Platelet adhesion and plasma protein adsorption control of collagen surfaces by He+ ion implantation

He+ ion implanted collagen-coated tubes with a fluence of 1 x 10(14) ions/cm(2) were exhibited antithrombogenicity. To investigate the mechanisms of antithrombogenicity of these samples, plasma protein adsorption assay and platelet adhesion experiments were performed. The adsorption of fibrinogen (Fg) and von Willebrand factor (vWf) was minimum on the He+ ion implanted collagen with a fluence of 1 x 10(14) ions/cm(2). Platelet adhesion (using platelet rich plasma) was inhibited on the He+ ion implanted collagen with a fluence of 1 x 10(14) ions/cm(2) and was accelerated on the untreated collagen and ion implanted collagen with fluences of 1 x 10(13), 1 x 10(15) and 1 x 10(16) ions/cm(2). Platelet activation with washed platelets was observed on untreated collagen and He+ ion implanted collagen with a fluence of 1 x 10(14) ions/cm(2) and was inhibited with fluences of 1 x 10(13), 1 x 10(15) and 1 x 10(16) ions/cm(2). Generally, platelets can react with a specific ligand inside the collagen (GFOGER sequence). The results of platelets adhesion experiments using washed platelets indicated that there were no ligands such as GFOGER on the He+ ion implanted collagen over a fluence of 1 x 10(13) ions/cm(2). On the 1 x 10(14) ions/cm(2) implanted collagen, no platelet activation was observed due to the influence of plasma proteins. From the above, it is concluded that the decrease of adsorbed Fg and vWf caused the antithrombogenicity of He+ ion implanted collagen with a fluence of 1 x 10(14) ions/cm(2) and that plasma protein adsorption took an important role repairing the graft surface. (C) 2003 Elsevier Science B.V. All rights reserved.