| Abstract
| - We have examined the initial phase of fibrin formation, thrombin-catalyzed fibrinopeptidecleavage, from adsorbed fibrinogen using surface plasmon resonance and liquid chromatography−massspectrometry. Fibrinogen adsorption impaired thrombin−fibrinogen interactions compared to the interactionsof thrombin with fibrinogen in solution. The properties of the underlying substrate significantly affectedthe extent and kinetics of fibrinopeptide cleavage, and the conversion of adsorbed fibrinogen to fibrin.Fibrinogen adsorbed on negatively charged surfaces (carboxyl-terminated self-assembled monolayers)released a smaller amount of fibrinopeptides, at a reduced rate relative to those of hydrophobic, hydrophilic,and positively charged surfaces (methyl-, hydroxyl-, and amine-terminated self-assembled monolayers,respectively). Additionally, the conversion of adsorbed fibrinogen to fibrin was comparatively inefficientat the negatively charged surface. These data correlated well with trends previously reported for fibrinproliferation as a function of surface properties. We conclude that thrombin interactions with adsorbedfibrinogen determine the extent of subsequent fibrin proliferation on surfaces.
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