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Advances in Process Controls and End-Point Determination
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Kevin A. Macias, M. Teresa Carvajal
Studies on the powder surface chemistry and its effect on particle cohesion-adhesion and wettability of powders are anticipated to play an important role during its use in producing agglomerates for formulations during new product development. The comprehensive characterization of powder surface properties is necessary to facilitate the manufacture of granules by adding appropriate binder solutions and for controllable critical attributes. The surface characterization can analytically be obtained for surface energetics via inverse gas chromatography (iGC) measurements [96–98] and surface composition via X-ray Photoelectron Spectroscopy (XPS) or electron spectroscopy for chemical analysis (ESCA) measurements [94,99]. With complete understanding, empirically driven screening studies to perform binder selection and binder quantity could become obsolete.
Toxic Effects and Biodistribution of Ultrasmall Gold Nanoparticles *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Gunter Schmid, Wolfgang G. Kreyling, Ulrich Simon
Why is the 1.4 nm Au cluster so special? The reason for its special behavior is to be seen in the electronic behavior. It can be described as the transition between bulk and molecule. The stability of the two-shell cluster Au55(PPh3)12Cl6 results from an impressive experiment. Surface deposited Au55 clusters, separated from each other, and compared with smaller and larger Au clusters, are treated with an oxygen plasma to remove the ligand shell. X-ray photoelectron spectroscopy (XPS) shows changes of all other particles, but not of Au55 [7]. Figure 15.7 shows the results. Au55 only shows a weak oxidic shoulder of a few clusters that are not exactly of full-shell type. All other species show well-expressed signals for oxidic species. This method can, therefore, be used to check the purity of a sample of Au55(PPh3)12Cl6.
The Use of Syzygium cumini in Nanotechnology
Published in K. N. Nair, The Genus Syzygium, 2017
Avnesh Kumari, Vineet Kumar, Sudesh Kumar Yadav
X-ray-based methods such as x-ray absorption (XAS), x-ray fluorescence (XRF), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD) provide information about the surface structure, crystallographic structure, and elemental composition (López-Serrano et al. 2014).
A comprehensive proteomics analysis of the response of Pseudomonas aeruginosa to nanoceria cytotoxicity
Published in Nanotoxicology, 2023
Lidija Izrael Živković, Nico Hüttmann, Vanessa Susevski, Ana Medić, Vladimir Beškoski, Maxim V. Berezovski, Zoran Minić, Ljiljana Živković, Ivanka Karadžić
A colloidal dispersion of ceria particles (sol) was characterized as detailed in previous work (Stevanović et al. 2020; Riđošić et al. 2021). X-ray diffraction (XRD) data confirmed that the synthesized CeO2 particles exhibited a fluorite-type crystal structure (space group: Fm3m, JCPDS 34-0394). The average crystallite size of ca. 4 nm, calculated according to the Scherrer equation, validated the method used to prepare the nano-sized ceria. X-ray photoelectron spectroscopy (XPS) is generally used to inspect the surface state of a material. Here, we report a significant amount (27%) of Ce3+ in CeO2 nanoparticles, along with prevailing Ce4+. As previously described, both Ce3+ and Ce4+ oxidation states are present in ceria particles, while the amount of Ce3+ increases with decreasing particle size.
The treatment of hepatocellular carcinoma with SP94 modified asymmetrical bilayer lipid-encapsulated Cu(DDC)2 nanoparticles facilitating Cu accumulation in the tumor
Published in Expert Opinion on Drug Delivery, 2023
Hao Liu, Yihan Kong, Xue Liang, Zixu Liu, Xueting Guo, Bing Yang, Tian Yin, Haibing He, Jingxin Gou, Yu Zhang, Xing Tang
X-ray powder diffraction of the Cu(DDC)2, DOPA, DOPA-coated Cu(DDC)2 nanoparticles were examined, and a physical mixture of DOPA and Cu(DDC)2 were examined using a D/Max 2500 PC X-ray diffractometer (rigaku, Japan) to verify whether the negatively charged DOPA could bind with copper ion to wrap up the Cu(DDC)2 nanoparticles. The diffraction angle (2θ) was scanned from 3 to 50° at a rate of 3°/min. The infrared spectrometer (Burker tensor 27, Germany) was adopted to record FT-IR spectra of the Cu(DDC)2, DOPA, DOPA-coated Cu(DDC)2 nanoparticles with the KBr pellet method in the spectral range of 4000 to 500/cm. X-ray photoelectron spectroscopy (XPS) analysis was performed on a spectrometer (Thermo ESCALAB250, USA) with the radiation provided by a monochromatic X-ray source (Alka,1486.6 eV) operated at a 150 W emission power.
Surface-modified polymeric nanoparticles for drug delivery to cancer cells
Published in Expert Opinion on Drug Delivery, 2021
Arsalan Ahmed, Shumaila Sarwar, Yong Hu, Muhammad Usman Munir, Muhammad Farrukh Nisar, Fakhera Ikram, Anila Asif, Saeed Ur Rahman, Aqif Anwar Chaudhry, Ihtasham Ur Rehman
The surface chemistry of polymeric nanoparticles determines the interaction of surfaces with water molecules, ions, biomolecules, and cells. The surface reactivity relies on chemical composition, pre-treatment, and fabrication process of nanoparticles. The specific or nonspecific interactions, protein adhesion, and cell attachment are affected by the presence of functional groups on the surfaces of nanoparticles. Therefore, the chemical characterization of nanoparticle surfaces is crucial. The elemental analysis of surfaces is performed by X-ray photoelectron spectroscopy (XPS) [140]. This technique works on the principle of emission of electrons from materials in response to irradiation by photons. The emitted energies are characteristic of the atoms from which they are emitted. XPS spectra may provide us information about the surface composition, presence and types of functional groups, and enrichment or depletion of elements on the surfaces of nanoparticles [141].