Possible mechanisms of the destruction of spores of the vaccine strain Bacillus anthracis STI-1 under the influence of alcohol sols of metal nanoparticles

2021 ◽  
pp. 16-28
Author(s):  
Georgiy Aleksandrovich Frolov ◽  
◽  
Natalya Vasilevna Zavyalova ◽  
Irina Aleksandrovna Lundovskikh ◽  
Marina Robertovna Shabalina ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Metal Nanoparticles ◽  
Vaccine Strain ◽  
Energy State ◽  
Cetylpyridinium Chloride ◽  
High Surface ◽  
Genetic Material ◽  
Temperature Plasma ◽  
Titanium Nanoparticles ◽  
The Moment

The results are presented of a comparative study of the sporicidal activity of alcohol sols of nanoparticles of titanium, copper, zinc and tantalum metals in the course of their interaction with a rehydrated lyophilized culture of spores of the vaccine strain Bacillus anthracis STI-1 with the loss of the ability of spores to germinate in nutrient media under optimal conditions using bacteriology and electronic microscopy. The most pronounced sporicidal effect is observed when titanium alcohol sol is exposed to spores. At the same time, spores of B. anthracis STI-1 in titanium alcohol sol are affected by ethyl alcohol, which causes dehydration and denaturation of the protein, the antiseptic cetylpyridinium chloride as a surfactant, which is also a strong electrophilic agent that destroys the exosporium and spore shells, and titanium nanoparticles, which, due to the high surface energy when exposed to spores, cause their pronounced massive adhesion. In addition, titanium nanoparticles, the zeta (? -) value of the potential of which is -44.5 mV, cause a stable energy state of the dispersed system of alcohol sol, which acts as a biocatalyst for intracellular enzymes, causing the hydrolysis of polymer structures of the spore shells and cortex, as well as destroyed nucleoid – an area of spores containing structured genetic material. Spores that do not have a nucleoid in electron microscopy acquire the form of "shadows". As a result of the action of titanium alcohol sol, the activation of germination and the formation of the so-called "metabolic" spores, from which the vegetative cells of B. anthracis STI-1 should have been formed, are prevented. The reason for the high sporicidal efficiency of the alcohol sol of titanium nanoparticles is associated both with the structure and properties and with the technology of synthesis of titanium nanoparticles in the low-temperature plasma zone with the formation, due to the excess of the surfactant cetylpyridinium chloride, of a two-layer shell around the metal nanoparticles, which leads to their "conservation" until the moment of contact with spores and a sharp slowdown in their oxidation in the aquatic environment. The destruction of the formed two-layer shell of metal nanoparticles begins with contact with spores with the simultaneous onset of the formation of titanium ions from the phase of nanoparticles, which actively destroy chemically the shells of the spores. Keywords: microorganisms, Bacillus anthracis STI-1, spores, metal nanoparticles, zeta potential, disinfectant compositions, sporicidal activity.

scholarly journals A Molecularly Cloned Schwarz Strain of Measles Virus Vaccine Induces Strong Immune Responses in Macaques and Transgenic Mice

2003 ◽  
Vol 77 (21) ◽  
pp. 11546-11554 ◽  
Author(s):  
Chantal Combredet ◽  
Valérie Labrousse ◽  
Lucile Mollet ◽  
Clarisse Lorin ◽  
Frédéric Delebecque ◽  
...  
Keyword(s):  
Vaccine Strain ◽  
Measles Virus ◽  
Genetic Material ◽  
Number Of Children ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Antibody Titers ◽  
Rescue System ◽  
Heterologous Antigens ◽  
Chicken Embryo Fibroblasts

ABSTRACT Live attenuated RNA viruses make highly efficient vaccines. Among them, measles virus (MV) vaccine has been given to a very large number of children and has been shown to be highly efficacious and safe. Therefore, this vaccine might be a very promising vector to immunize children against both measles and other infectious agents, such as human immunodeficiency virus. A vector was previously derived from the Edmonston B strain of MV, a vaccine strain abandoned 25 years ago. Sequence analysis revealed that the genome of this vector diverges from Edmonston B by 10 amino acid substitutions not related to any Edmonston subgroup. Here we describe an infectious cDNA for the Schwarz/Moraten strain, a widely used MV vaccine. This cDNA was constructed from a batch of commercial vaccine. The extremities of the cDNA were engineered in order to maximize virus yield during rescue. A previously described helper cell-based rescue system was adapted by cocultivating transfected cells on primary chicken embryo fibroblasts, the cells used to produce the Schwarz/Moraten vaccine. After two passages the sequence of the rescued virus was identical to that of the cDNA and of the published Schwarz/Moraten sequence. Two additional transcription units were introduced in the cDNA for cloning foreign genetic material. The immunogenicity of rescued virus was studied in macaques and in mice transgenic for the CD46 MV receptor. Antibody titers and T-cell responses (ELISpot) in animals inoculated with low doses of rescued virus were identical to those obtained with commercial Schwarz MV vaccine. In contrast, the immunogenicity of the previously described Edmonston B strain-derived MV clone was much lower. This new molecular clone will allow for the production of MV vaccine without having to rely on seed stocks. The additional transcription units allow expressing heterologous antigens, thereby providing polyvalent vaccines based on an approved, safe, and efficient MV vaccine strain that is used worldwide.

Metal nanoparticles: ligand free approach towards coupling reactions

2021 ◽  
Vol 01 ◽  
Author(s):  
Sharwari K. Mengane ◽  
Ronghui Wu ◽  
Liyun Ma ◽  
Chhaya S. Panse ◽  
Shailesh N. Vajekar ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Medium ◽  
Coupling Reactions ◽  
Research Activities ◽  
Ligand Free

: Catalysis is the multidisciplinary field involving many areas of chemistry, notably in organometallic chemistry and materials science. It has great applications in synthesis of many industrially applicable compounds such as fuels and fine chemicals. The activity and selectivity are a key issue in catalysis that generally allied to high surface area. The current research activities mainly deal with the homogeneous and heterogeneous catalysis. Homogeneous and heterogeneous catalysis have certain drawbacks which restricts their application to great extent but have their own advantages. Hence, it has a predominant concern of current research to find out an alternate to overcome their drawbacks. Therefore, it is highly desirable to find a catalytic protocol that offers high selectivity and excellent product yield with quick and easy recovery. Along with their various applications as alternatives to conventional bulk materials nanomaterial have established its great role in different industrial and scientific applications. Nanocatalysis has emerged as new alternative to the conventional homogeneous and heterogeneous catalysis. The nanomaterials are responsible to enhance surface area of the catalyst, which ultimately increases the catalyst reactants contacts. In addition, it acts as robust material and has high surface area like heterogeneous catalysts. Insolubility of such nanomaterial in reaction medium makes them easily separable, hence, catalyst can be easily separate from the product. Hence, it has been proven that nanocatalysts behave like homogeneous as well as heterogeneous catalysts which work as a bridge between the conventional catalytic systems. Considering these merits; researchers has paid their attention towards applications of nanocatalyst in several organic reactions. This review article focused on the catalytic applications of metal nanoparticles (MNPs) such as Pd, Ag, Au, Cu, Pt in ligand free coupling reactions. In addition, it covers applications of bimetallic and multimetallic nanoparticles in ligand free coupling reactions.

scholarly journals Metal Nanoparticles as Green Catalysts

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3602 ◽  
Author(s):  
Neel Narayan ◽  
Ashokkumar Meiyazhagan ◽  
Robert Vajtai
Keyword(s):  
Catalytic Activity ◽  
Composite Materials ◽  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Significant Role ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Materials Development

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.

2-D reference map of Bacillus anthracis vaccine strain A16R proteins

PROTEOMICS ◽  
2005 ◽  
Vol 5 (17) ◽  
pp. 4488-4495 ◽  
Author(s):  
Junjun Wang ◽  
Tianyi Ying ◽  
Hengliang Wang ◽  
Zhaoxing Shi ◽  
Mingzhu Li ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Vaccine Strain ◽  
Reference Map

scholarly journals Coupling of Energy Failure and Dissipative K+ Flux during Ischemia: Role of Preischemic Plasma Glucose Concentration

1993 ◽  
Vol 13 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Anders Ekholm ◽  
Ken-Ichiro Katsura ◽  
Bo K. Siesjö
Keyword(s):  
Plasma Glucose ◽  
Glucose Concentration ◽  
Energy State ◽  
Ion Homeostasis ◽  
Plasma Glucose Concentration ◽  
Tissue Temperature ◽  
Ischemic Depolarization ◽  
The Moment ◽  
Tissue Contents

The present experiments were undertaken to assess the influence of preischemic hypo- or hyperglycemia on the coupling among changes in extracellular K+ concentration (K+e) and in cellular energy state, as the latter is reflected in the tissue concentrations of phosphocreatine (PCr), Cr, ATP, ADP, and AMP, and in the calculated free ADP (ADPf) concentrations. The questions posed were whether the final release of K+ was delayed because the extra glucose accumulated by hyperglycemic animals produced enough ATP to continue supporting Na+–K+-driven ATPase activity, and whether the additional acidosis altered the ionic transients. As expected, preischemic hypoglycemia shortened and hyperglycemia prolonged the phase before K+e rapidly increased. This was reflected in corresponding changes in tissue ATP content. Thus, hypoglycemia shortened and hyperglycemia prolonged the time before the fall in ATP concentration accelerated. When tissue was frozen at the moment of depolarization, the tissue contents of ATP were similar in hypo-, normo-, and hyperglycemic groups, ∼ 30% of control. This suggests that hyperglycemia retards loss of ion homeostasis by leading to production of additional ATP. However, hyperglycemia did not reduce the rate at which the PCr concentration fell, and the ATP/ADPf ratio decreased. There were marked differences in the amount of lactate accumulated between the groups. Thus, massive depolarization in hypoglycemic groups occurred at a tissue lactate content of ∼4 m M kg−1. This corresponds to a decrease in intracellular pH (pHi) from ∼7.0 to ∼6.9. In the hyperglycemic groups, depolarization occurred at a lactate content of about 12 mm kg−1, corresponding to a pHi of ∼6.4. This fall in pHi, or the accompanying fall in extracellular pH (pHe), did not affect the maximal rate of efflux of K+. Measurements of ischemic depolarization at constant tissue temperature (37°C) suggest that the influence of the plasma glucose concentration on the terminal depolarization time is restricted. Thus, the time to depolarization varied between 30 s (hypoglycemia) and 90 s (moderate to severe hyperglycemia). Previous results obtained without temperature control may well have reflected a combination between hyperglycemia and a fall in tissue temperature.

Biosynthesis of Silver Nanoparticles: Minireview

2020 ◽  
Vol 6 (2) ◽  
pp. 114-119
Author(s):  
Alaa Alnaimat ◽  
Intesar Aljamaeen
Keyword(s):  
Metal Nanoparticles ◽  
Pathogenic Bacteria ◽  
Wide Spectrum ◽  
High Surface ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Macro Scale ◽  
Physical And Chemical ◽  
Nano Size ◽  
And Chemical Properties

In principle, nanoscience focus on the understanding of the structure, physical and chemical properties of nano size objects. Nanoscience and nanotechnology are both recent and active ongoing branch of science includes multi interdisciplinary sciences. On the other hand, nanotechnology considered as the invested outcomes of the obtained fundamental knowledge about nano objects in various commercial, industrial, environmental and medical sectors. All nano scale matters regardless of their nature referred to as nano-objects were the prefix ‘nano’ mean one millionth of millimeter size. Due to their nano size and high surface area, metal nanoparticles exhibits unique and novel physical and chemical properties compared to their macro scale counterparts. They are considered as very interesting and popular antimicrobial agent with wide spectrum activity against the variety of pathogenic bacteria and fungi. Three main methods were routinely used for metal nanoparticles formation that are chemical, physical and biological approaches. As eco-friendly, cheap and safe synthesis approach without the use of toxic chemicals and free of resulted hazardous byproducts several extracellular and intracellular biological methods using bacteria, fungi, plants or their extracts were reported that known collectively as green nanotechnology

Applications of Gold Nanoparticles in Biosensors

Nano LIFE ◽  
2016 ◽  
Vol 06 (02) ◽  
pp. 1642001 ◽  
Author(s):  
Xinjun Yu ◽  
Yang Jiao ◽  
Qinyuan Chai
Keyword(s):  
Heavy Metals ◽  
Gold Nanoparticles ◽  
Optical Properties ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Surface Functionalization ◽  
High Surface ◽  
High Surface Area ◽  
Synthetic Methods ◽  
Future Perspective

Gold nanoparticles (AuNPs) as one of the most stable metal nanoparticles have demonstrated extensive applications in recent years. This paper will give a focus on the AuNPs as biosensors, due to their inertness, unique optical properties, high surface area, and various surface functionalization methods. Synthesis of AuNps and the surface functionalization will be discussed in the first part. The size, shape, and stability can be controlled by different synthetic methods, while reductant usually needed. By surface functionalization with different molecules such as polymers, nucleic acids, and proteins, AuNPs will aggregate when specified molecule linkages showing up enables selective detections. The application in biosensing to detect proteins, oligonucleotide, glucose, and heavy metals will be exemplified, followed by the summary and future perspective part in the conclusion.

Scalable Manufacturing of Metal Nanoparticles by Thermal Fiber Drawing

2016 ◽  
Author(s):  
Jingzhou Zhao ◽  
Abdolreza Javadi ◽  
Ting-Chiang Lin ◽  
Injoo Hwang ◽  
Yingchao Yang ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
High Surface ◽  
Continuous Manufacturing ◽  
Molten Metals ◽  
Fiber Drawing ◽  
Energy Applications ◽  
Low Viscosity ◽  
Thermal Drawing ◽  
Scalable Production ◽  
Glass Metal

Thermal fiber drawing has emerged as a novel process for the continuous manufacturing of semiconductor and polymer nanoparticles. Yet a scalable production of metal nanoparticles by thermal drawing is not reported due to the low viscosity and high surface tension of molten metals. Here we present a generic method for the scalable nanomanufacturing of metal nanoparticles via thermal drawing based on droplet break-up emulsification of immiscible glass/metal systems. We experimentally show the scalable manufacturing of metal Sn nanoparticles (<100 nm) in Polyethersulfone (PES) fibers as a model system. This process opens a new pathway for scalable manufacturing of most metal nanoparticles as well as composites with embedded metal nanoparticles, which may find exciting photonic, electrical, or energy applications.

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