The effect of exogenous zinc concentration on the responsiveness of MC3T3-E1 pre-osteoblasts to surface microtopography: Part I (migration)

Initial cell-surface interactions are guided by the material properties of substrate topography. To examine if these interactions are also modulated by the presence of zinc, we seeded murine pre-osteoblasts (MC3T3-E1, subclone 4) on micropatterned polydimethylsiloxane (PDMS) containing wide (20 μm width, 30 μm pitch, 2 μm height) or narrow (2 μm width, 10 μm pitch, 2 μm height) ridges, with flat PDMS and tissue culture polystyrene (TC) as controls. Zinc concentration was adjusted to mimic deficient (0.23 μM), serum-level (3.6 μM), and zinc-rich (50 μM) conditions. Significant differences were observed in regard to cell morphology, motility, and contact guidance. We found that cells exhibited distinct anisotropic migration on the wide PDMS patterns under either zinc-deprived (0.23 μM) or serum-level zinc conditions (3.6 μM). However, this effect was absent in a zinc-rich environment (50 μM). These results suggest that the contact guidance of pre-osteoblasts may be partly influenced by trace metals in the microenvironment of the extracellular matrix.