Otsuka Y., Ben-Nissan B., Kono H., Sasaki T., Kikuchi M. . Mechanochemical synthesis and characterization of strontium substituted apatite for biomedical application . Open Ceramics162023 · 記述言語： 日本語 出版者・発行元： Open Ceramics Strontium-substituted apatite has been proposed as a promising material for osteoporosis treatment. Several synthesis methods have been attempted in the past. In this study, we investigated a method known as the mechanochemical synthesis method. Characterization was carried out using different amounts of strontium ions in the hydroxyapatite (HAp) matrix with FT-IR spectral analysis, X-ray diffraction, lattice constant measurements, differential thermal analysis (DTA), terahertz spectroscopy, and investigation of the basic morphology using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX). We report that the development and performance of mechanochemical synthetic pathways are more efficient and economical than other substituted apatite formation methods and are useful in the biomedical field to produce calcium phosphate-based clinical materials. The FTIR spectra, terahertz spectra, and XRD analysis results revealed that the mixture of dicalcium phosphate dihydrate (DCPD), Ca(OH)2 and Sr(OH)2 8H2O was phase-transformed into strontium-containing carbonate amorphous apatite by this simple and economical mechanochemical synthesis method. DOI： 10.1016/j.oceram.2023.100459 Scopus
Kurosawa Y., Otsuka Y., Goto S. . Increased selectivity of sodium deoxycholate to around Tryptophan213 in bovine serum albumin upon micellization as revealed by singular value decomposition fo2022 · 記述言語： 日本語 出版者・発行元： Colloids and Surfaces B: Biointerfaces In the present study, we investigated the effect of bile salts (sodium deoxycholate, NaDC) on the conformation of a globular protein (bovine serum albumin, BSA). The two Tryptophan (Trp) residues of BSA and the fluorescence energy of NaDC are in a three-way relationship, and singular value decomposition (SVD) was used to separate each element in the fluorescence spectra. SVD was used to separate the elements in the fluorescence spectra. SVD showed that NaDC had a particularly large effect on the microenvironment around Trp213 and that micellar NaDC enhanced the selectivity for Trp213. In addition, the Stern-Volmer plots of the warfarin (WAR) specific domain (domain I) and ketoprofen (KP) specific domain (domain II) in the presence and absence of NaDC showed that the effect of NaDC was selective for domain II, where Trp213 is located. These results indicate that NaDC induces a localized and selective conformational change in BSA, and that the selectivity varies depending on the aggregation state of NaDC. DOI： 10.1016/j.colsurfb.2022.112344 Scopus
