scholarly journals Investigating the Role of Shape and Size of Gold Nanoparticles on Their Toxicities to Fungi

2018 ◽  
Author(s):  
Kangze Liu ◽  
Zhonglei He ◽  
Hugh J. Byrne ◽  
James F. Curtin ◽  
Furong Tian
Keyword(s):  
Gold Nanoparticles ◽  
Survival Rates ◽  
Toxicity Assessment ◽  
Fungal Species ◽  
Wide Spread ◽  
Mucor Hiemalis ◽  
Wide Range ◽  
Living Organisms ◽  
Shape And Size

The possibility of releasing gold nanoparticles (GNP) into the environment has been rapidly increasing with the wide spread and flourishing application of gold nanoparticles (GNPs) in a wide range of areas. Consequently, environmental effects of GNP, especially toxicities to living organisms have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of shape and size of GNPs on their toxicities to fungi, which could help reveal the ecotoxicity of GNPs. Aspergillus niger, Mucor hiemalis and Penicillium chrysogenum were chosen for toxicity assessment, and spherical and star/flower-shaped GNPs sized from 0.7 nm to large aggregates of 400 nm have been synthesised. After exposure to GNPs and their corresponding reaction agents and incubation for 48 hours, the survival rates of each kind of fungus was calculated and compared. The results indicated that fungal species was the major determinant of the variation of survival rates, whereby A. niger was most sensitive and M. himalis was least sensitive to GNP exposure. Additionally, larger and non-spherical GNPs had relatively stronger toxicities.

scholarly journals Investigating the Role of Shape and Size of Gold Nanoparticles on Their Toxicities to Fungi

2018 ◽  
Author(s):  
Kangze Liu ◽  
Zhonglei He ◽  
Hugh J. Byrne ◽  
James Curtin ◽  
Furong Tian
Keyword(s):  
Gold Nanoparticles ◽  
Penicillium Chrysogenum ◽  
Survival Rates ◽  
Relative Survival ◽  
Toxicity Assessment ◽  
Mucor Hiemalis ◽  
Wide Range ◽  
Living Organisms ◽  
Shape And Size

The possibility of releasing gold nanoparticles (GNP) into the environment has been rapidly increasing with the wide spread and flourishing application of gold nanoparticles (GNPs) in a wide range of areas. Consequently, environmental effects of GNP, especially toxicities to living organisms have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of shape and size of GNPs on their toxicities to fungi, which could help reveal the ecotoxicity of GNPs. Aspergillus niger, Mucor hiemalis and Penicillium chrysogenum were chosen for toxicity assessment, and circular and star/flower-shaped GNPs sized from 0.7 nm to large aggregates of 400 nm have been synthesised. After mixed with GNPs and reacting agents of GNPs accordingly and incubated for 48 hours, the relative survival rates of each kind of fungus was calculated and compared. The results indicated that with similar sizes, star/flower-shaped GNPs are more toxic to fungi than circular-shaped GNPs; the toxicity of star/flower-shaped GNPs increases with smaller sizes. The results also showed that different species of fungus reacts differently to same GNPs, and Penicillium chrysogenum was relatively more sensitive under the exposure to GNPs.

scholarly journals The signalling role of ROS in the regulation of seed germination and dormancy

2019 ◽  
Vol 476 (20) ◽  
pp. 3019-3032 ◽  
Author(s):  
Christophe Bailly
Keyword(s):  
Seed Germination ◽  
Oxygen Species ◽  
Direct Oxidation ◽  
Cellular Events ◽  
Seed Physiology ◽  
Spatiotemporal Regulation ◽  
Wide Range ◽  
Living Organisms ◽  
Hormone Signalling

Abstract Reactive oxygen species (ROS) are versatile compounds which can have toxic or signalling effects in a wide range living organisms, including seeds. They have been reported to play a pivotal role in the regulation of seed germination and dormancy but their mechanisms of action are still far from being fully understood. In this review, we sum-up the major findings that have been carried out this last decade in this field of research and which altogether shed a new light on the signalling roles of ROS in seed physiology. ROS participate in dormancy release during seed dry storage through the direct oxidation of a subset of biomolecules. During seed imbibition, the controlled generation of ROS is involved in the perception and transduction of environmental conditions that control germination. When these conditions are permissive for germination, ROS levels are maintained at a level which triggers cellular events associated with germination, such as hormone signalling. Here we propose that the spatiotemporal regulation of ROS production acts in concert with hormone signalling to regulate the cellular events involved in cell expansion associated with germination.

scholarly journals New Relevant Descriptor of Linear QNAR Models for Toxicity Assessment of Silver Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1459
Author(s):  
Alexey Kudrinskiy ◽  
Pavel Zherebin ◽  
Alexander Gusev ◽  
Olga Shapoval ◽  
Jaeho Pyee ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Colloidal Stability ◽  
Chemical Nature ◽  
Equilibrium Concentration ◽  
Toxicity Assessment ◽  
Yeast Cells ◽  
Wide Range ◽  
Silver Nps ◽  
Living Organisms

The use of silver nanoparticles (NPs) in medical, industrial and agricultural fields is becoming more widespread every year. This leads to an increasing number of experimental toxicological and microbiological studies of silver NPs aimed at establishing the risk–benefit ratio for their application. The following key parameters affecting the biological activity of silver dispersions are traditionally taken into consideration: mean diameter of NPs, surface potential of NPs and equilibrium concentration of Ag+. These characteristics are mainly predetermined by the chemical nature of the capping agent used for stabilization. However, the extent to which they influence the biological activity and the toxicity of silver NPs varies greatly. In this work, dispersions of silver NPs stabilized with a wide array of substances of different chemical nature were used for quantitative evaluation of whether the various measurable properties of silver NPs fit as descriptors of linear QNAR (quantitative nanostructure–activity relationship) models for silver NP toxicity evaluation with respect to a model eukaryotic microorganism—Saccharomyces cerevisiae yeast cells. It was shown that among the factors that determine silver NP toxicity, the charge of particles, their colloidal stability and the ability to generate Ag+ ions carry more importance than the descriptors related to the particle size. A significant synergistic effect between the ζ-potential and the colloidal stability of silver NPs on their toxicity was also discovered. Following this, a new descriptor has been proposed for the integral characterization of the silver dispersion colloidal stability. According to the obtained data, it can be considered applicable for building QNAR models of higher efficacy. The validity testing of the proposed model for theoretical prediction of silver NP toxicity using a wide range of living organisms has shown that this new descriptor correlates with toxicity much better compared to most traditionally used descriptors. Consequently, it seems promising in terms of being used not only in situations involving the rather narrow array of the objects tested, but also for the construction of silver NP toxicity models with respect to other living organisms.

scholarly journals Zika virus infection drives epigenetic modulation of immunity by the histone acetyltransferase CBP of Aedes aegypti

2021 ◽  
Author(s):  
Anderson de Mendonca Amarante ◽  
Isabel Caetano de Abreu da Silva ◽  
Amanda Roberta Revoredo Vicentino ◽  
Vitor Coutinho Carneiro ◽  
Marcia de Amorim Pinto ◽  
...  
Keyword(s):  
Virus Infection ◽  
Aedes Aegypti ◽  
Zika Virus ◽  
Histone Deacetylases ◽  
Histone Acetyltransferase ◽  
Fat Body ◽  
Survival Rates ◽  
Immune Genes ◽  
Wide Range

Epigenetic mechanisms are responsible for a wide range of biological phenomena in insects, controlling embryonic development, growth, aging and nutrition. Despite this, the role of epigenetics in shaping insect-pathogen interactions has received little attention. Gene expression in eukaryotes is regulated by histone acetylation/deacetylation, an epigenetic process mediated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). In this study, we explored the role of the Aedes aegypti histone acetyltransferase CBP (AaCBP) after infection with Zika virus, focusing on the two main immune tissues, the midgut and fat body. We showed that the expression and activity of AaCBP could be positively modulated by blood meal and Zika infection. Nevertheless, Zika-infected mosquitoes that were silenced for AaCBP revealed a significant reduction in the acetylation of H3K27 (CBP target-marker), followed by downmodulation of the expression of immune genes, higher titers of Zika virus and lower survival rates. Importantly, in Zika-infected mosquitoes that were treated with sodium butyrate, a histone deacetylase inhibitor, their capacity to fight virus infection was rescued. Our data point to a direct correlation among histone hyperacetylation by AaCBP, upregulation of antimicrobial peptide genes and increased survival of Zika-infected-A. aegypti.

scholarly journals Mycotoxins and the Enteric Nervous System

Toxins ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 461 ◽  
Author(s):  
Sławomir Gonkowski ◽  
Magdalena Gajęcka ◽  
Krystyna Makowska
Keyword(s):  
Nervous System ◽  
Gastrointestinal Tract ◽  
Enteric Nervous System ◽  
Current Knowledge ◽  
Fungal Species ◽  
Regulatory Processes ◽  
Wide Range ◽  
Living Organisms ◽  
The Impact ◽  
Harmful Effects

Mycotoxins are secondary metabolites produced by various fungal species. They are commonly found in a wide range of agricultural products. Mycotoxins contained in food enter living organisms and may have harmful effects on many internal organs and systems. The gastrointestinal tract, which first comes into contact with mycotoxins present in food, is particularly vulnerable to the harmful effects of these toxins. One of the lesser-known aspects of the impact of mycotoxins on the gastrointestinal tract is the influence of these substances on gastrointestinal innervation. Therefore, the present study is the first review of current knowledge concerning the influence of mycotoxins on the enteric nervous system, which plays an important role, not only in almost all regulatory processes within the gastrointestinal tract, but also in adaptive and protective reactions in response to pathological and toxic factors in food.

scholarly journals Impact of Biocorrosion on the Durability of Etics and Empirical Findings About the Periodocity of Maintenance

2013 ◽  
Vol 21 (2) ◽  
pp. 21-28
Author(s):  
Naďa Antošová
Keyword(s):  
Building Materials ◽  
Composite System ◽  
Chemical Processes ◽  
Biological Factors ◽  
Wide Range ◽  
Living Organisms ◽  
Physical And Chemical ◽  
The Impact ◽  
Complete Collapse

Abstract Generally, the role of living organisms (especially bacteria, cyanophytes, algae and fungi) in the physical and chemical processes of the biocorrosion of an external thermal insulation composite system (ETICS) is underestimated. These organisms are the ones that are responsible for a wide range of changes in or "diseases" of building materials and constructions, including damage to a building´s appearance or the destruction and complete collapse of the characteristics and requirements of materials and the ETICS construction. The following article concerns the impact of biological factors on the durability of ETICS. It shows the importance of and necessity to maintain it, and the method and periodicity of the maintenance.

scholarly journals Gold Nanoparticles: Biosynthesis and Potential of Biomedical Application

2021 ◽  
Vol 12 (4) ◽  
pp. 70
Author(s):  
Ekaterina O. Mikhailova
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Biomedical Application ◽  
Biological Activities ◽  
Target Cells ◽  
Biological Method ◽  
Capping Agents ◽  
Action Mechanisms ◽  
Wide Range ◽  
Living Organisms

Gold nanoparticles (AuNPs) are extremely promising objects for solving a wide range of biomedical problems. The gold nanoparticles production by biological method (“green synthesis”) is eco-friendly and allows minimization of the amount of harmful chemical and toxic byproducts. This review is devoted to the AuNPs biosynthesis peculiarities using various living organisms (bacteria, fungi, algae, and plants). The participation of various biomolecules in the AuNPs synthesis and the influence of size, shapes, and capping agents on the functionalities are described. The proposed action mechanisms on target cells are highlighted. The biological activities of “green” AuNPs (antimicrobial, anticancer, antiviral, etc.) and the possibilities of their further biomedical application are also discussed.

scholarly journals The role of selenium metabolism and selenoproteins in cartilage homeostasis and arthropathies

2020 ◽  
Vol 52 (8) ◽  
pp. 1198-1208 ◽  
Author(s):  
Donghyun Kang ◽  
Jeeyeon Lee ◽  
Cuiyan Wu ◽  
Xiong Guo ◽  
Byeong Jae Lee ◽  
...  
Keyword(s):  
Redox Homeostasis ◽  
Selenium Deficiency ◽  
Cartilage Destruction ◽  
Metabolic System ◽  
Selenium Metabolism ◽  
Wide Range ◽  
Matrix Metabolism ◽  
Living Organisms ◽  
Low Selenium

Abstract As an essential nutrient and trace element, selenium is required for living organisms and its beneficial roles in human health have been well recognized. The role of selenium is mainly played through selenoproteins synthesized by the selenium metabolic system. Selenoproteins have a wide range of cellular functions including regulation of selenium transport, thyroid hormones, immunity, and redox homeostasis. Selenium deficiency contributes to various diseases, such as cardiovascular disease, cancer, liver disease, and arthropathy—Kashin–Beck disease (KBD) and osteoarthritis (OA). A skeletal developmental disorder, KBD has been reported in low-selenium areas of China, North Korea, and the Siberian region of Russia, and can be alleviated by selenium supplementation. OA, the most common form of arthritis, is a degenerative disease caused by an imbalance in matrix metabolism and is characterized by cartilage destruction. Oxidative stress serves as a major cause of the initiation of OA pathogenesis. Selenium deficiency and dysregulation of selenoproteins are associated with impairments to redox homeostasis in cartilage. We review the recently explored roles of selenium metabolism and selenoproteins in cartilage with an emphasis on two arthropathies, KBD and OA. Moreover, we discuss the potential of therapeutic strategies targeting the biological functions of selenium and selenoproteins for OA treatment.

scholarly journals The Role of Exosomes in Stemness and Neurodegenerative Diseases—Chemoresistant-Cancer Therapeutics and Phytochemicals

2020 ◽  
Vol 21 (18) ◽  
pp. 6818
Author(s):  
Narasimha M. Beeraka ◽  
Shalini H. Doreswamy ◽  
Surya P. Sadhu ◽  
Asha Srinivasan ◽  
Rajeswara Rao Pragada ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Neurodegenerative Diseases ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Cancer Therapeutics ◽  
Biological Properties ◽  
Anticancer Peptides ◽  
Wide Range ◽  
Living Organisms

Exosomes exhibit a wide range of biological properties and functions in the living organisms. They are nanometric vehicles and used for delivering drugs, as they are biocompatible and minimally immunogenic. Exosomal secretions derived from cancer cells contribute to metastasis, immortality, angiogenesis, tissue invasion, stemness and chemo/radio-resistance. Exosome-derived microRNAs (miRNAs) and long non-coding RNAs (lnc RNAs) are involved in the pathophysiology of cancers and neurodegenerative diseases. For instance, exosomes derived from mesenchymal stromal cells, astrocytes, macrophages, and acute myeloid leukemia (AML) cells are involved in the cancer progression and stemness as they induce chemotherapeutic drug resistance in several cancer cells. This review covered the recent research advances in understanding the role of exosomes in cancer progression, metastasis, angiogenesis, stemness and drug resistance by illustrating the modulatory effects of exosomal cargo (ex. miRNA, lncRNAs, etc.) on cell signaling pathways involved in cancer progression and cancer stem cell growth and development. Recent reports have implicated exosomes even in the treatment of several cancers. For instance, exosomes-loaded with novel anti-cancer drugs such as phytochemicals, tumor-targeting proteins, anticancer peptides, nucleic acids are known to interfere with drug resistance pathways in several cancer cell lines. In addition, this review depicted the need to develop exosome-based novel diagnostic biomarkers for early detection of cancers and neurodegenerative disease. Furthermore, the role of exosomes in stroke and oxidative stress-mediated neurodegenerative diseases including Alzheimer’s disease (AD), and Parkinson’s disease (PD) is also discussed in this article.

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