Quantifying the adherence of fibroblasts to titanium and its enhancement by substrate-attached material

Normal human skin fibroblasts were cultured on tissue culture polystyrene a nd on commercially pure titanium. Zn addition, substrate-attached material that remained on the surfaces after detachment of fibroblasts with a chelat ing agent was examined. The force required to detach 50% of the fibroblasts from each substrate was assessed by centrifugation. The results showed a t ime-dependent decrease in the force required to detach fibroblasts from tit anium not seen on tissue culture polystyrene. Nearly all cells detached fro m the titanium surfaces at 7.85 x 10(x3) dynes/cell after 3 or 5 days in cu lture, whereas few cells detached from tissue culture polystyrene. Cells fr eshly seeded onto titanium substrates that had been coated with substrate-a ttached material by prior culture of fibroblasts for 3 or 5 days showed an approximately sixfold increased adherence. The results of immunofluorescenc e staining for fibronectin and its receptor suggest that the nature of the interaction between this extracellular matrix ligand and the substrate may be important in determining cellular stiffness at the cell-extracellular ma trix interface. (C) 2000 John Wiley & Sons, Inc.