Fig. 4.

Differentiation assay with primary human osteoblast-like cells. Cells were cultured for 21 days with medium only (Medium), the titanium control (CTRL), the modified K-wire (Porous), and the gentamicin-loaded K-wires (Genta) in growth medium (GM) or osteogenic differentiation medium (DM); n = 6 samples per group. A) GM: Culturing the cells with the different K-wires had no effect on the metabolic activity, the alkaline phosphatase activity or the mineralization (Alizarin red). B) DM: The gentamicin-loaded K-wires significantly reduced the alkaline phosphatase activity (p = 0.0453), while the other assays showed no significant alterations. Statistics: all groups compared to CTRL; n = 6. C) Exemplary pictures showing the cell morphology at day 21 in differentiation medium. No morphological differences were detectable between the groups.