This investigation was undertaken to determine the role that humoral components play in the biological response to ion beam textured and smooth PTFE. It was found that exudates obtained from smooth PTFE implants contained factors capable of promoting the attachment and growth of cells in uitro. Exudates obtained from textured PTFE contained significantly more growth promoting activity at 2 days after implantation and significantly more attachment promoting activity at 2 and 7 days after implantation than corresponding exudates obtained from smooth PTFE. The underlying reasons for the temporal nature of these results are not known, but cellular mechanisms were proposed to explain the observed differences. In order to examine protein adsorption to implants in z w o , ' a technique was developed utilizing the Selye air pocket and electrocautery to minimize cell adhesion to the implants. The results demonstrated the dynamic quality of protein adsorption to surfaces and indicated that the nature of protein exchange at the material surface differed between textured and smooth PTFE for the first 30 min post-implantation. Both albumin and fibrinogen were identified on textured and smooth surfaces, but fibronectin was not identified on any of the surfaces.