| Summary: | 博士 === 國立臺灣科技大學 === 材料科學與工程系 === 107 === Selective internal radiotherapy (SIRT) is the potential candidate of novel cancer treatments, which placed the radioactive source directly near the tumor to deliver high doses radiation directly to malignant cells without damaging healthy tissues, especially for cancers where the response to chemotherapy and external radiotherapy is poor like deeply seated liver cancer. For this application 90Y was element of choice, since 90Y emits pure beta radiation, which has an average range of 2.5 mm in soft tissue, has an acceptable half-life (64.1 h) and can be formed by neutron activation of the naturally occurring 89Y, which is 100 % abundant.
In this study, Y contain silicate base powders were synthesized using spray pyrolysis (SP). The phase compositions of these powders were characterized by X-ray diffraction. The morphologies of these glassy powders were observed using scanning electron microscopy (SEM), and then use transmission electron microscopy (TEM) to determine its inner structure. The Y-distribution was measured using focused ion beam (FIB). In addition, the
bioactivities of Y-doped BG and GN- treated Y-doped BG powders were confirmed using Fourier transform infrared spectroscopy (FTIR). The experiment can be subdivided into three experiments. The first experiment was control of Y-distribution in the yttrium aluminium silicate (YAS) glass using yttrium nitrate(YN) and yttrium acetate (YAc) salts as Y sources. Because of YN and YAc salts have high solubility, Y ion dispersed homogenously throughout the particle for YN -derived YAS glassy powder case, where as it distributed at surface of particle for YAc-derived YAS glassy powder. The second experiment was controlling of Y in Y-doped bioactive glass (Y-BG) powders. We found that for YN- derived Y-doped BG, Y distributed simultaneously in the whole particle whereas for YAc- derived Y-doped BG, Y-concentrated on the surface of particle. In addition, YN
derived Y-doped BG powder has high bioactivity than YAc -derived Y-doped BG powder and pure BG powder, correlating directly with the observed surface areas. The third experiment was preparation of hollow Y-doped BG powder using glycine nitrate (GN) as hollow forming agent. The obtained result indicates that 1M GN-treated Y-doped BG powder consists more fraction of hollow particles and also better in bioactivity.
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