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Introduction
Published in Antonietta Morena Gatti, Stefano Montanari, Advances in Nanopathology From Vaccines to Food, 2021
Antonietta Morena Gatti, Stefano Montanari
What was interesting and, indeed, baffling was something which had nothing to do with the original question, that is, what we found on the surface of the device and, more in particular, at the fracture point. Looking there through an electron microscope and with the aid of an instrument called energy-dispersive spectrometer (EDS), we found chemical elements which did not belong either to the filter or to the human body. Why they were there was a question we had no answer to, and somewhat sadly, it was something which did not interest the doctors we consulted.
Identifying Nanotoxicity at the Cellular Level Using Electron Microscopy
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
Kerry Thompson, Alanna Stanley, Emma McDermott, Alexander Black, Peter Dockery
SEM and TEM are the key enabling technologies that provide adequate resolution for nanoparticle visualisation. Although the chemical nature and subsequent electron contrast of specific nanoparticles may restrict visualisation to higher atomic number particles, elemental analysis techniques such as energy dispersive spectroscopy or electron energy loss spectroscopy provide data on the distribution of particles of low atomic number. It is important to consider the small volume of tissue that can be imaged via EM, in particular typical TEM section thickness of 50–70 nm. The use of three-dimensional reconstruction techniques such as ET and the SBF sectioning methods have greatly expanded imaging potential and offer new possibilities in the field of intracellular nanoparticle localisation research (Denk and Horstmann, 2004). A caveat on these approaches is that, despite providing detailed ultrastructure, they are time-consuming and result in huge datasets on limited sample sizes, which rightly raises concerns regarding sampling bias.
Nanotechnology-Derived Orthopedic Implant Sensors
Published in Iniewski Krzysztof, Integrated Microsystems, 2017
Sirinrath Sirivisoot, Thomas J. Webster
In order to estimate how such sensors would do for bone growth, osteoblasts were cultured for 21 days and energy-dispersive spectroscopy (EDS) was performed to verify the presence of the various minerals in newly formed bone. Figure 29.5 shows the results of one such study doing this in which the peaks of many inorganic substances, consisting of magnesium (Mg), phosphorus (P), sulfur (S), potassium (K), and calcium (Ca) were detected. The Ca/P weight ratio of minerals deposited by osteoblasts in that study on Ti (1.34) was less than that on a MWCNT-Ti sensor (1.52). However, the Ca/P ratio of HA, the main calcium–phosphate crystallite in bone, is typically about 1.67 [32,33]. This study demonstrated that the minerals deposited by osteoblasts on MWCNT-Ti were more similar to natural bone than the minerals deposited on Ti. X-ray diffraction (XRD) analysis also showed that more HA was deposited on MWCNT-Ti sensors than on both conventional and anodized Ti after 21 days of culture, as shown in Figure 29.6. In addition, the amount of calcium deposited by osteoblasts as determined by a calcium quantification assay kit was 1.481 μg/cm2 for 7 days, 1.597 μg/cm2 for 14 days, and 2.483 μg/cm2 for 21 days on conventional Ti, as shown in Figure 29.10b. These results imply a greater deposition of calcium by osteoblasts on MWCNT-Ti sensors than currently implanted Ti.
Homogeneity of amorphous solid dispersions – an example with KinetiSol®
Published in Drug Development and Industrial Pharmacy, 2019
Scott V. Jermain, Dave Miller, Angela Spangenberg, Xingyu Lu, Chaeho Moon, Yongchao Su, Robert O. Williams
Scanning electron microscopy (SEM) is a widely-utilized technique to characterize particle morphology of amorphous solid dispersions by using a monochromatic electron beam to probe the surface and near-surface areas of materials [35]. Energy-dispersive X-ray spectroscopy (EDS) is often combined with SEM (SEM/EDS) and is able to provide semi-quantitative identification of elemental information for the area ionized by the SEM beam [36]. The X-ray photons escape from depths of several µm within the sample upon excitation from the SEM beam, so the EDS technique is considered to be sensitive to surface and near-surface elements in the sample [35]. When combined with the SEM beam, a two-dimensional image can be created that maps the elemental distribution across the sample [37]. By identifying an element or elements unique to the drug of interest, SEM/EDS can be utilized to evaluate homogeneous dispersion of a drug-polymer system at a spatial resolution of several µm [35,37].
Scanning electron microscopy in analysis of urinary stones
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2019
Martin Racek, Jaroslav Racek, Ivana Hupáková
Chemical characteristics of materials including kidney stones can be also achieved with X-ray spectroscopy analytical methods. The use of these methods requires primary irradiation of the sample, which leads to ejection of electrons from the sample atoms. The resulting unstable state leads to an effect where the hole is filled by an electron from a higher orbital. The difference of the energy is balanced by a release of a photon with energy/wavelength characteristic for a given element. The characteristic X-rays emission can be reached in various ways, which is determinative for each method. The sample may be irradiated by high-energy protons (PIXE [47,48]), high-energy electrons (coupled with SEM, [29,35,38]) or primary X-rays (XRF [47–50]). The emitted X-rays can then be characterized based on their energy (energy-dispersive spectroscopy [EDS]) or wavelength (wavelength-dispersive spectroscopy [WDS]).
Green synthesis of silver nanoparticles using transgenic Nicotiana tabacum callus culture expressing silicatein gene from marine sponge Latrunculia oparinae
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Yuri N. Shkryl, Galina N. Veremeichik, Dmitriy G. Kamenev, Tatiana Y. Gorpenchenko, Yulia A. Yugay, Dmitriy V. Mashtalyar, Aleksander V. Nepomnyaschiy, Tatiana V. Avramenko, Aleksandr A. Karabtsov, Vladimir V. Ivanov, Victor P. Bulgakov, Sergey V. Gnedenkov, Yury N. Kulchin, Yury N. Zhuravlev
The morphology of the synthesized silver nanoparticles was characterized by scanning electron microscopy (SEM) using Hitachi S-5500 (Japan) at the accelerating voltage of 2.0 kV. The local energy-dispersive spectroscopy (EDS) data were obtained on a Thermo Scientific (USA) spectrometer. Purified nanoparticles were also characterized using an atomic-force microscopy (AFM) using a Pacific Nanotechnology, Inc. Nano-DST (USA). A small volume of sample was spread on a well-cleaned glass cover slip surface mounted on the AFM stub and was dried in vacuum at room temperature. Images were obtained in tapping mode using a silicon probe cantilever of 225 μm length, resonance frequency 145–230 kHz, spring constant 20–95 N/m. Hydrodynamic diameter and zeta potential of the obtained nanoparticles were measured by nanoparticle tracking analysis (NTA) using a Nanosight NS500 system (NanoSight, UK) following the manufacturer’s instructions. Samples were diluted with water to obtain approximately 20 particles per image before being analysed with the NTA system. The measurements were made at room temperature and 60 s capture of video clips of particle movement under Brownian motion. The captured videos (10 videos per sample) were then processed and analysed by NTA analytical software version 2.2. For zeta potential estimation, the script for video recording and analysis designed by the manufacturer was employed.