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Molecules (Basel, Switzerland) Jan 2022While bio-based but chemically synthesized polymers such as polylactic acid require industrial conditions for biodegradation, protein-based materials are home... (Review)
Review
While bio-based but chemically synthesized polymers such as polylactic acid require industrial conditions for biodegradation, protein-based materials are home compostable and show high potential for disposable products that are not collected. However, so far, such materials lack in their mechanical properties to reach the requirements for, e.g., packaging applications. Relevant measures for such a modification of protein-based materials are plasticization and cross-linking; the former increasing the elasticity and the latter the tensile strength of the polymer matrix. The assessment shows that compared to other polymers, the major bottleneck of proteins is their complex structure, which can, if developed accordingly, be used to design materials with desired functional properties. Chemicals can act as cross-linkers but require controlled reaction conditions. Physical methods such as heat curing and radiation show higher effectiveness but are not easy to control and can even damage the polymer backbone. Concerning plasticization, effectiveness and compatibility follow opposite trends due to weak interactions between the plasticizer and the protein. Internal plasticization by covalent bonding surpasses these limitations but requires further research specific for each protein. In addition, synergistic approaches, where different plasticization/cross-linking methods are combined, have shown high potential and emphasize the complexity in the design of the polymer matrix.
Topics: Biocompatible Materials; Cross-Linking Reagents; Enzymes; Hot Temperature; Mechanical Phenomena; Plasticizers; Proteins
PubMed: 35056758
DOI: 10.3390/molecules27020446 -
Journal of Exposure Science &... Jul 2023Non-targeted analysis (NTA) and suspect screening analysis (SSA) are powerful techniques that rely on high-resolution mass spectrometry (HRMS) and computational tools to... (Review)
Review
Non-targeted analysis (NTA) and suspect screening analysis (SSA) are powerful techniques that rely on high-resolution mass spectrometry (HRMS) and computational tools to detect and identify unknown or suspected chemicals in the exposome. Fully understanding the chemical exposome requires characterization of both environmental media and human specimens. As such, we conducted a review to examine the use of different NTA and SSA methods in various exposure media and human samples, including the results and chemicals detected. The literature review was conducted by searching literature databases, such as PubMed and Web of Science, for keywords, such as "non-targeted analysis", "suspect screening analysis" and the exposure media. Sources of human exposure to environmental chemicals discussed in this review include water, air, soil/sediment, dust, and food and consumer products. The use of NTA for exposure discovery in human biospecimen is also reviewed. The chemical space that has been captured using NTA varies by media analyzed and analytical platform. In each media the chemicals that were frequently detected using NTA were: per- and polyfluoroalkyl substances (PFAS) and pharmaceuticals in water, pesticides and polyaromatic hydrocarbons (PAHs) in soil and sediment, volatile and semi-volatile organic compounds in air, flame retardants in dust, plasticizers in consumer products, and plasticizers, pesticides, and halogenated compounds in human samples. Some studies reviewed herein used both liquid chromatography (LC) and gas chromatography (GC) HRMS to increase the detected chemical space (16%); however, the majority (51%) only used LC-HRMS and fewer used GC-HRMS (32%). Finally, we identify knowledge and technology gaps that must be overcome to fully assess potential chemical exposures using NTA. Understanding the chemical space is essential to identifying and prioritizing gaps in our understanding of exposure sources and prior exposures. IMPACT STATEMENT: This review examines the results and chemicals detected by analyzing exposure media and human samples using high-resolution mass spectrometry based non-targeted analysis (NTA) and suspect screening analysis (SSA).
Topics: Humans; Environmental Pollutants; Exposome; Plasticizers; Soil; Dust; Water
PubMed: 37380877
DOI: 10.1038/s41370-023-00574-6 -
Mutation Research 2012Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both... (Review)
Review
Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and environmental (medical devices, contamination of food, or intake from air, water and soil) routes of exposure to DEHP are of concern for human health. There is sufficient evidence for carcinogenicity of DEHP in the liver in both rats and mice; however, there is little epidemiological evidence on possible associations between exposure to DEHP and liver cancer in humans. Data are available to suggest that liver is not the only target tissue for DEHP-associated toxicity and carcinogenicity in both humans and rodents. The debate regarding human relevance of the findings in rats or mice has been informed by studies on the mechanisms of carcinogenesis of the peroxisome proliferator class of chemicals, including DEHP. Important additional mechanistic information became available in the past decade, including, but not limited to, sub-acute, sub-chronic and chronic studies with DEHP in peroxisome proliferator-activated receptor (PPAR) α-null mice, as well as experiments utilizing several transgenic mouse lines. Activation of PPARα and the subsequent downstream events mediated by this transcription factor represent an important mechanism of action for DEHP in rats and mice. However, additional data from animal models and studies in humans exposed to DEHP from the environment suggest that multiple molecular signals and pathways in several cell types in the liver, rather than a single molecular event, contribute to the cancer in rats and mice. In addition, the toxic and carcinogenic effects of DEHP are not limited to liver. The International Agency for Research on Cancer working group concluded that the human relevance of the molecular events leading to cancer elicited by DEHP in several target tissues (e.g., liver and testis) in rats and mice can not be ruled out and DEHP was classified as possibly carcinogenic to humans (Group 2B).
Topics: Animals; Carcinogens; Diethylhexyl Phthalate; Humans; Immune System; Kidney; Liver; Liver Neoplasms; Lung; Male; Mice; Peroxisome Proliferators; Plasticizers; Rats; Testicular Neoplasms; Testis
PubMed: 22198209
DOI: 10.1016/j.mrrev.2011.12.004 -
Environmental Research Oct 2022Sea turtles are particularly vulnerable to plastic exposures, and the associated chemical additives, due to their feeding strategies. The species Caretta caretta is a...
Sea turtles are particularly vulnerable to plastic exposures, and the associated chemical additives, due to their feeding strategies. The species Caretta caretta is a proposed sentinel of plastic pollution worldwide. Thus, there is a need to find adequate biomarkers of plastic exposure through non-invasive protocols for this IUCN protected species. Plasmatic acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and carboxylesterase (CE) which participate in xenobiotic and endogenous metabolic reactions could all serve as biomarkers, as they are responsive to plasticizers and have already proved adequate for identifying organophosphorus esters exposures. Here we measured plasmatic B-esterases in wild specimens captured as accidental by-catch. Measurements were taken in each individual either at entry into the rehabilitation program or immediately before release after a recovery period. For CE measurements, 4 commercial substrates were used as potentially indicative of distinct enzyme isoforms. Increased activity was seen with the butyrate-derived substrates. Plasmatic CE activities were over one order of magnitude higher than AChE and BuChE substrates. Moreover, an in vitro protocol with the inclusion of plastic additives such as tetrabromobisphenol A (TBBPA), bisphenol A and some of its analogues was considered a proxy of enzymatic interactions. A clear inhibition by TBBPA was found when using commercially purified AChE and recombinant CE proteins. Overall, from in vitro and in vivo evidences, CEs in plasma are sensitive and easily measurable and have been shown to significantly increase after turtles have been rehabilitated in rescue centres. Nevertheless, the inclusion of plastic (or plasticizers) characterisation would help to confirm its association with plasmatic enzyme modifications before they can be adopted as biomarkers of plastic contamination.
Topics: Acetylcholinesterase; Animals; Biomarkers; Butyrylcholinesterase; Esterases; Plasticizers; Plastics; Turtles; Water Pollutants
PubMed: 35688215
DOI: 10.1016/j.envres.2022.113639 -
Advances in Clinical and Experimental... Jul 2017Tissue conditioners (TCs) are short-term soft liners, formed in situ from a mixture of a polymer powder and a liquid plasticizer. This article reviews the recent... (Review)
Review
Tissue conditioners (TCs) are short-term soft liners, formed in situ from a mixture of a polymer powder and a liquid plasticizer. This article reviews the recent advances in the composition, functions, clinical use, gelation process, and physical properties of TCs and their effects on denture bases and oral mucosa. TCs are used to improve the fit and function of an ill-fitting denture. They can also be used to treat abused mucosal tissues underlying ill-fitting acrylic dentures as temporary expedients. TCs are recommended as provisional liners to maintain the fit of removable dentures and to prevent mechanical irritation from the denture. TCs may also be used to rehabilitate cancer patients. The polymer powder, used in the formulation of TCs generally consists of polyethyl methacrylate (PEMA) and the liquid plasticizer is ester-based in ethyl alcohol solution without an acrylic monomer. The plasticizers are low molecular weight aromatic esters. Mixing of the powder and liquid results in polymer chain entanglement and the formation of a coherent gel characterized by viscoelastic behavior appropriate to its intended clinical use. The loss of surface integrity and surface roughness of TCs are regarded as the main problems in the denture bearing oral mucosa conditions resulting in inflammation of oral mucosa of the denture-bearing area - denture stomatitis. TCs provide an even distribution of masticatory force, accurately modeling itself to the changes which occur during the healing of lesion of substrate and can act therapeutically by incorporating antifungal or antibacterial agents.
Topics: Denture Bases; Denture Liners; Humans; Methylmethacrylates; Plasticizers
PubMed: 28691420
DOI: 10.17219/acem/62634 -
World Journal of Gastroenterology Nov 2013Pharmaceutical companies that produce gastrointestinal (GI) medications often utilize phthalates for their ability to localize medication release. Commonly prescribed GI... (Review)
Review
Pharmaceutical companies that produce gastrointestinal (GI) medications often utilize phthalates for their ability to localize medication release. Commonly prescribed GI medications that may utilize phthalates are 5-Aminosalicylates, proton pump inhibitors, and pancreatic enzymes. Our understanding of the cumulative health effects of phthalates from medications remains unclear, and there is increasing evidence that phthalates are not harmless. Experimental studies in animals have shown that phthalates, specifically dibutyl phthalate and Di-(2-ethyl-hexyl) phthalate, have the potential to alter and/or inhibit reproductive biology and in utero development. Despite the lack of definitive human data, many cohort and cross-sectional studies demonstrate concerning associations between phthalates and poor health status, specifically developmental problems. Longitudinal studies and studies with larger sample sizes are required to determine whether phthalates actually cause negative health consequences. It is also important that physicians regularly review and discuss with patients the medicinal ingredients in their medications and supplements, specifically in pregnant woman with inflammatory bowel disease.
Topics: Animals; Drug Contamination; Female; Gastrointestinal Agents; Humans; Inflammatory Bowel Diseases; Male; Patient Safety; Phthalic Acids; Plasticizers; Pregnancy; Pregnancy Complications; Risk Assessment; Risk Factors
PubMed: 24222946
DOI: 10.3748/wjg.v19.i41.7042 -
The Kaohsiung Journal of Medical... Jul 2012The May 23, 2011, plasticizer incident was one of the most serious food safety issues that ever occurred in Taiwan. Most, if not all, plasticizer-contaminated food items... (Review)
Review
The May 23, 2011, plasticizer incident was one of the most serious food safety issues that ever occurred in Taiwan. Most, if not all, plasticizer-contaminated food items were due to malicious replacement of palm oil with phthalate plasticizer(s) in the cloudy-agent formulas by two upstream manufacturers. The incumbent agencies in Taiwan took necessary actions to minimize the harm caused by the incident and to ease the panic of the general public. In this paper, the incident was briefly reviewed and the situations of phthalate exposure in general public and pregnant women were assessed. Subsequently, the associations between phthalates exposure and the adverse health effects, such as shortened anogenital distance in baby boys, premature thelarche in young girls, endometriosis, adenomyosis, and leiomyoma in women, and decreased semen quality in men, were discussed. Food safety issue has become a worldwide concern and early detection of potential new toxicants in the foods is indispensable. Therefore, it is imperative to establish an international network for early warning or sentinel on food safety.
Topics: Animals; Asthma; Diethylhexyl Phthalate; Environmental Exposure; Food Contamination; Government Regulation; Humans; Phthalic Acids; Plasticizers; Taiwan
PubMed: 22871596
DOI: 10.1016/j.kjms.2012.05.005 -
Critical Reviews in Toxicology May 2006The industrial plasticizer di-(2-ethylhexyl)phthalate (DEHP) is used in manufacturing of a wide variety of polyvinyl chloride (PVC)-containing medical and consumer... (Review)
Review
The industrial plasticizer di-(2-ethylhexyl)phthalate (DEHP) is used in manufacturing of a wide variety of polyvinyl chloride (PVC)-containing medical and consumer products. DEHP belongs to a class of chemicals known as peroxisome proliferators (PPs). PPs are a structurally diverse group of compounds that share many (but perhaps not all) biological effects and are characterized as non-genotoxic rodent carcinogens. This review focuses on the effect of DEHP in liver, a primary target organ for the pleiotropic effects of DEHP and other PPs. Specifically, liver parenchymal cells, identified herein as hepatocytes, are a major cell type that are responsive to exposure to PPs, including DEHP; however, other cell types in the liver may also play a role. The PP-induced increase in the number and size of peroxisomes in hepatocytes, so called 'peroxisome proliferation' that results in elevation of fatty acid metabolism, is a hallmark response to these compounds in the liver. A link between peroxisome proliferation and tumor formation has been a predominant, albeit questioned, theory to explain the cause of a hepatocarcinogenic effect of PPs. Other molecular events, such as induction of cell proliferation, decreased apoptosis, oxidative DNA damage, and selective clonal expansion of the initiated cells have been also been proposed to be critically involved in PP-induced carcinogenesis in liver. Considerable differences in the metabolism and molecular changes induced by DEHP in the liver, most predominantly the activation of the nuclear receptor peroxisome proliferator-activated receptor (PPAR)alpha, have been identified between species. Both sexes of rats and mice develop adenomas and carcinomas after prolonged feeding with DEHP; however, limited DEHP-specific human data are available, even though exposure to DEHP and other phthalates is common in the general population. This likely constitutes the largest gap in our knowledge on the potential for DEHP to cause liver cancer in humans. Overall, it is believed that the sequence of key events that are relevant to DEHP-induced liver carcinogenesis in rodents involves the following events whereby the combination of the molecular signals and multiple pathways, rather than a single hallmark event (such as induction of PPARalpha and peroxisomal genes, or cell proliferation) contribute to the formation of tumors: (i) rapid metabolism of the parental compound to primary and secondary bioactive metabolites that are readily absorbed and distributed throughout the body; (ii) receptor-independent activation of hepatic macrophages and production of oxidants; (iii) activation of PPARalpha in hepatocytes and sustained increase in expression of peroxisomal and non-peroxisomal metabolism-related genes; (iv) enlargement of many hepatocellular organelles (peroxisomes, mitochondria, etc.); (v) rapid but transient increase in cell proliferation, and a decrease in apoptosis; (vi) sustained hepatomegaly; (vii) chronic low-level oxidative stress and accumulation of DNA damage; (viii) selective clonal expansion of the initiated cells; (ix) appearance of the pre-neoplastic nodules; (x) development of adenomas and carcinomas.
Topics: Animals; Cell Proliferation; Hepatocytes; Humans; Peroxisomes; Phthalic Acids; Plasticizers; Species Specificity
PubMed: 16954067
DOI: 10.1080/10408440600779065 -
Journal of Environmental and Public... 2012High molecular-weight phthalates, such as diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP), are widely used as plasticizers in the manufacturing of polymers... (Review)
Review
High molecular-weight phthalates, such as diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP), are widely used as plasticizers in the manufacturing of polymers and consumer products. Human biological monitoring studies have employed the metabolites of DINP and DIDP as biomarkers to assess human exposure. In this review, we summarize and analyze publicly available scientific data on chemistry, metabolism, and excretion kinetics, of DINP and DIDP, to identify specific and sensitive metabolites. Human biological monitoring data on DINP and DIDP are scrutinised to assess the suitability of these metabolites as biomarkers of exposure. Results from studies carried out in animals and humans indicate that phthalates are metabolised rapidly and do not bioaccmulate. During Phase-I metabolism, ester hydrolysis of DINP and DIDP leads to the formation of hydrolytic monoesters. These primary metabolites undergo further oxidation reactions to produce secondary metabolites. Hence, the levels of secondary metabolites of DINP and DIDP in urine are found to be always higher than the primary metabolites. Results from human biological monitoring studies have shown that the secondary metabolites of DINP and DIDP in urine were detected in almost all tested samples, while the primary metabolites were detected in only about 10% of the samples. This indicates that the secondary metabolites are very sensitive biomarkers of DINP/DIDP exposure while primary metabolites are not. The NHANES data indicate that the median concentrations of MCIOP and MCINP (secondary metabolites of DINP and DIDP, resp.) at a population level are about 5.1 μg/L and 2.7 μg/L, respectively. Moreover, the available biological monitoring data suggest that infants/children are exposed to higher levels of phthalates than adults.
Topics: Animals; Biomarkers; Environmental Exposure; Environmental Monitoring; Environmental Pollutants; Humans; Phthalic Acids; Plasticizers; Rats
PubMed: 22505951
DOI: 10.1155/2012/810501 -
Environmental Science & Technology Jan 2024Hazardous chemicals in building and construction plastics can lead to health risks due to indoor exposure and may contaminate recycled materials. We systematically...
Hazardous chemicals in building and construction plastics can lead to health risks due to indoor exposure and may contaminate recycled materials. We systematically sampled new polyvinyl chloride floorings on the Swiss market ( = 151). We performed elemental analysis by X-ray fluorescence, targeted and suspect gas chromatography-mass spectrometry analysis of -phthalates and alternative plasticizers, and bioassay tests for cytotoxicity and oxidative stress, and endocrine, mutagenic, and genotoxic activities (for selected samples). Surprisingly, 16% of the samples contained regulated chemicals above 0.1 wt %, mainly lead and bis(2-ethylhexyl) phthalate (DEHP). Their presence is likely related to the use of recycled PVC in new flooring, highlighting that uncontrolled recycling can delay the phase-out of hazardous chemicals. Besides DEHP, 29% of the samples contained other -phthalates (mainly diisononyl and diisodecyl phthalates, DiNP and DiDP) above 0.1 wt %, and 17% of the samples indicated a potential to cause biological effects. Considering some overlap between these groups, they together make up an additional 35% of the samples of potential concern. Moreover, both suspect screening and bioassay results indicate the presence of additional potentially hazardous substances. Overall, our study highlights the urgent need to accelerate the phase-out of hazardous substances, increase the transparency of chemical compositions in plastics to protect human and ecosystem health, and enable the transition to a safe and sustainable circular economy.
Topics: Humans; Plasticizers; Diethylhexyl Phthalate; Ecosystem; Phthalic Acids; Plastics; Hazardous Substances
PubMed: 38241221
DOI: 10.1021/acs.est.3c04851