparticles lead to inhibition of the accumulation of divalent metal cations: Mg, Mn, and Sr - in the kidneys; Ba - in the kidneys and spleen; the content of Ca under the influence of nanoparticles increased in the kidneys, but decreased in the gonads. The effects on the bioaccumulation of trivalent elements Cr and B had different directions depending on the form of Ni in different organs. A number of effects exhibited by NiNp in animals were absent or had the opposite sign in the comparison group receiving Ni salt. The effects exerted by NiNp on microelement homeostasis should be taken into account in the toxicological assessment of their safety and health risks, especially in conditions of combined contamination of the habitat with heavy metal salts.

  • Open access
  • 18 Reads
Reusable tin-modified biomass-derived carbon network interlayers for dendrite-free and flexible zinc anodes
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Published: 05 May 2023 by MDPI in The 4th International Online Conference on Nanomaterials session Poster

Zinc ion batteries (ZIBs) with low cost, high safety and environment friendliness, are expected to be the promising candidates for energy storage. Unfortunately, their practical application is hindered by the Zn dendrites and hydrogen evolution reaction (HER). Zn dendrites can reduce the capacity and coulombic efficiency, even puncture separators and short-circuit the battery. The HER will corrode the Zn anode surface, and the generated gas exacerbate the battery inflation. The strategies to solve the above issues are categorized as anode design, interface modification, electrolyte adjustment and separator design. Among them, the multifunctional artificial interlayer is a competitive strategy for reversible and homogenous Zn deposition. The interlayer is required of rapid electron/ion transfer and superior zincophilicity to regulate the interfacial electrodeposition kinetics, which mainly focuses on the carbon materials. Herein, a Sn-modified carbonized bacterial cellulose network interlayer is proposed for dendrite-free and stable Zn anode. The low-cost CBC delivers a 3D porous network, providing abundant active sites. And its high mechanical properties and electrical conductivity can meet the requirements for independent interlayers. Besides, the Sn nanoparticles not only reduce the barrier of Zn nucleation and induce homogeneous Zn deposition, but also inhibit the HER and slow the corrosion of Zn anodes. Due to these merits, the independent CBC@Sn interlayer endows a superior cycle stability of Zn||Zn symmetric battery, a low nucleation overpotential and a high coulombic efficiency of Zn||Cu asymmetric battery, and an excellent rate and cycle performance of Zn||VOPO4 full battery. This flexible and reusable interlayer demonstrates a feasible approach of commercial energy storage with cost-effectiveness and eco-friendliness.

  • Open access
  • 21 Reads
Nanomaterials as Sensor : For Water and Air Pollutants
Published: 05 May 2023 by MDPI in The 4th International Online Conference on Nanomaterials session Poster

Abstract: Environmental restoration is one of the global concerns today. The degradation of environment is impacting it's biodiversity and also is showing an adverse effect on human health. Hydrocarbons, CO, chlorofluorocarbons, volatile organic compounds, and nitrogen oxides are the principal contributors to air pollution. Water that has been contaminated with both organic and inorganic substances. The main sources of water contamination are sewage water, industrial effluents and inadequate use of pesticides and fertilisers. The need of better technological advancements are required to reduce pollution levels. There is a lot of interest in the potential applications of nanomaterials in better systems for monitoring and cleaning up water and air contaminants. Nanomaterials, such as zeolites, carbon nanotubes, and nano-adsorbents, are a few examples that can be employed for the removal of metallic contaminants from water and wastewater. Various nanomaterials have also been produced for the detection and removal of gaseous pollutants from air, such as carbon, graphene, metal and metal oxide nanomaterias etc. Due to their significant specific surface areas and high reactivities, nanomaterials are ideal adsorbents, catalysts, and sensors. It can help in designing new methods for sensing and detection of pollutants. The present review gives an insight of the major applications of nanomaterials for removing contaminants from air and water.

  • Open access
  • 16 Reads
The annealing effect of structured nickel octahedra nanoparticles on the performance of NiO supported on silica in combined steam and dry reforming of a model biogas mixture

The octahedral family of NiO nanoparticles is gaining significant attention as an assembly with unique physicochemical properties and outcomes in electromagnetics, shielding, and absorption. In this study, a mesoporous structured Ni60%SiO2(Comm), chosen owing to its NiO species existing in an octahedral shape, was evaluated for synthesis gas (syngas: H2(g) and CO(g) mixtures) production via combined steam and dry reforming of a model biogas mixture (T= 800 °C, (H2O(g) + CO2(g))/CH4(g)= 1.2). To the best of our knowledge, the consideration of Ni octahedra-based nanomaterials as potential catalysts for reforming reactions, particularly biogas reforming, towards syngas generation has not been yet considered in the available literature. In comparison to a standard Ni5%SiO2 catalyst, slightly higher reactivity levels along with significantly lower amounts of carbonaceous deposits were obtained over the commercial Ni60%SiO2(Comm) catalyst for 10 h on stream. The high coke resistance of originally shaped NiO octahedra was ascribed to an annealing effect, generated during H2(g)-treatment (prior to catalysis), yielding mesoporous metallic Ni0 nanorods with H2(g)-storage capacities. Stored hydrogen within Ni0 layers acted as active centers for continuous in situ coke gasification, preventing thus C(s) accumulation while keeping Ni0 sites accessible for catalysis.

  • Open access
  • 17 Reads
Investigation of the Dielectric Response of PPy/V2C Mxene-ZnO Using Quantum mechanical Calculations.

With the proliferation of electronic gadgets and the internet of things comes a great need for lightweight, affordable, sustainable, and long-lasting power devices to combat the depletion of fossil fuel energy and the pollution produced by chemical energy storage. The use of high-energy-density polymer/ceramic composites is generating more curiosity for future technologies, and they require a high breakdown strength and dielectric constant. Interface polarization and electric percolation are responsible for the high dielectric constant. To create composite dielectrics, high-conductivity ceramic particles are combined with polymers to increase the dielectric constant. In this work, ternary nanocomposites with better dielectric characteristics are created using a nanohybrid filler of V2C Mxene-ZnO in a polypyrrole (PPy) matrix. Then, the bonding and the non-uniform distribution of charges in the ceramic/ceramic interface zone are investigated using quantum mechanical calculations. This non-uniform distribution of charges is intended to improve the ceramic/ceramic interface's dipole polarization (dielectric response). The interfacial chemical bond formation can also improve the structural stability of the hybrid filler and, consequently, of the composite films. To comprehend the electron-transfer process, the density of state and electron localization function of the PPy with hybrid fillers are also studied. The polymer nanocomposite is anticipated to provide a suitable dielectric response for energy storage applications.

  • Open access
  • 14 Reads
Preparation of dual pH- and temperature- sensitive nanogels for curcumin delivery

Curcumin (Cur) is a valuable ingredient from turmeric with many bioactivities. Cur was used in various traditional therapies. However, the low solubility and poor bioavailability limit its therapeutic application. In this work, we preparation the dual pH- and thermo-sensitive nanogels (NGs) from poly-N-isopropylacrylamide (PNIPAm) and polyacrylamide (PAAm) [P(NIPAAm-co-AAm) NGs] to delivery Cur. The P(NIPAAm-co-AAm) NGs were characterized by SEM, TEM, ¹H-NMR, XPS, FT-IR, and DLS. The cytotoxicity test on the liver cancer cells (HepG2 cells) showed low cytotoxicity and high biocompatibility of the NGs. The NGs were also subjected to pH and temperature-sensitive in vitro Cur-loading and Cur-release experiments. We control the pH and temperature conditions to switch the NGs between swelling and deswelling to loading and releasing Cur. The synthesized copolymer PNIPAm-co-PAAm HG showed about ~65% of Cur loading. The zeta potential of NGs was decreased when the pH conditions increased and the phage transition of NGs happened at 40 ℃ with concentration-dependent properties. After 4 h under pH 5.5 and 40 °C, nearly 100% of Cur has successfully been released from the NGs. The newly synthesized NGs could release the drug according to the physical stimulus (i.e. pH and temperature). Therefore, the NGs have potential application value in solid tumor-targeted therapy.

  • Open access
  • 31 Reads
Development of green gold nanoparticles against antibiotic resistant Staphylococcus aureus; A shift from chemical to biological synthesis

Development of bacterial resistance towards existing antibiotics is a universal problem for human and animal health as well as for food security. In an attempt to overcome this problem, nanotechnology has contributed with nano formulations. However, these are associated with risks and drawbacks including environmental toxicity, cell injury, issues of high production cost and scarcity of active ingredients. On the other hand, green synthesis of nano formulations by biological methods is a simple, innovative, ecofriendly, cost effective and advanced approach for the treatment of lethal infections caused by multidrug resistant organisms like staphylococcus aureus . About 30% of humans are asymptomatic carriers of S. aureus in their upper respiratory tract.Clinical disease caused by S. aureus infections range from mild to severe and may be manifested in the form of pneumonia, osteomyelitis, skin and deep tissue infections Here, we prepared plant-mediated gold nanoparticles from Camellia sinensis and Cocos nucifera. The green biocompatible nanoparticles were characterized by using UV-Visible spectroscopy (UV-Vis spectroscopy), X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), Dynamic.light.scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). Moreover, these green gold nanoparticles were investigated for their antimicrobial activity by checking minimum inhibitory concentration (MIC). We found that the newly developed bionanoparticles showed strong activity against the multidrug resistant Staphylococcus aureus.

  • Open access
  • 23 Reads
Applications Of Nanomaterials in Food Industry: A Review

Nanotechnology covers the production, processes and applications of nano-sized materials. Biological and physical approaches bring materials with new functions in the food industry by using common and innovative food processing technologies to adapt materials to the nanoscale. Making sense of the properties of natural and modified food ingredients when they come together is important for the development process of nanostructured materials. The functionalization of nanostructured materials finds many applications in the food industry. Some of these areas are; nanosensors, new packaging materials that emerged with the improvement of mechanical and restrictive properties, targeted food delivery systems [1]. In food packaging, it can be possible to obtain antioxidant featured nanomaterials by using nanoparticles, nanofibers, nanocrystals, nanoemulsions. They are treated with antioxidants and polymers to make them resistant to oxidation of lipids and proteins in the food [2]. It is thought that the applications of nanotechnology in the food field will be carried to the most advanced level with studies on nanostructures and methods for controlling the interaction between different molecules. Besides that, it is important to find suitable food nanomaterial for consumer and environment. So, the researchers also studied about harmfulness of food nanomaterials on human in case of a long time usage [1].

References

[1] Augustin, M. A., & Sanguansri, P. (2009). Nanostructured materials in the food industry. Advances in food and nutrition research, 58, 183-213.

[2] Cheng, H., Chen, L., McClements, D. J., Xu, H., Long, J., Zhao, J., & Jin, Z. (2022). Recent advances in the application of nanotechnology to create antioxidant active food packaging materials. Critical Reviews in Food Science and Nutrition, 1-16.

  • Open access
  • 13 Reads
Nafion Based Layer-by-Layer Coatings with Antimicrobial Activity

With the need for non-antibiotic approaches to microbial pathogenesis being ever present, development of alternatives centred around infection prevention are of deep importance.

Antimicrobial surface coatings offer a promising approach, as they can possess multiple favourable qualities such as low toxicity, longevity and the capacity for re-coating. Of the possible coating methods, Layer-by-Layer (LbL) deposition provides a particularly useful approach, allowing for facile creation of multi-layered coatings on pre-existing surfaces.

For these LbL coatings, Nafion, a synthetic polymer with excellent mechanical properties, was used as a stable foundation for two model tri-layer systems. Both sets of systems were comprised of Nafion layered alongside compounds with well-established antimicrobial activity: lysozyme, chitosan, and carbon dots (CDots). In addition to their antimicrobial properties, lysozyme and chitosan are both non-toxic and biocompatible, making them ideal for biomedical applications. Similarly, CDots have low toxicity but also possess fluorescent properties, opening up the potential for the assessment of coating integrity, making these coatings suitable for high-wear surfaces. As such, the two tri-layer systems were made up of Nafion, lysozyme and chitosan, with the other comprising of Nafion, lysozyme, and CDots.

When assessed against the representative Gram negative and Gram positive species Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) respectively, both tri-layer systems showed excellent antimicrobial activity, producing up to 3 log reductions in colony forming units compared with a control.

The activity of both sets of systems, alongside the similar activity between systems, showed both good synergy between and interchangeability of layer components, opening up the possibility for further tailoring in future.

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