An in vitro model to evaluate cell adhesion to metals used in implantation shows significant differences between palladium and gold or platinum.

Adhesion of tissue cells to metallic implants is a major factor that is important for proper tissue integration. Adhesion of Swiss mouse 3T3 fibroblasts to gold, platinum and palladium surfaces was investigated. Immunofluorescence staining for the integrin subunits alphav and beta1 and the focal contact protein vinculin revealed that cells growing on gold and platinum expressed many focal contacts. In contrast, cells on palladium surfaces had reduced numbers of focal contacts shown by vinculin staining and failed to demonstrate expression of alphav and beta1 in focal contacts. Spread cell area was also significantly reduced on palladium than on other surfaces suggesting that cells on palladium were more weakly attached. This may be due to either a different molecular composition of focal contacts in cells grown on palladium surfaces or unusual microstructural properties of the palladium surface. This model is useful to evaluate adhesion of cells to different metal surfaces.