Initial Adhesion Behavior of Fibroblasts onto Hydroxyapatite Nanocrystals

The initial adhesion, spreading and cytoskeleton changes of fibroblast NIH3T3 cells onto hydroxyapatite (HAp) and oxidized poly(styrene) (PSox) sensors pre- adsorbed fetal bovine serum were analyzed by using a quartz crystal microbalance with dissipation technique and an atomic force microscopy (AFM). The frequency shift (Δf) and the dissipation shift (ΔD) curves on HAp nanocrystals showed the decrease in Δf with increasing ΔD for 80min and the subsequent increase in Δf with decreasing ΔD, while those on PSox showed the decrease in Δf for 120min with increasing ΔD for 50min and then with subsequent decreasing ΔD. The different adhesion behavior dependent on the surfaces was attributed to the cell-surface interactions; the cells on HAp had rough fibrous pseudopods and those on PSox had dense particulate pseudopods. The different structures indicated that the cytoskeleton changes and the rearrangement of the extracellular matrix at the interface caused the different adhesion behavior.