Silver nanoparticles: safety and efficiency for human health

2021 ◽  
Vol 19 (3) ◽  
pp. 247-257
Author(s):  
Yuliya A. Morozova ◽  
Dmitry S. Dergachev ◽  
Mikhail A. Subotyalov
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Human Health ◽  
Antimicrobial Agents ◽  
Inhibitory Effect ◽  
Modern Medicine ◽  
Laboratory Animals ◽  
High Biological Activity ◽  
The Past ◽  
Wide Range

Over the past few decades, nanoparticles of metals, and in particular silver, with a diameter of less than 100 nm have significantly expanded their field of application for various biomedical purposes. So, silver nanoparticles have great potential in a wide range of applications as antimicrobial agents, coatings for biomedical products, carriers for drug delivery, bioengineering, since they have discrete physical properties and wide biochemical functionality. Studies have shown that the size, morphology, stability and properties (chemical and physical) of metal nanoparticles are strongly influenced by the conditions of the experiment, the kinetics of the interaction of metal ions with reducing agents and the adsorption processes of the stabilizer with metal nanoparticles. This review aims to analyze the use of silver nanoparticles in modern medicine based on data from domestic and foreign literature over the past five years. The study confirmed the high biological activity of drugs with nanoserebrum as anti-inflammatory, antimicrobial agents, antifungals, the presence of an inhibitory effect on protozoa, antioxidant and anticancer effects, and substantiated the relevance of use in bioengineering and dentistry. However, rapid advances and advances in technology have led to concerns about the potential risk associated with the use and application of silver nanoparticles to human health and the environment. Therefore, this review attempts to characterize and quantify the potential harmful effects of silver nanoparticles on the health of laboratory animals and humans, and focuses on ways to neutralize or reduce the toxic effects of silver nanoparticles on the human body.

scholarly journals Semi-third-day fever in view of modern medicine

2021 ◽  
Vol 25 (4) ◽  
pp. 192-194
Author(s):  
Marina G. Avdeeva
Keyword(s):  
Infectious Disease ◽  
Clinical Observation ◽  
Modern Medicine ◽  
Differential Diagnostics ◽  
Doctor Who ◽  
The Past ◽  
Wide Range ◽  
Acute Infectious Disease ◽  
Diagnostic Capabilities

It is difficult for a modern doctor who relies on a wide range of laboratory diagnostic capabilities to imagine the path of mistakes, insights and delusions traveled by doctors of the past. How exactly through clinical observation the disease was observed. The archival article Half-tree-day fever published in the journal is an example of a clinical and epidemic description of an outbreak of an acute infectious disease, the etiology of which remains unknown. The more interesting are the distinguishing issues of differential diagnostics.

scholarly journals From Impure to Purified Silver Nanoparticles: Advances and Timeline in Separation Methods

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3407
Author(s):  
Catarina S. M. Martins ◽  
Helena B. A. Sousa ◽  
João A. V. Prior
Keyword(s):  
Silver Nanoparticles ◽  
Human Health ◽  
Environmental Contamination ◽  
Separation Techniques ◽  
Medical Treatments ◽  
Real Samples ◽  
Size And Shape ◽  
The Past ◽  
Exponential Increase ◽  
Synthesis Medium

AgNPs have exceptional characteristics that depend on their size and shape. Over the past years, there has been an exponential increase in applications of nanoparticles (NPs), especially the silver ones (AgNPs), in several areas, such as, for example, electronics; environmental, pharmaceutical, and toxicological applications; theragnostics; and medical treatments, among others. This growing use has led to a greater exposure of humans to AgNPs and a higher risk to human health and the environment. This risk becomes more aggravated when the AgNPs are used without purification or separation from the synthesis medium, in which the hazardous synthesis precursors remain unseparated from the NPs and constitute a severe risk for unnecessary environmental contamination. This review examines the situation of the available separation methods of AgNPs from crude suspensions or real samples. Different separation techniques are reviewed, and relevant data are discussed, with a focus on the sustainability and efficiency of AgNPs separation methods.

scholarly journals Mycogenic Metal Nanoparticles for the Treatment of Mycobacterioses

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 569 ◽  
Author(s):  
Marta Filipa Simões ◽  
Cristiane Angélica Ottoni ◽  
André Antunes
Keyword(s):  
Infectious Disease ◽  
Silver Nanoparticles ◽  
Antimicrobial Resistance ◽  
Metal Nanoparticles ◽  
Causes Of Death ◽  
Antimicrobial Agents ◽  
Mycobacterial Infections ◽  
New Approaches ◽  
The World

Mycobacterial infections are a resurgent and increasingly relevant problem. Within these, tuberculosis (TB) is particularly worrying as it is one of the top ten causes of death in the world and is the infectious disease that causes the highest number of deaths. A further concern is the on-going emergence of antimicrobial resistance, which seriously limits treatment. The COVID-19 pandemic has worsened current circumstances and future infections will be more incident. It is urgent to plan, draw solutions, and act to mitigate these issues, namely by exploring new approaches. The aims of this review are to showcase the extensive research and application of silver nanoparticles (AgNPs) and other metal nanoparticles (MNPs) as antimicrobial agents. We highlight the advantages of mycogenic synthesis, and report on their underexplored potential as agents in the fight against all mycobacterioses (non-tuberculous mycobacterial infections as well as TB). We propose further exploration of this field.

scholarly journals A NANOCOMPOSITE BASED ON MICROBIAL SYNTHESIS OF HUMIC PRECURSORS AND OF METAL NANOPARTICLES USED AS AN ANTIMICROBIAL COMPOUND IN SOIL

2019 ◽  
Vol 13 (2) ◽  
pp. 201-210
Author(s):  
Sorin Matei ◽  
Gabi-Mirela Matei ◽  
Gina Cogălniceanu ◽  
Alexandru Brînzan
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Microbial Consortia ◽  
Biochemical Processes ◽  
Mobile Fraction ◽  
High Reduction ◽  
Reduction Capacity

Soil humic precursors could be considered the most active and mobile fraction and are highly significant to a series of biochemical processes in all types of soil. The microbial biosynthesized humic precursors attracted increasing attention on green synthesis of nanocomposite compounds realized between biopolymers and metal nanoparticles. Silver nanoparticles are the most used engineered nanocomposite serving as antimicrobial agents. In the present study we used aqueous solution of humic precursors synthesized by four microbial consortia (C1-C4) and selected on the basis of high quantities of exometabolites with structural similarities to soil humic acid fraction. The humic precursors were used as capping agents of silver nanoparticles in the nanocompozite synthesis. Biosynthesized humic precursors act as reductive and stabilizative agents of nanoparticles which are found between 5-300nm in size and with spherical preponderant shape. The presence of humus precursors and the biosynthesized silver nanoparticles was confirmed by FTIR and UV-Vis. At a given precursor concentration, the efficiency of nanocomposite synthesis increased with particle concentration and time of reaction, property which can be attributed to the high reduction capacity of humic precursors. The induced antimicrobial effect of exposure to nanocomposites differs due to the size, time of preparation and stability. Stabilization of nanocomposite by specific metal-ligand bonds was obtained in the solution for three months without any precipitate. The antimicrobial effect of nanocomposites was estimated under laboratory agar well diffusion tests against mycotoxigenic soil fungal isolate Aspergillus niger (A27). The green synthesis of nanocomposite material with the best antimicrobial effect against test fungus was realized by microbial consortium C3and C4.

scholarly journals Glycol Chitosan: A Water-Soluble Polymer for Cell Imaging and Drug Delivery

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4371 ◽  
Author(s):  
Fengming Lin ◽  
Hao-Ran Jia ◽  
Fu-Gen Wu
Keyword(s):  
Antimicrobial Agents ◽  
Tumor Imaging ◽  
Water Soluble ◽  
Glycol Chitosan ◽  
Water Soluble Polymer ◽  
The Past ◽  
Wide Range ◽  
Microbial Infections ◽  
Functional Biomaterials ◽  
Shed Light

Glycol chitosan (GC), a water-soluble chitosan derivative with hydrophilic ethylene glycol branches, has both hydrophobic segments for the encapsulation of various drugs and reactive functional groups for facile chemical modifications. Over the past two decades, a variety of molecules have been physically encapsulated within or chemically conjugated with GC and its derivatives to construct a wide range of functional biomaterials. This review summarizes the recent advances of GC-based materials in cell surface labeling, multimodal tumor imaging, and encapsulation and delivery of drugs (including chemotherapeutics, photosensitizers, nucleic acids, and antimicrobial agents) for combating cancers and microbial infections. Besides, different strategies for GC modifications are also highlighted with the aim to shed light on how to endow GC and its derivatives with desirable properties for therapeutic purposes. In addition, we discuss both the promises and challenges of the GC-derived biomaterials.

scholarly journals Biosynthesis of Metal Nanoparticles: A Review

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Narendra Kulkarni ◽  
Uday Muddapur
Keyword(s):  
Metal Nanoparticles ◽  
Human Health ◽  
Metallic Nanoparticles ◽  
Chemical Method ◽  
Nanoparticle Synthesis ◽  
Particle Morphology ◽  
Biological Method ◽  
Protein Cages ◽  
The Past ◽  
Environmentally Friendly Method

The synthesis of nanostructured materials, especially metallic nanoparticles, has accrued utmost interest over the past decade owing to their unique properties that make them applicable in different fields of science and technology. The limitation to the use of these nanoparticles is the paucity of an effective method of synthesis that will produce homogeneous size and shape nanoparticles as well as particles with limited or no toxicity to the human health and the environment. The biological method of nanoparticle synthesis is a relatively simple, cheap, and environmentally friendly method than the conventional chemical method of synthesis and thus gains an upper hand. The biomineralization of nanoparticles in protein cages is one of such biological approaches used in the generation of nanoparticles. This method of synthesis apart from being a safer method in the production of nanoparticles is also able to control particle morphology.

scholarly journals Silver Nanoparticles Synthesized through Green Methods Using Escherichia coli Top 10 (Ec-Ts) Growth Culture Medium Exhibit Antimicrobial Properties against Nongrowing Bacterial Strains

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Esther Baltazar-Encarnación ◽  
Carlos E. Escárcega-González ◽  
Ximena G. Vasto-Anzaldo ◽  
María Elena Cantú-Cárdenas ◽  
J. Rubén Morones-Ramírez
Keyword(s):  
Silver Nanoparticles ◽  
Metal Nanoparticles ◽  
Antimicrobial Agents ◽  
Culture Media ◽  
Size Distributions ◽  
Bacterial Strains ◽  
Ag Nps ◽  
E Coli ◽  
Low Concentrations ◽  
Metabolic States

Finding novel antibiotics and antimicrobial materials has become of great importance to modern society due to the alarming increase in the development of multidrug resistance in various bacterial strains. This problem is even more complex when infections involve bacterial strains in stationary metabolic states, since most of the antibiotics found in the market do not have an effect on bacteria in dormant metabolic states. A promising field to aid in the solution of this problem is nanotechnology, since it offers a wide avenue for the development of potential therapeutics, specifically the use of silver metal nanoparticles. Silver nanoparticles have proven to be highly effective antimicrobial agents and excellent candidates to be engineered and designed into clever delivery systems, taking advantage of their rapid and potent toxicity on prokaryotic cells at low concentrations. Metal nanoparticles are most commonly synthetized through one or a series of redox chemical reactions using powerful but environmentally toxic-reducing agents. Therefore, in this work, we propose a biosynthesis method that allows the production of nanoparticles, with homogenous shapes and narrow size distributions, through an environmentally friendly technique that does not produce toxic residues. Here, silver nanoparticles were produced from silver salt (AgNO3) using three different growth culture media residues from E. coli top 10. The three different culture media residues used included LB, LBN, and LBE; all of them displaying a different chemical and nutrient composition. Here, after characterization of the different silver nanoparticles produced with the different media, we demonstrated that the LB culture-conditioned media was the most suitable to produce them since they displayed the most narrow size distribution, with an average 10.6 nm in diameter, a relatively low standard deviation of 5.5 nm, and a narrow UV-vis spectrum absorption peak at 420 nm. The other methods presented larger nanoparticle sizes and broader size distributions. Furthermore, nanoparticles produced with LB Lennox were found to be, at very low concentrations, effective antimicrobial agent against E. coli top 10 at stationary phase. Therefore, these results seem to contribute knowledge linked to the production of antimicrobial nanoparticles (Ag-NPs) through green synthesis and represent a platform to treat infections caused by nongrowing bacteria.

scholarly journals Estetica dell’infezione: dal cyborg al teriomorfo

Venezia Arti ◽  
2020 ◽  
Author(s):  
Roberto Marchesini ◽  
Karin Andersen
Keyword(s):  
Human Health ◽  
Cultural History ◽  
Scientific Research ◽  
Environmental Crisis ◽  
Artistic Production ◽  
The Past ◽  
Self Sufficiency ◽  
Wide Range ◽  
Cultural Self ◽  
New Vision

As long as cultural history has been passed on, art and science have always been connected. However in the past decades, while it has become more and more evident that traditional anthropocentric and humanistic values have led to a huge and unprecedented environmental crisis, the dialogue between scientific research and artistic production has been increasingly focusing on a new vision of humanity as an open, undetermined and transitory entity. This essay examines how recent technoscientific advancements and relating artistic imagery have boosted the evolution of a posthumanistic idea of identity, moving away from the concept of human cultural self-sufficiency and gaining consciousness of our dependance on interaction and blending with alterity. A series of selected examples evidence the wide range of mutation spreading in contemporary audiovisual culture, oscillating between the two archetypical concepts of the Cyborg and the Theriomorph. The viral diffusion of hybrid contents, as the emerging idea of organisms and technology invading each other, suggests that we are approaching a paradigm of infection, not in the sense of a dangerous invasion of human health, integrity and purity, but in terms of a deeply necessary hybridisation with otherness.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

Pursuit of the Abscopal Effect

2020 ◽  
Vol 04 (04) ◽  
pp. 369-372
Author(s):  
Paul B. Romesser ◽  
Christopher H. Crane
Keyword(s):  
Tumor Immunology ◽  
Antitumor Immunity ◽  
Clinical Success ◽  
Immune Recognition ◽  
Immune Modulators ◽  
Cancer Subtypes ◽  
The Past ◽  
Tumor Irradiation ◽  
Wide Range ◽  
Tumor Recognition

AbstractEvasion of immune recognition is a hallmark of cancer that facilitates tumorigenesis, maintenance, and progression. Systemic immune activation can incite tumor recognition and stimulate potent antitumor responses. While the concept of antitumor immunity is not new, there is renewed interest in tumor immunology given the clinical success of immune modulators in a wide range of cancer subtypes over the past decade. One particularly interesting, yet exceedingly rare phenomenon, is the abscopal response, characterized by a potent systemic antitumor response following localized tumor irradiation presumably attributed to reactivation of antitumor immunity.

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