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Hemolytic Assay of Biocompatible Nanomaterials in Drug Delivery Systems
Published in Ali Pourhashemi, Sankar Chandra Deka, A. K. Haghi, Research Methods and Applications in Chemical and Biological Engineering, 2019
Poonam Khullar, Lavanya Tandon, Rajpreet Kaur, Divya Mandial
From accidental exposure, potential hazards can originate and to prevent them, their toxicological effects have been studied from toxicological, environmental, health, and scientific perspectives. Crystalline silica dust is used in mining operations, foundry work, mineral processing, and construction sites. Chronic obstructive pulmonary disease, silicosis, or even lung cancer is induced through inhalation of crystalline silica. Amorphous fumed or precipitated silica is considered safe and is also used as a food or animal feed ingredient. It has been found that inhalation of amorphous silica possess minimal or no health-related risks. Amorphous silica is used in nanobiotechnology which has covered vast areas including diagnostics, drug delivery, bioanalysis and imaging, and gene transfer; therefore, it is conceivable that amorphous silica can be incorporated into the human body by oral ingestion, inhalation, intravenous injection, and transdermal delivery. In future, silica can be used as the biomaterial, therefore, information regarding its biodistribution, retention, absorption, degradation, clearance, and safety of silica is of vital importance. Through Stöber (sol-gel) process, silica is prepared in the solution by the hydrolysis and polycondensation of silicon alkoxide.
Understanding the Risk
Published in C. Anandharamakrishnan, S. Parthasarathi, Food Nanotechnology, 2019
S.K. Sivakama Sundari, J.A. Moses, C. Anandharamakrishnan
Silica exists in its amorphous or crystalline forms. Among the crystalline forms of silica, quartz is the best known form in natural and synthetic formulae. Like crystalline silica, amorphous silica also exists in two different forms, namely, natural and human-made formulae (Napierska et al., 2010). Silica nanoparticles are generally used in various types of food products, including wine and beer for clarification, and as powders for preventing caking in various food products (Dekkers et al., 2013). Apart from food applications, silica nanoparticles are also used in the field of biotechnology for cancer therapy, drug delivery, and enzyme immobilization (Kumar et al., 2004). With their innumerable applications, entry of these nanoparticles can easily occur through skin absorption, ingestion or injection (Ye et al., 2010b). It is very common that once the size of the particle is brought down to the nanoscale, its property changes.
Acid Rock Drainage
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
Silicon, a brittle, gray metalloid, is the most abundant metal and the second most abundant element in the earth’s crust. Relatively unreactive, it occurs in nature as the oxide form, silica, of which quartz is the most common mineral, and in numerous silicate minerals which include many of the most common constituents of igneous and metamorphic rocks. Silicon is essential to many living organisms, particularly plants and many marine invertebrates. It is not toxic to humans. The majority of silicon is used in specialized alloys. However, the most important applications are in electronics where silicon is used in transistors, computer chips and photovoltaic cells. Silica is used to make glass, cement and refractory materials. Silicon metal is produced from high purity silica in an electric arc furnace.
Engineered/designer hierarchical porous carbon materials for organic pollutant removal from water and wastewater: A critical review
Published in Critical Reviews in Environmental Science and Technology, 2021
Mengxue Zhang, Avanthi Deshani Igalavithana, Liheng Xu, Binoy Sarkar, Deyi Hou, Ming Zhang, Amit Bhatnagar, Won Chul Cho, Yong Sik Ok
Hard templates are generally rigid forms, held together by stable inorganic solids (Fu et al., 2011). The inorganic solids can be different types of silica, such as silica monolith (Wang et al., 2012), silica spheres (Chen et al., 2016), silica colloidal crystals (Yonghui et al., 2007; Zhang et al., 2014), silica opal (Li et al., 2013; Zhao et al., 2008), etc. In addition, CaCO3 (Zhu et al., 2008) and Na2CO3 (Ilnicka & Lukaszewicz, 2015) are also commonly used as porogens of hard templates. Soft templates are typically organic polymers that can be thermally decomposed and removed (Fu et al., 2011; Liang et al., 2019; Song et al., 2019). The thermally decomposed polymers can be polystyrene (PS) (Chai et al., 2004; Woo et al., 2008), polymethyl methacrylate (PMMA) (Seo et al., 2014), polyurethane (PU) and surfactants (Meng et al., 2005).
Segregation of respirable dust for chemical and toxicological analyses
Published in Archives of Environmental & Occupational Health, 2021
Teresa L. Barone, Taekhee Lee, Emanuele G. Cauda, Andrew L. Mazzella, Robert Stach, Boris Mizaikoff
Exposure to crystalline silica is a major cause of dust-related respiratory illnesses (Donaldson, 2012; Cook et al. 2005).16‒17 Illnesses such as silicosis and lung cancer are associated with exposure to respirable crystalline silica (RCS).18 Mechanistic studies indicate that RCS carcinogenicity depends on the surface properties of the original source dust.8,19–22 Source dust properties can be investigated by collecting representative samples from ambient air. However, lengthy collection times are needed to obtain enough airborne material in the respirable size range for health effects studies. Alternatively, respirable dust samples can be obtained by bulk dust segregation. Bulk dust can be acquired from granular source material (e.g. soils) or industrial dust collectors (e.g. cyclones leading to baghouse filters23). Subsequently, bulk dust can be segregated by an array of methods.
Silica exposure in a mining exploration operation
Published in Archives of Environmental & Occupational Health, 2018
V. H. Arrandale, S. Kalenge, P. A. Demers
Occupational exposure to crystalline silica occurs in a variety of industries, including construction, manufacturing and mining. In mining operations, silica exposure can result from tasks that involve cutting, sawing, drilling, and crushing of rock and stone products. Prolonged silica exposure can lead to reduced lung function, chronic obstructive pulmonary disease, silicosis and lung cancer.1,2 In 1997, the International Agency for Research on Cancer classified crystalline silica as a Group 1 human carcinogen.3 In Ontario Canada, the current exposure limit (OEL) for crystalline silica is 0.1 mg-m−3; this regulatory limit is higher than the threshold limit value (TLV) recommended by the America Conference of Governmental Industrial Hygienists (ACGIH) of 0.025 mg-m−3 for respirable silica. The Ontario OEL for respirable dust is 3mg-m−3, the TLV recommended by the ACGIH.