Allergic Contact Dermatitis from Rubber and Plastic Gloves
Robert N. Phalen, Howard I. Maibach in Protective Gloves for Occupational Use, 2023
Sensitization to an epoxy resin used as a plasticizer has been reported by Fregert and Rorsman.72 Epoxy resins can be used as plasticizers and stabilizers in PVC (e.g., gloves), PVAc plastics, and neoprene.73 A patient at the FIOH having allergic contact dermatitis from the use of certain PVC gloves of household type reacted on patch testing repeatedly to her gloves and bisphenol A. Interestingly, one of five previous patients sensitized from their plastic gloves had been sensitized from the use of PVC household gloves of the same brand but was not allergic to bisphenol A.2 Since then two other patients, after using disposable PVC gloves, reacted to their glove materials and bisphenol A. Chemical analyses of the glove materials revealed bisphenol A, which was probably the cause of their hand dermatitis.33,34 On further follow-up, one of these three patients, a female dentist who primarily had worn PVC gloves started to use NRL gloves after becoming sensitized to bisphenol A. In less than a half year her dermatitis renewed and she was found to be sensitized to dithiocarbamates used in the production of these NRL gloves, kindly provided by the manufacturer for patch testing. The dentist continued her work and used disposable nitrile gloves with polyethylene gloves under them.74
Identifying Nanotoxicity at the Cellular Level Using Electron Microscopy
Suresh C. Pillai, Yvonne Lang in Toxicity of Nanomaterials, 2019
Embedding in resin involves the infiltration of the sample with, most commonly, acrylic or epoxy resins, followed by polymerisation into a block so that ultrathin sections can be obtained. Acrylic resins are hydrophilic making them useful when immunocytochemistry is required. These resins are prone to uneven polymerisation and are not as stable under the electron beam as epoxy resins. The infiltration and polymerisation of epoxy resins is more reliable, there is minimal shrinkage within the sample and more stable sections can be obtained (Dykstra and Reuss, 2003, Schrand et al., 2010). As noted by Schrand, there is no preferred resin for cell-nanoparticle interaction studies, but it is worth investigating the different resins as they can be formulated to match the hardness of the nanoparticle of interest, therefore reducing potential sectioning artefacts.
Contact Urticaria Syndrome from Epoxy Resin
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
Epoxy resin is commonly used. Examples of occupational exposure are components of paints, cement additives for quick bonding, and in manufacturing electrical equipment for enclosing transformers, condensers, and other components in aircraft and other industries for adhesive purposes these application represent mainly occupational exposure.[1–4] Nonoccupational exposure is also common; for example clothes,[5] hairpins,[6] ostomy bags,[7] and nasal cannulae.[8]
Modified self-healing cementitious materials based on epoxy and calcium nitrate microencapsulation
Published in Journal of Microencapsulation, 2021
Fahimeh Farshi Azhar, Aylin Ahmadinia, Alireza Mohammadjafari Sadeghi
Epoxy resin because of its excellent chemical, physical, mechanical and thermal properties, is an effective candidate for healing agent. A wide variety of curing agents such as amines and anhydrides can be used for curing of epoxy resin at different temperatures (Reaz Chowdhury et al. 2015). Also, epoxy resin has the most matches with urea–formaldehyde in microencapsulation. Blaiszik et al. (2009) synthesised microcapsules containing PUF shell containing reactive epoxy resins core with different diluents. The prepared capsules meet the requirements for use in self-healing composites, containing processing survivability, thermal stability and efficient in situ rupture for delivery of the healing agents. Jin et al. (2012) studied the microcapsules comprise of hollow PUF shell and epoxy-amine healing agent. Yuan and Liang (2008) evaluated some effective factors in size and surface morphology of PUF microcapsules containing epoxy resins, such as type and concentration of surfactant, adjusting time for pH value and heating rate. But, in these studies, healing behaviour of the host matrix was not reported. On the other hand, the PUF-epoxy microcapsules have been studied mostly for self-healing in polymer-based composites by now, and few researches have been reported on its utilisation in cementitious materials (Dong et al.2016, Perez et al.2015).
Microchannel-embedded implantable device with fibrosis suppression for prolonged controlled drug delivery
Published in Drug Delivery, 2022
Han Bi Ji, Jae Young Hong, Cho Rim Kim, Chang Hee Min, Jae Hoon Han, Min Ji Kim, Se-Na Kim, Cheol Lee, Young Bin Choy
The PMMA plates (thickness = 2 mm) and PEG (average MW = 6 kDa) were purchased from ENGP (Incheon, Republic of Korea) and Acros Organics (Geel, Belgium), respectively. The DF (99.9% purity), TR (98% purity), phosphoric acid, acetonitrile, Tween® 80, ammonium bicarbonate, and formalin (neutral buffered, 10%) were obtained from Sigma (St. Louis, MO). Intravenous catheters and ethylenediaminetetraacetic acid (EDTA) tubes were purchased from BD Biosciences (Franklin Lakes, NJ). Ethanol and ammonium acetate were purchased from Daejung Chemicals (Siheung, Republic of Korea). Betadine was obtained from Green Pharmaceutical (Seoul, Republic of Korea). Phosphate-buffered saline (PBS; pH 7.4) and Ideal 9144 masking tapes were obtained from the Seoul National University Hospital Biomedical Research Institute (Seoul, Republic of Korea) and American Biltrite (Lowell, MA), respectively. Medical epoxy (EPO-TEK® 301-2) was obtained from Epoxy Technology (Billerica, MA).
Antimicrobial effectiveness of root canal sealers against Enterococcus faecalis
Published in Biomaterial Investigations in Dentistry, 2022
Paola Castillo-Villagomez, Elizabeth Madla-Cruz, Fanny Lopez-Martinez, Idalia Rodriguez-Delgado, Jorge Jaime Flores-Treviño, Guadalupe Ismael Malagon-Santiago, Myriam Angelica de La Garza-Ramos
Complete removal of microorganisms from the root canal system in all patients is impossible; therefore, filling materials with antimicrobial activity for the root canal are used to reduce microorganisms and prevent infections. On the other hand, many endodontic failures occur after removing necrotic or inflammatory tissue with microorganisms. These tissues need to be retreated and managed with apical surgery; however, filtration failure occurs in 15% to 22% [4]. These complications are attributed to the lack of root canal sealing after endodontic treatment due to the high hydrophobicity and water absorption caused by the solubility of the cement. The development of new ceramic-type materials has improved sealing to reduce this problem. Epoxy resin is widely used as a gold standard, although it still has limitations, such as mutagenicity, cytotoxicity, inflammation, and hydrophobicity. Calcium silicate-based sealers with high biocompatibility and hydrophilicity have also been introduced. Both cements reduce microfiltration thanks to properties in their dynamic environment and being biocompatible in this application [5].
Related Knowledge Centers
- Adhesive
- Epoxide
- Ethylene Oxide
- Polymer
- Curing
- Prepolymer
- Cross-Link
- Thiol
- Thermosetting Polymer
- Fibre-Reinforced Plastic