Background: Nonwoven single-walled nanotubes (SWNTs) are novel materials with a nanotopography macroscopic surface and pure-carbon composition, which may serve as coatings on implants in blood-contact environments.
Methods: The adsorption behavior of albumin, fibrinogen, and fresh plasma on SWNT membranes was studied using scanning electron microscopy (SEM), energy-dispersive x-ray, and direct enzyme-linked immunosorbent assay, respectively. Platelet adhesion and activation were investigated in vitro using SEM observation, and via flow cytometry analysis by PAC-1, which binds to GPIIb/IIIa expressed on activated platelets.
Results: Nonwoven SWNTs clearly displayed greater adsorption preference for fibrinogen than for albumin. However, adhered platelets were not observed by SEM. Results obtained from flow cytometry analysis further proved very low expression of GPIIb/IIIa on platelets caused by nonwoven SWNTs.
Conclusion: The function of adsorbed fibrinogen to mediate platelet recognition, adhesion, activation, and aggregation was significantly suppressed, which induced extremely low levels of platelet adhesion and activation.