Snow accumulation on trees plays a major role for the snow cover structure in snow hydrology, and in avalanche protection of boreal and subalpine forests. In order to better understand the processes associated with this, we investigated snow accumulation on boards of dierent sizes, shapes, and incli
Cytotoxicity evaluation of ceramic particles of different sizes and shapes
โ Scribed by Yamamoto, Akiko ;Honma, Rieko ;Sumita, Masae ;Hanawa, Takao
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 313 KB
- Volume
- 68A
- Category
- Article
- ISSN
- 0021-9304
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โฆ Synopsis
Abstract
When artificial hip or knee joints are implanted in the human body, they release metallic, ceramic, and polymeric debris into the surrounding tissues. The toxicity of the released particles is of two types: chemical, caused by the released soluble ions and monomers, and mechanical, a result of mechanical stimulation produced by the insoluble particles. In this study, the cytotoxicity of particles of TiO~2~, Al~2~O~3~, ZrO~2~, Si~3~N~4~, and SiC for murine fibroblasts and macrophages were examined to evaluate just their mechanical toxicity because these particles are not expected to release soluble metal ions. Different sizes and shapes of TiO~2~ particles were used to evaluate the effect of size and shape on particle cytotoxicity. The results suggest that the cytotoxicity of ceramic particles does not depend on their chemical species. Cytotoxicity levels were lower than those of corresponding metal ions, indicating that the mechanical toxicity of particles is lower than the chemical toxicity of released soluble ions and monomers. The differences in size did not affect the mechanical toxicity of these particles. The dendritic particles had a higher cytotoxicity level for macrophages than did spindle and spheric particles. ยฉ 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 244โ256, 2004
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