相対細胞増殖率に及ぼすZr, Sn, Nb, Ta, Pd, Mo, Co, Cr, Si, Ni, Fe濃度の影響

Abstract

The effects of metallic concentrations of Zr, Sn, Nb, Ta, Pd, Mo, Co, Cr, Si, Ni and Fe in the medium on the relative growth ratios of fibroblasts L929, osteoblasts MC3T3-E1 cells and the colony formation ratio of fibroblasts V79 cells were investigated. The change in the relative growth ratio of L929 cells after 346 ks(4 d) of incubation in different extraction time, namely, 86 ks(24 h), 173 ks(48 h), 259 ks(72 h), 346 ks(96 h) and 432 ks(120 h) were estimated. It was observed that, the relative growth ratio of L929 cells was equal to unity for Ti, Zr, Sn, Nb, Ta, Cr and Si, whereas, the relative growth ratio was approximately equal to 0 for Mo, Ni, Co, and Fe. Also, the relative growth ratio of L929 cells became equal to 0 at the extraction time of 346 ks(96 h) for Pd. From the anodic polarization studies in the medium solution, it can be seen that Ta, Nb and Si exhibited excellent corrosion resistance. On the other hand Cr, Ni, Co and Fe exhibited a relatively low corrosion resistance. These results were in good match with the results of the relative growth ratios of L929, MC3T3-E1 and V79 cells. The effect of the weight from 1 to 5 g of Nb, Ta and Zr powders on the relative growth ratios of MC3T3-E1 cells in α-MEM (α-modified Minimum Essential Medium not containing fetal bovine serum and 7.5% NaHCO3) solution and α-Medium extractions were also examined. The relative growth ratios of MC3T3-E1 cells were equal to unity for Nb at all weights from 2.5 to 5 g. A marked decrease in the relative growth ratio of MC3T3-E1 cells was observed for Zr and Ta as the weight increased from 2.5 to 5 g. Since Mo, Pd, Co, Ni, Fe and Si were released in the medium, the effects of dilution on the relative growth ratio of L929 and MC3T3-E1 cells were carried out. The relative growth ratios of L929 and MC3T3-E1 cells markedly decreased at a metallic concentration of more than 3 mass ppm for all the metal powders used.