Organo-Modified Siloxane Polymers for Conditioning Skin and Hair
Randy Schueller, Perry Romanowski in Conditioning Agents for Hair and Skin, 2020
In general, organo-silicon nomenclature is applied to any structure containing at least one silicon atom. Silanes (R4Si) are silicon-containing compounds with one silicon atom and four directly bonded groups. Silicones, containing alternating silicon and oxygen atoms, are cyclic, linear, branched, caged, or three-dimensional polymers of the monomeric siloxy group. The prefix to these siloxane polymers designates the number of silicon atoms in the polymer—that is, disiloxane has two silicon atoms, while trisiloxane has three silicon atoms, etc. Siloxanes and silanes are named similarly; the root describes whether it is a siloxane (Si-O-Si backbone) or silane (only one Si atom), and the organofunctional portion describes the type and amount of substitution: hexamethyldisiloxane, decamethylpentacyclosiloxane, Tris(trimethylsiloxy)silane, and (poly)dimethylsiloxane.
Medication: Nanoparticles for Imaging and Drug Delivery
Harry F. Tibbals in Medical Nanotechnology and Nanomedicine, 2017
Silicon-based devices have played a central role in the development of microelectronics, MEMS, and nanodevices. Silicon and other solid-state semiconductor materials served as the platforms for pioneering work that proved concepts and demonstrated implementations for nanoscale electronics, sensors, and mechanical devices. Thus far in this overview we have focused on quantum dots, polymers, and other materials, but now it is time to look at silicon and similar materials. There is an enormous wealth of technology and experience in solid-state semiconductor and thin-film fabrication, which holds potential for application to nanodevices for medical applications. Because of its unique electronic and chemical properties, silicon can be useful as the material for functional nanoparticles for diagnostic sensing and drug delivery, as well as a fabrication material for more elaborate devices.
Nutrients in Bamboo Shoots
Nirmala Chongtham, Madho Singh Bisht in Bamboo Shoot, 2020
Silicon (Si) is a non-metallic element and the second most abundant element in the Earth’s crust with a great affinity for oxygen, forming 92% silica and silicates. It is also the most abundantly available trace element after iron and zinc. Chemically, silica is an oxide of silicon, viz. silicon dioxide and is generally colourless to white and insoluble in water. When associated with metals or minerals the family of silicates is formed. Humans are exposed to numerous sources of silica/silicon including dust, food, pharmaceuticals, cosmetics and medical implants and devices. As a metalloid, silicon has been used in many industrial applications including use as an additive in the food and beverage industry. As a result, humans are exposed to silicon through both environmental exposures and also as a dietary component. Bamboo extract is the richest known source of natural silica, containing over 70% organic silica. This is more than 10 times the level found in the widely used Horsetail plant (Equisetum) that contains 5% to 7% silica.
Formation of organosilica nanoparticles with dual functional groups and simultaneous payload entrapment
Published in Journal of Microencapsulation, 2018
Ya-Ling Su, Chien-Yu Lin, Shih-Jiuan Chiu, Teh-Min Hu
Silicon is the second most abundant element in the Earth’s crust (Peng et al. 2014), and it is an indispensable element in the history of technological advance of mankind; i.e. from the early use of glass to the modern ‘Silicon Revolution’—associated first with computer chips and then with the recent development of solar panels (Rowlatt 2014). Silicon can be found in the human body in the form of silica (silicon dioxide, SiO2) through food intake (Sripanyakorn et al. 2004, 2009). Moreover, silica materials have been widely used in food and pharmaceutical industry (Dave 2008, Contado et al. 2013). In particular, silica nanomaterials have been extensively studied as drug carriers for improving drug delivery (Slowing et al. 2008, Cohen and Sukenik 2016). Currently, various silica nanoparticles (SiNPs), mesoporous or nanoporous, have been extensively studied for intelligent and precision delivery (i.e. targeted and responsive) of drugs or imaging agents, as well as various biomedical applications (Slowing et al. 2007, He and Shi 2011, Bitar et al. 2012, Colilla et al. 2013, Tang and Cheng 2013, Carpenter et al. 2014). Although it is not quite the beginning of a biomedical Silicon Revolution, the first human trials on the use of SiNPs for clinical imaging has been ongoing (Phillips et al. 2014).
Airborne pollutants as potential triggers of systemic autoimmune rheumatic diseases: a narrative review
Published in Acta Clinica Belgica, 2022
Hannelore Celen, Anne-Cathérine Dens, Steven Ronsmans, Stijn Michiels, Ellen De Langhe
Silica is an oxide of silicon with the chemical formula SiO2. Silica exists in crystalline (orientation of silicon molecules in a fixed orientation) and amorphous forms (orientation of silicon molecules in a random molecular arrangement). The most common form of free crystalline silica is α-quartz. α-Quartz is a basic component of sand, granite, and many other minerals. Exposure to respirable crystalline silica (<10 µm in size) often occurs in occupational settings, specifically when materials containing crystalline silica are reduced to dust such as in construction, mines, stone quarries and granite production, ceramic and pottery industries, steel production and many others. In 2006, approximately 5.3 million workers were exposed to respirable crystalline silica in the European Union [12]. Most of these workers were employed in the construction industry [12].
Comparison of properties of dust in alveolar of rats and the workplace
Published in Experimental Lung Research, 2021
Xu Zhang, Zheng Zhang, Peng Wang, Shuyu Xiao, Ke Han, Yali Tang, Heliang Liu, Yuping Bai, Yulan Jin, Jinlong Li, Xiaoming Li, Qingan Xia, Fuhai Shen
In this study, we found that there was no significant difference in the α-SiO2 content of dust in the lung lavage and the workplace. It was suggested that the α-SiO2content does not change after the dust enters the body. It might be due to the silicon element in α-SiO2 exists in the form of a compound. The chemical properties of α-SiO2 were stable, difficult to be dissolved and not easily metabolized. Some researchers conducted epidemiological investigations on several mining areas in southwestern China and found that some coal mines have similar SiO2 content. However, there were differences in the incidence and latency of pneumoconiosis.17,18 Someone reported that potassium, calcium, and aluminum adsorbed on the surface of dust could reduce the cytotoxicity of dust. Removal of potassium, calcium, and aluminum from the dust surface could improve the cytotoxicity of dust.