Japan-China international study on standardization of dissolution tests and safety evaluation of biomedical polymers
Grant-in-Aid for Overseas Scientific Survey.
|Allocation Type||Single-year Grants|
|Research Institution||Tokyo Medical and Dental University|
SATO Atsushige Tokyo Medical and Dental University, 歯学部, 教授 (40045985)
HONGO Toshio Tokyo Medical and Dental University, 歯学部, 助手 (60142444)
SATO Kazuko Tokyo Medical and Dental University, 歯学部, 助手 (50046083)
KUMEI Yasuhiro Tokyo Medical and Dental University, 歯学部, 講師 (30161714)
顧 国珍 上海第二医科大学, 生物材料研究室, 助手
張 彩霞 上海第二医科大学, 生物材料研究室, 教授
薛 みや 上海第二医科大学, 生物材料研究室, 教授
GU Guozhen Shanghai Second Medical University
XUE Miao Shanghai Second Medical University
ZHANG Cai-Xia Shanghai Second Medical University
|Project Fiscal Year
Completed(Fiscal Year 1991)
|Keywords||Biomedical materials / Dissolution test / Acrylic resin denture / Unreacted monomer / Safety evaluation / Cytotoxicity test|
The toxicity of biomedical polymers originates in the toxicity and solubility of chemicals dissolved from the polymers. Considering the importance of international balances, an international scientific project between Japan and China was conducted on the dissolution tests and safety evaluation of biomedical polymers on. the following items.
1. Development of basic protocol for dissolution tests.
Information exchanges were done with Prof. Xue Miao of Shanghai Second Medical University. Prof. Zhang Cal-Xia visited Prof. Atsushige Sato at Tokyo Medical and Dental University and made up a draft of the basic common protocol for dissolution tests.
2. Study on the fundamentals for dissolution tests.
A Chinese researcher, Dr. Gu Guozhen, was invited to Tokyo Medical and Dental University for 3 months engage in searching the basic condition for dissolution tests. A piece (10 x 15 x 1.7 min) of polymerized acrylic resin for denture use was immersed in dissolution medium. The dissolved products were
analyzed by high performance liquid chromatography (HPLC). The reverse phase column, water/acetonitrile mobile phase, temperature at 40ﾟC, flow rate at 1 ml/min, UV absorbance at 235 nm for detection wave length and one-point absolute calibration method were adopted as the standard common protocol. The major components of test materials were methyl methacrylate (MMA), hydroquinone, ethylene glycol dimethacrylate, benzoyl peroxide (BPO), polymethyl methacrylate and cosmetics. The test material resin was heat-cured and immersed either in ultrapure water or in methanol. No chemicals were detected on water imme rsion, whereas peaks of MMA, BPO and undefined substances were obtained on methanol immersion. The dissolution of MMA disappeared on the 7th day of immersion, while that of BPO continued to the 21st day of immersion. The total amounts of dissolution from one gram of heat-cured resin during 15 days immersion were 17.3 mg of MMA and 4mg of BPO, indicating that more than 10% of monomer was dissolved.
3. International standardization of safety evaluation method. The International Standardization Organization (ISO TC 194), the Federation Dentaire Internationals (FDI 106), and the cytotolfcity tests adopted in Germany, England, China and Japan were compared. The Cr release assay, agar overlay assay, and millipore filter assay were adopted in ISO/FDI the agar overlay assay and protein quantification assay were in Japan, and the ^<51>Cr-release assay, agar overlay assay, protein quantification assay and neutralized assay were adopted in Germany. It was recognized that the standardization for test cells and standard toxic substances is needed. Considering the inter-and intra-institutional reproducibility, the neutralred assay using test material extracts and L-929 cell line was nominated as the primary candidate for the standardized test method. This international scientific project offered a lot of basic valuable information for standardizing test method of biomedical materials. Less
Research Output (4results)