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International Journal of Environmental... Feb 2022Public complaints have raised concerns that some mattresses in the current marketplace may be potential sources of airborne fiberglass. Although mattress foam is often...
Public complaints have raised concerns that some mattresses in the current marketplace may be potential sources of airborne fiberglass. Although mattress foam is often marketed as chemical-free, their cover compositions are not as well understood by the general public. To fill these basic information gaps, the covers of four newly purchased mattresses were sampled and analyzed using polarized light microscopy, SEM-EDS, and FTIR microspectroscopy. Two of the mattress covers contained over 50% fiberglass in their inner sock layers. Up to 1% of the fiberglass had migrated to adjacent fabric layers, representing a potential risk of consumer exposure if the zipper on the outer cover is opened. The observed fiberglass fragments had calculated aerodynamic diameters ranging between 30 and 50 µm, suggesting they are potentially inhalable into the nose, mouth, and throat, but are likely too large to penetrate deeper into the lungs. No fiberglass was observed on the brand new mattresses' outer surfaces. Synthetic fibers also present in the sock layers were consistent with flame resistant modacrylic containing vinyl chloride and antimony. The use of fiberglass and other chemicals in mattress covers poses a potential health risk if these materials are not adequately contained. The apparent non-inclusion of mattress covers in chemical-free certifications suggests that further improvements are needed in mattress labeling and education of consumers.
Topics: Antimony; Beds; Glass
PubMed: 35162717
DOI: 10.3390/ijerph19031695 -
Journal of Oncology Pharmacy Practice :... Jul 2023PF-06439535 (bevacizumab-bvzr; Zirabev) is a bevacizumab biosimilar. The stability profile and functional activity of PF-06439535 after dilution for intravenous infusion...
INTRODUCTION
PF-06439535 (bevacizumab-bvzr; Zirabev) is a bevacizumab biosimilar. The stability profile and functional activity of PF-06439535 after dilution for intravenous infusion was evaluated following extended storage conditions.
METHODS
PF-06439535 drug product was diluted in 0.9% sodium chloride to produce final concentrations of 1.4 and 16.5 mg/mL of PF-06439535, representing clinically relevant low and high doses for intravenous infusion. Three drug product lots and three infusion bag types (polyolefin, ethylene vinyl acetate, and polyvinyl chloride) were tested. To simulate the potential preparation and administration conditions encountered in a clinical setting, prepared drug solutions were initially stored at 25 ± 5°C for 24 ± 2 h, and then at 5 ± 3°C for up to 6 weeks. Extended storage was followed by storage at 25 ± 5°C for 24 ± 2 h before testing. Physicochemical and biological stability were evaluated according to visual characteristics and pH, protein concentration, particulate content, the proportions of molecular weight variants and charge variants, and relative potency. A wide range of analytical techniques optimized for PF-06439535 assessment were employed, such as size-exclusion chromatography, non-reducing sodium dodecyl sulfate capillary electrophoresis, cation-exchange chromatography, far-UV circular dichroism spectroscopy, differential scanning calorimetry, and an cell-based bioassay.
RESULTS
For all concentrations, drug product lots, infusion bag types, and time points tested, there were no significant changes in protein concentration and no notable differences in visual characteristics (color, clarity, and visible particulates). The abundance of molecular weight variants and charge variants remained stable over the 6-week study period. There were no stability concerns with regard to sub-visible particles. There were no significant changes in primary, secondary, or tertiary structure. Finally, the relative potency of PF-06439535 was maintained throughout the study period.
CONCLUSIONS
The stability and biological activity of PF-06439535 was maintained after dilution and storage for up to 6 weeks at 2-8°C, demonstrating the integrity of diluted PF-06439535 under extended in-use conditions.
Topics: Humans; Bevacizumab; Biosimilar Pharmaceuticals; Drug Stability; Infusions, Intravenous; Infusions, Parenteral; Drug Storage
PubMed: 35312402
DOI: 10.1177/10781552221088020 -
Cancers Dec 2021Malignant vascular tumors of the head and neck are rare neoplasms with variable clinical presentation, wide age distribution, and variable clinical courses. The... (Review)
Review
Malignant vascular tumors of the head and neck are rare neoplasms with variable clinical presentation, wide age distribution, and variable clinical courses. The heterogeneous presentation of angiosarcomas and epithelioid hemangioendothelioma often leads to misdiagnosis and unsuitable treatment. While risk factors for angiosarcomas are previous radiation, chronic lymphedema, and exposure to arsenic, thorium oxide, or vinyl chloride, there are only limited and retrospective data available on prognostic factors in EHE. In both angiosarcomas and EHE, surgery is the mainstay of treatment. There is limited evidence regarding the role of radiotherapy in EHE, although EHE is considered relatively radiosensitive. In angiosarcomas, adjuvant radiotherapy is recommended according to retrospective case series. A standard medical therapy for metastasized malignant vascular tumors is lacking. Chemotherapy, which is effective in angiosarcoma, is mostly ineffective in EHE. Targeted therapy, antiangiogenetic drugs and immunotherapy have been studied as new treatment options. The goal of this review is to summarize the current data regarding malignant vascular tumors along with their diagnosis and management.
PubMed: 34944821
DOI: 10.3390/cancers13246201 -
Frontiers in Chemistry 2023Poly (vinyl chloride) (PVC) is commonly used to manufacture biomedical devices and hospital components, but it does not present antimicrobial activity enough to prevent...
Poly (vinyl chloride) (PVC) is commonly used to manufacture biomedical devices and hospital components, but it does not present antimicrobial activity enough to prevent biofouling. With the emergence of new microorganisms and viruses, such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that was responsible for the global pandemic caused by Coronavirus Disease 2019 (COVID-19), it is evident the importance of the development of self-disinfectant PVC for hospital environments and medical clinics where infected people remain for a long time. In this contribution, PVC nanocomposites with silver nanoparticles (AgNPs) were prepared in the molten state. AgNPs are well-known as antimicrobial agents suitable for designing antimicrobial polymer nanocomposites. Adding 0.1 to 0.5 wt% AgNPs significantly reduced Young's modulus and ultimate tensile strength of PVC due to the emergence of microstructural defects in the PVC/AgNP nanocomposites, but the impact strength did not change significantly. Furthermore, nanocomposites have a higher yellowness index (YI) and lower optical bandgap values than PVC. The PVC/AgNP nanocomposites present virucidal activity against SARS-CoV-2 (B.1.1.28 strain) within 48 h when the AgNP content is at least 0.3 wt%, suitable for manufacturing furniture and hospital equipment with self-disinfectant capacity to avoid secondary routes of COVID-19 contagion.
PubMed: 36993814
DOI: 10.3389/fchem.2023.1083399 -
Polymers Mar 2021This study examined, the effect of chemically extracted raspberry pomace on the thermal stability, mechanical properties, flammability, chemical structure and processing...
This study examined, the effect of chemically extracted raspberry pomace on the thermal stability, mechanical properties, flammability, chemical structure and processing of poly(vinyl chloride). It was observed that the pomace in this study was used to extract naphtha, thereby permitting the removal of bio-oil as a factor preventing the obtaining of homogeneous composites. Furthermore, adding 20% raspberry pomace filler after extraction extended the thermal stability time for the composites by about 30%. It was observed that composite density, impact strength, and tensile strength values decreased significantly with increasing concentrations of filler in the PVC matrix. At the same time, their modulus of elasticity and Shore hardness increased. All tested composites were characterized by a good burning resistance with a flammability rating of V0 according to the UL94 test. Adding 20 to 40% of a natural filler to the PVC matrix made it possible to obtain composites for the production of flame resistant elements that emitted less hydrogen chloride under fire conditions while ensuring good rigidity.
PubMed: 33805463
DOI: 10.3390/polym13071079 -
Polymers Oct 2019In this study, we investigated the influence of methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles as a plasticizer and thermal...
In this study, we investigated the influence of methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles as a plasticizer and thermal stabilizer for a poly(vinyl chloride) (PVC) homopolymer and for a poly(vinyl chloride)/dissononyl cyclohexane-1,2-dicarboxylate (PVC/DINCH) binary blend system. The PVC and the PVC/DINCH blend both became flexible, with decreases in their glass transition temperatures and increases in their thermal decomposition temperatures, upon an increase in MA-POSS content, the result of hydrogen bonding between the C=O groups of MA-POSS and the H-CCl units of the PVC, as determined using infrared spectroscopy. Furthermore, the first thermal decomposition temperature of the pure PVC, due to the emission of HCl, increased from 290 to 306 °C, that is, the MA-POSS nanoparticles had a retarding effect on the decomposition of the PVC matrix. In tensile tests, all the PVC/DINCH/MA-POSS ternary blends were transparent and displayed flexibility, but their modulus and tensile strength both decreased, while their elongation properties increased, upon an increase in MA-POSS concentration, both before and after thermal annealing. In contrast, the elongation decreased, but the modulus and tensile strength increased, after thermal annealing at 100 °C for 7 days.
PubMed: 31635274
DOI: 10.3390/polym11101711 -
Genes and Environment : the Official... Jun 2021Etheno (and ethano) derivatives of nucleic acid bases have an extra 5-membered ring attached. These were first noted as wyosine bases in tRNAs. Some were fluorescent,... (Review)
Review
Etheno (and ethano) derivatives of nucleic acid bases have an extra 5-membered ring attached. These were first noted as wyosine bases in tRNAs. Some were fluorescent, and the development of etheno derivatives of adenosine, cytosine, and guanosine led to the synthesis of fluorescent analogs of ATP, NAD, and other cofactors for use in biochemical studies. Early studies with the carcinogen vinyl chloride revealed that these modified bases were being formed in DNA and RNA and might be responsible for mutations and cancer. The etheno bases are also derived from other carcinogenic vinyl monomers. Further work showed that endogenous etheno DNA adducts were present in animals and humans and are derived from lipid peroxidation. The chemical mechanisms of etheno adduct formation involve reactions with bis-electrophiles generated by cytochrome P450 enzymes or lipid peroxidation, which have been established in isotopic labeling studies. The mechanisms by which etheno DNA adducts miscode have been studied with several DNA polymerases, aided by the X-ray crystal structures of these polymerases in mispairing situations and in extension beyond mispairs. Repair of etheno DNA adduct damage is done primarily by glycosylases and also by the direct action of dioxygenases. Some human DNA polymerases (η, κ) can insert bases opposite etheno adducts in DNA and RNA, and the reverse transcriptase activity may be of relevance with the RNA etheno adducts. Further questions involve the extent that the etheno adducts contribute to human cancer.
PubMed: 34130743
DOI: 10.1186/s41021-021-00199-x -
Scientific Reports Mar 2022To inhibit the agglomeration of nanotitanium dioxide, a poly (vinyl chloride) (PVC) composite film doped with folic acid-modified titanium dioxide was synthesized and...
To inhibit the agglomeration of nanotitanium dioxide, a poly (vinyl chloride) (PVC) composite film doped with folic acid-modified titanium dioxide was synthesized and characterized using X-ray powder diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The average grain size of the folic acid-modified titanium dioxide was found to decrease by 1.3 nm, indicating that the cohesiveness of the nanoparticles is decreased. The lowest temperature for 1.0% thermal decomposition of PVC was determined to be 230.0 °C. The decomposition rate at the peak temperature is found to be 39.6% lower than that of a control sample. The stability of the PVC is improved due to a lower number of surface chlorine atoms as well intermolecular attraction. A mechanism for folic acid modification of titanium dioxide-doped PVC is proposed. After doping, the ester groups in the plasticizer show a significant decrease in the vibration peak intensities observed at 1264 cm, 1736 cm and 1106 cm. The doped PVC film suppresses the release of CO, and the strongest vibration peak at 1264 cm is found to be 17.2% lower than that for the blank sample, indicating that doping is beneficial for plasticizer recovery.
Topics: Folic Acid; Plasticizers; Polyvinyl Chloride; Titanium; Vinyl Chloride
PubMed: 35233000
DOI: 10.1038/s41598-022-07177-5 -
International Journal of Environmental... Mar 2023On 3 February 2023, a train derailed in the village of East Palestine, Ohio, home to approximately 4700 residents [...].
On 3 February 2023, a train derailed in the village of East Palestine, Ohio, home to approximately 4700 residents [...].
Topics: Vinyl Chloride; Ohio; Railroads
PubMed: 36981940
DOI: 10.3390/ijerph20065032 -
Toxics Dec 2023Poly(vinyl chloride) (PVC) is widely used to produce various consumer goods, including food packaging, toys for children, building materials, and cosmetic products....
Poly(vinyl chloride) (PVC) is widely used to produce various consumer goods, including food packaging, toys for children, building materials, and cosmetic products. However, despite their widespread use, phthalate plasticizers have been identified as endocrine disruptors, which cause adverse health effects, thus leading to increasing concerns regarding their migration from PVC products to the environment. This study proposed a method for rapidly measuring the migration of phthalates, particularly di(2-ethylhexyl) phthalate (DEHP), from PVC products to commonly encountered liquids. The release of DEHP under various conditions, including exposure to aqueous and organic solvents, different temperatures, and household microwaves, was investigated. The amount of DEHP released from both laboratory-produced PVC films and commercially available PVC products was measured to elucidate the potential risks associated with its real-world applications. Furthermore, tests were performed to evaluate cytotoxicity using estrogen-dependent and -independent cancer cell lines. The results revealed a dose-dependent impact on estrogen-dependent cells, thus emphasizing the potential health implications of phthalate release. This comprehensive study provides valuable insights into the migration patterns of DEHP from PVC products and forms a basis for further research on the safety of PVC and plasticizers.
PubMed: 38276720
DOI: 10.3390/toxics12010007