Methodological foundations for substantiating safe levels of exposure to artificial nanomaterials (for example, carbon nanotubes) (literature review)

2021 ◽  
Vol 29 (6) ◽  
pp. 5-15
Author(s):  
Gyuzel A. Timerbulatova ◽  
Liliya M. Fatkhutdinova
Keyword(s):  
Carbon Nanotubes ◽  
Government Regulation ◽  
Production Control ◽  
Harmful Effect ◽  
Control Program ◽  
Sources Of Information ◽  
Standard Material ◽  
In Vivo Experiments

Introduction. The unique physicochemical properties of carbon nanotubes allow them to be used in many fields. The global nanomaterials market is growing every year. An important step in introducing products to the domestic and world markets is to determine the safe exposure levels of CNTs. Establishing a corporate standard can serve as a preliminary stage before the approval of a state hygiene standard. Material and methods. The material for the analysis was the sources of information on the available standards for the content of CNTs in the air of the working area using information from regulatory agencies, research centers, CNT manufacturers, bibliographic and abstract databases Web of Science, Scopus, PubMed, RSCI. Results. A scheme for justifying safe levels of exposure to CNTs (corporate standard) has been developed, consisting of several stages: characterization of CNTs in the air at workplaces, selection of experimental doses of CNTs, preparation of CNT dispersions, and conducting toxicological and hygienic experiments. Justification of the corporate standard is carried out in in vitro and in vivo experiments. The planning of experiments should be carried out taking into account the target organ under the influence of CNT - the respiratory system. The recommended dose / concentration range for experiments should include doses / concentrations derived from calculated and literature data. A necessary step is to obtain homogeneous dispersions in which CNTs become bioavailable for biological systems. In vitro and in vivo experiments determine the level of exposure at which no harmful effect is observed and / or the lowest level of exposure at which there is a harmful effect on the cell culture / respiratory tract of animals. After the stage of substantiating the corporate standard, the enterprise should take measures for several years to adjust the corporate standard based on data from clinical and hygienic studies, during which the working conditions and health status of workers are monitored, and extended toxicological and hygienic studies. Conclusion. The presence of a corporate standard will allow the manufacturer of CNTs to carry out activities for the development and implementation of a production control program with the introduction of monitoring the air condition in the working area. The development of a corporate regulation can be seen as a preparatory stage before the establishment of a government regulation.

METHODOLOGICAL FOUNDATIONS FOR SUBSTANTIATING SAFE LEVELS OF EXPOSURE TO ARTIFICIAL NANOMATERIALS (FOR EXAMPLE, CARBON NANOTUBES)

2021 ◽  
Author(s):  
G.A. Timerbulatova ◽  
◽  
Keyword(s):  
Carbon Nanotubes ◽  
Harmful Effect ◽  
Exposure Level ◽  
In Vivo Experiments ◽  
World Markets ◽  
Dose Concentration ◽  
Exposure Levels ◽  
Planning Of Experiments

Abstract: The unique physicochemical properties of carbon nanotubes allow them to be used in many fields. The global nanomaterials market is growing every year. An important step in introducing products to the domestic and world markets is to determine the safe exposure levels of CNTs. Establishing a corporate standard can serve as a preliminary stage before the approval of a state hygiene standard. Justification of the corporate standard is carried out in in vitro and in vivo experiments. The planning of experiments should be carried out taking into account the target organ under the influence of CNT - the respiratory system. The recommended dose / concentration range for experiments should include doses / concentrations derived from calculated and literature data. A necessary step is to obtain homogeneous dispersions in which CNTs become bioavailable for biological systems. During in vitro and in vivo experiments, the exposure level is determined at which no harmful effect is observed and / or the lowest level of exposure at which there is a harmful effect on the cell culture / respiratory tract of animals.

ANTITUMOR EFFECT OF COLLOIDAL SILVER BISILICATE IN EXPERIMENTAL IN VITRO AND IN VIVO STUDIES

2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Human Tumor ◽  
Significant Inhibition ◽  
In Vivo Studies ◽  
Ehrlich Carcinoma ◽  
In Vivo Experiments

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.

scholarly journals Plant-Derived Extracellular Vesicles: Current Findings,Challenges, and Future Applications

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 411
Author(s):  
Nader Kameli ◽  
Anya Dragojlovic-Kerkache ◽  
Paul Savelkoul ◽  
Frank R. Stassen
Keyword(s):  
Human Health ◽  
Extracellular Vesicles ◽  
Preliminary Results ◽  
In Vivo Experiments ◽  
Health And Disease ◽  
Conducting Research ◽  
Protocol Standardization ◽  
Insight Into

In recent years, plant-derived extracellular vesicles (PDEVs) have gained the interest of many experts in fields such as microbiology and immunology, and research in this field has exponentially increased. These nano-sized particles have provided researchers with a number of interesting findings, making their application in human health and disease very promising. Both in vitro and in vivo experiments have shown that PDEVs can exhibit a multitude of effects, suggesting that these vesicles may have many potential future applications, including therapeutics and nano-delivery of compounds. While the preliminary results are promising, there are still some challenges to face, such as a lack of protocol standardization, as well as knowledge gaps that need to be filled. This review aims to discuss various aspects of PDEV knowledge, including their preliminary findings, challenges, and future uses, giving insight into the complexity of conducting research in this field.

scholarly journals Osteoprotective Effects of Loganic Acid on Osteoblastic and Osteoclastic Cells and Osteoporosis-Induced Mice

2020 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
Eunkuk Park ◽  
Chang Gun Lee ◽  
Eunguk Lim ◽  
Seokjin Hwang ◽  
Seung Hee Yun ◽  
...  
Keyword(s):  
Osteoclast Differentiation ◽  
Osteoblastic Differentiation ◽  
Common Disease ◽  
Root Extract ◽  
Mouse Bone Marrow ◽  
Mineral Density ◽  
Bone Mineral Density Loss ◽  
In Vivo Experiments

Osteoporosis is a common disease caused by an imbalance of processes between bone resorption by osteoclasts and bone formation by osteoblasts in postmenopausal women. The roots of Gentiana lutea L. (GL) are reported to have beneficial effects on various human diseases related to liver functions and gastrointestinal motility, as well as on arthritis. Here, we fractionated and isolated bioactive constituent(s) responsible for anti-osteoporotic effects of GL root extract. A single phytochemical compound, loganic acid, was identified as a candidate osteoprotective agent. Its anti-osteoporotic effects were examined in vitro and in vivo. Treatment with loganic acid significantly increased osteoblastic differentiation in preosteoblast MC3T3-E1 cells by promoting alkaline phosphatase activity and increasing mRNA expression levels of bone metabolic markers such as Alpl, Bglap, and Sp7. However, loganic acid inhibited osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. For in vivo experiments, the effect of loganic acid on ovariectomized (OVX) mice was examined for 12 weeks. Loganic acid prevented OVX-induced bone mineral density loss and improved bone structural properties in osteoporotic model mice. These results suggest that loganic acid may be a potential therapeutic candidate for treatment of osteoporosis.

scholarly journals Regorafenib-Attenuated, Bleomycin-Induced Pulmonary Fibrosis by Inhibiting the TGF-β1 Signaling Pathway

2021 ◽  
Vol 22 (4) ◽  
pp. 1985
Author(s):  
Xiaohe Li ◽  
Ling Ma ◽  
Kai Huang ◽  
Yuli Wei ◽  
Shida Long ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Signaling Pathway ◽  
Transforming Growth Factor ◽  
Kinase Inhibitor ◽  
In Vivo Experiments ◽  
Age Related ◽  
And Migration ◽  
Tgf Β1

Idiopathic pulmonary fibrosis (IPF) is a fatal and age-related pulmonary disease. Nintedanib is a receptor tyrosine kinase inhibitor, and one of the only two listed drugs against IPF. Regorafenib is a novel, orally active, multi-kinase inhibitor that has similar targets to nintedanib and is applied to treat colorectal cancer and gastrointestinal stromal tumors in patients. In this study, we first identified that regorafenib could alleviate bleomycin-induced pulmonary fibrosis in mice. The in vivo experiments indicated that regorafenib suppresses collagen accumulation and myofibroblast activation. Further in vitro mechanism studies showed that regorafenib inhibits the activation and migration of myofibroblasts and extracellular matrix production, mainly through suppressing the transforming growth factor (TGF)-β1/Smad and non-Smad signaling pathways. In vitro studies have also indicated that regorafenib could augment autophagy in myofibroblasts by suppressing TGF-β1/mTOR (mechanistic target of rapamycin) signaling, and could promote apoptosis in myofibroblasts. In conclusion, regorafenib attenuates bleomycin-induced pulmonary fibrosis by suppressing the TGF-β1 signaling pathway.

scholarly journals Bioactive Compounds from Herbal Medicine Targeting Multiple Myeloma

2021 ◽  
Vol 11 (10) ◽  
pp. 4451
Author(s):  
Coralia Cotoraci ◽  
Alina Ciceu ◽  
Alciona Sasu ◽  
Eftimie Miutescu ◽  
Anca Hermenean
Keyword(s):  
Multiple Myeloma ◽  
Survival Rate ◽  
Plasma Cells ◽  
Inhibition Of Proliferation ◽  
In Vivo Experiments ◽  
Clonal Proliferation ◽  
Hematological Cancers ◽  
Monoclonal Proteins

Multiple myeloma (MM) is one of the most widespread hematological cancers. It is characterized by a clonal proliferation of malignant plasma cells in the bone marrow and by the overproduction of monoclonal proteins. In recent years, the survival rate of patients with multiple myeloma has increased significantly due to the use of transplanted stem cells and of the new therapeutic agents that have significantly increased the survival rate, but it still cannot be completely cured and therefore the development of new therapeutic products is needed. Moreover, many patients have various side effects and face the development of drug resistance to current therapies. The purpose of this review is to highlight the bioactive active compounds (flavonoids) and herbal extracts which target dysregulated signaling pathway in MM, assessed by in vitro and in vivo experiments or clinical studies, in order to explore their healing potential targeting multiple myeloma. Mechanistically, they demonstrated the ability to promote cell cycle blockage and apoptosis or autophagy in cancer cells, as well as inhibition of proliferation/migration/tumor progression, inhibition of angiogenesis in the tumor vascular network. Current research provides valuable new information about the ability of flavonoids to enhance the apoptotic effects of antineoplastic drugs, thus providing viable therapeutic options based on combining conventional and non-conventional therapies in MM therapeutic protocols.

scholarly journals Occupational Exposure to Carbon Nanotubes and Carbon Nanofibres: More Than a Cobweb

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 745
Author(s):  
Enrico Bergamaschi ◽  
Giacomo Garzaro ◽  
Georgia Wilson Jones ◽  
Martina Buglisi ◽  
Michele Caniglia ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Animal Studies ◽  
Chemical Properties ◽  
Biological Behavior ◽  
Cross Sectional ◽  
Carbon Nanofibres ◽  
Material Entity ◽  
Cross Sectional Design

Carbon nanotubes (CNTs) and carbon nanofibers (CNFs) are erroneously considered as singular material entities. Instead, they should be regarded as a heterogeneous class of materials bearing different properties eliciting peculiar biological outcomes both in vitro and in vivo. Given the pace at which the industrial production of CNTs/CNFs is increasing, it is becoming of utmost importance to acquire comprehensive knowledge regarding their biological activity and their hazardous effects in humans. Animal studies carried out by inhalation showed that some CNTs/CNFs species can cause deleterious effects such as inflammation and lung tissue remodeling. Their physico-chemical properties, biological behavior and biopersistence make them similar to asbestos fibers. Human studies suggest some mild effects in workers handling CNT/CNF. However, owing to their cross-sectional design, researchers have been as yet unable to firmly demonstrate a causal relationship between such an exposure and the observed effects. Estimation of acceptable exposure levels should warrant a proper risk management. The aim of this review is to challenge the conception of CNTs/CNFs as a single, unified material entity and prompt the establishment of standardized hazard and exposure assessment methodologies able to properly feeding risk assessment and management frameworks.

scholarly journals UBE2C Drives Human Cervical Cancer Progression and Is Positively Modulated by mTOR

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
An-Jen Chiang ◽  
Chia-Jung Li ◽  
Kuan-Hao Tsui ◽  
Chung Chang ◽  
Yuan-chin Ivan Chang ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cancer Progression ◽  
Cancer Staging ◽  
Cervical Squamous Cell Carcinoma ◽  
Cancer Cell Proliferation ◽  
Gynecological Malignancy ◽  
In Vivo Experiments ◽  
Ubiquitin Conjugating Enzyme

Cervical cancer is a common gynecological malignancy, accounting for 10% of all gynecological cancers. Recently, targeted therapy for cervical cancer has shown unprecedented advantages. Several studies have shown that ubiquitin conjugating enzyme E2 (UBE2C) is highly expressed in a series of tumors, and participates in the progression of these tumors. However, the possible impact of UBE2C on the progression of cervical squamous cell carcinoma (CESC) remains unclear. Here, we carried out tissue microarray analysis of paraffin-embedded tissues from 294 cervical cancer patients with FIGO/TNM cancer staging records. The results indicated that UBE2C was highly expressed in human CESC tissues and its expression was related to the clinical characteristics of CESC patients. Overexpression and knockdown of UBE2C enhanced and reduced cervical cancer cell proliferation, respectively, in vitro. Furthermore, in vivo experiments showed that UBE2C regulated the expression and activity of the mTOR/PI3K/AKT pathway. In summary, we confirmed that UBE2C is involved in the process of CESC and that UBE2C may represent a molecular target for CESC treatment.

scholarly journals Exosomal Vimentin from Adipocyte Progenitors Protects Fibroblasts against Osmotic Stress and Inhibits Apoptosis to Enhance Wound Healing

2021 ◽  
Vol 22 (9) ◽  
pp. 4678
Author(s):  
Sepideh Parvanian ◽  
Hualian Zha ◽  
Dandan Su ◽  
Lifang Xi ◽  
Yaming Jiu ◽  
...  
Keyword(s):  
Wound Healing ◽  
Osmotic Stress ◽  
Mechanical Stress ◽  
Impaired Wound Healing ◽  
In Vivo Experiments ◽  
Adipocyte Progenitors ◽  
Osmotic Balance ◽  
Induced Apoptosis

Mechanical stress following injury regulates the quality and speed of wound healing. Improper mechanotransduction can lead to impaired wound healing and scar formation. Vimentin intermediate filaments control fibroblasts’ response to mechanical stress and lack of vimentin makes cells significantly vulnerable to environmental stress. We previously reported the involvement of exosomal vimentin in mediating wound healing. Here we performed in vitro and in vivo experiments to explore the effect of wide-type and vimentin knockout exosomes in accelerating wound healing under osmotic stress condition. Our results showed that osmotic stress increases the size and enhances the release of exosomes. Furthermore, our findings revealed that exosomal vimentin enhances wound healing by protecting fibroblasts against osmotic stress and inhibiting stress-induced apoptosis. These data suggest that exosomes could be considered either as a stress modifier to restore the osmotic balance or as a conveyer of stress to induce osmotic stress-driven conditions.

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