Effects of niobium ions released from calcium phosphate invert glasses containing Nb2O5 on osteoblast-like cell functions.

The effects of niobium ions released from 60CaO-30P(2)O(5)-(10-x)Na(2)O-xNb(2)O(5) (mol %, x = 0-10) glasses on MC3T3-E1 cell functions were evaluated by culture tests with two systems; cell culture on glass plates, or in culture media containing glass extracts. Alkaline phosphatase (ALP) activity in the cells cultured on the glass plates containing 3 and 5 mol % of Nb(2)O(5) was significantly higher than that on the Nb(2)O(5)-free glass, although proliferation was not enhanced on all glasses containing Nb(2)O(5). Cells cultured in the medium containing 3 × 10(-7) M niobium ions showed the highest ALP activity in comparison with other Nb-containing media or normal medium, regardless of the presence of osteogenic factors (ascorbic acid, β-glycerophosphate and dexamethasone) in the media.