Adhesion of microvascular endothelial cells to metallic implant surfaces

The objective of this study was to explore the molecular mechanisms of adhe sion of endothelial cells (ECs) to implant grades of titanium alloy (Ti) an d stainless steel (SS), compared to tissue culture polystyrene (PS). The id ea is that promotion of EC adhesion to implant surfaces during the initial stages of healing may be critical in the formation of a capillary bed intim ately associated with the implant surface. Ultimately this could be expecte d in turn to promote bone formation close to the surface and a more stable implant/bone interface. Surfaces were coated with either peak 1 fibrinogen gamma A gamma A, fibrinogen Fr I-9, fibrinogen fragment D1, fibronectin, vi tronectin, or fetal calf serum and then post-coated with bovine serum album in (BSA) to block non-specific cell adhesion. Surfaces with BSA alone and n o other protein coating were also evaluated. Fibronectin coating maximized cell adhesion on all three surfaces, and adhesion was highest on PS. BSA bl ocked cell adhesion to PS (and most adhesion to SS) much better than to Ti. These results provide evidence that BSA adsorption on the metal surface is unable to effectively block the adhesion of the cells to the Ti. These dat a may provide a basis for understanding in vivo observations that soft tiss ue becomes attached to a Ti surface more rapidly and with more bone formati on than to SS. Evidence is also presented that alpha(v)beta(3) plays an imp ortant role in adhesion of ECs to the Ti surface. These experiments also pr ovide preliminary data which may reflect some of the features of initial EC adhesion to metal implants. (C) 2000 Kluwer Academic Publishers.