Cytotoxicity of Metal and Ceramic Particles in Different Sizes

摘要

The wear debris caused by joint prosthesis is well known to induce an inflammation in the peripheral tissue. The authors carried out two kinds of experiments, to clarify the phagocytable size of wear particles and the cytotoxicity of macrophage related to the size and materials. The test materials were Al_2O_3, SiO_2, TiO_2 fine particles and Ti-6Al-4V, Co-28Cr-6Mo wear particles. The results showed that the phagocytable particle size was less than 11.9 +- 11.2 μm. It appears that the cytotoxicity did not depend on the particle size, even if the particles were phagocytable size. In the relationship between material type and inflammation, damage levels were found to be different between SiO_2 and TiO_2 particles, even if neither material released metal ions. The cells were damaged more severely by SiO_2 particles than by Co-28Cr-6Mo for which the eluted ion could not be ignored (damage levels; SiO_2>Co-28Cr-6Mo>Ti-6Al-4V >Al_2O_3 ≧ TiO_2). For these reasons, it was confirmed that there was a factor in addition to the toxicity of the eluted metal ion (i.e., the implant material's corrosion resistance ability), which influenced the inflammation.