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Frontiers in Public Health 2022Nanomaterials are suspected of causing health problems, as published studies on nanotoxicology indicate. On the other hand, some of these materials, such as... (Review)
Review
BACKGROUND
Nanomaterials are suspected of causing health problems, as published studies on nanotoxicology indicate. On the other hand, some of these materials, such as nanostructured pyrogenic and precipitated synthetic amorphous silica (SAS) and silica gel, have been used for decades without safety concerns in industrial, commercial, and consumer applications. However, in addition to many and studies that have failed to demonstrate the intrinsic toxicity of SAS, articles periodically emerge, in which biological effects of concern have been described. Even though most of these studies do not meet high-quality standards and do not always use equivalent test materials or standardized test systems, the results often trigger substance re-evaluation. To put the results into perspective, an extensive literature study was carried out and an example of amorphous silica will be used to try to unravel the reliability from the unreliable results.
METHODS
A systematic search of studies on nanotoxicological effects has been performed covering the years 2013 to 2018. The identified studies have been evaluated for their quality regarding material and method details, and the data have been curated and put into a data collection. This review deals only with investigations on amorphous silica.
RESULTS
Of 18,162 publications 1,217 have been selected with direct reference to experiments with synthetically produced amorphous silica materials. The assessment of these studies based on defined criteria leads to a further reduction to 316 studies, which have been included in this systematic review. Screening for quality with well-defined quantitative criteria following the GUIDE nano concept reveals only 27.3% has acceptable quality. Overall, the and data showed low or no toxicity of amorphous silica. The data shown do not support the hypothesis of dependency of biological effects on the primary particle size of the tested materials.
CONCLUSION
This review demonstrates the relatively low quality of most studies published on nanotoxicological issues in the case of amorphous silica. Moreover, mechanistic studies are often passed off or considered toxicological studies. In general, standardized methods or the Organization for Economic Cooperation and Development (OECD) guidelines are rarely used for toxicological experiments. As a result, the significance of the published data is usually weak and must be reevaluated carefully before using them for regulatory purposes.
Topics: Nanostructures; Particle Size; Reproducibility of Results; Silicon Dioxide
PubMed: 35784253
DOI: 10.3389/fpubh.2022.902893 -
Journal of Environmental Health Science... Jun 2022Today air pollution caused by particulate matter (PM) is a global issue, especially in densely populated and high-traffic cities. The formation of reactive oxygen... (Review)
Review
UNLABELLED
Today air pollution caused by particulate matter (PM) is a global issue, especially in densely populated and high-traffic cities. The formation of reactive oxygen species (ROS) by various toxicological studies is considered as one of the important effects caused by airborne particles that can lead to adverse effects on human health. In this study, to answer the question of whether particle size affects oxidative potential (OP), we searched the main databases, including PubMed, Scopus, Embase, and Web of Science, and defined search strategy based on the MESH terms for the above-mentioned search engines. All articles published until 2021 were searched. An ANOVA was run using R software to show the correlation between the size distributions of particulate matter and oxidative potential (base on mass and volumetric units) in ambient air. As expected, the regression results showed that the relationship between particle size and OP values for the studies based on mass-logarithm has a significant difference in the different distribution size categories, which was related to the difference between the <2.5 and < 1 categories. However, ANOVA analysis did not show a significant difference in the volumetric OP logarithm in the different distribution size categories. In this study, it was found that sizes higher than 2.5 μm did not have much effect on human health, and it is recommended that future research focus on PM2.5.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s40201-021-00768-w.
PubMed: 35669811
DOI: 10.1007/s40201-021-00768-w -
Frontiers in Pharmacology 2022Although numerous nanoparticle formulations have been developed for ocular administration, concerns are being raised about a possible mismatch between potential...
Although numerous nanoparticle formulations have been developed for ocular administration, concerns are being raised about a possible mismatch between potential promises made by the field of nanoparticle research and demonstration of actual therapeutic benefit. Therefore, the primary focus of this present review was to critically assess to what extent nanoencapsulation of ocular drugs improved the therapeutic outcome when treating conditions in the anterior segment of the eye. A systematic search was conducted using Medline, PubMed, and Embase databases as well as Google Scholar for published peer-reviewed articles in English focusing on conventional nanoparticles used as drug delivery systems to the anterior segment of the eye in studies. The major therapeutic outcomes were intraocular pressure, tear secretion, number of polymorphonuclear leucocytes and pupil size. The outcome after encapsulation was compared to the non-encapsulated drug. From the search, 250 results were retrieved. Thirty-eight studies met the inclusion criteria. Rabbits were used as study subjects in all but one study, and the number of animals ranged from 3 to 10. Coated and uncoated liposomes, lipid-based and polymeric nanoparticles, as well as micelles, were studied, varying in both particle size and surface charge, and encapsulating a total of 24 different drugs, including 6 salts. The majority of the studies demonstrated some improvement after nanoencapsulation, but the duration of the benefit varied from less than 1 h to more than 20 h. The most common methods performed in the studies were drug release, transcorneal permeation, and mucin interaction. Nanoparticles that are small and mucoadhesive, often due to positive surface charge, appeared beneficial. Although assays can unravel more of the hidden and sophisticated interplay between the encapsulated drug and the nanoparticle structure, they suffered from a lack of - correlation. Therefore, more research should be focused towards developing predictive models, allowing rational design and systematic optimization of ocular nanoparticles with minimal animal experimentation.
PubMed: 35645827
DOI: 10.3389/fphar.2022.903519 -
Environmental Science. Nano Feb 2022A systematic review of the use of single particle ICP-MS to analyse engineered nanomaterials (ENMs) in biological samples (plants, animals, body fluids) has highlighted... (Review)
Review
A systematic review of the use of single particle ICP-MS to analyse engineered nanomaterials (ENMs) in biological samples (plants, animals, body fluids) has highlighted that efforts have focused on a select few types of ENMs (, Ag and TiO) and there is a lack of information for some important tissues (, reproductive organs, skin and fatty endocrine organs). The importance of sample storage is often overlooked but plays a critical role. Careful consideration of the ENM and matrix composition is required to select an appropriate protocol to liberate ENMs from a tissue whilst not promoting the transformation of them, or genesis of new particulates. A 'one size fits all' protocol, applicable to all possible types of ENM and biological matrices, does not seem practical. However, alkaline-based extractions would appear to show greater promise for wide applicability to animal tissues, although enzymatic approaches have a role, especially for plant tissues. There is a lack of consistency in metrics reported and how they are determined ( size limit of detection, and proportions of recovery), making comparison between some studies more difficult. In order to establish standardised protocols for regulatory use, effort is needed to: develop certified reference materials, achieve international agree on nomenclature and the use of control samples, and to create a decision tree to help select the best sample preparation for the type of tissue matrix.
PubMed: 35309016
DOI: 10.1039/d1en00680k -
BMJ Open Feb 2022Despite the uptake of nutrigenetic testing through direct-to-consumer services and healthcare professionals, systematic reviews determining scientific validity are...
OBJECTIVES
Despite the uptake of nutrigenetic testing through direct-to-consumer services and healthcare professionals, systematic reviews determining scientific validity are limited in this field. The objective of this review was to: retrieve, synthesise and assess the quality of evidence (confidence) for nutrigenetic approaches related to the effect of genetic variation on plasma lipid, lipoprotein and apolipoprotein responsiveness to omega-3 fatty acid intake.
DESIGN
A systematic review was conducted using three search engines (Embase, Web of Science and Medline) for articles published up until 1 August 2020. We aimed to systematically search, identify (select) and provide a narrative synthesis of all studies that assessed nutrigenetic associations/interactions for genetic variants (comparators) influencing the plasma lipid, lipoprotein and/or apolipoprotein response (outcomes) to omega-3 fatty acid intake (intervention/exposure) in humans-both paediatric and adult populations (population). We further aimed to assess the overall quality of evidence for specific priority nutrigenetic associations/interactions based on the following inclusion criteria: nutrigenetic associations/interactions reported for the same genetic variants (comparators) influencing the same plasma lipid, lipoprotein and/or apolipoprotein response (outcomes) to omega-3 fatty acid intake (intervention/exposure) in humans-both paediatric and adult populations (population) in at least two independent studies, irrespective of the findings. Risk of bias was assessed in individual studies. Evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach with a modification to further consider biological plausibility.
RESULTS
Out of 1830 articles screened, 65 met the inclusion criteria for the narrative synthesis (n=23 observational, n=42 interventional); of these, 25 met the inclusion criteria for GRADE evidence evaluation. Overall, current evidence is insufficient for gene-diet associations related to omega-3 fatty acid intake on plasma apolipoproteins, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein (LDL)-cholesterol and LDL particle size. However, there is strong (GRADE rating: moderate quality) evidence to suggest that male -E4 carriers (rs429358, rs7412) exhibit significant triglyceride reductions in response to omega-3-rich fish oil with a dose-response effect. Moreover, strong (GRADE rating: high quality) evidence suggests that a 31-SNP nutrigenetic risk score can predict plasma triglyceride responsiveness to omega-3-rich fish oil in adults with overweight/obesity from various ethnicities.
CONCLUSIONS
Most evidence in this area is weak, but two specific nutrigenetic interactions exhibited strong evidence, with generalisability limited to specific populations.
PROSPERO REGISTRATION NUMBER
CRD42020185087.
Topics: Apolipoproteins; Child; Cholesterol; Fatty Acids, Omega-3; Humans; Lipoproteins; Male; Nutrigenomics; Triglycerides
PubMed: 35193914
DOI: 10.1136/bmjopen-2021-054417 -
International Journal of Dentistry 2021This study aimed to evaluate the effect of sandblasting on the bond strength of denture base resin to soft liners. (Review)
Review
OBJECTIVES
This study aimed to evaluate the effect of sandblasting on the bond strength of denture base resin to soft liners.
MATERIALS AND METHODS
This report follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Embase, Cochrane, Scopus, and OpenGrey databases were searched for in vitro studies that compared sandblasting with no treatment in terms of the tensile, shear, and peel bond strength of resilient lining materials (acrylic-based or silicone-based) to polymethyl methacrylate denture base resin. Based on the outcome, the analysis was carried out in three groups of tensile, shear, and peel bond strength. Subgroup analysis was done for the effect of size of particles on sandblasting, blasting pressure, and type of soft liner whenever possible. Heterogeneity was evaluated among the studies, and meta-analysis was performed with random effect models ( < .05).
RESULTS
After screening, 16 articles met the inclusion criteria for meta-analyses. No treatment showed significantly higher tensile ( < 0.001) or peel (=0.04) bond strength, although shear bond strength of sandblasted resin was significantly better (=0.008). Results of subgroup analyses of particle size favored the control group in 50 AlO particle size ( < 0.001). In analyses of blasting pressure, the control group had significantly better tensile bond strength than specimens with blasting pressure ≤1 bar ( < 0.001) while specimens with blasting pressure beyond 1 bar showed significantly more tensile strength than control group (=0.03). In silicon-based liners, groups without any surface treatment had significantly higher tensile bond strength ( < 0.001).
CONCLUSION
According to the in vitro studies, sandblasting would not lead to significant increase in bond strength of soft liner to the denture base resin.
PubMed: 34976062
DOI: 10.1155/2021/5674155 -
Nutrition Reviews Apr 2022Moderate alcohol consumption is associated with decreased risk of cardiovascular disease (CVD) and improvement in cardiovascular risk markers, including lipoproteins and...
CONTEXT
Moderate alcohol consumption is associated with decreased risk of cardiovascular disease (CVD) and improvement in cardiovascular risk markers, including lipoproteins and lipoprotein subfractions.
OBJECTIVE
To systematically review the relationship between moderate alcohol intake, lipoprotein subfractions, and related mechanisms.
DATA SOURCES
Following PRISMA, all human and ex vivo studies with an alcohol intake up to 60 g/d were included from 8 databases.
DATA EXTRACTION
A total of 17 478 studies were screened, and data were extracted from 37 intervention and 77 observational studies.
RESULTS
Alcohol intake was positively associated with all HDL subfractions. A few studies found lower levels of small LDLs, increased average LDL particle size, and nonlinear relationships to apolipoprotein B-containing lipoproteins. Cholesterol efflux capacity and paraoxonase activity were consistently increased. Several studies had unclear or high risk of bias, and heterogeneous laboratory methods restricted comparability between studies.
CONCLUSIONS
Up to 60 g/d alcohol can cause changes in lipoprotein subfractions and related mechanisms that could influence cardiovascular health.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO registration no. 98955.
Topics: Alcohol Drinking; Apolipoproteins B; Cardiovascular Diseases; Cholesterol, HDL; Humans; Lipoproteins; Lipoproteins, LDL
PubMed: 34957513
DOI: 10.1093/nutrit/nuab102 -
Cureus Oct 2021Our objective is to analyze the risk of particle spread through mastoidectomy during the COVID-19 pandemic with an aim to assess the tools used to mitigate the... (Review)
Review
Our objective is to analyze the risk of particle spread through mastoidectomy during the COVID-19 pandemic with an aim to assess the tools used to mitigate the spread. A systematic review was conducted using PRISMA guidelines. Our search terms included: MASTOIDECTOMY + COVID-19 or MASTOIDECTOMY + SAR- CoV-2 or MASTOIDECTOMY + CORONAVIRUS. Studies consistent with the inclusion and exclusion criteria were included in the review. Of the 20 articles identified in the initial search, six met the inclusion criteria. The included articles were all experimental studies, with five studies using cadaver subjects and one study using live human subjects. Three studies measured droplet spread and three studies measured aerosolized particle spread. The maximum distance of particle spread ranged from 30 cm to 208 cm. Four studies assessed the use of a barrier system, with two using the OtoTent and two using a barrier drape. Two studies defined the microscope alone as a possible mitigatory tool. One study compared burr type and size to determine the effects on particle spread. During the coronavirus disease 2019 (COVID-19) pandemic, evaluation of tools to mitigate particle spread is imperative for the safety of the surgical team and the healthcare system at large. Barrier drapes, OtoTents and microscopes all have proven to mitigate particle spread; however, further research needs to be performed to compare their efficacy and develop a standard of safety.
PubMed: 34853757
DOI: 10.7759/cureus.19040 -
International Journal of Environmental... Oct 2021Particulate matter (PM) is a complex mixture of solid particles and liquid droplets suspended in the air with varying size, shape, and chemical composition which... (Review)
Review
Particulate matter (PM) is a complex mixture of solid particles and liquid droplets suspended in the air with varying size, shape, and chemical composition which intensifies significant concern due to severe health effects. Based on the well-established human health effects of outdoor PM, health-based standards for outdoor air have been promoted (e.g., the National Ambient Air Quality Standards formulated by the U.S.). Due to the exchange of indoor and outdoor air, the chemical composition of indoor particulate matter is related to the sources and components of outdoor PM. However, PM in the indoor environment has the potential to exceed outdoor PM levels. Indoor PM includes particles of outdoor origin that drift indoors and particles that originate from indoor activities, which include cooking, fireplaces, smoking, fuel combustion for heating, human activities, and burning incense. Indoor PM can be enriched with inorganic and organic contaminants, including toxic heavy metals and carcinogenic volatile organic compounds. As a potential health hazard, indoor exposure to PM has received increased attention in recent years because people spend most of their time indoors. In addition, as the quantity, quality, and scope of the research have expanded, it is necessary to conduct a systematic review of indoor PM. This review discusses the sources, pathways, characteristics, health effects, and exposure mitigation of indoor PM. Practical solutions and steps to reduce exposure to indoor PM are also discussed.
Topics: Air Pollutants; Air Pollution; Air Pollution, Indoor; Cooking; Environmental Monitoring; Humans; Particle Size; Particulate Matter
PubMed: 34769574
DOI: 10.3390/ijerph182111055 -
Environmental Science and Pollution... Jan 2022After the spread of Covid 19 worldwide, the use of cloth masks increased significantly due to a shortage of medical masks. Meanwhile, there were different opinions about... (Review)
Review
After the spread of Covid 19 worldwide, the use of cloth masks increased significantly due to a shortage of medical masks. Meanwhile, there were different opinions about the effectiveness of these masks and, so far, no study has been done to find the best fabric masks. This study reviews and summarizes all studies related to fabric masks' effectiveness and various fabrics against coronavirus. This systematic review is based on PRISMA rules. Two researchers separately examined three databases: PubMed, Scopus, and Web of Science. Laboratory and clinical studies were included. After extracting the articles, their quality was assessed with the Joanna Briggs Institute (JBI) tool. In addition to efficacy, other factors, including the penetration of masks, pressure drop, and quality factor, were examined to select the best fabrics. Of the 42 studies selected, 39 were laboratory studies, and 3 were clinical studies. Among the various fabrics examined, cotton quilt 120 thread per inch (TPI), copy paper (bonded), hybrid of cotton with chiffon/ silk, and flannel filtration were found to have over 90% effectiveness in the particle size range of Covid-19. The results and comparison of different factors (pressure drop, filtration efficacy, penetration, filtration quality, and fit factor have been evaluated) showed that among different fabrics, hybrid masks, 2-layered cotton quilt, 2-layered 100% cotton, cotton flannel, and hairy tea towel + fleece sweater had the best performance. Clinical studies have not explicitly examined cloth masks' effectiveness in Covid-19, so the effectiveness of these types of masks for Covid 19 is questionable, and more studies are needed.
Topics: COVID-19; Filtration; Humans; Masks; SARS-CoV-2; Textiles
PubMed: 34689269
DOI: 10.1007/s11356-021-16847-2