EFFECTS OF TI, AL AND V CONCENTRATIONS ON CELL VIABILITY

The effects of Ti, Al and V concentrations and the extraction conditio ns on the cell viabilities of murine fibroblast L929 cells, murine ost eoblast-like MC3T3-E1 cells and fibroblast V79 cells taken from the lu ngs of Chinese hamsters were investigated by the cell culture method u sing metallic particles. The particles were sterilized under a U.V. la mp for 14.4 ks (4 h) and suspended independently in Eagle's minimum es sential medium (Eagle's medium) for the L929 cell seeding and alpha mo dified Eagle's medium (alpha medium) for the MC3T3-E1 cell seeding con taining 10 vol% fetal bovine serum and 7.5% NaHCO3. These mediums were kept for 172.8 ks (48 h) in an incubator under a 95%air-5%CO2 atmosph ere (defined as medium extraction). Medium without metallic particles was also kept inside the incubator under similar conditions and was us ed as the control for all the cell cultures. These mediums were filter ed with a 0.2 mu m filter. 1.0 x 10(4) to 5.0 x 10(4) L929 cells/mL, 5 x 10(4) MC3T3-E1 cells/mL and 10(2) V79 cells/dish were seeded in bot h the control and in the medium extract using the metallic particles. For the titanium particle extraction, the maximum Ti concentrations in the Eagle's medium and a medium were 0.2 and 0.3 mass ppm, respective ly. Hence the L929 and MC3T3-E1 cells proliferated in the same ratio a s those of the control. Also, the colony formation ratio (number of co lonies in the medium extract with metallic particles/average number of colonies in the control) of V79 cells was unity. For the Al particle extraction with ultrapure water for 172.8 ks (48 h), gel formation of aluminum hydroxide was observed. However, the relative growth ratio (t he number of cells in medium extract with metallic particles/average n umber of cells in control) of the L929 cells was unity when the Eagle' s medium was prepared after filtering with a 0.2 mu m membrane filter. On the contrary, the relative growth ratios of the L929 cells for bot h Eagle's MEM extract without fetal bovine serum and the Eagle's mediu m extract were zero. For the aluminum particle extraction, the relativ e growth ratios of the L929 and MC3T3-E1 cells sharply decreased as th e Al concentration in the medium increased to approximately 0.2 to 0.5 mass ppm. This aluminum effect on L929 cell viability tended to be st ronger in the Eagle's medium containing a small quantity of V ions (le ss than or equal to 0.03 ppm). The effects of Al concentration on the colony formation ratio of the V79 cells showed the same tendency as th ose of the relative growth ratios of the L929 and MC3T3-E1 cells. The relative growth ratio of the L929 cells sharply decreased when V conce ntration in the Eagle's medium increased to 0.2 mass ppm and became ze ro at approximately 0.5-mass ppm. The effects of V concentration on th e colony formation ratio of the V79 cells were also similar to the rel ative growth ratio of the L929 cells. The relative growth ratio of the MC3T3-E1 cells decreased from 0.002 mass ppm of V concentration and a pproached zero at approximately 0.2 mass ppm.