Transient adsorption of fibrinogen on foreign surfaces: similar behavior in plasma and whole blood.

The adsorption of fibrinogen from both human whole blood and plasma to a number of "foreign" surfaces is reported. Adsorption was measured as a function of plasma or blood dilution using radioiodine labeling. We showed previously that adsorption of fibrinogen from plasma exhibits a maximum at a plasma dilution of about 100:1, and have attributed this behavior to competition from other plasma proteins. (The same phenomenon is manifest as a time transient in fibrinogen adsorption.) In the present work we show that exactly the same trends are observed in whole blood. For each of the four surfaces, glass, siliconized glass, collagen-coated glass and polyethylene, the adsorption of fibrinogen as a function of dilution is the same in whole blood as in plasma. Each of these surfaces shows a unique dependence of fibrinogen adsorption on plasma or blood dilution. On cuprophane and a hydrophilic polyether urethane there is essentially no adsorption of fibrinogen from blood or plasma. For the hydrophilic polyurethane this result may be artifactual, but the absence of fibrinogen binding to cuprophane in blood or plasma is real since fibrinogen is found to be adsorbed in monolayer amounts from buffer.