EFFECT OF TI, AL AND V CONCENTRATION ON T HE RELATIVE GROWTH RATIO OFBIO-CELLS

The effects of Ti, V and Al concentrations on the relative growth rati os of L929, MC3T3-E1 cells and on the colony formation ratio of V79 ce lls by cell culture method with metallic powders were investigated. Th ese powders were sterilized under U.V. lamp for 14 ks (4 h), suspended in the medium and were extracted for 173 ks (48 h), 259 ks (72 h) and 346 ks (96 h) in the incubator under a 95% air-5%CO2 atmosphere. The medium not containing ang metallic powder (control) was also extracted under similar conditions. After filtering with a 0.2 mu m filter, 1.0 x 10(4) similar to 5.0 x 10(4) L929 cells/ml, 5 x 10(4) MC3T3-E1 cell s/ml and 10(2) V79 cells/ml were seeded in control and in the filtrate s of the medium containing metallic powder. The number of cells were c ounted using a coulter counter from 86 ks (1 d) to 605 ks (7 d). The n umber of L929 cells after 346 ks (4 d) of incubation were almost simil ar for Ti extraction and control, whereas in the case of Al and V extr actions the number of cells were too low as compared to that of contro l. The relative growth ratios of L929 cells for Ti, Al and V after 346 ks (4 d) of incubation were about 1, 0.05 and 0.02 respectively. Also , similar trends were observed for MC3T3-E1 and V79 cells. The relativ e growth ratio (number of cells in test medium/number of cells in cont rol) of L929 cells for Ti powder was almost equal to one in 1 similar to 10 g of Ti powder. On the contrary, the relative growth ratio of L9 29 cells for Al decreased with the increase in the weight of Al powder from 1 g to 3 g for both Eagle's MEM (Minimum Essential Medium not co ntaining fetal bovine serum and 7.5%NaHCO3) and Eagle's medium extract ions. No colonies of V79 cells were found for Al. Further, the concent ration of Al in the medium increased with the increase in the weight o f the Al powder. The relative growth ratio of L929 cells decreased as the initial number of L929 cells increased. Moreover, dilutions from 1 to 10 times in the case of Al and from 1 to 5000 times in the case of V were made. The relative growth ratios of L929, MC3T3-E1 and V79 cel ls became equal to 1 at 5 times dilution for Al and at 4000 times dilu tion for V, As the metallic concentration of Al and V ion in the mediu m increased from 0.2 to 0.5 mass ppm, the relative growth ratio of L92 9 and colony formation ratio of V79 cells decreased from 1 to almost 0 . But, for MC3T3-E1 cells, the effect from a much lower concentration of V ion (0.02 ppm) was observed.