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Drug Delivery Potential of Dendrimeric Formulation
Published in Neelesh Kumar Mehra, Keerti Jain, Dendrimers in Nanomedicine, 2021
Musarrat Husain Warsi, Mohammad Akhlaquer Rahman, Mohammad Yusuf, Abuzer Ali, Abdul Muheem, Saima Amin, Javed Ahmad
Clay minerals, composed of particles with a diameter below 2 μm, are defined as hydrous aluminosilicates that are dominant in the clay-sized fraction of soil. There are two structural features in their crystal structures–tetrahedron and octahedron, differing in number and arrangement of oxygen ions. Organo-clays with incorporated dendrimers find many applications. However, the possibility of their biomedical use seems particularly interesting. Both dendrimers and clay minerals are tested as drug carriers (Massaro et al. 2017). PAMAM dendrimer-functionalised halloysite is a suitable material for effective drug delivery. Such a system is capable of increased adsorption and/or reduced release rate of a given drug compared to pristine clay (Kurczewska et al. 2018). This area of scientific research is not as widely developed as the previously described applications, but it has great potential for development in the nearest future.
Clays and Clay Minerals
Published in Benny K.G. Theng, Clay Mineral Catalysis of Organic Reactions, 2018
Because of its potential in nanotechnological applications, including organic catalysis, the tubular forms of halloysite (Figure 1.11) have attracted a great deal of attention (Du et al. 2010; Rawtani and Agrawal 2012; Lvov and Abdullayev 2013; Tan et al. 2014; Pasbakhsh and Churchman 2015; Yuan et al. 2015; Hanif et al. 2016; Liu et al. 2016; Pasbakhsh et al. 2016). The length of halloysite tubules ranges from 50 to 5000 nm, the outer diameter from 20 to 200 nm, and the inner (lumen) diameter from 5 to 70 nm (Joussein et al. 2005; Pasbakhsh et al. 2013; Yuan et al. 2015; Zhang et al. 2016). Interestingly, a spherical halloysite from New Zealand shows a pronounced anti-inflammatory activity as indicated by its ability to inhibit edema in mice (Cervini-Silva et al. 2016). Table 1.3 lists a number of organic reactions catalyzed by halloysite.
Sensitive pyroclastic-derived halloysitic soils in northern New Zealand: Interplay of microstructure, minerals, and geomechanics
Published in Tatiana Rotonda, Manuela Cecconi, Francesco Silvestri, Paolo Tommasi, Volcanic Rocks and Soils, 2016
Vicki G. Moon, David J. Lowe, Michael J. Cunningham, Justin B. Wyatt, Willem P. de Lange, G.J. (Jock) Churchman, Tobias Mörz, Stefan Kreiter, Max O. Kluger, M. Ehsan Jorat
Halloysite is a 1:1 kaolin-group clay mineral with a similar composition to kaolinite, but with interlayer water that can be driven off, giving hydrated and dehydrated forms or end members. The hydrated form has a 1.0 nm (10 Å) d-spacing, and the dehydrated form has a d-spacing of 0.7 nm (7 Å). Halloysite can adopt a continuous series of hydration states, from 2 to 0 molecules of H2O per Si2Al2O5(OH)4 aluminosilicate layer, and these are interpreted as a type of interstratification of the two end member types (Churchman, 2015). This dehydration, and the associated d-spacing change, is one of the key characteristics distinguishing halloysites from kaolinite (Churchman and Lowe, 2012). Under normal environmental conditions, dehydration of halloysite micelles is an irreversible process (Joussein et al., 2005; Keeling, 2015).
Geomechanical Characterization of Experimental Mud Bricks from La Joya Archaeological Site: Effect of the Addition of Additives on Their Mechanical Properties
Published in International Journal of Architectural Heritage, 2023
Jhonny Peraza-Gongora, Carlos Rolando Rios-Soberanis, Annick Jo Elvire Daneels Verriest, Jose Rodriguez-Laviada
The same nine samples were analysed in the X-ray diffractometer in order to contribute to the identification of the main components of the soil used to manufacture them. The peaks obtained as a result of the crystallinity exhibited by the compounds were analysed. The analytic diffractograms of four representative samples along with the identified components are presented in Figure 2. All analysed soil samples indicated a significant concentration of quartz and feldspars. These results are supported by the high concentrations of SiO2 and Al2O3 in Table 3. In lower concentrations, minerals such as cristobalite, calcite, augite and paragonite were mainly identified. In the same way, clays of the montmorillonite type ((Na,Ca)0.3(Al,Mg)2Si4O10(OH)2●nH2O) were identified as smectite. Additionally, halloysite clay that may display tubular, spheroidal or platy morphologies with a chemical formula of Al2Si2O5(OH)4●2H2O was also exhibited. Halloysite is chemically related to kaolin. The identification of clays in oriented fractions was analysed in triplicate of each sample: one was analysed without any treatment (pristine), the second sample was treated with ethylene glycol and the third was calcined at 550°C for 1 hour. Finally, the diffractograms of these fractions oriented in the interval of 4–35° 2θ were performed.
The emergence of nanoporous materials in lung cancer therapy
Published in Science and Technology of Advanced Materials, 2022
Deepika Radhakrishnan, Shan Mohanan, Goeun Choi, Jin-Ho Choy, Steffi Tiburcius, Hoang Trung Trinh, Shankar Bolan, Nikki Verrills, Pradeep Tanwar, Ajay Karakoti, Ajayan Vinu
In addition to the reports on inorganic and organic nanohybrids, another promising nanomaterial for drug delivery is halloysite nanotube (HNT). Halloysite, is a naturally occurring aluminosilicate clay with unique tubular morphology with 25–100 nm diameter and is considered a promising drug delivery carrier for lung cancers due to its low toxicity [312]. HNT loaded with a model dye triazole brilliant green (Figure 8A) and covered with dextrin was tested as a drug delivery vehicle. The triazole brilliant green is capable to kill mitochondria of the malignant cells. The dextrin molecule seals the pores of the HNT, retaining the drug inside the tube (Figure 8B). Dextrin is cleaved by intercellular glycosol hydrolases opening the pores and thus releasing the drug intracellularly [313]. A high drug loading of 4 mg/mg of HNT was achieved by this method. The delivery efficiency of HNT was analysed in both suspended (Hep3b) and the attached cell lines (A549). It is also noted that the uptake of drug in the A549 cells is higher than the Hep3b, but the dextrin didn’t demonstrate a stopper effect in the A549 cells, and the difference in the drug uptake could be due to the differential uptake of the particles by different cells.
Mineralogical and geochemical characterisation of kaolin deposit from Debre Tabor area northwestern, Ethiopia
Published in Applied Earth Science, 2021
Alemu Mesele, Teklay Gidey, Tilahun Weldemaryam, Wuletaw Mulualem, Tamrat Mekuria, Yahya Ali, Gizachew Mulugeta, Betelhem Tesfaye, Mulgeta Brihan
Clay minerals are the chemical weathering product of granite and feldspathic rocks (Idenyi and Nwajagu 2003) when rocks are in contact with water, air (Kabeto et al. 2012), and hydrothermal fluid (Okunlola 2008). Mostly they are found in soil, sedimentary rocks, and hydrothermal deposits (Idenyi and Nwajagu 2003; Murray 2007). The polymorphs of clay minerals are kaolinite, halloysite, nacrite, and dickite, which are characterised by the same chemistry but different structures (Baker and Uren 1982). The rate of clay minerals formation is controlled by the composition of pre-existing rock mineralogy, the nature of parent rock, the intensity of weathering, and the length of time (Murray and Kogel 2005; Akinola and Obasi 2014). According to Mosser (1980) and Mosser et al. (1991), clay minerals can preserve the geochemical fingerprint of trace elements from the source rock.