Surface characterization and platelet adhesion studies on polyurethane surface immobilized with C60.

Due to its distinctive molecular configuration, C60 and its derivatives have been the research focus in exploring its electrical, mechanical, optical, and even biological applications during the past decades. In this investigation, C60 molecules are grafted onto the polyurethane surface, which is pretreated with oxygen plasma activation, through amine-terminated silane coupling agents. ESCA analysis indicates that the C60 molecules spontaneously grafted onto the amine-terminated PU substrate through nucleophilic additions to the fullerene double bonds which fuse two six-membered rings. More amine functional groups are formed on the PU surface if 4-aminobutyldimethylmethoxysilane is used as the coupling agent. In vitro platelet adhesion assay shows the C60 grafted PU are more platelets activating than the nontreated PU control. This might be attributed to the synergistic effect of the grafted C60 molecules and the few residual amine functional groups which are left after the C60 grafting reaction. Further applications using these C60 grafted polyurethane surfaces as the cell adhesion and cell growth substrates are currently under exploration.