Abstract
The effects of Ti and Al oxide films on the relative growth ratio of murine fibroblast L929 and the colony formation ratio of fibroblast V79 cells derived from the lung of a Chinese hamster were investigated. Titanium and aluminum particles were oxidized inside an oven at 453 K (180°C) for 7.2 ks. These particles were suspended in Eagle’s medium and kept for 173 ks (48 h) inside an incubator under a 95%air-5%CO2 atmosphere. Eagle’s medium without metallic particles was also kept inside the incubator under similar conditions for the control. The mediums were filtered with a 0.2 μm membrane filter to remove metallic particles (Eagle’s medium extract). 3.0×104 L929 cells/dish and 102 V79 cells/dish were seeded in both the control and in the Eagle’s medium extracts. In the case of oxidized Al particle extraction, the relative growth ratio of L929 cells was 0.8±0.07 after 346 ks (4 d) of incubation. A relatively strong oxide film formed on the surfaces of the Al particles, hence the relative growth ratio of the L929 cells markedly increased.
Al and Ti plates were polished to a mirror-like finish using diamond paste and alcohol, well proliferated colonies of V79 cells were observed on the mirror-like finished Ti plate (Ra=4.8±0.2 nm), whereas no colonies existed on the mirror-like finished Al plate (Ra=38.5±8.4 nm). However, the colonies appeared when the Al plates were acid-treated with a solution of NaHCO3 and C2H4O2 (Ra=43.4±10.1 nm) after mirror-like finishing, and also when roughening with #240 water-proof emery paper (Ra=1548±169 nm). The colony formation ratio of the V79 cells was found to depend on the surface roughness (Ra) and strength of the Al oxide film.
