Preparation of Hollow Y₂O₃ Microspheres for In Situ Radiotherapy of Cancer by Enzymatic Reaction

Abstract:

Chemically durable microspheres 20−30 µm in diameter containing a large amount of yttrium are useful for in situ radiotherapy of cancer as they can be activated by neutron bombardment to become β-emitters and can be injected in the vicinity of the cancer to provide a large localized dose of β-radiation. In this study, preparation of hollow Y2O3 microspheres using an enzymatic reaction was attempted, and the structure and chemical durability of the resulting microspheres were investigated. Hollow Y2O3 microspheres 20–30 &m in diameter were successfully prepared by this enzymatic method. The outer surface of the microspheres was smooth and dense, whereas the inner parts had a honeycombed structure. In simulated body fluids at pH 6 and 7, the hollow Y2O3 microspheres showed high chemical durability.

• Periodical: Key Engineering Materials (Volumes 309-311)
• Pages: 461-464
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.309-311.461
• Online since: May 2006
• Authors: Kawashita Masakazu, Yoshihisa Takayama, Tadashi Kokubo, Gikan H. Takaoka, Norio Araki, Masahiro Hiraoka
• Keywords: Cancer, Enzymatic Reaction, Hollow Microsphere, Radiotherapy, Yttrium

References

[1] M.J. Hyatt and D.E. Day: J. Am. Ceram. Soc. Vol. 70 (1987), p.283.

[2] D.E. Day and T.E. Day: Radiotherapy Glasses in An Introduction to Bioceramics (World Scientific, Singapore 1993).

[3] S. Ho, W. Y. Lau, T. W. Leung, and P. J. Johnson: Cancer Vol. 83 (1998), p.1894.

[4] M. Kawashita, R. Shineha, H. -M. Kim, T. Kokubo, Y. Inoue, N. Araki, Y. Nagata, M. Hiraoka, and Y. Sawada: Biomaterials Vol. 24 (2003), p.2955.

DOI: 10.1016/s0142-9612(03)00094-2

[5] S. Kato, T. Makino, H. Unuma, and M. Takahashi: J. Ceram. Soc. Japan Vol. 109 (2001), p.369.

[6] T. Kokubo, H. Kushitani, S. Sakka, T. Kitsugi, and T. Yamamuro: J. Biomed. Mater. Res. Vol. 24 (1990).