In vitro platelet adhesion and activation of polyethylene terephthalate modified by acetylene plasma immersion ion implantation and deposition

Acetylene (C₂H₂) plasma immersion ion implantation-deposition (PIII-D) was conducted on polyethylene terephthalate (PET) to improve its blood compatibility. The platelet adhesion and activation behavior of PET treated by C₂H₂ PIII-D at different working pressures was investigated. Raman spectroscopy results show that amorphous carbon films were successfully deposited on the PET surfaces. X-ray photoelectron spectroscopy (XPS) analysis indicates that carbon films of various sp²/sp³ composition are formed at different working pressures and the sp³ hybridized C content in the films increases as a function of pressure. Platelet adhesion experiments were conducted to examine the blood compatibility in vitro. Optical microscopy reveals that the amounts of adherent platelets on all modified PET films are less than that on the untreated surface. The adhered platelets on carbon films deposited at 0.5 Pa and 1.0 Pa working pressure are about 32% and 55%, respectively, of that for the untreated PET surface. The platelets are observed to be isolated and round on carbon films deposited at 0.5 Pa, indicating that fewer platelets are activated on the amorphous carbon films. These results thus shows that amorphous carbon films deposited on PET by C₂H₂ PIII-D suppress platelet adhesion and activation, and the extent of the improvement is related to the structure of the carbon films. © 2005 Elsevier B.V. All rights reserved.